Log-rank Test (log-rank + test)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Exact Log-Rank Tests for Unequal Follow-Up

BIOMETRICS, Issue 4 2003
Georg Heinze
Summary. The asymptotic log-rank and generalized Wilcoxon tests are the standard procedures for comparing samples of possibly censored survival times. For comparison of samples of very different sizes, an exact test is available that is based on a complete permutation of log-rank or Wilcoxon scores. While the asymptotic tests do not keep their nominal sizes if sample sizes differ substantially, the exact complete permutation test requires equal follow-up of the samples. Therefore, we have developed and present two new exact tests also suitable for unequal follow-up. The first of these is an exact analogue of the asymptotic log-rank test and conditions on observed risk sets, whereas the second approach permutes survival times while conditioning on the realized follow-up in each group. In an empirical study, we compare the new procedures with the asymptotic log-rank test, the exact complete permutation test, and an earlier proposed approach that equalizes the follow-up distributions using artificial censoring. Results confirm highly satisfactory performance of the exact procedure conditioning on realized follow-up, particularly in case of unequal follow-up. The advantage of this test over other options of analysis is finally exemplified in the analysis of a breast cancer study. [source]


A laboratory assessment of coronal bacterial leakage in root canals filled with new and conventional sealers

INTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2009
A. U. Eldeniz
Abstract Aim, To evaluate the resistance to ex vivo bacterial leakage over a 40-day period of root canal fillings with five new root canal sealers: RC Sealer, Epiphany, EndoREZ, GuttaFlow and Acroseal, compared with Apexit, AH Plus and RoekoSeal. Methodology, One hundred and forty-four single rooted human teeth were divided randomly into eight test (n = 15) and two control groups (n = 12). The root canals were filled using a single cone technique with gutta-percha except in the Epiphany and EndoREZ groups. These were filled with Resilon and resin-coated gutta-percha, respectively. The gutta-percha surface of the GuttaFlow group was coated with an experimental primer prior to filling. Positive controls were filled with gutta-percha without sealer and tested with bacteria, whereas negative controls were sealed with wax to test the seal between the chambers. Filled roots were incorporated in a split chamber model system using Streptococcus mutans as a microbial marker. Leakage was assessed for turbidity of the broth in the lower chamber every day for 40 days. Survival analysis was performed using the Kaplan,Meier product limit method and event times were compared using the Log-rank test (, = 0.05). Results, Epiphany, GuttaFlow with test primer and Apexit prevented leakage significantly better than AH Plus, RC Sealer, RoekoSeal, EndoREZ and Acroseal (P < 0.05). None of the specimens in the AH Plus, RC Sealer, RoekoSeal and EndoREZ groups resisted bacterial penetration for 40 days. Conclusion, The new sealers, Epiphany and GuttaFlow with primer, along with Apexit, showed better resistance to bacterial penetration than the other new or traditional sealers tested. [source]


p73 G4C14-to-A4T14 polymorphism and risk of second primary malignancy after index squamous cell carcinoma of head and neck

INTERNATIONAL JOURNAL OF CANCER, Issue 11 2009
Fanglin Li
Abstract P73 plays an important role in modulating cell-cycle control, inducing apoptosis, and inhibiting cell growth. A novel noncoding p73 G4C14-to-A4T14 exon 2 polymorphism was associated with risk of squamous cell carcinoma of the head and neck (SCCHN). We hypothesized that p73 G4C14-to-A4T14 polymorphism modulates risk of second primary malignancies (SPM) in patients after index SCCHN. We followed a cohort of 1,384 patients diagnosed with incident SCCHN between May 1995 and January 2007 for SPM development. Log-rank test and Cox proportional hazard models were used to compare SPM-free survival and SPM risk between the different genotype groups. Our results showed that patients carrying the p73 variant AT allele were less likely to develop SPM compared with the patients with p73 GC/GC genotype (Log-rank test, p = 0.013). Compared with the p73 GC/GC genotype, there was a significantly reduced risk of SPM associated with the p73 GC/AT genotype (HR, 0.61, 95% CI, 0.40,0.93) and the combined p73 GC/AT+AT/AT genotypes (HR, 0.59, 95% CI, 0.39,0.89), but a nonsignificantly reduced risk for p73 AT/AT genotype (HR, 0.44, 95% CI, 0.14,1.41). The p73 AT allele was significantly associated with risk of SPM in an allele dose-response manner (p = 0.011 for trend). The risk of SPM associated with p73 variant genotypes (GC/AT+AT/AT) was more pronounced in several subgroups (e.g., older patients, men, minorities, ever smokers, and ever drinkers). Our results support that this p73 polymorphism may be a marker for risk of SPM among patients with an incident SCCHN. © 2009 UICC [source]


Predicting Recurrence of Vasovagal Syncope: A Simple Risk Score for the Clinical Routine

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2009
MUHAMMET A. AYDIN M.D.
Background: Predictors for recurrence of syncope are lacking in patients with vasovagal syncope. The aim of this study was to identify risk factors for recurrence of syncope and develop a simple prognostic risk score of clinical value. Methods: Two hundred seventy-six patients with a history of vasovagal syncope were prospectively followed for 2 years. Diagnosis of vasovagal syncope was based on clinical history and negative standard work-up. Inclusion in the study was independent from the result of the head-up tilt test, which was performed in all cases. Risk factors for syncope recurrence were evaluated by the Cox proportional hazards regression model and implemented in a risk score, which was validated with the log-rank test and an internal cross-validation. Results: The Cox-regression analysis identified the number of previous syncopal events, history of bronchial asthma, and female gender as predictors for syncope recurrence (all P < 0.05). In contrast, head-up tilt test response had no predictive value (P = 0.881). Developing a risk score, study patients were identified as having high (recurrence rate during 2 years of follow-up: 37.2%), intermediate (24.8%), and low (6.5%) risk for syncope recurrence (receiver operating characteristic [ROC] of score 0.83, P < 0.01; Log-rank test for event-free survival, P < 0.005). Conclusions: In patients with vasovagal syncope, risk of recurrence can be stratified and is predictable based on a simple risk score. [source]


Preoperative topical non-steroidal anti-inflammatory drug or steroid and clinical outcomes after trabeculectomy

