Low-risk characteristics of breast ductal carcinoma in situ (DCIS)
ER-positive tumors, ER-negative tumors, Cancer
RECURRENCE, BREAST DUCTAL CARCINOMA IN SITU, DCIS, DISEASE, BREAST, EVENTS, CANCER
Radiotherapy (RT) following breast-conserving surgery (BCS) is commonly used to decrease local recurrence of breast ductal carcinoma in situ (DCIS) [In the Dana Farber/Harvard Cancer Institute trial, Wong et al. showed that the 5-year IBTR rate was 12% in breast DCIS patients who met the criteria of low- to intermediate-grade disease, had a margin width of 10 mm, and had undergone BCS alone [The randomized trial UK/ANZ (UK, Australia, and New Zealand) DCIS trial, which enrolled breast DCIS patients irrespective of low-risk or high-risk characteristics, showed that among patients who underwent BCS alone, administration of tamoxifen (20 mg/day for 5 years) significantly reduced ipsilateral (Hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.59–0.98; Among 732 patients (41%) with breast DCIS who received tamoxifen from the original National Surgical Adjuvant Breast and Bowel Project B-24 population, in which ER-positive tumors were 76%, Allred et al. showed that tamoxifen administration significantly diminished ipsilateral and contralateral recurrent breast events in those with ER-positive tumors, but did not impede recurrent events in those with ER-negative tumors [