medwireNews: Treatment with radical prostatectomy (RP) plus adjuvant external beam radiotherapy (EBRT) and androgen deprivation therapy (ADT) can offer equivalent survival outcomes to a nonsurgical approach in patients with high-risk prostate cancer, research shows.
The nonsurgical approach, termed MaxRT, consisted of EBRT, brachytherapy, and ADT, explain Anthony D’Amico (Brigham and Women’s Hospital, Boston, Massachusetts, USA) and colleagues in JAMA Oncology.
They say: “The clinical significance of these observations is that they provide evidence to support the importance of adding both adjuvant EBRT and ADT after RP in men with biopsy Gleason score 9–10 prostate cancer to reduce the risk of PCSM [prostate cancer-specific mortality] and ACM [all-cause mortality] so that their outcomes may become comparable to those of men undergoing MaxRT.”
The study included 639 men with clinical T1–4, N0M0 biopsy Gleason score 9–10 prostate cancer treated between 1992 and 2013, of whom 80 received MaxRT and 559 underwent RP alone or alongside adjuvant radiotherapy or ADT.
The MaxRT and RP groups were followed-up for a median 4.8 and 5.5 years, respectively, during which time 161 men died, including 106 deaths from prostate cancer.
The researchers report that the men undergoing RP had a significant 2.8-fold increased risk for PCSM and a 1.65-fold increased risk for ACM compared with those receiving MaxRT.
However, when the team only considered the 50 men who received RP plus EBRT and ADT, collectively termed MaxRP, there was no significant difference in PCSM or all-cause mortality compared with those who received MaxRT.
The estimated 5-year PCSM rates were 2.2% for men undergoing MaxRT, 21.9% for men undergoing RP, and 9.8% for men undergoing MaxRP. The corresponding rates of all-cause mortality were 6.8%, 26.6%, and 15.6%.
Of note, there was also no significant difference in outcomes between the 88 men who received RP plus adjuvant RT compared with those who received MaxRT, but survival was significantly worse among the 49 who received RP plus ADT.
When the team used plausibility indexes to assess the likelihood for equivalence in the risk for PCSM and all-cause mortality after treatment, they found that men undergoing MaxRP had the highest likelihood for achieving such equivalence compared with men undergoing MaxRT, at 76.8% and 78.0%, respectively.
This compared with corresponding rates of 5.4% and 23.6% for RP, 58.2% and 62.3% for RP plus adjuvant RT, and 4.8% and 4.6% for RP plus ADT.
D’Amico et al conclude that their findings “provide the only available evidence to date to support that it is plausible that treatment with MaxRP or MaxRT can lead to equivalent risk of PCSM and ACM in men with biopsy Gleason score 9-10 prostate cancer.”
By Laura Cowen
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