Survival after Radical Prostatectomy or Radiotherapy for Locally Advanced (cT3) Prostate Cancer – Beyond the Abstract

In this study, we compared outcomes of patients with cT3N0-1 prostate cancer (PCa) according to treatment type. Specifically, we examined the effect of radical prostatectomy (RP) or external beam radiotherapy (EBRT) on cancer-specific mortality. The strength of our study is in the number of patients included (n=5,500) and in the complexity of analyses performed. In fact, our study is the first that compared cancer-specific outcomes after RP or EBRT in such a large population (other studies enrolled no more than 1000 pts). Moreover, to verify the hypothesis tested (RP reduced cancer-specific mortality), we relied on sub-group analysis (cT3N0 patients), other cause mortality propensity score adjustment and landmark analyses, which serve the purpose of rejecting the possibility that the null hypothesis of no differences between RP and EBRT was incorrectly rejected.  Only patients with complete clinical and oncological data were included to accomplish the aim of the study without variable imputation.
We found that RP was associated with lower 10-year CSM rates (Hazard ratio: 0.62, 95% confidence interval: 0.45-0.86, p = 0.004) through the entire range of baseline PSA values compared to EBRT (Fig.). These findings were confirmed in the cT3N0 subgroup, after OCM propensity adjustment and after 6, 12, 24, and 36 months landmark analyses.

Despite its design limitation, our findings qualify for being considered an important signal that should prompt the design of a randomized controlled trial comparing RP to EBRT in cT3N0-1 PCa. Until such trial is completed and its results yield mature observations, similar analyses should be performed in other large-scale databases to corroborated or refute our findings.

In absence of contradictory findings, our study represents the largest and most contemporary source of evidence prompting the use of RP in cT3 patients. Although it would be tempting to generalize such practice to all cT3N0-1 PCa patients, we must restrict our interpretation to cT3N0 patients, since sample size limitations precluded us from performing valid comparisons in cT3N1 patient subgroup.

or radiotherapy for locally advanced cT3
Written by: Marco Bandini, MD, Division of Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy.
Authors disclose no conflict of interest on the topic of this paper.

Read the Abstract