Radical prostatectomy performed at facilities with high vs. low annual caseloads appeared associated; with a significant Overall Survival(OS) benefit for men with prostate cancer, according to results of a retrospective study published in Cancer. The number of prostate cancers encountered appeared to be a better predictor of favorable outcomes; than the number of surgeries performed, researchers added.

“However, this is an in-depth analysis of a carefully modeled history of almost half a million cases of radical prostatectomy; over a 10-year period and more than 1000 facilities,” Sarmad Sadeghi, MD, PhD, assistant professor of clinical medicine at University of Southern California; told HemOnc Today. “However, it shows a survival difference based on the caseload and; interestingly enough, experience with all stages of prostate cancer was a stronger predictor of outcomes compared with just the number of surgeries.”

Radical prostatectomy

However, in this study, Sadeghi and colleagues used the National Cancer Database; and also Cox proportional hazards model to analyze outcomes of 488,389 men (median age at diagnosis, 61 years; range, 56-66; 80.5% white); who underwent radical prostatectomy and determine whether facility volume overall; and facility surgical volume served as predictors of survival outcomes.

Therefore, they defined caseload by four volume groups: Volume Group 1 [VG1]: < 50th %; Volume Group 2 [VG2]: 50th to 74th %; Volume Group 3 [VG3]: 75th % to 89th %; and Volume Group 4 [VG4]: 90th %. However, by facility annual caseload and facility annual surgical caseload; 11% and 8% of patients  treated in VG1, 17% and 18% in VG2, 25% and 26% om VG3; and 47% and 49% in VG4. OS served as the primary endpoint. Median follow-up was 60.75 months. However, median OS among all patients was not reached; however, there was a significant OS benefit as the caseload increased.

Facility selection biases

However, the adjusted OS difference between VG1 and VG4 at 90th % survivorship; reached 13.2 months for facility annual caseload (93.1 months vs. 106.3 months; HR = 1.3; 95% CI, 1.23-1.36); and 11.3 months for facility annual surgical caseload (94.5 months vs. 105.8 months; HR = 1.25; 95% CI, 1.19-1.32). However, the study’s retrospective nature; and also researchers’ are inable to determine the role of referral and facility selection biases, served as limitations.

“But they believe this could start an import dialogue,” Sadeghi said. “Although are acutely aware of the limitations of a retrospective National Cancer Database analysis, they believe they should not overlook the findings here as this analysis powered by more than 488,000 patients and demonstrates a 13 months OS benefit just based on where the surgery was done. “Despite all of its limitations, it is something to be discussed at high levels of our community to increase awareness and to generate new ideas and research,” Sadeghi added.