Microcalcifications matter: Diagnostic and biological differences in DCIS

INTRODUCTION: Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer increasingly detected through screening. While microcalcifications are the most common feature, a subset lacks them, posing diagnostic and management challenges. We investigated the relationship between radiological presentation (calcified vs. non-calcified) and the risk of upstaging to invasive carcinoma. MATERIALS AND METHODS: We retrospectively analyzed 196 patients with biopsy-proven DCIS who underwent surgery between 2000 and 2023. Ninety-eight (98) non-calcified cases diagnosed via ultrasound-guided vacuum-assisted biopsy were matched with 98 calcified cases diagnosed via stereotactic vacuum-assisted biopsy, based on age, grade, and macroscopic removal. We investigated the associations between upstaging and potential predictors, including calcification status, age at biopsy, lesion size, and histologic grade at biopsy. RESULTS: The overall underestimation rate was 13.8% (27/196). Non-calcified DCIS showed a higher upstaging rate than calcified DCIS (19% vs. 8%; multivariable OR for calcified DCIS: 0.31, 95% CI: 0.12-0.78, p = 0.013). Larger lesions increased the risk of underestimation (OR per 5 mm: 1.21, 95% CI: 1.06-1.38, p = 0.005), while age was not significant (OR per 5 years: 1.01, p = 0.91). CONCLUSIONS: Non-calcified DCIS and larger lesion size seemed independently associated with upstaging to invasive carcinoma, highlighting the clinical relevance of radiological presentation for risk stratification.