ACTA OPHTHALMOLOGICA, Issue 2009
I STALMANS
Purpose To investigate the benefit of preoperative topical non-steroidal anti-inflammatory drug (NSAID) or steroid after trabeculectomy. Methods In this prospective randomized placebo-controlled trial, 61 patients scheduled for trabeculectomy were randomized to one of 3 study medication groups: NSAID (ketorolac), steroid (fluorometholone) or placebo (artificial tears). Patients instilled one drop 4x daily for 1 month preoperatively and were examined on day 1, 2, at weeks 1, 2, and 4, and at months 3, 6, 12, 18 and 24 following trabeculectomy. Main outcome measures were incidence of postoperative interventions and IOP-lowering medications; complete and qualified success rate; final IOP and relative IOP reduction. Results Fifty-four eyes were entered for analysis. The percentage of patients requiring needling within the first year was 41% in the placebo, 6% in the NSAID and 5% in the steroid group (P = 0.006). The percentage of patients requiring IOP-lowering medication at one year was 24% in the placebo, 18% in the NSAID and 0% in the steroid group (P = 0.054 overall; P = 0.038 for steroids versus others). Log-rank test showed a significant (P = 0.019) difference in medication-free survival curves between the different groups; patients in the steroid group needed significantly less medication (P = 0.007). The inter-group differences in one-year IOP, relative IOP reduction and success rates were not significant. Conclusion Topical ketorolac or fluorometholone for one month preoperatively was associated with improved trabeculectomy outcomes in terms of likelihood of postoperative needling. Within the steroid group, there was a significant reduced need for postoperative IOP-lowering medication. [source]


Kidney graft survival in patients with hepatitis C: a single center experience

CLINICAL TRANSPLANTATION, Issue 1 2008
J Arango
Abstract:, Hepatitis C virus (HCV) infection is highly prevalent in renal transplant candidates; however, its effect on the transplant outcome is still controversial. The aim of the present study was to determine the effect of HCV infection in the outcome of kidney transplantation in a single transplant center. The study population 144 HCV, randomized selected patients and 64 HCV+ patients transplanted from 1973 to 2000, followed for up to 60 months post-transplantation. This retrospective study included the following variables: type of dialysis, time on renal replacement therapy, number of transfusions before and after transplantation, number of transplants, type of donor, immunosuppression, and rejection episodes. The Kaplan,Meier method was used to estimate graft and patient survival. Log-rank test was used to assess the difference in survival between HCV+ and HCV,. A multivariate Cox proportional hazards model was used to analyze the relation between graft and patient survival. HCV+ and HCV, patients had similar demographic and clinical characteristics; however, a higher number of HCV+ patients received blood transfusions after transplantation. Patient survival was not significantly different in 39 HCV+ and 96 HCV, patients transplanted with living-related donors (71% and 77% at five yr, respectively). Similarly, there was not significant difference in 25 HCV+ and 48 HCV, patients transplanted with kidneys from deceased donors, although there was a tendency to better outcome in HCV, patients (55% and 72% at five yr respectively). Regarding graft survival, there was also no differences in HCV+ and HCV, recipients of living-related grafts (61% and 66% at five yr post-transplant, respectively) and recipients of kidneys from deceases donors (44% and 41%, respectively). The results show that HCV+ patients can be transplanted with the same success than HCV, patients. [source]


Carvedilol Produces Sustained Long-Term Benefits: Follow-Up at 12 Years

CONGESTIVE HEART FAILURE, Issue 1 2009
John F. MacGregor MD
The authors measured long-term outcomes of patients who initiated carvedilol between 1990 and 1992 to test the hypothesis that carvedilol produces sustained benefits in heart failure patients. The study population consisted of 57 patients who completed a carvedilol placebo-controlled phase II trial. Patients were given open-label carvedilol and were titrated to the maximum dose. Patients were assessed by serial multigated acquisition, echocardiography, and symptom scores. Survival was assessed for all patients and censored as of January 1, 2004. Survival for ischemic vs nonischemic patients was compared using the log-rank test and further compared using Cox regression, controlling for covariates. Etiology of heart failure was ischemic in 15 patients and nonischemic in 42 patients. Median follow-up was 12.9 years. Resting left ventricular ejection fraction (LVEF) and heart failure symptom scores improved at 4 months of treatment and were sustained at 24 months. Left ventricular internal diameter in systole (LVIDS) and left ventricular internal diameter in diastole decreased significantly at 4 and 8 months, respectively, and LVIDS continued to improve at 24 months. Overall mortality was 43% in nonischemic patients and 73% in ischemic patients. In a multivariate analysis, ischemic etiology and baseline LVEF were significant predictors of mortality. Carvedilol produces sustained improvements in left ventricular remodeling and symptoms. Long-term survival is good, particularly in nonischemic patients. [source]


Survival with Rett syndrome: comparing Rett's original sample with data from the Australian Rett Syndrome Database

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 10 2010
MICHAEL FREILINGER
Aim, Rett syndrome is a severe neurodevelopmental disorder that typically affects females. Little is known about the natural history and survival time of these females. Method, We compared the survival of all Austrian female participants from Rett's historical cohort (1966) with that of affected females registered in the Australian Rett Syndrome Database. The analysis included both Kaplan,Meier analysis and a log-rank test for equality of survivor functions. Results, Of females in the original Austrian group, three are still alive. The median age at death was 13 years 4.8 months. The probability of survival up to the age of 25 years was 21%, compared with 71% in the Australian cohort (p<0.001). We found no practical or statistically significant differences in survival between the various birth year groups within the Australian cohort. Interpretation, Our data indicate that survival of females with Rett syndrome has improved since the late 1960s but that there has been shown no change in survival over the last 30 years, possibly because the follow-up time has been too short. [source]


