Molecular-pathologic and clinicopathologic study on the heterogeneity of early development and progression of ovarian cancer

点击翻译按钮获取中文摘要

Little is known about the early pathogenic process of ovarian carcinogenesis, because more than half of ovarian cancer patients are diagnosed at the advanced stages. Ovarian epithelial tumors originate from the surface epithelium covering the ovary, and there are three types with distinct clinicopathology ; benign cystadenoma, tumor of low malignant potential (LMP), and invasive carcinoma. However, it is unknown whether ovarian carcinomas occur de novo in the ovarian surface or develop as a result of the malignant transformation of benign or LMP tumors of the ovary. To address this issue, we studied the clinical course in detail of ovarian cancer development, and molecular pathologic analysis on heterogeneity of genetic alterations in ovarian tumors. In addition, we examined the expression of various genes with reference to the tumor progression.Analysis of the clinical findings of ovarian cancer development in infertility patients revealed that serous carcinomas are frequently at the … More advanced stages when the tumor was first recognized, whereas endometrioid or clear cell carcinomas arising in endometriotic cyst are at the early stage. Expression of gonadotropin receptors in ovarian cancers and apoptosis-inhibitory effect of gonadotropins in ovarian cancer cells suggest that gonadotropins play an important role in ovarian carcinogenesis.Immunohistochemical analysis of p53 protein expression in ovarian tumors showed that p53-positive tumor cells are homogeneously distributed in serous carcinomas, whereas heterogeneous in mucinous carcinomas. K-ras-mutated tumor cells are also heterogeneously present in accordance with histopathology. These findings suggest that serous carcinomas arise de novo in the ovarian surface, whereas mucinous carcinomas develop in the benign or LMP tumors.Overexpression of C-erbB-2 gene and decreased expression of metastasis-related nm23 gene are both important for distant metastasis of ovarian carcinomas. However, nm23 gene mutation is rare in ovarian carcinomas. Overexpression of vascular endothelial growth factor (VEGF) may play an essential role in peritoneal involvement with ascites formation in ovarian carcinomas, and serum VEGF levels is a novel tumor marker in ovarian cancer patients. Less