Prognostic impact of positive surgical margins in surgically treated prostate cancer: multi-institutional assessment of 5831 patients.

OBJECTIVES: To assess the prognostic significance of a positive surgical margin in the radical prostatectomy specimen, and to test for the presence of statistically significant interactions between surgical margin status and select pathologic stage variables. METHODS: We combined prospectively collected data from 7816 consecutive patients treated with radical prostatectomy at eight institutions. The pretreatment serum prostate-specific antigen level, pathologic Gleason sum, surgical margin status (positive versus negative), presence of extracapsular extension, seminal vesicle involvement, and pelvic lymph node status were examined as predictors of the rate of biochemical progression in 5831 patients with complete records. RESULTS: In multivariate Cox regression models, a positive surgical margin was associated with a 3.7-fold greater risk of progression (P = 0.001). Moreover, a statistically significant interaction was found between surgical margin status and Gleason sum 7 to 10 (P = 0.008) and lymph node invasion (P < 0.001). CONCLUSIONS: The presence of a positive surgical margin in the radical prostatectomy specimen has an adverse effect on prognosis. The greatest risk of biochemical recurrence may be expected if a positive surgical margin is present with Gleason sum 7 to 10 disease or lymph node invasion.

International validation of a preoperative nomogram for prostate cancer recurrence after radical prostatectomy.

PURPOSE: We evaluated the predictive accuracy of a recently published preoperative nomogram for prostate cancer that predicts 5-year freedom from recurrence. We applied this nomogram to patients from seven different institutions spanning three continents. METHODS: Clinical data of 6,754 patients were supplied for validation, and 6,232 complete records were used. Nomogram-predicted probabilities of 60-month freedom from recurrence were compared with actual follow-up in two ways. First, areas under the receiver operating characteristic curves (AUCs) were determined for the entire data set according to several variables, including the institution where treatment was delivered. Second, nomogram classification-based risk quadrants were compared with actual Kaplan-Meier plots. RESULTS: The AUC for all institutions combined was 0.75, with individual institution AUCs ranging from 0.67 to 0.83. Nomogram predictions for each risk quadrant were similar to actual freedom from recurrence rates: predicted probabilities of 87% (low-risk group), 64% (intermediate-low-risk group), 39% (intermediate-high-risk group), and 14% (high-risk group) corresponded to actual rates of 86%, 64%, 42%, and 17%, respectively. The use of neoadjuvant therapy, variation in the prostate-specific antigen recurrence definitions between institutions, and minor differences in the way the Gleason grade was reported did not substantially affect the predictive accuracy of the nomogram. CONCLUSION: The nomogram is accurate when applied at international treatment institutions with similar patient selection and management strategies. Despite the potential for heterogeneity in patient selection and management, most predictions demonstrated high concordance with actual observations. Our results demonstrate that accurate predictions may be expected across different patient populations.

Validation study of the accuracy of a postoperative nomogram for recurrence after radical prostatectomy for localized prostate cancer.

PURPOSE: A postoperative nomogram for prostate cancer was developed at Baylor College of Medicine. This nomogram uses readily available clinical and pathologic variables to predict 7-year freedom from recurrence after radical prostatectomy. We evaluated the predictive accuracy of the nomogram when applied to patients of four international institutions. PATIENTS AND METHODS: Clinical and pathologic data of 2,908 patients were supplied for validation, and 2,465 complete records were used. Nomogram-predicted probabilities of 7-year freedom from recurrence were compared with actual follow-up in two ways. First, the area under the receiver operating characteristic curve (AUC) was calculated for all patients and stratified by the time period of surgery. Second, calibration of the nomogram was achieved by comparing the predicted freedom from recurrence with that of an ideal nomogram. For patients in whom the pathologic report does not distinguish between focal and established extracapsular extension (an input variable of the nomogram), two separate calculations were performed assuming one or the other. RESULTS: The overall AUC was 0.80 when applied to the validation data set, with individual institution AUCs ranging from 0.77 to 0.82. The predictive accuracy of the nomogram was apparently higher in patients who were operated on between 1997 and 2000 (AUC, 0.83) compared with those treated between 1987 and 1996 (AUC, 0.78). Nomogram predictions of 7-year freedom from recurrence were within 10% of an ideal nomogram. CONCLUSION: The postoperative Baylor nomogram was accurate when applied at international treatment institutions. Our results suggest that accurate predictions may be expected when using this nomogram across different patient populations.