Infiltrating lobular carcinoma--a comparison of diagnosis, management and outcome with infiltrating duct carcinoma.

The treatment and outcomes for 182 patients with lobular carcinoma were compared with 1612 patients with infiltrating ductal carcinoma managed concurrently at The Strathfield Breast Centre. The lobular carcinomas were larger (P < 0.0001) but of lower grade (P < 0.0001). Diagnosis with mammography and FNA was less sensitive in ILC (mammography P = 0.0002, FNA P < 0.0001). Although similar numbers of patients underwent initial attempted conservation, patients with ILC were more likely to have positive margins at attempted breast conservation surgery and the final mastectomy rate was higher (58.2% ILC versus 47% IDC, P = 0.0041). Of the patients who had successful conservation, the local recurrence rates for ILC (3.9%) were equivalent to the patients with IDC (5.3%). There was no significant difference in overall survival (90% ILC, 87% IDC, median follow-up 3.6 years ILC, 4.3 years IDC) or disease free survival (87.9% ILC, 81.6% IDC). Although mastectomy is more likely to be necessary to obtain clear margins, breast conservation therapy is reasonable in patients with infiltrating lobular carcinoma where clear margins can be obtained.