Prognostic factors in invasive lobular carcinoma of the breast: a multivariate analysis. A multicentre study after seventeen years of follow-up.

Background and goals: The purpose of this study was to characterize the biologic determinants that affect the behavior of invasive lobular carcinoma of the breast.

Material and methods: A prospectively accrued data base containing 9,619 breast cancer cases was queried for specific pathological features. From this data base, 390 patients with invasive lobular carcinoma of the breast treated and followed at any of these three centers: San Carlos Hospital, Doce de Octubre Hospital or The Jimenez Diaz Foundation in Madrid (Spain) were reviewed and results, in terms of overall survival and disease-free survival were recorded for a long-term follow-up of 206 months (17 years).

Results: The parameters that showed an important statistical influence on survival were the stage at diagnosis, the tumor size and nodal status, as well as the tumor grade. Age showed a limited influence, and multicentricity, or the type of surgical procedure had no statistical impact on survival.

Conclusions: Our analysis specifies the clinico-pathological features that influence the prognosis of invasive lobular carcinoma of the breast, and confirms that conservative therapy may be an appropriate treatment for this type of cancer.