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
Menée auprès de 687 patients atteints d'un cancer de la prostate de stade localisé (âge médian : 68 ans), cette étude évalue, du point de vue des résultats auto-rapportés concernant les fonctions urinaire, digestive, sexuelle et hormonale, l'intérêt d'ajouter à une radiothérapie externe une curiethérapie de type boost à faible débit de dose
Purpose : To compare patient reported disease specific functional outcomes after external beam radiation therapy (EBRT) and combined EBRT with low-dose rate brachytherapy prostate boost (EB-LDR) among men with localized prostate cancer. Methods : The prospective, population-based Comparative Effectiveness Analysis of Surgery and Radiation (CEASAR) study enrolled men with localized prostate cancer in 2011-2012. The 26-item Expanded Prostate Cancer Index Composite (EPIC) measured patient-reported disease-specific function at baseline, six, 12 and 36 months. Higher domain scores indicate better function. Minimal clinically important difference was defined as 6 for urinary incontinence, 5 for urinary irritative, 4 for bowel, 12 for sexual and 4 for hormonal function. Multivariable linear and logistic regression models were fit to estimate the effect of treatment on patient reported outcomes. Results : 578 men received EBRT and 109 EB-LDR. Median age was 68 years, and 70% had intermediate- or high-risk disease. Men in the EB-LDR group were younger (p<0.001) and less likely to receive androgen deprivation therapy (p<0.001). Baseline urinary, bowel, sexual and hormonal function was similar between treatment groups (p>0.05). On multivariable analyses, EB-LDR men reported worse urinary irritative function at six months (adjusted mean difference [AMD] -14.4, p<0.001), 12 months (-12.9, p<0.001), and 36 months (-4.7, p=0.034) than EBRT men. At 12 months, EB-LDR men reported worse bowel function (-5.8, p=0.002), but these differences were not seen at 36 months. There were no significant differences in sexual or hormone function between treatment groups. Conclusion : Men treated with EB-LDR report worse bowel function at one year and worse urinary irritative function through three years compared to men treated with EBRT alone. These side effect profiles should be discussed with patients considering EB-LDR vs. EBRT treatment.