Kaplan-Meier Curves (kaplan-meier + curve)

Distribution by Scientific Domains

Selected Abstracts

Prediction of survival in patients with head and neck cancer

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]

The association of HLA-DR13 with lower graft survival rates in hepatitis B and primary sclerosing cholangitis caucasian patients receiving a liver transplant

Yasuro Futagawa
We investigated an association of human leukocyte antigen (HLA)-DR13 to graft survival in liver transplantation among Caucasian recipients. 28,708 deceased liver transplants performed between January 1990 and December 2002 in the United States as reported to the United Network for Organ Sharing registry were utilized to compare survival rates. We utilized Caucasian adult patients (>20 years) by Kaplan-Meier curves, log-rank tests, and Cox proportional hazard analyses. HLA-DR13-negative hepatitis B virus (HBV) and primary sclerosing cholangitis (PSC) recipients yielded significantly lower graft survival rates than those of DR13-negative patients (P = 0.002, P = 0.015, respectively). This negative association was still significant after adjusting potential confounding factors. The Cox test demonstrated that HLA-DR13-positive groups have a significantly higher hazard ratio in PSC (1.40; P = 0.029; 95% confidence interval, 1.04-1.90) and HBV patients (1.78; P = 0.032; 95% confidence interval, 1.05-3.02). In conclusion, our data suggest that HLA-DR13 is a strong, positive predictor of increased risk for graft loss in HBV and PSC liver transplant recipients. Further study is needed to test the hypothesis that DR13-related immune responses may play a role in mediating graft loss in HBV and PSC liver transplantations. Liver Transpl 12:600,604, 2006. © 2006 AASLD. [source]

Genetic polymorphisms in the metabolic pathway and non-Hodgkin lymphoma survival,

Xuesong Han
Metabolic pathway enzymes, such as Cytochrome P450 (CYP), glutathione S-transferase (GST), and N -acetyltransferases (NAT) are involved in activation and detoxification of environmental carcinogens as well as drug metabolism. We hypothesized that the genetic variations in such metabolic pathways may affect NHL prognosis and survival. Follow-up information of 496 female NHL incident cases diagnosed during 1996,2000 in Connecticut were abstracted from the Connecticut Tumor Registry in 2008; survival analyses were conducted by comparing the Kaplan-Meier curves, and hazard ratios (HR) were computed from the Cox Proportional Hazard models adjusting for demographic and tumor characteristics which were suggested by previous studies to be determinants of NHL survival. We identified six SNPs from four metabolism genes (CYP2E1, GSTP1, GSTT1, and NAT1) that were associated with NHL survival. Specifically, polymorphisms in GSTT1 were associated with follicular lymphoma survival; and polymorphisms in CYP2E1, GSTP1, and NAT1 were associated with survival of chronic lymphocytic leukemia/small lymphocytic lymphoma. Our study suggests that genetic polymorphisms in metabolic pathways may help improve the prediction of NHL survival and prognosis. Am. J. Hematol., 2010. © 2009 Wiley-Liss, Inc. [source]

Is Rhythm-Control Superior to Rate-Control in Patients with Atrial Fibrillation and Diastolic Heart Failure?

Melissa H. Kong M.D.
Background: Although no clinical trial data exist on the optimal management of atrial fibrillation (AF) in patients with diastolic heart failure, it has been hypothesized that rhythm-control is more advantageous than rate-control due to the dependence of these patients' left ventricular filling on atrial contraction. We aimed to determine whether patients with AF and heart failure with preserved ejection fraction (EF) survive longer with rhythm versus rate-control strategy. Methods: The Duke Cardiovascular Disease Database was queried to identify patients with EF > 50%, heart failure symptoms and AF between January 1,1995 and June 30, 2005. We compared baseline characteristics and survival of patients managed with rate- versus rhythm-control strategies. Using a 60-day landmark view, Kaplan-Meier curves were generated and results were adjusted for baseline differences using Cox proportional hazards modeling. Results: Three hundred eighty-two patients met the inclusion criteria (285 treated with rate-control and 97 treated with rhythm-control). The 1-, 3-, and 5-year survival rates were 93.2%, 69.3%, and 56.8%, respectively in rate-controlled patients and 94.8%, 78.0%, and 59.9%, respectively in rhythm-controlled patients (P > 0.10). After adjustments for baseline differences, no significant difference in mortality was detected (hazard ratio for rhythm-control vs rate-control = 0.696, 95% CI 0.453,1.07, P = 0.098). Conclusions: Based on our observational data, rhythm-control seems to offer no survival advantage over rate-control in patients with heart failure and preserved EF. Randomized clinical trials are needed to verify these findings and examine the effect of each strategy on stroke risk, heart failure decompensation, and quality of life. Ann Noninvasive Electrocardiol 2010;15(3):209,217 [source]


