Infiltrating lobular carcinoma of the breast: tumor characteristics and clinical outcome

Invasive lobular carcinoma (ILC) comprises approximately 10% of breast cancers and appears to have a distinct biology. Because it is less common than infiltrating ductal carcinoma (IDC), few data have been reported that address the biologic features of ILC in the context of their clinical outcome. In the present study we undertook an extensive comparison of ILC and IDC using a large database to provide a more complete and reliable assessment of their biologic phenotypes and clinical behaviors.

The clinical and biological features of 4140 patients with ILC were compared with those of 45,169 patients with IDC (not otherwise specified). The median follow-up period was 87 months.