Positive prostate biopsy following radiotherapy can predict metastasis-free survival in localized prostate cancer

• Published in: Reports of practical oncology and radiotherapy Vol. 25; no. 1; pp. 55 - 59
• Main Authors: Zapatero, A., Adrados, M., Torres, L., Talaya, M.S., Cruz Conde, A., Martin de Vidales, C., Vega Piris, L., Olivier, C., Murillo, M.T.
• Format: Journal Article
• Language: English
• Published: Poland Elsevier B.V 01.01.2020; Elsevier
• Subjects: Biopsy; Intensity-modulated radiotherapy; Original research article; Post-treatment; Prostate cancer; Radiation therapy; Survival; Intensity-modulated radiotherapy; Radiation therapy; Post-treatment; Biopsy; Prostate cancer; Survival
• ISSN: 1507-1367; 2083-4640
• DOI: 10.1016/j.rpor.2019.12.003

To determine the impact of post-treatment biopsy results on 10-year metastasis-free survival (MFS), overall survival (OS) and cause-specific survival (CSS) in localized prostate cancer (PCa) patients treated with high-dose radiotherapy (RT). Retrospective analysis of 232 patients with T1c-T3bN0M0 PCa who underwent a prostate biopsy 24–36 months after high-dose RT. Biopsies were categorized as positive biopsy (PB) if H&E staining showed evidence of residual malignancy and negative biopsy (NB) if no malignant cells were present. Kaplan-Meier estimates of 10-year MFS, OS and CSS rates were calculated for each group and Cox proportional-hazards models were used to estimate the hazard ratios. The median follow-up was 124 months (range 26–267). Sixty-two of 232 (26.7%) patients had post-treatment positive biopsies (PB). A positive post-treatment biopsy was significantly associated with a lower 10-year MFS (78.4% vs. 95.4%, p = 0.001, HR: 3.9, 95% CI: 1.8–8.3). Although patients with PB had worse outcomes that those with NB, we could not show a statistically significant difference in OS (81.0% vs. 87.9%, p = 0.282, HR: 1.3, 95% CI: 0.7–2.3) or CSS (96.2% vs. 99.4% (p = 0.201, HR. 2.4, 95% CI: 0.6–9.7). After multivariate analysis, the strongest predictor of MFS was the post-treatment biopsy status (p < 0.001, HR: 5.4, 95% CI 2.26–12.85) followed by Gleason score (p = 0.002, HR: 2.24, 95% CI 1.33–3.79). A positive biopsy following RT can predict MFS in localized prostate cancer. These data highlight the relevance of achieving a local control and support the use of aggressive local therapeutic interventions for PCa.