S. K. Thompson
Purpose Controversy exists over the 2nd edition of the TNM staging system introduced by the American Joint Committee in Cancer in 1988, and revised in 2002. Prognostic pathological factors such as the number of positive lymph nodes and any extracapsular lymph node invasion may refine this current staging system and optimize patient treatment. Methodology All patients who underwent surgical resection for oesophageal cancer were identified in a prospectively-maintained database. Patients without invasive adenocarcinoma or squamous cell cancer were excluded. Pathology slides were reviewed by a single pathologist. Survival data was calculated using Kaplan-Meier curves, and prognostic factors were examined using the log rank test. Results 235 surgical specimens met inclusion criteria, and 95 specimens have been reviewed so far. The 5-yr overall survival rate was 43% (median 31.4 months). Subdividing pN-stage into 1,2 positive nodes and >2 positive nodes showed significant differences in 5-yr survival between both groups: 41% vs. 6.0%, respectively (P = 0.0003). Similarly, including absence and presence of extracapsular lymph node invasion into our pathology review showed significant differences in 5-yr survival: 40% vs. 7.8%, respectively (P < 0.01). A negative circumferential margin, and the absence of both vascular and perineural invasion were also found to significantly improve survival rates. Conclusions The number and characteristics of metastatic invasion of lymph nodes should be included in current oesophageal cancer staging systems. Clinicians will then have more accurate prognostic information, and treatment can be better tailored to patients' needs. [source]

Superficial bladder tumours: analysis of prognostic factors and construction of a predictive index

B. Ali-El-Dein
OBJECTIVES To assess the prognostic factors that could be used to predict tumour recurrence and progression, and to construct and validate a predictive index. PATIENTS AND METHODS Between June 1991 and December 2000, 533 patients (418 men and 115 women; mean age 55.4 years) underwent complete transurethral resection of histologically confirmed pTa and pT1 transitional cell carcinoma of the bladder, after which 377 (test series) were randomized into two subsequent studies, of six groups, to receive adjuvant intravesical sequential bacillus Calmette-Guérin (BCG) and epirubicin, BCG alone, epirubicin (50 or 80 mg), adriamycin 50 mg or no adjuvant therapy. Factors potentially affecting tumour recurrence or progression were assessed using univariate and multivariate analysis, i.e. tumour stage, histological grade, DNA ploidy, history of recurrence, multiplicity, size, tumour configuration, associated carcinoma in situ, recurrence at the first 3-month check cystoscopy and the use of adjuvant therapy. The regression coefficients determined by Cox regression analysis were used to construct a predictive index (PI). The algebraic sum of the regression coefficients of the factors with independent and significant association with disease-free survival for each case represented a proportional hazard score (PHS). The PI was validated in another series of 156 patients (validation series) in whom the same regression coefficients for the same significant factors as the test series were used to categorize it into three risk groups. Kaplan-Meier survival curves were plotted to compare the different risk categories in both test and validation series. RESULTS The mean (sd, range) follow-up in the test and validation series were 58 (19, 5,96) and 28.3 (14.9, 2,94) months, respectively. In the test series, tumour stage, DNA ploidy, multiplicity, history of recurrence, tumour configuration, cystoscopy result and the type of adjuvant therapy had independent significance for recurrence on multivariate analysis. For progression, the cystoscopy result, DNA ploidy and grade were the only independent and significant predictors. The ranges of PHS for the factors affecting recurrence-free and progression-free survival were 0.0,7.14 and 0.0,5.84, respectively, which were divided equally into three risk categories with significant differences on Kaplan-Meier curves and a log-rank test (P < 0.001). The three categories in the validation series were significantly different from each other and each was comparable with that in the test series. CONCLUSIONS Tumour stage, DNA ploidy, multiplicity, history of recurrence, tumour configuration and type of adjuvant therapy affected independently the rate of recurrence after resecting superficial bladder tumour. Recurrence at the 3-month cystoscopy, histological grade and DNA ploidy were the only predictors of progression to muscle-invasion. The PI dividing the patients into three risk groups with different treatment and follow-up strategies for recurrence and progression was reproducible in a validation series. [source]

Yes-associated protein is an independent prognostic marker in hepatocellular carcinoma

