Objective: to investigate the expression of folate receptor(FR)α in ovarian epithelial tumors and its clinopathological significance.
Methods: tissue microarrays (TMAs) were constructed from 86 epithelial ovarian cancers and 29 borderline ovarian tumors, followed by the FRα expression evaluation by immunohistochemistry. FRα mRNA expression was investigated by quantitative real-time PCR using fresh-frozen tissues from 40 cases of ovarian carcinoma and 14 cases of borderline tumor. FRα expression levels in ovarian tumors were also analyzed in correlation with tumor morphology, pathogenesis and FIGO stage.
Results: FRα expression was detected in 40 of 86 (46.5%) of ovarian cancers, with the highest rate of expression observed in serous carcinomas (62.7%, 32/51) compared with that of the other cancer types (P = 0.000). Depending on pathogenesis type, FRα expressions in type II ovarian carcinomas were significantly higher than those in type I ovarian carcinomas (P = 0.001). Ovarian carcinomas had a tendency to express higher FRα than the borderline tumors (46.5% vs 27.6%), although statistically not significant (P = 0.074). FRα expressions in ovarian carcinomas showed no correlation with the FIGO stage (P = 0.498). However, real-time PCR showed that FRα mRNA levels were significantly higher in ovarian carcinomas compared with that of the borderline tumors (P = 0.000) and also higher in serous ovarian borderline tumors compared with mucinous type (P = 0.007).
Conclusion: higher level of FRα expression occurs frequently in ovarian epithelial tumors, especially in carcinomas and ovarian serous tumors.