Objectives: To describe 5- and 10-year rates of metastasis-free survival (MFS) stratified by Gleason score (GS) and prostate-specific antigen doubling time (PSADT) for patients receiving salvage radiation therapy (SRT) after biochemical recurrence (BR) postradical prostatectomy (RP).
Methods: A total of 236 patients who underwent SRT without receiving concomitant androgen deprivation therapy at a single institution after BR post-RP were retrospectively reviewed. The Kaplan-Meier methods and log-rank analysis were used to determine the MFS rates.
Results: Median follow-up post-SRT was 7.1 years. As of last follow-up, 59 men (25%) had developed metastasis. On univariate analysis, both GS and PSADT predicted MFS (P<0.001). Five- and 10-year rates of MFS were calculated for patients with GS 2 to 6, 7, and 8 to 10 and for patients with PSADT < 3, 3 to 9, 9 to 15, and >15 months, who received no additional salvage therapy until the development of metastases. The 5- and 10-year MFS for GS 8 to 10 were 62% and 50%, respectively, compared with 94% at both 5 and 10 years for GS 2 to 6. The 5- and 10-year MFS for PSADT < 3 months were 70% and 61%, respectively, compared with 100% and 90% at 5 and 10 years, respectively, for PSADT >15 months.
Conclusions: After BR post-RP, SRT results in low 5- and 10-year rates of metastasis after initial BR. Importantly, a substantial proportion of patients with high-risk disease (GS 8 to 10 or PSADT < 3 mo) are free from metastasis at these same time points. Therefore, SRT should not be withheld from patients based solely on the presence of adverse disease risk factors.
Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
F.Y.F. and D.A.H. are the co-authors.
The authors declare no conflicts of interest.
Reprints: Felix Y. Feng, MD, The University of Michigan Medical Center, 1500 E. Medical Center Drive, Ann Arbor, MI 48109. E-mail: firstname.lastname@example.org.