CANCER, Issue 19 2009
Michelle Z. Xu MD
Abstract BACKGROUND: Yes-associated protein (YAP), a downstream target of the Hippo signaling pathway, was recently linked to hepatocarcinogenesis in a mouse hepatocellular carcinoma (HCC) model. The objective of the current study was to investigate the clinical significance of YAP in HCC and its prognostic values in predicting survival and tumor recurrence. METHODS: The authors collected 177 pairs of tumor and adjacent nontumor tissue from HCC patients with definitive clinicopathologic and follow-up data. YAP expression was determined by immunohistochemistry, Western blot analysis, and quantitative polymerase chain reaction. Association of YAP with each clinicopathologic feature was analyzed by Pearson chi-square test, and HCC-specific disease-free survival and overall survival by Kaplan-Meier curves and log-rank test. Multivariate Cox regression analyses of YAP in HCC were also performed. RESULTS: YAP was expressed in the majority of HCC cases (approximately 62%) and mainly accumulated in the tumor nucleus. Overexpression of YAP in HCC was significantly associated with poorer tumor differentiation (Edmonson grade; P = .021) and high serum ,-fetoprotein (AFP) level (P < .001). Kaplan-Meier and Cox regression data indicated that YAP was an independent predictor for HCC-specific disease-free survival (hazards ratio [HR], 1.653; 95% confidence interval [95% CI], 1.081-2.528 [P = .02]) and overall survival (HR, 2.148; 95% CI, 1.255-3.677 [P = .005]). CONCLUSIONS: YAP is an independent prognostic marker for overall survival and disease-free survival times of HCC patients and clinicopathologically associated with tumor differentiation and serum AFP level. It is a potential therapeutic target for this aggressive malignancy. Cancer 2009. © 2009 American Cancer Society. [source]

Effect of the number of lymph nodes sampled on postoperative survival of lymph node-negative esophageal cancer

CANCER, Issue 6 2008
Alexander J. Greenstein MD
Abstract BACKGROUND The presence of lymph node (LN) metastases in esophageal cancer has important prognostic and treatment implications. However, the optimal number of LNs that should be examined for accurate staging is controversial. In the current study, the association between survival and the number of LNs evaluated was examined in patients who underwent resection of lymph node-negative (American Joint Committee on Cancer [AJCC] TNM stage I-IIA) esophageal cancer. METHODS All patients were identified who underwent surgery for lymph node-negative esophageal cancer between 1988 and 2003 from the Surveillance, Epidemiology, and End Results cancer registry. Patients were classified into 3 groups by the number of negative LNs sampled during surgery (,10 LNs, 11-17 LNs, and ,18 LNs). Esophageal cancer-specific survival was compared among these LN groups using Kaplan-Meier curves. Stratified and Cox regression analyses were used to evaluate the association between survival and the number of negative LNs after adjusting for potential confounders. RESULTS A total of 972 patients were included in the study. Disease-specific survival rates increased with a higher number of negative LNs. The 5-year disease-specific survival rate was 55% among patients with ,10 negative LNs, compared with 66% and 75%, respectively, for those with 11 to 17 negative LNs and ,18 negative LNs. The number of negative LNs was found to be significantly associated with survival in analyses stratified by tumor status. On multivariate regression controlling for age, race/ethnicity, sex, histology, tumor status, and postoperative radiotherapy, a higher number of negative LNs was found to be independently associated with higher disease-specific survival. CONCLUSIONS The presence of LN metastases in patients with esophageal cancer appears to have important prognostic and treatment implications. Data from the current study suggest that patients undergoing surgical resection for esophageal cancer should have at least 18 LNs removed. Cancer 2008. © 2008 American Cancer Society. [source]

Neural networks compared with Cox regression

Purpose Survival prediction is useful in patient care and research. Most studies rely on Cox analysis and Kaplan-Meier curves whereas we have preferred neural networks. The aim of this presentation is to compare these methods and to discuss the advantages and limitations of each. Methods This presentation will be based on our experience with uveal melanoma. A neural network was trained with data from 1780 patients and evaluated with data from another 874 patients. Clinical, histopathological and cytogenetic data were included in the model. All cause mortality was reported, both for patients and for the matched general population. Results Cox analysis assumes linear correlations between variables and proportional hazards throughout the follow-up period. Kaplan-Meier analysis requires large patient categories, so that the precision of any prognostication is reduced. Neural networks overcome these limitations. Our model does censor non-metastatic deaths so that melanoma-related mortality is not exaggerated in groups of patients with significant competing risks. Conclusion Neural networks allow large numbers of variables to be included in predictive models with relatively small numbers of patients, thereby improving prognostication. Nevertheless, care must be taken when interpreting survival results to avoid serious misconceptions about the natural history of a disease and the impact of treatment. [source]