The expression of DBC1/CCAR2 is associated with poor prognosis of ovarian carcinoma

BACKGROUND Recent reports have shown that deleted in breast cancer 1 (DBC1/CCAR2) is an indicator of poor prognosis of various human cancers. However, its expression in ovarian carcinoma has not been reported. METHODS We investigated the immunohistochemical expression of DBC1 and BRCA1 and their prognostic significance in 104 ovarian carcinomas. Survival analyses were performed according to the Kaplan-Meier method, as well as univariate and multivariate Cox proportional hazard regression analysis. RESULTS Positive expression of DBC1 and BRCA1 were seen in 63% (66/104) and 44% (46/104) of overall ovarian carcinomas, respectively. DBC1 expression was significantly associated with advanced clinicopathological factors such as high tumor stage, latent distant metastasis, platinum-resistance, elevated serum levels of CA125, high histologic grade, and BRCA1 expression. In the histological subtypes of ovarian carcinomas, DBC1 expression was more common in serous carcinoma (72%, 54/75) than mucinous carcinoma (15%, 3/20). BRCA1 expression was significantly associated with latent distant metastasis, platinum-resistance, and higher histologic grade. In addition, DBC1 expression was significantly associated with shorter overall survival (OS) and relapse-free survival (RFS) in 104 ovarian carcinomas (OS; P < 0.001, RFS; P < 0.001) and 63 high-grade serous carcinomas (OS; P = 0.008, RFS; P = 0.023) by univariate analysis. BRCA1 expression was significantly associated with OS and RFS in 104 ovarian carcinomas (OS; P = 0.005, RFS; P = 0.002) and 75 serous carcinomas (OS; P = 0.047, RFS; P = 0.038) by univariate analysis. Moreover, DBC1 expression was an independent prognostic indicator for OS in both 104 ovarian carcinomas (P = 0.021) and 63 high-grade serous carcinomas (P = 0.011) by multivariate analysis. CONCLUSIONS These results indicate that the expression of DBC1 and BRCA1 are closely related with in the progression of ovarian carcinomas and may have clinical utility in the prediction of prognosis of ovarian carcinomas. Especially, DBC1 expression could be employed as a significant prognostic indicator for ovarian carcinomas especially in high-grade serous carcinomas.