Can We Identify a Subset of Patients with DCIS that can be Treated by Wide Excision Alone?

Ductal carcinoma in situ (DCIS) represents the earliest stage of breast cancer and accounts for approximately 20% of new breast cancer diagnoses. Mastectomy was the surgical treatment of choice prior to seminal data from several randomized control trials which provided evidence supporting the efficacy of breast conservation surgery (BCS) in DCIS. Controversy, however, persists regarding all patients with DCIS require radiation treatment after lumpectomy. In this review, we summarize the findings from early clinical trials which attempted to identify risk factors associated with increased risk of local recurrence after BCS. We focus mainly on clinical features associated with women with “low risk DCIS”, i.e. those who may not need adjuvant radiation treatment after BCS. Clinical features that have been suggested as defining low risk DCIS include: older age at diagnosis, low or intermediate nuclear grade, smaller size of DCIS, absence of comedo necrosis and wide margins of resection (> 3 mm). We also review the results from several recent single arm studies examining the risk of local recurrence in women felt to have low risk DCIS treated by BCS without radiation. The mixed results of these studies indicate that the current risk stratification strategies for identifying low risk DCIS needs further refinement. Future directions will likely involve validated novel diagnostic and molecular methods to help guide the delivery of tailored treatment to women with DCIS.