Factors predictive of invasive ductal carcinoma in cases preoperatively diagnosed as ductal carcinoma in situ

BACKGROUND: Invasion is often found during postoperative pathological examination of cases diagnosed as ductal carcinoma in situ (DCIS) by histological examinations such as core needle biopsy (CNB) or vacuum-assisted biopsy (VAB). A meta-analysis reported that 25.9% of invasive ductal carcinoma (IDC) cases are preoperatively diagnosed by CNB as DCIS. Risk factors for invasion have been studied by postoperative examination, but no factors have been found that could be obtained preoperatively from blood tests. In this study, we investigated factors predictive of invasion based on preoperative blood tests in patients diagnosed with DCIS by preoperative biopsy. METHODS: In this study, 118 patients who were diagnosed with DCIS by preoperative biopsy were included. Biopsies were performed with 16-gauge CNB or VAB. Peripheral blood was obtained at the time of diagnosis. This study evaluated absolute platelet count, absolute lymphocyte count, lactate dehydrogenase, carcinoembryonic antigen, and cancer antigen 15–3 (CA15–3). The platelet–lymphocyte ratio (PLR) was calculated by dividing the absolute platelet count by the absolute lymphocyte count, and patients were grouped into high PLR (≥160.0) and low PLR (< 160.0) groups. RESULTS: Invasion was found more frequently after surgery in pathologically high-grade cases than in pathologically not-high-grade cases (p = 0.015). The median PLR was 138.9 and 48 patients (40.7%) were classified into the high PLR group. The high PLR group was significantly more likely to have invasion detected by the postoperative pathology than the low PLR group (p = 0.018). In multivariate analysis of factors predictive of invasion in postoperative pathology, a high PLR (p = 0.006, odds ratio [OR] = 3.526) and biopsy method (VAB vs. CNB, p = 0.001, OR = 0.201) was an independent risk factor. CONCLUSIONS: The PLR may be a predictor of invasion in the postoperative pathology for patients diagnosed with DCIS by preoperative biopsy.