BRCA1, Ki67, and β-Catenin Immunoexpression Is Not Related to Differentiation, Platinum Response, or Prognosis in Women With Low- and High-Grade Serous Ovarian Carcinoma.

Objective: The purpose of this study was to compare the immunohistochemical expression of BRCA1, Ki67, and β-catenin in women with low-grade (LGSOC) and high-grade serous ovarian carcinomas (HGSOC) and their relationship with clinicopathological features, response to platinum-based chemotherapy, and survival.

Methods: For this study, 21 LGSOC and 85 HGSOC stage I to IV cases, diagnosed and treated from 1996 to 2013 and followed-up until December 2016, were included. BRCA1, Ki67, and β-catenin expression was assessed using tissue microarray-based immunohistochemistry.

Results: Women with HGSOC were significantly more likely to have advanced-stage disease (P < 0.001), higher CA125 levels (P < 0.001), postsurgery residual disease (P < 0.01), and higher rates of disease progression and recurrence (P = 0.001). The percentage of women with HGSOC whose tumors expressed Ki67 was significantly higher compared with women with LGSOC (P < 0.001). The expression of BRCA1 and β-catenin did not differ between LGSOC and HGSOC (P = 0.12 and P = 1.00, respectively). The clinicopathological features and the response to platinum-based chemotherapy did not differ according to the BRCA1, Ki67, and β-catenin expression in either group. In HGSOC, only International Federation of Gynecology and Obstetrics stage was independently associated with poor survival (PFS and OS).

Conclusions: Ki67 expression was significantly higher in HGSOC. BRCA1 and β-catenin expression did not differ between LGSOC and HGSOC samples. BRCA1, Ki67, and β-catenin expression was neither related to clinicopathological features, response to platinum-based chemotherapy, nor survival. Only International Federation of Gynecology and Obstetrics stage remained associated with poor survival in women with HGSOC.