Researchers recently conducted a meta-analysis and found that adjuvant radiotherapy showed no improvement in event-free survival among men with localized or locally advanced prostate cancer. (The Lancet. September 28, 2020. doi: https://doi.org/10.1016/S0140-6736(20)31952-8)
“It is unclear whether adjuvant or early salvage radiotherapy following radical prostatectomy is more appropriate for men who present with localized or locally advanced prostate cancer,” wrote researchers. “We aimed to prospectively plan a systematic review of randomized controlled trials (RCTs) comparing these radiotherapy approaches.”
The research team used RCTs if they aimed to compare immediate adjuvant radiotherapy versus early salvage radiotherapy, following radical prostatectomy in men (age ≥18 years) with intermediate-risk or high-risk, localized or locally advanced prostate cancer. Additionally, the study authors identified RCTs via trial registers and conference proceedings until July 8, 2020.
Further methods for the study included the use of a harmonized definition of event-free survival. It was defined as the time from randomization until the first evidence of either biochemical progression, clinical or radiological progression, initiation of a non-trial treatment, death from prostate cancer, or a PSA level of at least 2·0 ng/mL at any time after randomization.
The authors predicted when they would have sufficient power to understand if adjuvant radiotherapy was superior to early salvage radiotherapy.
Based on the study methods, the authors identified three eligible trials. They obtained updated results for event-free survival for 2153 patients recruited between November 2007, and December 2016. Median follow-up ranged from 60 months to 78 months, with a maximum follow-up of 132 months. Of the identified patients, 1075 were randomly assigned to receive adjuvant radiotherapy and 1078 to a policy of early salvage radiotherapy, which 421 (39·1%) had commenced treatment at the time of analysis.
According to the findings of 270 events, the analysis showed no evidence that event-free survival was improved with adjuvant radiotherapy compared with early salvage radiotherapy (HR 0·95, 95% CI 0·75–1·21; P =0·70), with only a 1 percentage point (95% CI −2 to 3) change in 5-year event-free survival (89% vs 88%). The researchers noted that the results were consistent across the trials (heterogeneity P=0·18; I 2=42%).
“This collaborative and prospectively designed systematic review and meta-analysis suggests that adjuvant radiotherapy does not improve event-free survival in men with localized or locally advanced prostate cancer,” they concluded.
“Until data on long-term outcomes are available, early salvage treatment would seem the preferable treatment policy as it offers the opportunity to spare many men radiotherapy and its associated side-effects.”—Julie Gould
