Adding 6 months of androgen deprivation therapy (ADT) to dose-escalated radiation therapy (RT) does not provide a survival advantage to patients with intermediate-risk prostate cancer, but it does offer oncologic benefits, a new study finds.

In the NRG Oncology/Radiation Therapy Oncology Group 0815 study (Clinicaltrials.gov NCT00936390), investigators randomly assigned 1492 patients with stage T2b-T2c, Gleason score 7, or PSA of 10-20 ng/mL to dose-escalated RT alone (arm 1) or with short-term ADT (arm 2). ADT involved 6 months of a luteinizing hormone-releasing hormone agonist or antagonist plus the antiandrogen bicalutamide or flutamide. RT modalities were external-beam RT alone to 79.2 Gy or external-beam RT to 45 Gy with brachytherapy boost.

The 5-year overall survival estimates for arms 1 and 2 were 90% and 91%, respectively, a nonsignificant difference between the groups, Daniel J. Krauss, MD, of Oakland University William Beaumont School of Medicine in Royal Oak, Michigan, and colleagues reported in the Journal of Clinical Oncology. The addition of short-term ADT, however, significantly reduced the risk for PSA relapse, distant metastasis, and prostate cancer-specific mortality by 48%, 75%, and 90%, respectively. Men who received ADT had a 38% lower risk of requiring salvage ADT.

Adverse events rates were significantly higher with ADT use: 69% vs 21% in arm 1, the investigators reported. Acute grade 3 or higher adverse events occurred in 12% of the ADT group vs 2% of the RT-only group.

A companion study of the same patient population examined quality of life. The ADT group reported clinically meaningful declines in hormonal and sexual quality of life over the short term, but these effects diminished by 1 year, Benjamin Movsas, MD, of Henry Ford Cancer Institute in Detroit, Michigan, and colleagues reported. The investigators found no between-group differences in fatigue and bowel or urinary symptoms. The quality of instruments did not capture the effects of short-term ADT on bone and cardiovascular health.

“The data derived from this protocol, along with its companion patient-reported quality-of-life analysis by Movsas et al will allow clinicians to far more accurately counsel patients with [intermediate-risk prostate cancer] on the risks/benefits of adding [short-term ADT] to RT,” Dr Krauss’ team wrote. “Patients will be able to make more informed choices on the basis of quantified clinical advantages weighed against prospectively collected, patient-reported quality-of-life impacts.”

In an interview, Dr Krauss, who is affiliated with Corewell Health’s Beaumont Hospital in Royal Oak, Michigan, noted that findings from these studies provide “context” and “transparency” for more informed shared decision-making.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original references for a full list of authors’ disclosures.

References

Krauss DJ, Karrison T, Martinez AA, et al. Dose-escalated radiotherapy alone or in combination with short-term androgen deprivation for intermediate-risk prostate cancer: Results of a phase III multi-institutional trial. J Clin Oncol. Published online April 27, 2023. doi:10.1200/JCO.22.02390

Movsas B, Rodgers JP, Elshaikh MA, et al. Dose-escalated radiation alone or in combination with short-term total androgen suppression for intermediate-risk prostate cancer: Patient-reported outcomes from NRG/Radiation Therapy Oncology Group 0815 randomized trial. J Clin Oncol. Published online April 27, 2023. doi:10.1200/JCO.22.02389