Does Dose-Intensified Radiation Therapy Increase Survival in Prostate Cancer?

Dose-intensified (72 Gy) radiation therapy does not yield increased survival in patients with prostate cancer compared with conventional dosing (66 Gy), except in patients with a high Gleason score (GS), according to a study presented at the 2022 American Society for Radiation Oncology Annual Meeting.

To conduct this study, presenting author Hong-Zhen Li, MD, and colleagues enrolled 144 patients with stage III-IV prostate cancer between September 2011 and November 2016. The population of interest was randomly allocated to receive either 66 Gy in 33 fractions or 72 Gy in 36 fractions. The primary outcome of interest was defined as the difference in biochemical progression-free survival (bPFS) between the 2 groups. Kaplan-Meier methodology was used to analyze bPFS, cancer-specific survival (CSS), and overall survival (OS).

After an average follow-up time of 89.5 months, the findings showed no difference in 7-year bPFS between the 72 Gy and 66 Gy cohorts (70.3% vs 61.2%; P=0.274). However, in patients with a higher Gleason score (8-10), the researchers noted the 72 Gy cohort showed marked improvement in bPFS compared with the 66 Gy cohort (66.5% vs 30.2%; P=.012).

“Dose escalation (72 Gy) demonstrated no improvement in 7-year bPFS, CSS, and OS compared with the 66 Gy regimen. Patients with higher GS (8-10) might benefit from this high-dose (72 Gy) regimen,” the researchers concluded.

Source: Li HZ, Qi XS, Gao S, Ma MW, Qin SB. Dose-intensified postoperative radiation therapy for prostate cancer: seven-year outcomes from the PKUFH randomized phase III trial. Abstract 1050. Presented at the 2022 ASTRO Annual Meeting; October 23-26, 2022; San Antonio, TX.