Microcalcifications in 1657 Patients with Pure Ductal Carcinoma in Situ of the Breast: Correlation with Clinical, Histopathologic, Biologic Features, and Local Recurrence.

PURPOSE: This study was designed to determine the relationship of microcalcification morphology and distribution with clinical, histopathologic, biologic features, and local recurrence (LR) in patients with pure ductal carcinoma in situ (DCIS) of the breast.
METHODS: All patients with pure DCIS who underwent preoperative mammography at our institution from 1996 through 2009 were identified. Mammographic findings were classified according to the ACR BI-RADS lexicon. Associations between mammographic findings and clinical, histopathologic, biologic characteristics, and LR were analyzed. Statistical inference used multiple logistic regression and Cox proportional hazards regression adjusted for age and confounding due to bias from nonrandomized selection of radiation therapy.
RESULTS: We identified 1657 patients with microcalcifications visualized on mammography. The mean age at diagnosis was 55 years (SD, 11). The mean follow-up was 7 years (range 1-16). Ipsilateral LR was 4 % in segmentectomy (987) and 1.5 % in mastectomy (670) patients. Increased LR risk was seen in patients with dense breast tissue (p < 0.05) and larger DCIS size (p < 0.01). Radiation therapy was associated with a 2.8-fold decrease in the LR risk. Fine linear (branching) microcalcifications were associated with 5.2-fold increase in LR. Extremely dense breast tissue was associated with positive/close margins (p = 0.04) and multicentricity (p < 0.01). Younger women were more likely to have extremely dense breast tissue (p < 0.0001), multicentric disease (p < 0.0004), and undergo mastectomy (p < 0.0001).
CONCLUSIONS: Dense breast tissue, large DCIS size, and fine linear (branching) microcalcifications were associated with increased LR, yet overall LR rates remained low. Extremely dense breast tissue was a risk factor for multicentricity and positive margins in DCIS.