Is it possible to predict underestimation in ductal carcinoma in situ of the breast? Yes, using a simple score!

Approximately 30% of patients with an initial diagnosis of ductal carcinoma ductal in situ (DCIS) present stromal invasion in the final surgical specimen. This study aimed to describe the prevalence of upstaging in women with an initial diagnosis of pure DCIS and identify predictive factors of invasion.
 METHODS: This is a cross-sectional study including patients with an initial unilateral DCIS diagnosed through needle core or vacuum-assisted biopsy. All patients were submitted to surgical excision. Clinical, radiological and histological variables were retrospectively collected from our medical records.
 RESULTS: A total of 169 biopsies diagnosed with DCIS were included in this study. 53 patients presented upstaging for invasive carcinoma (31.4%). In the univariate analysis the following variables were significantly associated with invasive breast carcinoma (IBC) at final diagnosis: age < 46 years, the presence of a palpable mass, type of biopsy, nuclear grade, and comedonecrosis. The frequency of upstaging did not vary according to the tumor size or menopausal status. In the multivariate analysis, only the type of biopsy and the presence of comedonecrosis remained as independent predictors of invasion. Our score attributed specific points according to the type of biopsy and the presence of comedonecrosis, ranging from 0 to 2.5, showing a very good predictive ability.
 CONCLUSIONS: We were able to identify that the type of biopsy and comedonecrosis are predictive factors of stromal invasion among women with DCIS. The proposed score has shown a good predictive ability and its utilization in the clinical practice can improve therapeutic planning.