OBJECTIVETo explore the mRNA expression of breast cancer susceptibility gene 1 (BRCA1) in tumor cells isolated from malignant pleural and peritoneal effusions, and the predictive role of BRCA1 related to the efficacy of cisplatin-based chemotherapy.

METHODSTumor cells were isolated from malignant pleural and peritoneal effusions of 31 cancer patients. The response of these tumor cells to cisplatin was determined by CCK8 assay. Real time quantitative RT-PCR was used to examine the BRCA1 mRNA level in the primary culture cancer cells.

RESULTSThe expression level of BRCA1 mRNA was 0.618 (0.014 - 18.063) in primary culture tumor cells. The IC(50) of DDP was 2.809 µg/ml in the primary culture tumor cells (0.118 - 19.439 µg/ml). Both BRCA1 mRNA expression and the tumor cells IC(50) of DDP were not significantly related with patient age, gender, the type of primary tumor, whether to accept the chemotherapy and effusion type (P > 0.05). The level of BRCA1 mRNA was negatively correlated with the chemosensitivity in terms of IC(50) of cisplatin (P < 0.001).

CONCLUSIONAssessment of expression level of BRCA1 mRNA may be useful in predicting the efficacy of cisplatin-based chemotherapy in patients with metastatic malignant effusions.