Extensive Intraductal Component in Breast Cancer: What Role in Disease-Free Survival?

Introduction: Extensive intraductal component (EIC) associated to early breast cancer could increase the risk locoregional recurrence, but its impact on distant metastases is still unclear. The aim of the present study was to assess the role of EIC on 5-year survival outcomes in patients affected by early breast cancer treated with breast-conserving surgery. Methods: A total of 414 consecutive patients with a minimum follow-up of 60 mo were collected from January 2007 to December 2015. Disease-free survival (DFS), distant metastasis-free survival (DMFS), and locoregional recurrence-free survival at 5 y were assessed considering the presence or absence of EIC and other clinical and pathological features. Results: Absence of EIC was independently associated with worse 5-year DFS (hazard ratio [HR] 1.68, P = 0.008) and 5-year DMFS (HR 1.93, P = 0.007), whereas 5-year locoregional recurrence-free survival was not affected (HR 1.50, P = 0.16). Five-year DFS was increased by EIC in T1 patients (P = 0.03) but not in T2 stage. Moreover, EIC was associated to better DFS in G2 (P = 0.03) and G3 patients (P = 0.01) but not in G1 cases. Conclusions: Our results suggest that EIC is independently correlated with increased 5-year DFS and in particular with 5-year DMFS.