Risk factors predicting the outcome of salvage radiotherapy in patients with biochemical recurrence after radical prostatectomy

Abstract

Abbreviations & Acronyms ADT = androgen deprivation therapy CI = confidence interval c-index = concordance index CT = computed tomography DT = doubling time GS = Gleason score HR = hazard ratio pGS = Gleason score of prostatectomy PSA = prostate-specific antigen PSA-DT = prostate-specific antigen doubling time RT = radiotherapy Objectives: Salvage radiotherapy is the only curative treatment for patients with prostate cancer showing biochemical progression after radical prostatectomy. In this study, we evaluated the clinicopathological parameters that influence the outcome of salvage radiotherapy. Methods: Medical records of 49 patients who underwent salvage radiotherapy after radical prostatectomy from 1997 to 2008 at the Graduate School of Medicine, Kyoto University, were retrospectively reviewed. Radiotherapy was carried out with 66 Gy on the prostatic bed. Results: Biochemical progression-free survival after salvage radiotherapy at 2, 5 and 7 years was 51.0%, 42.2% and 42.2%, respectively. Significant parameters predicting biochemical progression after salvage radiotherapy by Cox regression analysis were prostatectomy Gleason score sum Ն8 (hazard ratio 0.08; 95% confidence interval 0.03-0.22; P = 0.001), prostate-specific antigen nadir after radical prostatectomy Ն0.04 ng/mL (hazard ratio 0.30; 95% confidence interval 0.13-0.69; P = 0.005) and negative surgical margin (hazard ratio 0.28; 95% confidence interval 0.12-0.70; P = 0.006). When the patients were subgrouped by these risk factors, the 5-year progression-free survival rates after salvage radiotherapy were 77.8%, 50.0% and 6.7% in patients with 0, 1 and Ն2 predictors, respectively. Conclusion: In order to discriminate favorable candidates for salvage radiotherapy, Gleason score of prostatectomy, prostate-specific antigen nadir after prostatectomy and positive surgical margin represent independent predictors. Thus, progression-free survival might be more precisely predicted according to the presence/absence of these risk factors. The significance of this risk classification should be confirmed by large prospective studies.

Salvage Radiotherapy after Radical Prostatectomy: Prediction of Biochemical Outcomes

“…Stephenson et al reported that patients with positive surgical margins are more likely to have better prognoses after salvage RT than those with negative margins (HR 1.7, 95% CI 1.4–2.5, p<0.001) [24]. Also Kinoshita et al reported that a negative surgical margin was an independent predictor of BCR-free survival after salvage RT (HR 0.28, 95% CI 0.12–0.70, p = 0.006) [25]. The overall analysis of the patients in the present study suggested that a positive surgical margin was a statistically significant predictor of longer BCR-free survival after salvage RT.…”

“…BCR after RP was defined as a PSA level of ≥0.2 ng/mL with 2 consecutive increases from a PSA value of <0.2 ng/mL, a PSA level that did not reduce to <0.2 ng/mL and increased twice, or the initiation of salvage therapy [4], [5]. The date on which BCR occurred was defined as the day on which the PSA level increased to ≥0.2 ng/mL or the day of the first follow-up visit if the PSA value did not decrease under 0.2 ng/mL [4].…”

Factors influencing biochemical recurrence in patients who have received salvage radiotherapy after radical prostatectomy: a systematic review and meta-analysis

“…In this meta-analysis, eight studies evaluated the surgical margins910131416171920 However, the overall effect showed no significant association between surgical margins and BCR (OR: 1.09; 95% CI: 0.83–1.43). The fixed-effects model was reported here because there was no evidence of heterogeneity ( I 2 = 30%) ( Figure 5 ).…”

“…BCR after RP was defined as PSA level ≥0.2 ng ml −1 with two consecutive increases from a baseline of <0.2 ng ml −1 . BCR after SRT was defined as a PSA level that had increased to ≥0.2 ng ml −1 from the post-RT nadir confirmed by one more consecutive result 1718…”

“…Five studies1115171920 including 561 patients showed a weak association between preoperative PSA ≥10 ng ml −1 group and preoperative PSA <10 ng ml −1 group (odds ratio [OR]: 1.36; 95% confidence interval [CI]: 0.94–1.96). The fixed-effects model was reported here because there was no evidence of heterogeneity ( I 2 = 29%) ( Figure 2 ).…”