Longitudinal analysis of patient-reported outcomes and cosmesis in a randomized trial of conventionally fractionated versus hypofractionated whole-breast irradiation.

Abstract

The authors compared longitudinal patient-reported outcomes and physician-rated cosmesis with conventionally fractionated whole-breast irradiation (CF-WBI) versus hypofractionated whole-breast irradiation (HF-WBI) within the context of a randomized trial. From 2011 to 2014, a total of 287 women with American Joint Committee on Cancer stage 0 to stage II breast cancer were randomized to receive CF-WBI (at a dose of 50 grays in 25 fractions plus a tumor bed boost) or HF-WBI (at a dose of 42.56 grays in 16 fractions plus a tumor bed boost) after breast-conserving surgery. Patient-reported outcomes were assessed using the Breast Cancer Treatment Outcome Scale (BCTOS), the Functional Assessment of Cancer Therapy-Breast, and the Body Image Scale and were recorded at baseline and 0.5, 1, 2, and 3 years after radiotherapy. Physician-rated cosmesis was assessed at the same time points. Outcomes by treatment arm were compared at each time point using a 2-sided Student t test. Multivariable mixed effects growth curve models assessed the effects of treatment arm and time on longitudinal outcomes. Of the 287 patients enrolled, 149 were randomized to CF-WBI and 138 were randomized to HF-WBI. At 2 years, the Functional Assessment of Cancer Therapy-Breast Trial Outcome Index score was found to be modestly better in the HF-WBI arm (mean 79.6 vs 75.9 for CF-WBI; P = .02). In multivariable mixed effects models, treatment arm was not found to be associated with longitudinal outcomes after adjusting for time and baseline outcome measures (P≥.14). The linear effect of time was significant for BCTOS measures of functional status (P = .001, improved with time) and breast pain (P = .002, improved with time). In this randomized trial, longitudinal outcomes did not appear to differ by treatment arm. Patient-reported functional and pain outcomes improved over time. These findings are relevant when counseling patients regarding decisions concerning radiotherapy. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2886-2894. © 2016 American Cancer Society.