Mitochondrial DNA mutations and mitochondrial DNA depletion in breast cancer

GENES, CHROMOSOMES AND CANCER, Issue 7 2006
Ling-Ming Tseng
Somatic mutations in mitochondrial DNA (mtDNA) have been demonstrated in various tumors, including breast cancer. However, it still remains unclear whether the alterations in mtDNA are related to the clinicopathological features and/or the prognosis in the breast cancer. We analyzed somatic mutations in the D-loop region, the common 4,977-bp deletion, and the copy number of mtDNA in breast cancer and paired nontumorous breast tissues from 60 Taiwanese patients. We found that 18 of the 60 (30%) breast cancers displayed somatic mutations in mtDNA D-loop region. The incidence of the 4,977-bp deletion in nontumorous breast tissues (47%) was much higher than that in breast cancers (5%). The copy number of mtDNA was significantly decreased in 38 of the 60 (63%) breast cancers as compared to their corresponding nontumorous breast tissues (P = 0.0008). The occurrence of D-loop mutations was associated with an older onset age (,50 years old, P = 0.042), and tumors that lacked expressions of estrogen receptor and progesterone receptor (P = 0.024). Patients with mtDNA D-loop mutation and breast cancer had significantly poorer disease-free survival than those without mutation, when assessed by Kaplan,Meier curves and log-rank test (P = 0.005). Multivariate Cox regression analysis indicated that a D-loop mutation is a significant marker that is independent of other clinical variables and that it can be used to assess the prognosis of patients. Our findings suggest that somatic mutations in mtDNA D-loop can be used as a new molecular prognostic indicator in breast cancer. © 2006 Wiley-Liss, Inc. [source]


Elective neck dissection in early-stage oral squamous cell carcinoma,does it influence recurrence and survival?

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2007
Ana Capote MD
Abstract Background. This study investigates the influence on survival and regional control rates of neck dissection therapy at the time of surgery of the primary tumor in early stages of squamous cell carcinoma (SCC) of the oral cavity. Methods. A series of 154 patients with pT1N0M0 and pT2N0M0 intraoral carcinomas was analyzed retrospectively. Neck dissection was associated with tumor ablation in 87 patients (56.5%), although 67 patients (43.5%) were treated with local resection exclusively. Survival and relapse rates were studied with the Kaplan,Meier curves and the log-rank test for univariate analysis and Cox proportional model for multivariate analysis (p < .05). Results. Regional recurrences occurred in 25 cases (16.2%), 7 cases (8%) with primary neck dissection and 18 cases (26.8%) with local excision alone. Neck dissection therapy was a significant prognostic factor for recurrences and survival (p < .05). The 5-year regional control rate was of 92.5% for patients with elective lymph node ablation versus 71.2% for patients without primary neck dissection. Neck dissection was also significant for recurrences in stage I and for survival and recurrences in stage II. Neck dissection therapy also showed independent prognostic value in the Cox analysis. Conclusions. In patients with intraoral carcinomas, elective neck treatment should be considered even in cases with a small primary tumor and negative clinical examination because of the high incidence of occult nodal metastases and the tendency to regional recurrences. © 2006 Wiley Periodicals, Inc. Head Neck 2007 [source]


Conservation laryngeal surgery versus total laryngectomy for radiation failure in laryngeal cancer,

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 9 2006
F. Christopher Holsinger MD
Abstract Background. Total laryngectomy is the standard of care for surgical salvage of radiation failure in laryngeal cancer. However, the role of conservation laryngeal surgery in this setting remains unclear. The objective was to compare the efficacy of conservation versus total laryngectomy for salvage of radiation failure in patients who initially presented with T1 or T2 squamous cancer of the larynx. Methods. A 21-year retrospective analysis of patients who received surgery at a single comprehensive cancer center after definitive radiation therapy is reported. At recurrence, the patients were reevaluated and then underwent a total laryngectomy or, if possible, a conservation laryngeal procedure. The charts of 105 patients who failed radiation treatment for primary laryngeal cancer and who subsequently underwent surgical salvage were reviewed for this study. Eighty-nine were male (84.8%). The mean age was 60.3 years. The median follow-up time after surgery was 69.4 months. Most patients with recurrence after radiotherapy required total laryngectomy (69.5%; 73/105). Conservation laryngeal surgery was performed for 32 patients (31.5%). Concomitant neck dissections were performed on 45 patients (45.5%). Results. In 14 patients, local or regional recurrence developed after salvage surgery: 9 patients after total laryngectomy (12.3%; 9/73), and 5 patients (15.6%; 5/32) after conservation laryngeal surgery. This difference was not statistically significant, nor was there a difference in disease-free interval for the two procedures (p = .634, by log-rank test). Distant metastasis developed in 13 patients. Most developed in the setting of local and/or regional recurrence, but distant metastasis occurred as the only site of failure in 6 of the patients who had undergone total laryngectomy but in 1 of the conservation surgery patients treated for a supraglottic laryngeal cancer. The overall mortality for patients who underwent total laryngectomy was also higher: 73.74% (54/73) versus 59.4% (19/32) for patients who underwent a conservation approach (p = .011 by log-rank test). Conclusions. Although conservation laryngeal surgery was possible in a few patients with local failure after radiotherapy, conservation laryngeal surgery is an oncologically sound alternative to total laryngectomy for these patients. © 2006 Wiley Periodicals, Inc. Head Neck, 2006 [source]


Prediction of survival in patients with head and neck cancer

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 9 2001
Robert Jan Baatenburg de Jong PhD
Abstract Background In patients with head and neck squamous cell carcinoma (HNSCC) the estimated prognosis is usually based on the TNM classification. The relative weight of the three contributing parameters is often not completely clear. Moreover, the impact of other important clinical variables such as age, gender, prior malignancies, etc is very difficult to substantiate in daily clinical practice. The Cox-regression model allows us to estimate the effect of different variables simultaneously. The purpose of this study was to design a model for application in new HNSCC patients. In our historical data-base of patients with HNSCC, patient, treatment, and follow-up data are stored by trained oncological data managers. With these hospital-based data, we developed a statistical model for risk assessment and prediction of overall survival. This model serves in clinical decision making and appropriate counseling of patients with HNSCC. Patients and Methods All patients with HNSCC of the oral cavity, the pharynx, and the larynx diagnosed in our hospital between 1981 and 1998 were included. In these 1396 patients, the prognostic value of site of the primary tumor, age at diagnosis, gender, T-, N-, and M-stage, and prior malignancies were studied univariately by Kaplan-Meier curves and the log-rank test. The Cox-regression model was used to investigate the effect of these variables simultaneously on overall survival and to develop a prediction model for individual patients. Results In the univariate analyses, all variables except gender contributed significantly to overall survival. Their contribution remained significant in the multivariate Cox model. Based on the relative risks and the baseline survival curve, the expected survival for a new HNSCC patient can be calculated. Conclusions It is possible to predict survival probabilities in a new patient with HNSCC based on historical results from a data-set analyzed with the Cox-regression model. The model is supplied with hospital-based data. Our model can be extended by other prognostic factors such as co-morbidity, histological data, molecular biology markers, etc. The results of the Cox-regression may be used in patient counseling, clinical decision making, and quality maintenance. © 2001 John Wiley & Sons, Inc. Head Neck 23: 718,724, 2001. [source]


