Irradiating the whole pelvis rather than just the prostate reduces the likelihood of recurrence in men with high-risk locally advanced prostate cancer, according to a randomized controlled trial.
Results from the trial, called POP-RT, were reported at the European Society for Radiology and Oncology 2020 Online Congress. Dr. Murthy and colleagues of Tata Memorial Centre in Mumbai, India conducted the POP-RT trial (NCT02302105). The study’s final analysis included 222 men with locally advanced prostate cancer who had node-negative disease based on MRI and PSMA PET but had a high risk for occult pelvic nodal involvement (20% or greater according to the Roach formula). The median nodal risk for the trial population was 37.8%.
The men were randomized to daily image-guided intensity-modulated radiotherapy to the prostate (68 Gy in 25 fractions to the gland and seminal vesicles) or to the whole pelvis (the former plus 50 Gy in 25 fractions to the pelvic nodes. All patients also received at least 2 years of androgen-deprivation therapy (ADT).
--At a median follow-up of 68 months, the 5-year rate of biochemical failure-free survival, the trial’s primary endpoint, was superior with whole-pelvis radiotherapy (WPRT), relative to prostate-only radiotherapy (PORT).
--Disease-free survival was better in the WPRT group than in the PORT group, and the same was true for distant metastasis-free survival.
“Prophylactic radiotherapy in this trial improved biochemical failure-free survival and disease-free survival in high-risk prostate cancer patients. The improvement in outcomes was seen in spite of giving long-term ADT and in spite of doing dose escalation,” Dr. Murthy summarized. “There is no overall survival difference as of yet, but that remains to be seen.” “Based on these results, it would be fair to say that whole-pelvis radiotherapy should be considered for these patients with high-risk and very-high-risk prostate cancer,” he concluded.
Source: Abstract OC-0613