Quality of life results of addition of androgen deprivation therapy and pelvic lymph node treatment to prostate bed salvage radiotherapy: NRG Oncology/RTOG 0534 SPPORT.

Abstract

This is the quality of life (QOL) analysis of the SPPORT trial of men with a detectable prostate specific antigen (PSA) after prostatectomy for prostate cancer. Primary analysis established a benefit of adding pelvic lymph node radiotherapy (PLNRT) and short-term androgen deprivation therapy (STADT) to salvage prostate bed radiotherapy (PBRT) for biochemical progression-free survival. Subjects were randomized to Arm 1, PBRT, Arm 2, 4-6 months of STADT + PBRT, and Arm 3, PLNRT + STADT + PBRT. QOL was assessed at baseline, 6 weeks after the start of RT, 1 and 5 years after the end of RT, including Expanded Prostate Cancer Index Composite (EPIC), Hopkins Symptom Checklist (HSCL-25), EuroQol (EQ-5D), and quality adjusted life years (QALYs). Statistical and clinical significance were calculated. Differences among arms were assessed using pairwise t-tests, Fisher's exact test, and mixed effects regression modeling, controlling for multiplicity. 644 patients consented to QOL; 81% white and 54% <65 years. EPIC, bowel and urinary scores decreased at 6 weeks then increased by years 1 and 5, although not to baseline. For sexual and hormonal domains, there were statistically significant differences between arms at 6 weeks and 1 year with STADT exhibiting poorer QOL scores, but no difference at 5 years. For HSCL-25, statistically significant differences at 6 weeks were not clinically significant. Comparisons of QALYs for overall survival showed no statistical significance. However, freedom from progression QALY means were 5.5, 6.2 and 6.6 years for Arms 1, 2, and 3, respectively, with Arms 3 and 2 indicating statistically significant improvement over Arm 1. While QOL generally declined the most among all arms at 6 weeks post RT start, and remained lower than baseline at 5 years, there were no clinically significant differences in QOL among arms at 1 and 5 years. QALYs for freedom from progression favored STADT + PLNRT + PBRT for salvage treatment of prostate cancer.