Hypofractionated Nodal Radiation Therapy for Breast Cancer Was Not Associated With Increased Patient-Reported Arm or Brachial Plexopathy Symptoms

Abstract

To determine whether nodal radiation therapy (RT) for breast cancer using modest hypofractionation (HF) with 2.25 to 2.5Gy per fraction (fx) was associated with increased patient-reported arm symptoms, compared with conventional fractionation (CF) ≤2Gy/fx. Two cancer registries were used to identify subjects who received computed tomography-planned nodal RT for pT1-3, pN0-2, M0 breast cancer, from 2007 to 2010 at 2 cancer institutions. After ethics approval, patients were mailed an explanatory letter and the Self-reported Arm Symptom Scale, a validated instrument with 8 questions about arm symptoms and 5 related to activities of daily living. Clinicopathologic characteristics and Self-reported Arm Symptom Scale scores were compared between HF/CF cohorts using nonparametric analysis, χ2 analysis, and multivariate ordinal regression. Of 1759 patients, 800 (45.5%) returned a completed survey. A total of 708eligible cases formed the study cohort. Of these, 406 (57%) received HFRT (40Gy/16 fx, 45Gy/20 fx), and 302 (43%) received CFRT (45-50Gy/25 fx, 50.4Gy/28 fx). Median time interval after RT was 5.7years. Forty-three percent and 75% of patients received breast-conserving surgery and chemotherapy, respectively. Twenty-two percent received breast boost RT, independent of fractionation. Median age at diagnosis was 59years (HF) and 53years (CF) (P<.001). The mean numbers of excised (n=12) and involved (n=3) nodes were similar between fractionation cohorts (P=.44), as were the mean sums of responses in arm symptoms (P=.17) and activities of daily living (P=.85). Patients receiving HF reported lower rates of shoulder stiffness (P=.04), trouble moving the arm (P=.02), and difficulty reaching overhead (P<.01) compared with the CF cohort. There was no difference in self-reported arm swelling or symptoms related to brachial plexopathy. Nodal RT with hypofractionation was not associated with increased patient-reported arm symptoms or functional deficits compared with CF. Subjects treated with CF reported more disability in certain aspects of arm/shoulder function. These data support shorter fractionation utilization when regional nodes are within the therapeutic target.