Towards optimal management of ductal carcinoma in situ of the breast.

Ductal carcinoma in situ (DCIS) represents a spectrum of heterogenous disease that accounts for approximately one fifth of all screen-detected breast cancers and is considered as a precursor of invasive breast cancer if left untreated (35-50% risk). DCIS can be treated by total mastectomy with or without immediate breast reconstruction, local excision (LE) plus adjuvant radiotherapy (RT) or LE alone. Total mastectomy is associated with low rates of local recurrence (1.4%) and breast cancer-specific mortality (0.59%). Three recent randomized controlled trials (RCTs) have demonstrated that adjuvant RT after LE of localized DCIS significantly reduces the incidence of local recurrence. However these trials did not identify any subgroups of patients where RT could be safely omitted. Retrospective studies suggest that RT can be safely omitted after adequate LE (margin width > or =1 cm) of small (< 15 mm), non-high grade DCIS not associated with necrosis. Further RCTs are required to validate these retrospective findings, with an emphasis on standardized and meticulous tissue processing and pathological evaluation. The role of adjuvant tamoxifen in the management of DCIS continues to evolve. Formal axillary dissection is not appropriate for DCIS, however, the potential role of the sentinel node biopsy (SNB) in selected high risk cases requires further evaluation. The International Breast Cancer Intervention Study (IBIS-II) trial aims to evaluate the potential role of third generation aromatase inhibitors in postmenopausal women with hormone-sensitive DCIS.Future research will focus on the relevance of gene expression profiling, proteomics, Laser therapy and mammary ductoscopy to the management of DCIS.