NASHVILLE, TN—A recent study compared patient-reported disease-specific functional outcomes after external beam radiation therapy (EBRT) and EBRT combined with low-dose-rate brachytherapy prostate boost (EB-LDR) among men with localized prostate cancer.
With results published in the International Journal of Radiology, Oncology, Biology & Physics, the prospective, population-based Comparative Effectiveness Analysis of Surgery and Radiation study enrolled men with localized prostate cancer in 2011 to 2012.1
A study team led by Vanderbilt University Medical School researchers and including participation from the Nashville VAMC used the 26-item Expanded Prostate Cancer Index Composite to measure patient-reported disease-specific function at baseline and at 6, 12 and 36 months. In that measure, higher domain scores indicate better function.
The trial defined minimal clinically important difference as 6 for urinary incontinence, 5 for urinary irritative function, 4 for bowel function, 12 for sexual function and 4 for hormonal function.
Overall, 578 men received EBRT and 109 received EB-LDR. Among participants, median patient age was 69 years, and 70% had intermediate- or high-risk disease. Although men in the EB-LDR group were younger (and less likely to receive androgen deprivation therapy, baseline urinary, bowel, sexual, and hormonal function was similar between treatment groups, study authors reported.
Results indicated that, on multivariable analyses, men receiving EB-LDR reported worse urinary irritative function at six months (adjusted mean difference [AMD] -14.4, P <0.001), 12 months (AMD -12.9, P<0.001) and 36 months (AMD -4.7, P = 0.034) than men receiving EBRT.
In addition, at 12 months, men receiving EB-LDR reported worse bowel function (AMD -5.8, P = 0.002), but those differences were not documented at 36 months. No significant differences in sexual or hormone function were detected between the treatment groups, however.
“Men treated with EB-LDR report worse bowel function at one year and worse urinary irritative function through three years compared with men treated with EBRT alone,” study authors concluded. “These side effect profiles should be discussed with patients when considering EB-LDR versus EBRT treatment.”
1. Lee DJ, Barocas DA, Zhao Z, Huang LC, et. Al. Comparison of Patient-reported Outcomes After External Beam Radiation Therapy and Combined External Beam With Low-dose-rate Brachytherapy Boost in Men With Localized Prostate Cancer. Int J Radiat Oncol Biol Phys. 2018 Sep 1;102(1):116-126. doi:10.1016/j.ijrobp.2018.05.043. Epub 2018 Jun 1. PubMed PMID: 30102188.