Surgery vs Radiotherapy in the Management of Biopsy Gleason Score 9-10 Prostate Cancer and the Risk of Mortality

Abstract

Importance: It is unknown how treatment with radical prostatectomy (RP) and adjuvant external beam radiotherapy (EBRT), androgen deprivation therapy (ADT), or both (termed MaxRP) compares with treatment with EBRT, brachytherapy, and ADT (termed MaxRT).

Objective: To investigate whether treatment of Gleason score 9-10 prostate cancer with MaxRP vs MaxRT was associated with prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) risk.

Design, setting, and participants: The study cohort comprised 639 men with clinical T1-4,N0M0 biopsy Gleason score 9-10 prostate cancer. Between February 6, 1992, and April 26, 2013, a total of 80 men were consecutively treated with MaxRT at the Chicago Prostate Cancer Center, and 559 men were consecutively treated with RP and pelvic lymph node dissection at the Martini-Klinik Prostate Cancer Center. Follow-up started on the day of prostate EBRT or RP and concluded on October 27, 2017.

Exposures: Of the 559 men managed with RP and pelvic lymph node dissection, 88 (15.7%) received adjuvant EBRT, 49 (8.8%) received ADT, and 50 (8.9%) received both.

Main outcomes and measures: Treatment propensity score-adjusted risk of PCSM and ACM and the likelihood of equivalence of these risks between treatments using a plausibility index.

Results: The cohort included 639 men, with a mean (SD) age of 65.83 (6.52) years. After median follow-ups of 5.51 years (interquartile range, 2.19-6.95 years) among 80 men treated with MaxRT and 4.78 years (interquartile range, 4.01-6.05 years) among 559 men treated with RP-containing treatments, 161 men had died, 106 (65.8%) from prostate cancer. There was no significant difference in the risk of PCSM (adjusted hazard ratio, 1.33; 95% CI, 0.49-3.64; P = .58) and ACM (adjusted hazard ratio, 0.80; 95% CI, 0.36-1.81; P = .60) when comparing men who underwent MaxRP vs MaxRT, with plausibility indexes for equivalence of 76.75% for the end point of the risk of PCSM and 77.97% for the end point of the risk of ACM. Plausibility indexes for all other treatment comparisons were less than 63%.

Conclusions and relevance: Results of this study suggest that it is plausible that treatment with MaxRP or MaxRT for men with biopsy Gleason score 9-10 prostate cancer can lead to equivalent risk of PCSM and ACM.

Figure.. Adjusted Estimates of Prostate Cancer–Specific Mortality (PCSM) and All-Cause Mortality (ACM)

A and B, Pairwise P values for PCSM are as follows: P = .002 for MaxRT vs RP, P < .001 for MaxRT vs RP plus adjuvant RT, P = .41 for MaxRT vs RP plus adjuvant EBRT, and P = .29 for MaxRT vs MaxRP. Pairwise P values for ACM are as follows: P = .09 for MaxRT vs RP, P = .003 for MaxRT vs RP plus adjuvant RT, P = .52 for MaxRT vs RP plus adjuvant EBRT, and P = .95 for MaxRT vs MaxRP. ACM indicates all-cause mortality; ADT, androgen deprivation therapy; EBRT, external beam radiotherapy; MaxRP, RP and both adjuvant RT and ADT; MaxRT, EBRT, brachytherapy, and ADT; RP, radical prostatectomy; and RT, radiotherapy.