Abstract P5-01-10: Clinical-pathological features and outcomes of Invasive lobular (ILC) vs Invasive ductal (IDC) breast cancer (BC): a mono-institutional series.

Purpose: The aim of our study was to investigate different clinico-biological behavior associated to ILC compared to IDC evaluating implications on survival outcomes Methods: We analyzed data from 3749 cases of IBC treated from 1995 to 2008 and categorized as having ILC, IDC and mixed/other. Associations between clinical-pathological variables and the ILC/IDC histotype were assessed using a χ 2 test. Log-rank test and Cox regression model were performed to evaluate the impact of hystologic types on overall survival (OS), Event Free Survival (EFS) and Post-Progression Survival (PPS). Results: We identified 445 (12%) ILC, 3021 (80.5%) IDC, 149 mixed (ductal-lobular) BC (3.9%) and 134 other hystotypes (3.6%). Median age was 61 (25–97) years. Compared with IDC, ILC occurred significantly (p 3 ILC pts, in whom a trend of worse prognosis (55.6 vs 60.2%) was observed. Conclusions: Despite the quite favorable biological pattern, ILC did not show a better outcomes than IDC. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-10.