Abstract
PURPOSE: To evaluate patient experiences with decisions regarding radiation therapy (RT) for ductal carcinoma in situ (DCIS), and to assess clinician views on the role of RT for DCIS with favorable features in the present era. METHODS AND MATERIALS: A sample of women with newly diagnosed breast cancer from the population-based Georgia and Los Angeles County Surveillance, Epidemiology, and End Results (SEER) registries were sent surveys approximately 2 months after undergoing breast-conserving surgery (BCS), with a 70% response rate. The analytic sample was limited to 538 respondents with unilateral DCIS. We also surveyed 761 surgeons and radiation oncologists treating breast cancer in those regions, of whom, 539 responded (71%). RESULTS: After BCS, 23% of patients omitted RT, with twice the rate of omission in Los Angeles County relative to Georgia (31% vs 16%; P < .001). The most common reasons for omitting RT were advice from a clinician that it was not needed (62%) and concern about side effects (24%). Cost and transportation were not reported as influential considerations. After covariate adjustment, low- and intermediate-grade disease (odds ratio [OR] 5.5, 95% confidence interval [CI] 2.5-12; and OR 3.2, 95% CI 1.7-6.1, respectively) and Los Angeles County SEER site (OR 4.3, 95% CI 2.3-8.2) were significantly associated with greater RT omission. Of the responding clinicians, 62% would discuss RT omission for a patient with DCIS with favorable features. Clinicians in Los Angeles County were more likely to discuss RT omission than were those in Georgia (67% vs 56%; P = .01). Approximately one third of clinicians would obtain the Oncotype DX DCIS score. CONCLUSIONS: The heterogeneity in RT omission after BCS for DCIS continues to be substantial, with systematic differences in provider opinions across the 2 regions we studied. Enhanced precision of recurrence estimates, guidance from professional organizations, and better communication are needed to improve the consistency of treatment in this controversial area.