Objective: BRCA1 mutations predispose to cancer in hormone responsive tissues. A predominance of estrogen receptor (ER)-negative breast cancers in BRCA1 mutation carriers and potential interactions between ERalpha and BRCA1 suggest a link between hormones and BRCA1. However, the expression pattern of ERalpha and other hormone receptors in BRCA1-associated ovarian cancer was unknown.
Methods: Twenty-two BRCA1-associated ovarian cancer cases were matched with sporadic cases (no family history of ovarian or breast cancer) for FIGO stage, grade, histologic subtype, and patient age and hormone receptor expression was measured immunohistochemically.
Results: ERalpha expression was similar in BRCA1-associated ovarian cancer compared with matched sporadic counterparts, in contrast with previous findings in BRCA1-linked breast cancer. There was also no significant difference in expression of progesterone receptors and androgen receptor between the matched cases in the two groups. However, differences were noted in the relative expression of receptor isotypes, in particular, levels of ERalpha and ERbeta were positively correlated in sporadic tumors but inversely related in BRCA1-associated tumors.
Conclusion: Similar hormone receptor expression in BRCA1-associated ovarian cancer and matched sporadic counterparts may be further evidence that at least a proportion of sporadic ovarian tumors and BRCA1-associated tumors develop through similar pathways.