Risk factors and occurrence of rash in HIV-positive patients not receiving nonnucleoside reverse transcriptase inhibitor: data from a randomized study evaluating use of protease inhibitors in nucleoside-experienced patients with very low CD4 levels (<50 cells/m,L)

HIV MEDICINE, Issue 1 2004
M Floridia
Background Most of the studies evaluating rash in HIV-positive patients have focused on nonnucleoside reverse transcriptase inhibitors (NNRTI), particularly nevirapine, and little is known about the occurrence of rash and the risk factors for its development in patients receiving regimens not based on NNRTI. Methods We evaluated all cases of rash observed during a 48-week randomized multicentre trial in 1251 nucleoside-experienced patients who started treatment with protease inhibitors (ritonavir or indinavir) at CD4 counts below 50 cells/,L. Incidence rates for rash were calculated according to gender, clinical status, age, use of highly active antiretroviral therapy (HAART), Pneumocystis carinii pneumonia (PCP) prophylaxis and use of individual antiretroviral drugs at enrolment. Differences between groups defined according to the above characteristics were tested for statistical significance using the log-rank test in a Kaplan-Meier survival analysis. All factors that gave results in the univariate analyses below the significance level of 0.05 were included in a multivariate analysis using a Cox regression model. Results During a follow-up period of 9690 person-months, 66 patients (5.3%) developed rash (0.68 events/100 person-months). In the univariate analyses, risk of rash did not differ with trial treatment (indinavir or ritonavir), clinical status, PCP prophylaxis, or age. During follow-up, rash was observed in 7.5% of enrolled women and in 4.5% of enrolled men (P=0.03). Serious rash occurred in 4.5% of enrolled women and in 1.6% of enrolled men (P=0.003). Use of HAART (P<0.001) and inclusion of zidovudine and of zalcitabine in the prescribed regimen (P=0.02) appeared to be associated with a lower risk of rash. In the multivariate analysis, the variables that remained significantly predictive of rash were gender (risk for women compared to men: 1.65, 95% confidence interval (CI): 1.00,2.72, P=0.048) and use of a non-HAART regimen (risk for non-HAART patients compared to HAART: 2.73, 95% CI: 1.49,5.02, P=0.001). Conclusions In our study, about 5% of HIV-positive patients who started treatment with protease inhibitors at very low CD4 counts developed rash, generally in the first few weeks after treatment. Risk was significantly higher in women and in patients who did not receive a HAART regimen. Our data indicate that women have a higher risk of rash than men, also with regimens that do not include NNRTI. [source]


MNS16A minisatellite genotypes in relation to risk of glioma and meningioma and to glioblastoma outcome

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2009
Ulrika Andersson
Abstract The human telomerase reverse transcriptase (hTERT) gene is upregulated in a majority of malignant tumours. A variable tandem repeat, MNS16A, has been reported to be of functional significance for hTERT expression. Published data on the clinical relevance of MNS16A variants in brain tumours have been contradictory. The present population-based study in the Nordic countries and the United Kingdom evaluated brain-tumour risk and survival in relation to MNS16A minisatellite variants in 648 glioma cases, 473 meningioma cases and 1,359 age, sex and geographically matched controls. By PCR-based genotyping all study subjects with fragments of 240 or 271 bp were judged as having short (S) alleles and subjects with 299 or 331 bp fragments as having long (L) alleles. Relative risk of glioma or meningioma was estimated with logistic regression adjusting for age, sex and country. Overall survival was analysed using Kaplan,Meier estimates and equality of survival distributions using the log-rank test and Cox proportional hazard ratios. The MNS16A genotype was not associated with risk of occurrence of glioma, glioblastoma (GBM) or meningioma. For GBM there were median survivals of 15.3, 11.0 and 10.7 months for the LL, LS and SS genotypes, respectively; the hazard ratio for having the LS genotype compared with the LL was significantly increased HR 2.44 (1.56,3.82) and having the SS genotype versus the LL was nonsignificantly increased HR 1.46 (0.81,2.61). When comparing the LL versus having one of the potentially functional variants LS and SS, the HR was 2.10 (1.41,3.1). However, functionality was not supported as there was no trend towards increasing HR with number of S alleles. Collected data from our and previous studies regarding both risk and survival for the MNS16A genotypes are contradictory and warrant further investigations. © 2009 UICC [source]


Putative functional polymorphisms of MMP9 predict survival of NSCLC in a Chinese population

INTERNATIONAL JOURNAL OF CANCER, Issue 9 2009
Guangfu Jin
Abstract Matrix metalloproteinases (MMPs) play a crucial role in cancer progression and their over-expression is often associated with unfavorable survival of non-small cell lung cancer (NSCLC). Because genetic variants can alter expression level or biological activity of MMPs, we hypothesized that potentially functional single nucleotide polymorphisms (SNPs) in key MMP genes may be associated with the survival of NSCLC patients. We selected and genotyped 14 putative functional SNPs in six MMP genes (MMP1, MMP2, MMP3, MMP7, MMP9 and MMP12) using PCR-RFLP methods in 561 NSCLC patients. Kaplan-Meier method with the log-rank test and Cox proportional hazard models were used for the survival analyses. The C-1562T, Arg279Gln and Arg668Gln polymorphisms in MMP9 were significantly associated with survival of patients with NSCLC (log-rank p values = 0.032, 0.038 and 0.036, respectively). The C-1562T and Arg668Gln loci were in complete linkage disequilibrium (r2 = 1). Patients carrying the 668Gln allele had improved survival with a median survival time (MST) of 51.6 months, compared with 21.8 months for those with the 668Arg/Arg genotype (log-rank p = 0.010). In contrast, the 279Gln/Gln genotype was associated with a significantly shortened MST (17.3 months, log-rank p = 0.030) in the recessive model. In the final multivariate Cox regression model, 279Gln/Gln was identified as an independent prognostic factor with an adjusted hazard ratio of 1.60 (95% confidence interval 1.07,2.41). The MMP9 Arg279Gln and Arg668Gln SNPs are potential predictors of survival in NSCLC patients. © 2008 Wiley-Liss, Inc. [source]


