To investigate if results in terms of absolute risk in mature randomized trials are relevant for contemporary decision making. To do so, we compared the outcome for men in the radical prostatectomy (RP) arm in the Scandinavian Prostate Cancer Group Study number 4 (SPCG-4) randomized trial with matched men treated in a contemporary era before and after compensation for the grade migration and grade inflation that have occurred since the 1980s.
A propensity score-matched analysis of prostate cancer mortality and all-cause mortality in SPCG-4 and matched men in the National Prostate Cancer Register (NPCR) of Sweden treated in 1998 - 2006 was conducted. Cumulative incidence of prostate cancer mortality and all-cause mortality was calculated. Cox proportional hazards regression analyses were used to estimate hazard ratio (HR) and 95% confidence interval (CI) for a matching on original Gleason Grade Groups (GGG) and second, matching with GGG increased one unit for men in NPCR.
Matched men in NPCR treated in 2005-2006 had half the risk of prostate cancer mortality compared to men in SPCG-4, HR 0.46; 95% CI, 0.19 - 1.14. In analysis of men matched on an upgraded GGG in NPCR, this difference was mitigated, HR 0.73; 95% CI, 0.36 - 1.47.
Outcome for men in SPCG-4 cannot be directly applied to RP men in the current era, mainly due to grade inflation and grade migration. However, by compensating for changes in grading, similar outcome after RP was observed in SPCG-4 and NPCR. In order to compare historical trials with current treatments, data on temporal changes in detection, diagnostics, and treatment have to be accounted for. This article is protected by copyright. All rights reserved.
BJU international. 2018 Sep 25 [Epub ahead of print]
Walter Cazzaniga, Hans Garmo, David Robinson, Lars Holmberg, Anna Bill-Axelson, Pär Stattin
Division of Experimental Oncology/Unit of Urology URI, IRCCS Ospedale San Raffaele, University Vita-Salute San Raffaele, Milan, Italy., Regional Cancer Centre Uppsala Örebro, Uppsala University Hospital, Uppsala, Sweden., Department of Urology, Ryhov Hospital, Jönköping, Sweden., Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.