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Concordance Index (concordance + index)
Selected AbstractsComparative performances of staging systems for early hepatocellular carcinomaHPB, Issue 5 2009Hari Nathan Abstract Background:, Several staging systems for patients with hepatocellular carcinoma (HCC) have been proposed, but studies of their prognostic accuracy have yielded conflicting conclusions. Stratifying patients with early HCC is of particular interest because these patients may derive the greatest benefit from intervention, yet no studies have evaluated the comparative performances of staging systems in patients with early HCC. Methods:, A retrospective cohort study was performed using data on 379 patients who underwent liver resection or liver transplantation for HCC at six major hepatobiliary centres in the USA and Europe. The staging systems evaluated were: the Okuda staging system, the International Hepato-Pancreato-Biliary Association (IHPBA) staging system, the Cancer of the Liver Italian Programme (CLIP) score, the Barcelona Clinic Liver Cancer (BCLC) staging system, the Japanese Integrated Staging (JIS) score and the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) staging system, 6th edition. A recently proposed early HCC prognostic score was also evaluated. The discriminative abilities of the staging systems were evaluated using Cox proportional hazards models and the bootstrap-corrected concordance index (c). Results:, Overall survival of the cohort was 74% at 3 years and 52% at 5 years, with a median survival of 62 months. Most systems demonstrated poor discriminatory ability (P > 0.05 on Cox proportional hazards analysis, c, 0.5). However, the AJCC/UICC system clearly stratified patients (P < 0.001, c= 0.59), albeit only into two groups. The early HCC prognostic score also clearly stratified patients (P < 0.001, c= 0.60) and identified three distinct prognostic groups. Discussion:, The early HCC prognostic score is superior to the AJCC/UICC staging system (6th edition) for predicting the survival of patients with early HCC after liver resection or liver transplantation. Other major HCC staging systems perform poorly in patients with early HCC. [source] A pretreatment nomogram predicting biochemical failure after salvage cryotherapy for locally recurrent prostate cancerBJU INTERNATIONAL, Issue 2 2010Philippe E. Spiess Study Type , Prognosis (retrospective cohort) Level of Evidence 2b OBJECTIVE To gather a pooled database from six tertiary-care referral centres using salvage cryotherapy (SC) for locally recurrent prostate cancer, and develop a pretreatment nomogram allowing a prediction of the probability of biochemical failure after SC, based on pretreatment clinical variables. PATIENTS AND METHODS We retrospectively analysed 797 men treated at six tertiary-care referral centres with SC for locally recurrent disease after primary radiotherapy with curative intent. The median duration of follow-up from the time of SC to the date of last contact was 3.4 years. The primary study endpoint was biochemical failure, defined as a serum prostate-specific antigen (PSA) level after SC of >0.5 ng/mL. RESULTS Overall, the rate of biochemical failure was 66% with a median of 3.4 years of follow-up. A logistic regression model was used to predict biochemical failure. Covariates included serum PSA level at diagnosis, initial clinical T stage, and initial biopsy Gleason score. On the basis of these results, a pretreatment nomogram was developed which can be used to help select patients best suited for SC. Our pretreatment nomogram was internally validated using 500 bootstrap samples, with the concordance index of the model being 0.70. CONCLUSION A pretreatment nomogram based on several diagnostic variables (serum PSA level at diagnosis, biopsy Gleason grade, and initial clinical T stage) was developed and might allow the selection of ideal candidates for SC. [source] The Shared Equal Access Regional Cancer Hospital (SEARCH) nomogram for risk stratification in intermediate risk group of men with prostate cancer: validation in the Duke Prostate Center databaseBJU INTERNATIONAL, Issue 2 2010Jayakrishnan Jayachandran Study Type , Prognosis (cohort) Level of Evidence 2a OBJECTIVES To validate the Shared Equal Access Regional Cancer Hospital (SEARCH) nomogram to better risk stratify men with intermediate-risk pathology after prostatectomy (positive surgical margins, PSM, and/or extracapsular disease, ECE, without seminal vesicle or lymph node involvement) in a tertiary referral centre (the Duke Prostate Center, DPC). PATIENTS AND METHODS We retrospectively analysed 485 men in the DPC cohort with PSM and/or ECE but without seminal vesicle or lymph node involvement. The predicted risk of biochemical progression-free probability at 1, 3 and 5 years was estimated by the SEARCH and updated Kattan postoperative nomograms. Calibration plots were generated and accuracy assessed with the concordance index. RESULTS The SEARCH nomogram appeared to be well calibrated, with the highest-risk quartile having a predicted <60% progression-free probability at 5 years, vs >80% for the lowest risk. In comparison, overall external calibration appeared to be similar for the updated Kattan nomogram, although there was less separation between the highest- and lowest-risk quartiles. The SEARCH model had an overall predictive accuracy of 0.65, which compared favourably with the updated Kattan nomogram (0.57). CONCLUSION In an external dataset, the SEARCH