Effects of base excision repair gene polymorphisms on pancreatic cancer survival

INTERNATIONAL JOURNAL OF CANCER, Issue 8 2007
Donghui Li
Abstract To explore the association between single nucleotide polymorphisms of DNA repair genes and overall survival of patients with pancreatic cancer, we conducted a study in 378 cases of pancreatic adenocarcinoma who were treated at The University of Texas M. D. Anderson Cancer Center between February 1999 and October 2004 and were followed up to April 2006. Genotypes were determined using genomic DNA and the MassCode method. Overall survival was analyzed using the Kaplan,Meier plot, log-rank test and Cox regression. We observed a strong effect of the POLB A165G and T2133C genotypes on overall survival. The median survival time (MST) was 35.7 months for patients carrying at least 1 of the 2 homozygous variant POLB GG or CC genotypes, compared with 14.8 months for those carrying the AA/AG or TT/TC genotypes (p = 0.02, log rank test). The homozygous variants of hOGG1 G2657A, APEX1 D148E and XRCC1 R194W polymorphisms all showed a weak but significant effect on overall survival as demonstrated by either log rank test or multivariate COX regression after adjusting for other potential confounders. In combined genotype analysis, a predominant effect of the POLB homozygous variants on survival was observed. When POLB was not included in the model, a slightly better survival was observed among those carrying none of the adverse genotypes than those carrying at least one of the adverse genotypes. These observations suggest that polymorphisms of base excision repair genes significantly affect the clinical outcome of patients with pancreatic cancer. These observations need to be confirmed in a larger study of homogenous patient population. © 2007 Wiley-Liss, Inc. [source]


The thymidylate synthase tandem repeat promoter polymorphism: A predictor for tumor-related survival in neoadjuvant treated locally advanced gastric cancer

INTERNATIONAL JOURNAL OF CANCER, Issue 12 2006
Katja Ott
Abstract We evaluated DNA polymorphisms in the thymidylate synthase (TS) and 5,10- methylene-tetrahydrofolate reductase (MTHFR) genes for an association with response and survival in locally advanced gastric cancer treated with 5-FU based preoperative chemotherapy (CTx). DNA of 238 patients (CTx-group: total n = 135, completely resected (R0) n = 102; without CTx: R0 n = 103) was isolated from blood or from nontumorous tissues. In the CTx-group, genotyping of the tandem repeat and the G/C polymorphism in the triple repeat in the promoter region of the TS gene and of the C677T polymorphism of the MTHFR gene was performed. None of the TS or MTHFR genotypes were associated with histopathological response and only the TS tandem repeat polymorphism was significantly related to survival (all patients n = 135, p = 0.002; R0 resected patients n = 102, p = 0.007; log-rank test). Multivariate analysis revealed ypN (p < 0.001) and the TS tandem repeat polymorphism as independent prognostic factors in the CTx-R0-group (p = 0.003). Analyzing the prognostic significance of the TS polymorphisms in the R0-group without CTx, TS genotypes were not significantly associated with survival. Comparing survival between R0 patients with and without CTx in the respective TS genotype groups of the tandem repeat polymorphism, a significant survival benefit for the patients with CTx was found for the 2rpt/2rpt (n = 49; p = 0.002) and 2rpt/3rpt genotypes (n = 99; p = 0.004), but not for the 3rpt/3rpt genotype (n = 57; p = 0.93). Patients' survival after CTx was associated with the TS tandem repeat polymorphism. CTx did not improve survival of patients with the 3rpt/3rpt genotype. Thus, a different therapy might be more appropriate for these patients. © 2006 Wiley-Liss, Inc. [source]


Preoperative hCG, and CA 72-4 are prognostic factors in gastric cancer

INTERNATIONAL JOURNAL OF CANCER, Issue 6 2004
Johanna Louhimo
Abstract In gastric cancer, the role of tumour markers in assessment of prognosis is unconfirmed. In our study, we evaluated the prognostic significance of serum tumour markers carcinoembryonic antigen (CEA), CA 19-9, CA 72-4, CA 242 and free , subunit of human chorionic gonadotropin (hCG,) in gastric cancer. Preoperative serum samples were obtained from 146 patients with gastric cancer, including 29 with stage I, 11 with stage II, 42 with stage III and 64 patients with stage IV cancer. Quantitation of CEA, CA 19-9, CA 72-4 and CA 242 in serum was performed with commercial assays. HCG, was measured with an in-house immunofluorometric assay based on monoclonal antibodies specific for the free ,-subunit of hCG. Survival analysis was performed with Kaplan-Meier life-tables and log-rank test, and with multivariate Cox regression analysis. Disease-specific cumulative 2-year survival rate was 40%. Serum levels of CEA, CA 72-4, CA 242 and hCG, showed significant correlation with stage (p<0.027); for CA 19-9 the association was of borderline significance (p=0.056). Of the studied markers, CA 19-9, CA 72-4, CA 242 and hCG, were found to be prognostic factors in univariate analysis (p< 0.022). In multivariate analysis, stage had the statistically most significant association with prognosis followed by hCG,, tumour histology according to the Laurén classification and by CA 72-4. In gastric cancer, tumour markers hCG, and CA 72-4 are independent prognostic factors in addition to stage and histological type of the tumour. © 2004 Wiley-Liss, Inc. [source]


Polymorphism in the proximal promoter region of the perforin gene and its impact on the course of HIV infection

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 2 2006
D. McIlroy
Summary Cytotoxic T lymphocytes (CTLs) play an essential role in the control of viral replication during human immunodeficiency virus (HIV) infection. However, the efficacy of the CTL response varies between individuals. We tested the hypothesis that genetic polymorphisms in the lytic effector molecule perforin could influence the progression of HIV infection. The perforin gene was screened for single nucleotide polymorphisms (SNPs) by denaturing high-performance liquid chromatography (dHPLC). Correlations were sought between perforin genotype, perforin expression and lytic function of CD8+ T lymphocytes from HIV-positive patients. Association of perforin genotype with disease progression was investigated in 426 seroconverters enrolled in the French SEROCO cohort. AIDS-free survival curves were constructed using the Kaplan,Meier method and compared using the log-rank test. Three SNPs were found in the proximal promoter region of the perforin gene: 63G (allelic frequency 0.029), 112G (allelic frequency 0.071) and 1012T (allelic frequency 0.070). The presence of the 1012T genotype correlated with fewer perforin+ cells among circulating CD8+ CTL. However, CTL lines from HIV -positive individuals heterozygous for the perforin 1012T SNP displayed normal lysis of target cells, and within the SEROCO cohort, patients heterozygous for the 1012T SNP showed normal disease progression. However, 1012T/T homozygotes showed a tendency towards slower disease progression (P = 0.08). In conclusion, polymorphism in the perforin gene is limited, and although the 1012T genotype appears to influence perforin expression, it was not conclusively associated with disease progression in HIV infection. [source]


