Brachytherapy boost improves survival and decreases risk of developing distant metastases compared to external beam radiotherapy alone in intermediate and high risk group prostate cancer patients.

BACKGROUND AND PURPOSE: Despite several prospective trials showing a clinical benefit of combining external beam radiotherapy (EBRT) with brachytherapy boost (BTB) for the treatment of intermediate- and high-risk prostate cancer (PCa) patients, none of these trials was designed to test for a survival difference. In this study, we aimed to collect a large multi-institutional database to determine whether BT boost was associated with a statistically significant improvement in survival and a reduction of distant metastases based on real-world data. MATERIAL AND METHODS: We collected the data of patients treated for intermediate- or high-risk PCa with definitive EBRT or BTB, with or without androgen deprivation therapy (ADT), between January 2003 and December 2014 at two tertiary institutions. The statistical endpoints included overall survival (OS), freedom from distant metastases (FFDM), and metastases-free survival (MFS). The impact of treatment modality was assessed using Cox regression models and log-rank testing after one-to-one propensity score matching. RESULTS: A total of 1641 patients treated with EBRT (n = 1148) or high-dose-rate BTB (n = 493) were analyzed. The median survival and clinical follow-up were 117.8 (IQR 78-143.3) and 60.7 months, respectively. The radiotherapy modality (BTB) remained an independent prognostic factor for OS (HR 0.75; 95% CI 0.63-0.88; p < 0.001), FFDM (HR 0.54; 95% CI 0.4-0.73; p < 0.001), and MFS (HR 0.72; 95% CI 0.61-0.85; p < 0.001). After propensity score matching, the remaining 986 patients were well-balanced in terms of age, maximum PSA, ISUP grade group, and TNM T stage. OS (p < 0.001), FFDM (p = 0.001) and MFS (p < 0.001) were significantly higher in the BTB group. CONCLUSIONS: There is a strong positive association between BTB and OS, FFDM, and MFS in PCa patients treated with definitive RT for intermediate- or high-risk PCa.

Pre-Treatment Hemoglobin Concentration and Absolute Monocyte Count as Independent Prognostic Factors for Survival in Localized or Locally Advanced Prostate Cancer Patients Undergoing Radiotherapy.

The prognostic value of inflammatory indices, such as the absolute monocyte count (AMC), has been a subject of interest in recent prostate cancer (PCa) studies, while hemoglobin concentration (HGB) has been recognized as a survival factor in castration-resistant metastatic prostate cancer, but its value remains unclear in localized diseases. The aim of this study was to test the prognostic value of these two simple and inexpensive biomarkers for survival and was based on a cohort of 1016 patients treated with primary radiotherapy and androgen deprivation therapy for localized or locally advanced intermediate- or high-risk PCa. Complete survival data were available for all cases and were based on the National Cancer Registry, with a median observation time of 120 months (Interquartile Range (IQR) 80.9-144.7). Missing blood test data were supplemented using the Nearest Neighbor Imputation, and the Cox Proportional Hazards Regression model was used for analysis. The median age was 68.8 years (IQR 63.3-73.5). The five-year overall survival was 82.8%, and 508 patients were alive at the time of analysis. The median time between blood tests and the first day of radiotherapy was 6 days (IQR 0-19). HGB (p = 0.009) and AMC (p = 0.003) were independent prognostic factors for survival, along with age, Gleason Grade Group, clinical T stage and maximum prostate-specific antigen concentration. This study demonstrates that HGB and AMC can be useful biomarkers for overall survival in patients treated with radiotherapy for localized intermediate- or high-risk PCa.