The Use of Radiation As a Component of Breast Conservation Therapy in National Comprehensive Cancer Network Centers

Abstract

Benchmark data regarding quality measures of breast cancer management are needed. We investigated rates of radiation use after breast conservation therapy (BCT) for patients treated for ductal carcinoma-in-situ (DCIS) or invasive breast cancer at National Comprehensive Cancer Network (NCCN) centers. We studied 3,333 consecutive patients treated between 1997 and 2002 with BCT for DCIS (n = 587) or for stage I or II breast cancer (n = 2,746) in eight NCCN centers. The overall rate of radiation therapy use was 91%, with a lower frequency of radiation use in DCIS versus invasive breast cancers (82% v 94%; odds ratio [OR] = 0.31; P < .0001). In a multivariable analysis of the patients with DCIS, the only factor significantly associated with lower rates of radiation use was low/intermediate grade (OR = 0.19; P = .0003). For patients with invasive breast cancer, significant factors were presence of comorbidity (OR = 0.53; P = .0005), tubular histology (OR = 0.39; P = .02), type of health insurance (P = .0072), and the NCCN institution (P = .0005). The model also showed lower rates of radiation use in patients with stage II disease who did not receive systemic therapy (OR = 0.01; P = .0001), younger patients who did not receive systemic therapy (P = .003); and older patients with stage I disease (P < .0001). Radiation use as a component of BCT was high for patients seen at NCCN centers; however, there was variability in practice patterns noted across institutions. Radiation was most commonly omitted in patients with favorable disease characteristics, patients with comorbidities, and patients who also did not receive guideline-recommended systemic treatment.