A model to predict upstaging to invasive carcinoma in patients preoperatively diagnosed with ductal carcinoma in situ of the breast

BACKGROUND: The aims of this study were to determine clinicopathological factors associated with postoperative upstaging to invasive carcinoma in patients preoperatively diagnosed with ductal carcinoma in situ (DCIS) and to develop a model to predict the risk of upstaging. METHODS: Pre- and post-operative pathological diagnoses and radiological findings were assessed for 1,187 consecutive patients. RESULTS: Of the patients, 306 (25.8%) were upstaged on the surgical specimen. In multivariate analysis, the following four factors were significantly associated with upstaging: 1) the presence of sclerosing adenosis on the preoperative biopsy specimen (odds ratio [OR] 0.46, P = 0.013); 2) pleomorphic calcifications on the mammogram (OR 1.68, P = 0.009); 3) a mass suspicious for invasive carcinoma on ultrasonography and/or MRI (OR 2.13, P < 0.001); 4) tumor size ≥2 cm on ultrasonography (OR 1.80, P = 0.032). HER2-positive (OR 1.54, P = 0.062) and comedo necrosis (OR 1.42, P = 0.056) demonstrated a trend towards significance. A prediction model incorporating these variables demonstrated that the risk of upstaging was 5.1% with score 0-2 and was 58.1% with score 10. CONCLUSIONS: The prediction model incorporating clinicopathological features may be used to guide the selection of patients with DCIS for sentinel lymph node biopsy.