Background: Ovarian serous carcinoma is the most common type of ovarian cancer. Abnormal protein expression in this type of cancer cells may identify prognosis of patient.

Objective: To determine the breast cancer type 1 (BRCA1) status by using immunostaining in ovarian serous carcinoma patients and compare with clinicopathological characteristics and survival outcome.

Materials and Methods: Serous ovarian cancer specimens and clinicopathological data were collected from Songkhlanagarind hospital between 2008 and 2017. There were 166 cases during that time. The BRCA1 protein expression was evaluated by tissue microarray and immunohistochemical staining of BRCA1 (clone MS110).

Results: The results showed loss of BRCA1 expression in 44 cases or 25.4%. In seven patients who had history of breast cancer, four cases or 57.0% lost BRCA1 protein expression. The median overall survival was 44.3 months, 32.5 months in loss of the expression group and 50.4 months in the expression group. The BRCA1 expression was not associated with survival outcome (p=0.90). Tumor staging was an independence prognostic factor.

Conclusion: The percentage of BRCA1 loss of expression in ovarian serous cancer was slightly high in Southern Thailand, but BRCA1 loss of expression did not statically associated with survival outcome.

Keywords: BRCA1; Immunohistochemistry; Ovarian cancer; Serous carcinoma; Survival

DOI: 10.35755/jmedassocthai.2022.11.13706

Received 4 July 2022 | Revised 11 August 2022 | Accepted 24 August 2022