Low risk of invasive lobular carcinoma of the breast in carriers of BRCA1 (hereditary breast and ovarian cancer) and TP53 (Li ‐Fraumeni syndrome) germline mutations

AbstractBackgroundInvasive lobular carcinoma (ILC) of the breast has epidemiological, molecular and clinical specificities, and should likely be considered a unique entity. As for genetic susceptibility,CDH1germline mutations predispose exclusively to ILC.Data are however scarce regarding ILC in women withBRCA1/2(Hereditary Breast and Ovarian Cancer) andTP53(Li ‐Fraumeni syndrome) germline mutations.MethodsWe included all breast cancers from female patients tested at our institute between 1992 and 2016 (n  = 3469) for which pathology data were available. ILC proportion comparison according to mutational status was performed by a chi‐squared test. The impact of susceptibility genes on ILC proportion was investigated by univariate logistic regression with wild‐type patients as reference.Results and discussionThere were 265 (7.64%) ILC: 2/342 (0.58%) inBRCA1patients, 24/238 (10%) inBRCA2patients, 1/57 (1.75%) inTP53patients and 238/2832 (8.4%) in non ‐carriers. The majority of breast cancers in all groups were invasive ductal and ductal in situ carcinomas. The difference in ILC proportion was highly significant (P <  0.001). Compared to wild‐type patients,BRCA1 was associated with a lower ILC proportion (OR 0.064 [95% CI 0.016;0.259],P  <  0.0001).BRCA2 OR was 1.222 [95%CI 0.785;1.902] (P = 0.374),TP53 OR was 0.195 [95%CI 0.027;1.412] (P = 0.105). ILC are therefore underrepresented inBRCA1 andTP53 mutation carriers. Formal significance (P = 0.05) was ...
Source: The Breast Journal - Category: Cancer & Oncology Authors: Tags: ORIGINAL ARTICLE Source Type: research