Biochemical failure and toxicity in treatment with brachytherapy and external beam radiotherapy compared with radical prostatectomy in localized prostate cancer.

Background: Localized prostate cancer (T1-3N0M0) has therapeutic options such as radical prostatectomy (RP), external beam radiation therapy (EBRT) and brachytherapy (BT). However, the evidence of the outcome of these treatments is limited and no studies have been conducted comparing biochemical failure (BF) and toxicity associated with surgical treatment and EBRT + high-dose brachytherapy (HDBT) in the region. Materials and methods: Retrospective cohort study, clinical records of patients diagnosed with localized prostate cancer between 2014 and 2018 were reviewed at one of the main private neoplasm centers in Lima, Peru; Cox regression was used for both the BF outcome and the grade 2 toxicity outcome, calculating the hazard ratio (HR) with 95% confodence interval (CI). Results: Of 549 patients, 76.3% (419) received RP as primary treatment, and 72% were between 50 and 70 years old at the time of diagnosis. The patients treated with EBRT + HDBT presented worse characteristics. The EBRT + HDBT group had a 40% lower risk of presenting BF (HR = 0.6; 95% CI: 0.4-0.9), and also a 50% greater risk of presenting toxicity greater than or equal to grade 2 (HR = 1.5; 95% CI: 1.0-2.0) than the group treated with RP. Conclusion: Our results show that when comparing patients treated with EBRT + HDBT and RP, BF was greater in RP, and post-treatment toxicity was greater in EBRT + HDBT.