Development of a Nomogram-Based Clinical Estimation Model for Pathological Upstaging in Patients With Preoperative Ductal Carcinoma In Situ.

Preoperative diagnosis of ductal carcinoma in situ (DCIS) may be followed by pathological upstaging to invasive ductal carcinoma (IDC) upon surgical excision, a discrepancy that significantly impacts surgical planning and decisions regarding sentinel lymph node biopsy (SLNB). This retrospective study aimed to evaluate clinical indicators associated with such upstaging and develop a nomogram-based clinical estimation model for risk stratification. We reviewed medical records of all consecutively diagnosed patients (n = 445) initially diagnosed with DCIS via core needle biopsy (CNB) or vacuum-assisted biopsy (VAB) between 2013 and 2022 at a single institution. Demographic, imaging, clinicopathological, immunohistochemical, and blood-based biomarkers were categorized and analyzed. Logistic regression analysis was employed to identify independent predictors, from which a visual risk estimation tool was constructed. Among the 445 patients, 137 (30.8%) were upstaged to IDC. In the multivariable analysis, clinical tumor size > 1.5 cm, biopsy modality, and high histologic grade at biopsy emerged as independent predictors of pathological upstaging. Notably, VAB was associated with a lower rate of underestimation than CNB. Subgroup analyses revealed that age > 50 years, larger lesion size, and high grade were associated with upstaging in the CNB group, whereas histologic grade was the primary predictor in the VAB group. The nomogram demonstrated modest discriminative performance (AUC = 0.690) for individualized preoperative assessment. In conclusion, clinical tumor size, biopsy method, and histologic grade provide valuable information for estimating the likelihood of occult invasive disease in patients with preoperative DCIS.