Survival outcomes of combined external beam radiotherapy and brachytherapy vs. brachytherapy alone for intermediate-risk prostate cancer patients using the National Cancer Data Base.

The purpose was to evaluate survival outcomes between external beam radiotherapy (EBRT) plus brachytherapy and brachytherapy alone for intermediate-risk prostate cancer, using the National Cancer Data Base.

The National Cancer Data Base was queried for cN0M0 intermediate-risk patients treated from 2004 to 2006, with available data for Gleason score (GS), prostate-specific antigen (PSA), tumor stage, and receipt of radiation therapy (RT) and androgen deprivation therapy. RT comparison groups were the following: EBRT (40-50. 4 Gy) plus brachytherapy and brachytherapy alone.

A total of 10,571 patients were included: 3,148 received EBRT plus brachytherapy and 7,423 received brachytherapy alone. Median followup was 84 months (2-122 months); median age was 68 years (40-90 years). Unadjusted 5- and 7-year overall survival (OS) rates between EBRT plus brachytherapy vs. brachytherapy alone were 91. 4% vs. 90. 2% and 85. 7% vs. 82. 9%, respectively (p < 0. 001). EBRT plus brachytherapy was associated with longer OS compared with brachytherapy alone under multivariate (hazard ratio [HR], 0. 84; 95% confidence interval [CI], 0. 75-0. 93; p = 0. 001) and propensity score-matched analyses (HR, 0. 85; 95% CI, 0. 75-0. 97; p = 0. 006). Further subset analysis performed based on the Radiation Therapy Oncology Group 0232 inclusion criteria (GS 7 if PSA < 10 or GS < 7 if PSA 10-20) also demonstrated longer OS with EBRT plus brachytherapy (HR, 0. 87; 95% CI, 0. 77-0. 98; p = 0. 026).

EBRT plus brachytherapy is associated with a modest OS improvement compared with brachytherapy alone in this population-based analysis. Although this benefit appears statistically significant, the relatively small difference in OS raises the question of overall clinical benefit with combined modality RT for intermediate-risk prostate cancer, given the potential increased risk for toxicities. Future results from Radiation Therapy Oncology Group 0232 should provide further insight on this topic.

Brachytherapy. 2016 Jan 26 [Epub ahead of print]

Arya Amini, Bernard L Jones, Matthew W Jackson, Chad G Rusthoven, Paul Maroni, Brian D Kavanagh, David Raben

Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO. Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO. , Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO. , Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO. , Department of Surgery, Division of Urology, University of Colorado School of Medicine, Aurora, CO. , Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO. , Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO.

PubMed