Histological type is not an independent prognostic factor for the risk pattern of breast cancer recurrences

Invasive lobular breast cancer (ILC) is less common than invasive ductal breast cancer (IDC) and appears to have a distinct biology. Inconsistent findings regarding disease-free survival (DFS) are probably due to the fact that histologic type is related to hormone receptor status. This study aims to determine whether the type of the primary breast cancer histology is an independent prognostic factor for DFS, the risk pattern of loco-regional recurrences and distant metastases (DM), and whether it is a prognostic factor for the site of DM. All Dutch women diagnosed between 2003 and 2005 with ILC ( n = 2,949) or IDC ( n = 22,378) were selected from the Netherlands Cancer Registry. DFS was assessed using proportional hazard regression analysis. Compared to patients with IDC, those with ILC were significantly older and more likely to have more than three positive lymph nodes and have larger, better differentiated, more multifocal, and hormone receptor positive tumors (all P