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.

Prostate-specific antigen kinetics and metastasis-free survival in patients treated with external beam radiotherapy combined with high-dose-rate brachytherapy boost and androgen deprivation therapy for localized prostate cancer.

PURPOSE: Serum prostate-specific antigen (PSA) kinetics has been linked to prognosis in prostate cancer (PCa) patients. Our goal was to analyze the association between PSA kinetics and metastasis-free survival (MFS) in patients with localized PCa treated with high-dose-rate (HDR) brachytherapy (BT) boost combined with external beam radiotherapy (EBRT). MATERIAL AND METHODS: We retrospectively analyzed multiple PSA kinetics related to PSA nadir (nPSA), PSA bouncing, and biochemical recurrence (BCR) in 186 PCa patients treated with neoadjuvant androgen deprivation therapy (ADT), followed by EBRT combined with HDR-BT boost. Uni- and multivariate Cox regression models were calculated to assess the value of PSA-related parameters for the prediction of MFS. RESULTS: 5- and 10-year MFS were 95% and 84%, respectively. Median nPSA was 0.011 (IQR, 0.007-0.057) ng/ml and predicted MFS in multivariable analysis. Implementation of nPSA improved c-index of baseline model from 0.8 to 0.68. nPSA of 0.2 ng/ml offered the most optimal discriminatory ability for identifying patients with better prognoses. Time to nPSA (median, 11 months; IQR, 8-18 months) and PSA bounce, which occurred in 12.4% of patients, were not significantly associated with MFS. CONCLUSIONS: Lower values of nPSA are significantly associated with decreased risk of developing metastases in patients treated with EBRT combined with HDR-BT boost and ADT, and improve the accuracy of a clinical model for MFS.

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.