Variations in treatment of ductal carcinoma in situ of the breast: A population-based study in the East Netherlands

This study shows variability in the treatment of DCIS in a geographically defined region. Approximately half of all patients were treated with mastectomy and 19% underwent an axillary staging procedure; this may represent aggressive, unwarranted treatment. In contrast, 38% of patients treated with breast-conserving surgery were not treated with radiation therapy after 1999, which may represent under-treatment.