Drew Moghanaki, MD, MPH, of Hunter Holmes McGuire VAMC in Richmond, VA, was a co-author of the study.
BOSTON—After prostatectomy, options for prostate cancer with adverse pathological features such as pT3 and/or positive margins can be managed with adjuvant radiotherapy (ART) or surveillance followed by early-salvage radiotherapy (ESRT) for biochemical recurrence. The best time for postoperative radiotherapy is unclear, however.
A study published in JAMA Oncology compared the clinical outcomes of postoperative ART and ESRT administered to patients with prostate cancer with adverse pathological features. The Massachusetts General Hospital/Harvard Medicine School research included participation from Hunter Holmes McGuire VAMC in Richmond, VA.1
Included in the multi-institutional, propensity score-matched cohort study were 1,566 consecutive patients who underwent postprostatectomy ART or ESRT at 10 U.S. academic medical centers between Jan. 1, 1987, and Dec. 31, 2013, with data collected in the first nine months of 2016. Analysis occurred from October 2016 to October 2017. The study sought to determine which patients, who averaged age 60, were free from post-irradiation biochemical failure and from distant metastases, as well as who had longer overall survival.
ESRT was provided to 1,195 patients with prostate-specific antigen levels lower than 0.1 ng/Ml, while 371 patients with prostate-specific antigen levels of 0.1 to 0.5 ng/mL received ART. Results indicated that, after propensity score matching, the median (interquartile range) follow-up after surgery was similar between the ESRT and ART groups (73.3 [44.9-106.6] months vs. 65.8 [40-107] months; P = .22).
In addition, adjuvant RT, compared with ESRT, was associated with higher freedom from biochemical failure (12-year actuarial rates: 69% [95% CI, 60%-76%] vs. 43% [95% CI, 35%-51%]; effect size, 26%), freedom from distant metastases (95% [95% CI, 90%-97%] vs. 85% [95% CI, 76%-90%]; effect size, 10%) and overall survival (91% [95% CI, 84%-95%] vs. 79% [95% CI, 69%-86%]; effect size, 12%).
Favorable prognostic features for biochemical failure were lower Gleason score and T stage, nodal irradiation and postoperative androgen deprivation therapy. Further analysis showed the decreased risk of biochemical failure associated with ART remained significant unless more than 56% of patients in the ART group were cured by surgery alone, with researchers noting that the threshold is greater than the estimated 12-year freedom from biochemical failure rate of 33% to 52% after radical prostatectomy alone, as determined by a contemporary dynamic nomogram.
“Adjuvant RT, compared with ESRT, was associated with reduced biochemical recurrence, distant metastases, and death for high-risk patients, pending prospective validation,” the study authors concluded. “These findings suggest that a greater proportion of patients with prostate cancer who have adverse pathological features may benefit from postprostatectomy ART rather than surveillance followed by ESRT.”
- Hwang WL, Tendulkar RD, Niemierko A, Agrawal S, et. al. Comparison Between Adjuvant and Early-Salvage Postprostatectomy Radiotherapy for Prostate Cancer With Adverse Pathological Features. JAMA Oncol. 2018 Jan 25:e175230. doi: 10.1001/jamaoncol.2017.5230. [Epub ahead of print] PubMed PMID:29372236.