Patients with localized prostate cancer who received radiotherapy (RT) had longer progression-free survival (PFS) when androgen deprivation therapy (ADT) was given in the adjuvant setting instead of the neoadjuvant setting, showed a meta-analysis in the Journal of Clinical Oncology.
The meta-analysis was based on patient-level data from 2 randomized phase 3 trials that evaluated optimal sequencing for ADT during prostate cancer treatment.
One trial, Ottawa 0101, compared neoadjuvant or concurrent short-term ADT with concurrent or adjuvant short-term ADT. The other trial, NRG Oncology’s Radiation Therapy Oncology Group 9413, compared neoadjuvant or concurrent adjuvant short-term ADT with adjuvant short-term ADT.
For the meta-analysis, the neoadjuvant group comprised patients from both trials who received neoadjuvant or concurrent ADT, and the adjuvant group comprised patients who received adjuvant ADT. A total of 1065 patients were included, 531 for the neoadjuvant group and 534 for the adjuvant group.
At a median follow-up of nearly 15 years, the adjuvant group had a significantly higher PFS compared with the neoadjuvant group (29% vs 36%; hazard ratio [HR], 1.25; 95% CI, 1.07-1.47; P =.01).
The adjuvant group also had lower likelihood of biochemical failure (subdistribution HR [sHR], 1.37; 95% CI, 1.12-1.68; P =.002) and distant metastasis (sHR, 1.40; 95% CI, 1.00-1.95; P =.04). In addition, the adjuvant group had a prolonged metastasis-free survival (HR, 1.17; 95% CI, 1.00-1.37; P =.050).
The adjuvant and neoadjuvant groups also had a similarly low frequency of late grade 3 or worse gastrointestinal toxicity (2% v 3%; P =.33) or genitourinary toxicity (5% vs 5%; P =.76).
The study authors concluded that their findings have “immediate” and “significant” clinical implications on the management of localized prostate cancer.
“They emphasize that a delay in initiating RT to allow receipt of neoadjuvant ADT is unnecessary and does not reduce long-term toxicity compared with an adjuvant approach in an unselected group of men treated with prostate-directed RT,” the study authors wrote.
Spratt DE, Malone S, Roy S, et al. Prostate radiotherapy with adjuvant androgen deprivation therapy (ADT) improves metastasis-free survival compared to neoadjuvant ADT: An individual patient meta-analysis. J Clin Oncol. Published online December 4, 2020. doi:10.1200/JCO.20.02438