Adjuvant methotrexate, vinblastine, adriamycin, and cisplatin chemotherapy has potential to prevent recurrence of bladder tumors after surgical removal of upper urinary tract transitional cell carcinoma

INTERNATIONAL JOURNAL OF UROLOGY, Issue 9 2008
Norihito Soga
Objectives: To evaluate the efficacy of adjuvant platinum based chemotherapy in upper urinary tract urothelial cancer following surgical resection in terms of survival benefit and inhibition of bladder cancer recurrence. Methods: Between April 1986 and August 2005, a total of 132 patients with a diagnosis of upper urinary tract urothelial cancer underwent radical nephroureterectomy with cuff of bladder at our department. A total of 46 patients (13 with pT2pN0M0 and 33 with pT3 pN0M0 transitional cell carcinoma without prior bladder cancer) were enrolled. Patients with locally advanced disease were divided into two groups: the adjuvant chemotherapy group (24 patients) who received adjuvant methotrexate, vinblastine, adriamycin, and cisplatin (M-VAC) and the non-adjuvant chemotherapy group who did not receive adjuvant M-VAC (22 patients). Results: There were no statistically significant differences in patient characteristics or 10-year survival between the two groups. The recurrence rate in the non-adjuvant chemotherapy group was significantly higher than in the adjuvant chemotherapy group (log-rank test, P < 0.0001). Only non-adjuvant chemotherapy was a significant and independent risk factor (hazard ratio 6.97) for the development of intravesical recurrence (P < 0.01). Conclusion: Adjuvant M-VAC is an important optional adjuvant therapy and can prevent recurrent bladder tumors following surgery for upper urinary tract transitional cell carcinoma. To determine whether adjuvant chemotherapy has further benefit, a randomized study would be needed. [source]


Hybrid Therapy of Radiofrequency Catheter Ablation and Percutaneous Transvenous Mitral Commissurotomy in Patients With Atrial Fibrillation and Mitral Stenosis

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2010
TAKESHI MACHINO M.D.
AF Ablation and PTMC.,Background: The rhythm control of atrial fibrillation (AF) associated with mitral stenosis (MS) is often difficult using antiarrhythmic drugs (AADs), even after a percutaneous transvenous mitral commissurotomy (PTMC). Few studies have examined the efficacy and safety of simultaneously performing radiofrequency catheter ablation (RFCA) and a PTMC in patients with MS and AF. Methods: Twenty consecutive patients with drug-resistant AF and rheumatic MS underwent RFCA combined with a PTMC (n = 10; persistent AF-8, long-lasting [>1 year] persistent AF-2; RFCA group) or transthoracic direct cardioversion (DC) following a PTMC (n = 10; persistent AF-7, long-lasting persistent AF-3; DC group). In all patients, the mitral valve morphology was amenable to a PTMC, and more than 2 AADs had been ineffective in maintaining sinus rhythm (SR). In the RFCA group, a segmental pulmonary vein isolation (PVI) was performed in the initial 5 patients, and an extensive PVI was performed in the remaining 5. Results: During a mean follow-up period of 4.0 ± 2.7 years, 8 patients (80%) in the RFCA group were maintained in SR, as compared to 1 (10%) in the DC group (hazard ratio, 0.16; 95% confidence interval, 0.03 to 0.75; P = 0.008 by the log-rank test). The prevalence of the concomitant use of class I and/or class III AADs was comparable between the 2 groups (P = 0.70). No complications occurred during the procedure or follow-up period in either group. Conclusions: The hybrid therapy using RFCA and a PTMC was safe and feasible, and significantly improved the AF free survival rate compared to DC following a PTMC. (J Cardiovasc Electrophysiol, Vol. 21, pp. 284,289, March 2010) [source]


Predicting Recurrence of Vasovagal Syncope: A Simple Risk Score for the Clinical Routine

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2009
MUHAMMET A. AYDIN M.D.
Background: Predictors for recurrence of syncope are lacking in patients with vasovagal syncope. The aim of this study was to identify risk factors for recurrence of syncope and develop a simple prognostic risk score of clinical value. Methods: Two hundred seventy-six patients with a history of vasovagal syncope were prospectively followed for 2 years. Diagnosis of vasovagal syncope was based on clinical history and negative standard work-up. Inclusion in the study was independent from the result of the head-up tilt test, which was performed in all cases. Risk factors for syncope recurrence were evaluated by the Cox proportional hazards regression model and implemented in a risk score, which was validated with the log-rank test and an internal cross-validation. Results: The Cox-regression analysis identified the number of previous syncopal events, history of bronchial asthma, and female gender as predictors for syncope recurrence (all P < 0.05). In contrast, head-up tilt test response had no predictive value (P = 0.881). Developing a risk score, study patients were identified as having high (recurrence rate during 2 years of follow-up: 37.2%), intermediate (24.8%), and low (6.5%) risk for syncope recurrence (receiver operating characteristic [ROC] of score 0.83, P < 0.01; Log-rank test for event-free survival, P < 0.005). Conclusions: In patients with vasovagal syncope, risk of recurrence can be stratified and is predictable based on a simple risk score. [source]


Decreased expression of Ep-CAM protein is significantly associated with the progression and prognosis of oral squamous cell carcinomas in Taiwan

