Salvage Radiotherapy versus Observation for Biochemical Recurrence following Radical Prostatectomy for Prostate Cancer: A Matched Pair Analysis

Abstract

Background: Salvage radiotherapy (SRT) improves oncologic outcomes in prostate cancer (PCa) patients who develop biochemical recurrence (BCR) after radical prostatectomy (RP). However, evidence on hard clinical endpoints is scarce. We compare long-term oncologic outcomes of SRT versus no radiotherapy (noRT) in patients with BCR after RP. Patients and methods: Within a multi-institutional database, we identified patients with BCR after RP between 1989 and 2016 for PCa. Patients with lymph node invasion, with adjuvant radiotherapy, or with additional androgen deprivation therapy at BCR were excluded. In all patients with SRT, SRT was delivered to the prostatic bed only. Propensity score matching (PSM) was performed to account for differences in pathologic tumor characteristics. Kaplan–Meier analyses and Cox regression models tested the effect of SRT versus no RT on metastasis-free (MFS) and overall survival (OS). Results: Of 1832 patients with BCR, 32.9% (n = 603) received SRT without ADT. The median follow-up was 95.9 months. Median total SRT dose was 70.2 Gy. After 1:1 PSM, at 15 years after RP, MFS and OS rates were 84.3 versus 76.9% (p < 0.001) and 85.3 versus 74.4% (p = 0.04) for SRT and noRT, respectively. In multivariable Cox regression models, SRT was an independent predictor for metastasis (HR: 0.37, p < 0.001) and OS (HR: 0.64, p = 0.03). Conclusion: This is the first matched-pair analysis investigating the impact of SRT versus observation only in post-RP recurrent PCa. After compensating for established risk factors, SRT was associated with better long-term MFS and OS. These results on clinical endpoints underline the curative potential of SRT.

Salvage Radiotherapy for Relapsed Prostate Cancer after Radical Prostatectomy Is Associated with Normal Life Expectancy

“…A comparison of the patient characteristics in our cohort and three larger studies [4,14,17] revealed a higher proportion of lower Gleason scores and lower median pre-SRT PSA values in our study. These more favorable parameters in our cohort may have a positive impact on the observed OS.…”

“…In a retrospective study of 501 patients, SRT was associated with a decreased risk of all-cause mortality after a median follow-up of 11.3 years [20]. In addition, a large matched-pair analysis comparing SRT and no SRT confirmed a positive impact of SRT on OS [17]. Our comparison of OS with survival data from an age-matched virtual sample of the general German male population revealed no significant difference, indicating not only improved OS but also normal life expectancy.…”

“…For comparisons with the literature data, we created a table of patient characteristics for our cohort and patient characteristics from three larger, previously published studies [4,14,17]. In particular, we performed Cox regression analysis of OS, with pre-SRT PSA dichotomized at 0.7 ng/mL and pre-SRT PSADT calculated only with PSA values above the limit of detection, for comparison with previously published data [4,8,18].…”

Overall and metastasis‐free survival of Afro‐Caribbean patients with biochemical recurrence after radical prostatectomy

“…These results, obtained for a Caucasian population, show a long‐term benefit of early salvage radiotherapy. The metastasis‐free and OS of the radiotherapy group were no better than that of our surveillance group 13 …”

“…The metastasis-free and OS of the radiotherapy group were no better than that of our surveillance group. 13 Among other studies, a study by Stish et al described a cohort of 1,106 patients treated with early salvage radiotherapy, for which the 10-year MFS rate was 80.1% and the 10-year OS rate 77.3%. 14 A study by Pompe et al investigated a cohort of 1,321 patients with biochemical recurrence who received salvage treatment (early salvage radiotherapy, hormone therapy, or chemotherapy).…”