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

BACKGROUNDThe 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. METHODSFrom 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. RESULTSOf 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). CONCLUSIONSIn 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. (c) 2016 American Cancer Society. Cancer 2016;122:2886-2894. (c) 2016 American Cancer Society