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 1 2009
Emily Ya-Chi Hwang
Background:, The epithelial cell adhesion molecule (Ep-CAM) is involved in cell signaling, migration, proliferation, cell-cycle regulation, and cancer metastasis. Methods:, This study used an immunohistochemical technique to examine the expression of Ep-CAM protein in 84 specimens of oral squamous cell carcinoma (OSCC), 98 specimens of oral epithelial dysplasia (OED, 31 mild, 41 moderate, and 26 severe OED cases), and 15 specimens of normal oral mucosa (NOM). Results:, We found that the mean Ep-CAM labeling indices (LIs) decreased significantly from NOM (80 ± 18%) and mild OED (76 ± 14%) through moderate OED (66 ± 22%) and severe OED (55 ± 20%) to OSCC samples (46 ± 16%, P < 0.001). A significant correlation was found between the lower mean Ep-CAM LI and OSCCs with larger tumor size (P = 0.003), positive lymph node metastasis (P = 0.022), more advanced clinical stages (P < 0.001), cancer recurrence (P = 0.021), or extracapsular spread of lymph node (P = 0.015). However, only Ep-CAM LI < 50% (P < 0.0001) was identified as an independent unfavorable prognosis factor by multivariate analyses with Cox proportional hazard regression model. Kaplan,Meier curve showed that OSCC patients with an Ep-CAM LI < 50% had a significantly poorer cumulative survival than those with an Ep-CAM LI , 50% (P < 0.00001, log-rank test). Conclusions:, We conclude that the decreased expression of Ep-CAM protein is an early event in oral carcinogenesis. The Ep-CAM LI in OSCC samples can predict the progression of OSCCs and the survival of OSCC patients. [source]


Low Ki-67 proliferation index is an indicator of poor prognosis in gastric cancer

JOURNAL OF SURGICAL ONCOLOGY, Issue 3 2010
Hee Eun Lee MD
Abstract Background and Objectives We designed this study to assess the biologic significance of Ki-67 proliferation index (PI) in gastric cancer. Methods Gastric cancer tissue from 245 patients were immunostained for Ki-67. Ki-67 PI was defined as the percentage of tumor cells positive for Ki-67. In addition, we have previously evaluated the expressions of nine epithelial mesenchymal transition (EMT)-related proteins. The relationship between Ki-67 PI and clinicopathologic parameters, patient survival, and EMT data were sought. Results Low Ki-67 PI was correlated with poorly differentiated histology (P,=,0.034), an advanced T stage (P,<,0.001), and lymph node metastasis (P,=,0.011). Also, the low PI group was found to have a significantly worse prognosis than the high PI group (P,=,0.003, log-rank test). Multivariate analysis revealed that Ki-67 PI remained as an independent prognostic factor (hazard ratio (95% CI),=,0.670 (0.450,0.999)). Furthermore, greater expressional changes of EMT-related proteins were found to be significantly associated with low Ki-67 PI (P,=,0.025). Conclusions These findings suggest that Ki-67 PI is an effective tool for predicting survival in gastric cancer. In addition, we found that an invasive property presented as EMT-related protein expressional changes was inversely correlated with a proliferative activity in gastric cancer. J. Surg. Oncol. 2010;102:201,206. © 2010 Wiley-Liss, Inc. [source]


LAPTM4B-35 is a novel prognostic factor of hepatocellular carcinoma

JOURNAL OF SURGICAL ONCOLOGY, Issue 5 2010
Hua Yang MD
Abstract Background LAPTM4B-35 is a 35-kDa tetra-transmembrane protein overexpressed in hepatocellular carcinoma (HCC) and promotes cell survival, proliferation, and tumorigenesis. However, the potential clinical implications of LAPTM4B-35 in HCC are still unclear. This study is aimed to investigate the correlations between LAPTM4B-35 expression and prognosis in patients with HCC. Methods Western blot and immunohistochemistry assays were used to determine the expression of LAPTM4B-35 in HCCs and their paired noncancerous liver tissues from 65 patients. The correlations of LAPTM4B-35 expression with clinicopathological parameters were assessed by Chi-square test. Patient survival was determined by Kaplan,Meier method and log-rank test. Cox regression was adopted for multivariate analysis of prognostic factors. Results LAPTM4B-35 overexpression occurred in 76.9% of HCC tissues, while only in 4.6% of noncancerous liver tissues. Overexpression of LAPTM4B-35 was significantly associated with TNM staging and invasive tumors. Patients with higher LAPTM4B-35 expression had significantly poorer overall survival (OS) and disease-free survival (DFS) (both P,<,0.001). On multivariate analysis, elevated expression of LAPTM4B-35 was found to be an independent prognostic factor for OS and DFS (P,=,0.009, 0.043, respectively). Conclusions LAPTM4B-35 overexpression is an independent prognostic factor for OS and DFS of HCC. J. Surg. Oncol. 2010; 101:363,369. © 2010 Wiley-Liss, Inc. [source]


Pancreatic adenocarcinoma in a young patient population,12-year experience at Memorial Sloan Kettering Cancer Center

JOURNAL OF SURGICAL ONCOLOGY, Issue 1 2009
A. Duffy MD
Abstract Background There is a dearth of data in a younger population of patients with pancreatic ductal adenocarcinoma (PAC) regarding epidemiology, genetics, prognosis, and outcome. This report examines a large cohort of patients with PAC ,45 years of age evaluated at MSKCC over a 12-year period. Methods A retrospective analysis of patients referred to MSKCC with PAC identified from the institutional tumor registry, who were ,45 years on the date of the diagnostic biopsy, between January 1995 and February 2008, was performed. Information reviewed included demographics, clinical and pathological staging, surgical management, therapy, date of relapse, death or last follow-up. Survival curves were estimated using the Kaplan,Meier method and compared using the log-rank test. Results One hundred thirty-six cases of PAC, age ,45 years at diagnosis, were identified. Seventy-four (54%) females, 62 (46%) males. Age range: 24,45; 4, 38, and 94 patients in age groups 20,29, 30,39, 40,45 years, respectively. Fifty (37%) had a smoking history. Fourteen (10.3%) had a positive family history of PAC. Thirty-five (25.7%) underwent a curative resection for localized disease. Twenty-eight (20.1%) presented with locally advanced, inoperable disease. Sixty-eight (50%) presented as AJCC Stage IV. Twenty-three (37%) of those resected underwent adjuvant chemoradiation. Thirteen received adjuvant gemcitabine. The median overall survival for the entire cohort was 12.3 months (95% CI 10.2,14.0 months). The median overall survival for the patients with locally resectable disease was 41.8 months (95% CI 20.3,47 months). The median overall survival for the patients who presented with locally advanced, unresectable disease was 15.3 months (95% CI 12,19.3 months). The median overall survival for those who presented with metastatic disease was 7.2 months (95% CI 5.2,9.5 months). Conclusions This is the largest reported cohort of young patients with PAC ,45 years of age. The data suggest that patients with stages I,II disease may have an improved prognosis, however the prognosis for stages III,IV patients appears to be similar to the typical (older) patient population with PAC. J. Surg. Oncol. 2009;100:8,12. © 2009 Wiley-Liss, Inc. [source]


