Background: PS2-expression is controlled by estrogens and is a prognostic factor for long-term and post-relapse survival. Breast carcinomas associated with a BRCA1 mutation (BRCA1-BC'S) exhibit many specific features, particularly for ER expression. Our purpose was to determine if pS2-expression was different in BRCA1-BC's compared with sporadic breast cancers.
Materials and methods: We studied, by immunohistochemistry pS2-cxpression in a series of 33 BRCA1-BC's and a series of 193 sporadic cases according to many parameter including hormone receptors (ER and PR).
Results: In BRCA1-BC's, pS2 was expressed in only 10/33 (30.3%) carcinomas, and 4/4 (100%) ER positive: among sporadic carcinomas, 133/193 (68.9%) cases were pS2-positive, 102/127(80.37%) ER positive; the difference was significant (p<0.0001). In univariate analysis, pS2-expression was correlated with many parameters including hormonal receptor status and absence of BRCA1 mutation. In multivariate analysis, pS2-expression was still correlated with ER but no more with BRCA1 mutation.
Conclusion: pS2-expression in BRCA1-BC's was significantly different from sporadic breast cancer (p<0.0001) and correlated in a multivariate analysis with the same factors in sporadic and BRCA1-BC's but not with BRCA1 mutation.