The association between mammographic calcifications and breast cancer prognostic factors in a population‐based registry cohort

BACKGROUND: Mammographic calcifications can be a marker of malignancy, but their association with prognosis is less well established. In the current study, the authors examined the relationship between calcifications and breast cancer prognostic factors in the population-based Carolina Mammography Registry. METHODS: The current study included 8472 invasive breast cancers diagnosed in the Carolina Mammography Registry between 1996 and 2011 for which information regarding calcifications occurring within 2 years of diagnosis was reported. Calcification-specific Breast Imaging Reporting and Data System (BI-RADS) assessments were reported prospectively by a radiologist. Tumor characteristic data were obtained from the North Carolina Central Cancer Registry and/or pathology reports. Multivariable-adjusted associations between the presence of calcifications in the breast affected by cancer and tumor characteristics were estimated using logistic regression. Statistical tests were 2-sided. RESULTS: The presence of calcifications was found to be positively associated with tumors that were high grade (vs low grade: odds ratio OR, 1.43; 95% confidence interval 95% CI, 1.10-1.88) or had an in situ component (vs without: OR, 2.15; 95% CI, 1.81-2.55). Calcifications were found to be inversely associated with hormone receptor-negative status (vs positive status: OR, 0.73; 95% CI, 0.57-0.93), size >35 mm (vs ≤8 mm: OR, 0.47; 95% CI, 0.37-0.61), and lobular tumors (vs ductal: OR, 0.39; 95% CI, 0.22-0.69). The association between the presence of calcifications and an in situ component was limited to BI-RADS category 4 and 5 calcifications and was absent for BI-RADS category 2 or 3 calcifications (P for heterogeneity <.01). The association with tumor size was found to be strongest for BI-RADS categories 3 and 4 (P for heterogeneity <.01). CONCLUSIONS: Calcifications were found to be associated with both unfavorable (high grade) and favorable (small size, hormone receptor positivity) prognostic factors. Detailed analysis of the biological features of calcifications is necessary to understand the mechanisms driving these associations. Cancer 2017;123:219-227. © 2016 American Cancer Society.