A two-stage procedure for comparing hazard rate functions

JOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 1 2008
Peihua Qiu
Summary., Comparison of two hazard rates is important in applications that are related to times to occurrence of a specific event. Conventional comparison procedures, such as the log-rank, Gehan,Wilcoxon and Peto,Peto tests, are powerful only when the two hazard rates do not cross each other. Because crossing hazard rates are common in practice, several procedures have been proposed in the literature for comparing such rates. However, most of these procedures consider only the alternative hypothesis with crossing hazard rates; many other realistic cases, including those when the two hazard rates run parallel to each other, are excluded from consideration. We propose a two-stage procedure that considers all possible alternatives, including ones with crossing or running parallel hazard rates. To define its significance level and p -value properly, a new procedure for handling the crossing hazard rates problem is suggested, which has the property that its test statistic is asymptotically independent of the test statistic of the log-rank test. We show that the two-stage procedure, with the log-rank test and the suggested procedure for handling the crossing hazard rates problem used in its two stages, performs well in applications in comparing two hazard rates. [source]


Stringent cessation criterion results in better durability of lamivudine treatment: a prospective clinical study in hepatitis B e antigen-positive chronic hepatitis B patients

JOURNAL OF VIRAL HEPATITIS, Issue 4 2010
L. Wang
Summary., The cessation criteria for lamivudine treatment vary in published articles and their results are contradictory, especially factors predicting relapse. To clarify these contradictions, this long-term follow-up study of 125 Chinese hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients was designed with stringent cessation criterion. All patients received lamivudine and achieved HBeAg seroconversion (group A, n = 82) or loss (group B, n = 43) with undetectable hepatitis B virus (HBV) DNA by PCR assay during the treatment. Lamivudine was withdrawn ,6 months after HBeAg seroconversion/loss occurred. The median treatment durations were 24 (12,54) months and 36 (18,89) months in group A and group B, respectively. Patients were followed up for median 24 (2,84) months. The cumulative relapse (defined as serum HBV DNA ,104 copies/mL) rates in the two groups at months 12, 24, 36 and 48 were 23.4%vs 35.0%, 25.0%vs 37.7%, 25.0%vs 41.1% and 29.4%vs 41.1%, respectively (log-rank test, P = 0.119). For patients whose total treatment duration ,18 months in group A, the cumulative relapse rates at months 12, 24, 36 and 48 were 18.3%, 20.1%, 20.1% and 25.1%, which was significantly lower than those with a shorter duration (log-rank test, P = 0.002). The mean age and median total duration were statistically different between relapsers and nonrelapsers in group A (33.9 ± 13.6 vs 23.1 ± 11.0 years, P < 0.001 and 24 vs 26 months, P = 0.003). Cox regression revealed that age was the only predictive factor for relapse (RR, 1.069; 95% CI, 1.032,1.106, P < 0.001). Patients aged <30 years relapsed less frequently in 5 years (12.3%vs 53.5%, P = 0.001). In conclusion, for patients who maintained HBeAg seroconversion for ,6 months and total duration for ,18 months, lamivudine withdrawal is a reasonable option. Prolonged treatment may be required for patients aged greater than 30 years to reduce relapse. [source]


Influence of anti-HBc seropositivity on the risk of hepatocellular carcinoma in HCV-infected patients after adjusting for confounding factors

JOURNAL OF VIRAL HEPATITIS, Issue 2 2010
T. Ohki
Summary., It is controversial whether past hepatitis B virus infection constitutes an additional risk of hepatocellular carcinoma (HCC) among patients with hepatitis C virus (HCV). The incidence of HCC between 1994 and 2004 was analysed among 1262 patients who were only positive for HCV. The cumulative incidence of HCC was assessed by Kaplan,Meier analysis and the difference between two groups was assessed by the log-rank test. The effect of anti-HBc positivity on the risk of HCC was assessed with multivariate Cox proportional analysis. Anti-HBc was positive in 522 (41.4%) patients. The proportion of male patients (56.7 vs 46.8%, P < 0.001) and mean age (60.8 vs 56.9 years, P < 0.001) were significantly higher in the anti-HBc positive group. HCC developed in 339 patients (mean follow-up 7.0 years), with cumulative incidence rates at 3, 5 and 10 years of 12.7, 24.5 and 41.9% in the anti-HBc positive group and 10.6, 17.7 and 33.4% in the negative group, respectively (P = 0.005). However, anti-HBc seropositivity did not reach statistical significance in multivariate analysis including age and gender (hazard ratio, 1.06; 95% CI, 0.85,1.31; P = 0.63). Anti-HBc positivity and HCC incidence were confounded by male gender and older age. [source]


Liver transplantation at the extremes of the body mass index,

LIVER TRANSPLANTATION, Issue 8 2009
André A. S. Dick
Controversies exist regarding the morbidity and mortality of patients undergoing liver transplantation at the extremes of the body mass index (BMI). A review of the United Network for Organ Sharing database from 1987 through 2007 revealed 73,538 adult liver transplants. Patients were stratified into 6 BMI categories established by the World Health Organization: underweight, <18.5 kg/m2; normal weight, 18.5 to <25 kg/m2; overweight, 25 to <30 kg/m2; obese, 30 to <35 kg/m2; severely obese, 35 to <40 kg/m2; and very severely obese, ,40 kg/m2. Survival rates were compared among these 6 categories via Kaplan-Meier survival curves with the log-rank test. The underweight and very severely obese groups had significantly lower survival. There were 1827 patients in the underweight group, 1447 patients in the very severely obese group, and 68,172 patients in the other groups, which became the control. Groups with extreme BMI (<18.5 and ,40) were compared to the control to assess significant differences. Underweight patients were more likely to die from hemorrhagic complications (P < 0.002) and cerebrovascular accidents (P < 0.04). When compared with the control, the very severely obese patients had a higher number of infectious complications and cancer events (P = 0.02) leading to death. In 3 different eras of liver transplantation, multivariable analysis showed that underweight and very severe obesity were significant predictors of death. In conclusion, liver transplantation holds increased risk for patients at the extremes of BMI. Identifying these patients and instituting aggressive new policies may improve outcomes. Liver Transpl 15:968,977, 2009. © 2009 AASLD. [source]