(UroToday.com) The 2023 ASTRO annual meeting included a session on clinical trials in prostate cancer, featuring a presentation by Dr. Deborah Bruner discussing the results of NRG Oncology/RTOG 0534 SPPORT, specifically quality of life with the addition of ADT and pelvic lymph node treatment to prostate bed salvage radiotherapy. The objective of this study presented at ASTRO 2023 was to report the quality of life analysis of the SPPORT trial of men with a detectable PSA after prostatectomy for prostate cancer randomized to:
Arm 1: Salvage prostate bed radiotherapy
Arm 2: 4-6 months of short-term ADT + prostate bed radiotherapy
Arm 3: Pelvic lymph node radiotherapy + short-term ADT + prostate bed radiotherapy
The primary analysis of this trial established the benefit of adding pelvic lymph node radiotherapy and short-term ADT to prostate bed radiotherapy.1 Importantly, there was higher short term but no statistically significant difference in long term adverse events with the exception of blood or bone marrow events.
Quality of life endpoints were assessed at baseline, 6 weeks after radiotherapy start, 1 and 5 years, including Expanded Prostate Cancer Index Composite (EPIC) (for bowel, urinary, sexual, and hormonal domains), Hopkins Symptom Checklist (HSCL-25) (for depressive symptoms), and the EuroQol (EQ-5D) (for health state weights used in quality adjusted life years). In addition to statistical significance, differences in scores were assessed using 0.5 standard deviation as the criterion for clinical importance. Overall, there were 644 patients consented to quality of life assessments, 210 on each arm. Baseline characteristics were not significantly different among arms: 81% were white and 54% were less than 65 years of age. The complete baseline characteristics are as follows:
For EPIC, bowel domain scores decreased at 6 weeks post-radiotherapy and then increased by years 1 and 5, although not to baseline levels. One clinically significant difference in bowel scores was Arm 3 versus Arm 1 at 6 weeks. For the EPIC urinary domain, scores decreased at 6 weeks post-radiotherapy and remained below baseline at 1 and 5 years, but there were no significant differences among arms. For the EPIC sexual domain, there were statistically significant differences between arms at 6 weeks and 1 year with patients receiving short-term ADT exhibiting poorer sexual quality of life scores. However, by year 5 the differences were no longer significant, and a similar pattern was seen for the EPIC hormonal domain. For HSCL-25, differences at 6 weeks were statistically but not clinically significant, and there were no significant differences at the later time points:
For quality adjusted life years, EQ-5D compliance was 79%, 70%, 68%, and 40% at baseline, 6 weeks, 1 year, and 5 years, respectively. Comparisons of quality adjusted life years for overall survival over a 12-year horizon showed no significant group differences, with a restricted mean of about 7.8 in each arm. With regards to freedom from progression, quality adjusted life years means were 5.7, 6.5, and 7.4 years for Arms 1, 2, and 3, respectively:
Dr. Bruner concluded her presentation by discussing the results of NRG Oncology/RTOG 0534 SPPORT, specifically quality of life with the addition of ADT and pelvic lymph node treatment to prostate bed salvage radiotherapy with the following take-home points:
- Quality of life generally declined among all arms at 6 weeks post-radiotherapy
- There were early differences showing poorer sexual function with the addition of ADT (Arms 2 and 3) and poorer bowel function with the further addition of pelvic lymph node radiotherapy (Arm 3)
- Yet, there were no clinically significant differences in quality of life among arms at 5 years
- Quality of life years for freedom from progression favored pelvic lymph node radiotherapy + short-term ADT + prostate bed radiotherapy for salvage treatment of prostate cancer
- This study also demonstrates the need for a comprehensive longitudinal collection of quality of life measures to establish the length of experimental effects, which are often transient
Presented by: Deborah Bruner, RN, PhD, Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, GA
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Wellstar MCG Health, @zklaassen_md on Twitter during the 2023 American Society for Therapeutic Radiation Oncology (ASTRO) 65th Annual Meeting held in San Diego, CA between October 1st and 4th, 2023
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