nomogram to predict progression-free probability for men at intermediate risk after prostatectomy was well calibrated and performed better than the updated postoperative Kattan nomogram. [source] Validation of a nomogram to predict disease progression following salvage radiotherapy after radical prostatectomy: results from the SEARCH databaseBJU INTERNATIONAL, Issue 10 2009Daniel M. Moreira OBJECTIVE To externally validate the nomogram published by Stephenson et al. (termed the ,Stephenson nomogram') to predict disease progression after salvage radiotherapy (SRT) among patients with prostate cancer from the Shared Equal Access Regional Cancer Hospital (SEARCH) database. PATIENTS AND METHODS We analysed data from 102 men treated with SRT for prostate-specific antigen (PSA) failure after prostatectomy, of whom 30 (29%) developed disease progression after SRT during a median follow-up of 50 months. The predicted 6-year progression-free survival (PFS) was compared to the actuarial PFS using calibration plots. The accuracy of the nomogram to risk-stratify men for progression was assessed by the concordance index. RESULTS The median PSA and PSA doubling time before SRT was 0.6 ng/mL and 10.3 months, respectively. The 6-year actuarial disease-free progression after SRT was 57% (95% confidence interval 42,69%). The overall concordance index of the Stephenson nomogram was 0.65. The nomogram predicted failure more accurately at the extremes of risk (lowest and highest) but in intermediate groups, the accuracy was less precise. Of the 11 variables used in the nomogram, only negative margins and high PSA level before SRT were significantly associated with increased disease progression. CONCLUSION The Stephenson nomogram is an important tool to predict disease progression after SRT following radical prostatectomy. It adequately predicted progression in SEARCH with reasonable accuracy. Also, in SEARCH, disease progression was predicted by similar disease characteristics. However, the overall modest performance of the model in our validation cohort indicates there is still room for improvement in predictive models for disease progression after SRT. [source] Do nomograms predict aggressive recurrence after radical prostatectomy more accurately than biochemical recurrence alone?BJU INTERNATIONAL, Issue 5 2009Florian R. Schroeck OBJECTIVE To compare the predictive accuracy (PA) of existing models in estimating risk of biochemical recurrence (BCR) vs aggressive recurrence (BCR with a prostate-specific antigen, PSA, doubling time, DT, of <9 months). PATIENTS AND METHODS The study included 1550 men treated with radical prostatectomy (RP) between 1988 and 2007 within the Shared Equal Access Regional Cancer Hospital database. The PA of nine different risk stratification models for estimating risk of BCR and risk of aggressive recurrence after RP was assessed using the concordance index, c. RESULTS The 10-year risks of BCR and aggressive recurrence were 47% and 9%, respectively. Across all nine models tested, the PA was a mean (range) of 0.054 (0.024,0.074) points higher for predicting aggressive recurrence than for predicting BCR alone (c = 0.756 vs 0.702). Similar results were obtained in four sensitivity analyses: (i) defining patients with BCR but unavailable PSADT (220) as having aggressive recurrence; (ii) defining these patients as not having aggressive recurrence; (iii) defining aggressive recurrence as a PSADT of <6 months; or (iv) defining aggressive recurrence as a PSADT of <12 months. The improvement in PA was greater for preoperative than for postoperative models (0.053 vs 0.036, P = 0.03). CONCLUSION Across nine different models the prediction of aggressive recurrence after RP was more accurate than the prediction of BCR alone. This is probably because current models mainly assess cancer biology, which correlates better with aggressive recurrence than with BCR alone. Overall, all models had relatively similar accuracy for predicting aggressive recurrence. [source] A predictive model for local recurrence after transanal endoscopic microsurgery for rectal cancer,,BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2009S. P. Bach Background: The outcome of local excision of early rectal cancer using transanal endoscopic microsurgery (TEM) lacks consensus. Screening has substantially increased the early diagnosis of tumours. Patients need local treatments that are oncologically equivalent to radical surgery but safer and functionally superior. Methods: A national database, collated prospectively from 21 regional centres, detailed TEM treatment in 487 subjects with rectal cancer. Data were used to construct a predictive model of local recurrence after TEM using semiparametric survival analyses. The model was internally validated using measures of calibration and discrimination. Results: Postoperative morbidity and mortality were 14·9 and 1·4 per cent respectively. The Cox regression model predicted local recurrence with a concordance index of 0·76 using age, depth of tumour invasion, tumour diameter, presence of lymphovascular invasion, poor differentiation and conversion to radical surgery after histopathological examination of the TEM specimen. Conclusion: Patient selection for TEM is frequently governed by fitness for radical surgery rather than suitable tumour biology. TEM can produce long-term outcomes similar to those published for radical total mesorectal excision surgery if applied to a select group of biologically favourable tumours. Conversion to radical surgery based on adverse TEM histopathology appears safe for p T1 and p T2 lesions. