Risk of invasive breast cancer after lobular intra-epithelial neoplasia: review of the literature.

OBJECTIVE: Lobular intra-epithelial neoplasia (LIN) is a rare breast disease that has been regarded alternately as a risk factor for invasive breast cancer in both breasts or a true breast cancer precursor. The controversy is largely dependent on the estimation of the IBC (Invasive Breast Cancer) risk after LIN; however a systematic review of the published data has not been previously performed. We aimed to review the IBC after LIN and the characteristics of those cancers.
METHODS: A PubMed search was performed to identify the published articles in English addressing the breast cancer risk after LIN.
RESULTS: There was a wide range in the figures estimating the risk of the breast cancer among the 22 studies that form the basis of this review. The cumulative average risk of invasive breast cancer (IBC) was 8.7% (range 0-33). It was 4.7% (range 0-25) for the ipsilateral and 4.2% (range 0-16) for the contralateral breast. 52% of the breast cancers occurred more than 10 years after the initial LIN. A lobular histotype was present in 30% (range 0-67%) of all IBC.
CONCLUSIONS: LIN should be considered both as a risk factor (low and similar level of IBC risk for both breasts, long delay between LIN and IBC) and a precursor for IBC (over-representation of lobular histotype).