Background: Serum CA-125 has been used as a biomarker of gynecological tumors. In this study, we investigated the CA-125 levels in cervical and vaginal secretions from Chinese patients with endometrial polyps, hyperplasia and carcinoma in comparison with those in endometrium and serum.
Material/Methods: An electro-chemiluminescent immunoassay was utilized to determine the levels of CA-125 in 51 healthy Chinese women and 97 patients with polyps, hyperplasia or endometrial cancer. An immunohistochemistry method was used to detect endometrial CA-125 expression in 242 subjects.
Results: Our study demonstrated that serum CA-125 levels were much lower than those in cervical and vaginal secretions in healthy and diseased women. The levels of CA-125 in serum, and cervical and vaginal secretions were significantly increased in complex hyperplasia and endometrial cancer. The increase of CA-125 content in serum, cervical and vaginal secretions was lesser significant in grade 3 cancer than that in grade 1 and 2 cancer. Generally, serum CA-125 levels correlated with those in cervical and vaginal secretions and CA-125 content in cervical secretion correlated with that in vaginal secretion. There was only a weak CA-125 expression in normal endometrium and simple endometrial hyperplasia. There was a significant difference in CA-125 expression among patients with pathological grade 1, 2 and 3 of endometrial carcinoma.
Conclusions: Endo.metrial CA-125 expression together with its levels in the serum and cervical and vaginal secretions can be used as a potential biomarker in the diagnosis of precancerous diseases and endometrial carcinoma

Keywords: Immunoassay, Endometrium - secretion, Endometrial Neoplasms - metabolism, Cervix Uteri - secretion, Carcinoma - metabolism, CA-125 Antigen - blood, Asian Continental Ancestry Group, Precancerous Conditions - metabolism, Tumor Markers, Biological - secretion, Vagina - secretion