Ductal carcinoma-in situ (DCIS) is a non-obligate precursor for invasive breast cancer and concern exists regarding the potential for overdiagnosis and overtreatment as the natural history of DCIS progression to invasive breast cancer may never occur or take decades in some cases. Preoperative systemic therapy window studies may provide powerful clues to best uncover which particular DCIS lesions respond to systemic therapies and allow for future selective personalized management recommendations. One of the main challenges for instituting active surveillance for DCIS with vacuum-assisted core needle biopsy alone and no surgery is concern for leaving untreated occult invasive carcinoma. Breast MRI lacks sufficient diagnostic ability to differentiate pure DCIS from invasive cancer with DCIS. Current novel randomized trials investigating active surveillance versus active management are described. Multigene expression assays may someday prove useful in stratifying patients at increased risk for progression to invasive breast cancer in the absence of surgery.
Keywords: DCIS; atypical ductal hyperplasia; breast cancer therapy; breast pathology; breast radiation; breast surgery; clinical trials; ductal carcinoma in situ; prognosis; tamoxifen.