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Validation of the postoperative nomogram for 12-year sarcoma-specific mortalityCANCER, Issue 10 2004Fritz C. Eilber M.D. Abstract BACKGROUND On the basis of a prospectively followed cohort of adult patients with primary soft tissue sarcoma (STS) who were treated at Memorial Sloan-Kettering Cancer Center (MSKCC; New York, NY), a nomogram for predicting sarcoma-specific mortality was developed. Although this nomogram was found to be accurate by internal validation tests, it had not been validated in an external patient cohort, and thus its universal applicability remained unproven. METHODS Between 1975 and 2002, 1167 adult patients (age , 16 years) underwent treatment for primary STS at the University of California,Los Angeles (UCLA; Los Angeles, CA). All patients treated with an ifosfamide-based chemotherapy protocol (n = 238) were excluded from the current analysis. The remaining 929 patients constituted the population on which the validation study was performed. The nomogram validation process comprised two activities. First, the extent of discrimination was quantified using the concordance index. Second, the level of calibration was assessed by grouping patients with respect to their nomogram-predicted mortality probabilities and then comparing group means with observed Kaplan,Meier estimates of disease-specific survival. RESULTS With median follow-up intervals of 48 months for all patients and 60 months for surviving patients, the 5-year and 10-year disease-specific survival rates were 77% (95% confidence interval [CI], 74,80%) and 71% (95% CI, 67,75%), respectively. Application of the nomogram to the UCLA data set yielded a concordance index of 0.76, and the observed correspondence between predicted and actual outcomes suggested a high level of calibration. CONCLUSIONS In the current study, the MSKCC Sarcoma Nomogram was found to provide accurate survival predictions when it was applied to an external cohort of patients who were treated at UCLA. Cancer 2004. © 2004 American Cancer Society. [source] The percentage of prostate needle biopsy cores with carcinoma from the more involved side of the biopsy as a predictor of prostate specific antigen recurrence after radical prostatectomy,,CANCER, Issue 11 2003Results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database Abstract BACKGROUND The authors previously found that, although the total percentage of prostate needle biopsy cores with carcinoma was a significant predictor of prostate specific antigen (PSA) failure among men undergoing radical prostatectomy (RP), there was a trend toward a lower risk of recurrence in patients with positive bilateral biopsies, suggesting that high-volume, unilateral disease was a worse predictor of outcome than an equivalent number of positive cores distributed over two lobes. In the current study, the authors sought to compare the total percentage of cores with carcinoma directly with the percentage of cores from the more involved or dominant side of the prostate with carcinoma for their ability to predict outcome among men who underwent RP. METHODS A retrospective survey of 535 patients from the Shared Equal Access Regional Cancer Hospital database who underwent RP at 4 different equal-access medical centers between 1988 and 2002 was undertaken. The total percentage of cores positive was compared with the percentage of cores positive from the dominant and nondominant sides for their ability to predict biochemical recurrence after RP. The best predictor then was compared with the standard clinical variables PSA, biopsy Gleason score, and clinical stage in terms of ability to predict time to PSA recurrence after RP using multivariate analysis. RESULTS The adverse pathologic features of positive surgical margins and extracapsular extension were significantly more likely to be ipsilateral to the dominant side on the prostate biopsy. The percentage of cores positive from the dominant side provided slightly better prediction (concordance index [C] = 0.636) for PSA failure than the total percentage of cores positive (C = 0.596) and markedly better than the percentage of cores from the nondominant side (C = 0.509). Cutoff points for percentage of cores positive from the dominant side were identified (< 34%, 34,67%, and > 67%) that provided significant risk stratification for PSA failure (P < 0.001). On multivariate analysis, the percentage of cores positive from the dominant side was the strongest independent predictor of PSA recurrence (P < 0.001). Biopsy Gleason score (P = 0.017) also was a significant, independent predictor of recurrence. There was a trend, which did not reach statistical significance, toward an association between greater PSA values and biochemical failure (P = 0.052). Combining the PSA level, biopsy Gleason score, and percentage of cores positive from the dominant side of the prostate resulted in a model that provided a high degree of prediction for PSA failure (C = 0.671). CONCLUSIONS The percentage of cores positive from the dominant side of the prostate was a slightly better predictor of PSA recurrence than was the total percentage of cores positive. Using the percentage of cores from the dominant side along with the PSA level and the biopsy Gleason score provided significant risk stratification for PSA failure. Cancer 2003. Published 2003 by the American Cancer Society. [source] | ||||||||||