Dosimetric Inhomogeneity Predicts for Long-Term Breast Pain After Breast-Conserving

Summary Breast pain after breastconserving therapy is common. A questionnaire characterizing long-term pain was completed by 285 patients with early-stage breast cancer. Of 135 patients who reported breast pain, 14% had pain constantly/daily; 11% had intense pain. Although 47% of patients had pain, most considered it tolerable. Breast volume receiving � 105% and � 110% of the prescribed dose predicted for pain, as did hormonal therapy and shorter time since treatment. Minimization of dosimetric inhomogeneity should be prioritized. Purpose: The objective of this cross-sectional study was to characterize long-term breast pain in patients undergoing breast-conserving surgery and radiation (BCT) and to identify predictors of this pain. Methods and Materials: We identified 355 eligible patients with Tis-T2N0M0 breast cancer who underwent BCT in 2007 to 2011, without recurrent disease. A questionnaire derived from the Late Effects Normal Tissue Task Force (LENT) Subjective, Objective, Management, Analytic (SOMA) scale was mailed with 7 items detailing the severity, frequency, duration, and impact of ipsilateral breast pain over the previous 2 weeks. A logistic regression model identified predictors of long-term breast pain based on questionnaire responses and patient, disease, and treatment characteristics. Results: The questionnaire response rate was 80% (nZ285). One hundred thirty-five patients (47%) reported pain in the treated breast, with 19 (14%) having pain constantly or at least daily; 15 (11%) had intense pain. The pain interfered with daily activities in 11 patients (8%). Six patients (4%) took analgesics for breast pain. Fourteen (10%) thought that the pain affected their quality of life. On univariable analysis, volume of breast tissue treated to � 105% of the prescribed dose (odds ratio [OR] 1.001 per cc, 95% confidence interval [CI] 1.000-1.002; PZ.045), volume treated to � 110% (OR 1.009 per cc, 95% CI 1.002-1.016; PZ.012), hormone therapy use (OR 1.95, 95% CI 1.12-3.39; PZ.02), and other sites of pain (OR 1.79, 95% CI 1.05-3.07; PZ.03) predicted for long-term breast pain. On multivariable analysis, volume � 110% (OR 1.01 per cc, 95% CI 1.003-1.017; PZ.007), shorter time since