Ovarian carcinoma is most frequently detected when disease has already disseminated intraabdominally, resulting in a 5-year survival rate of less than 20% owing to complications of metastasis. Peritoneal ascites is often present, establishing a unique microenvironmental niche comprised of tumor and inflammatory cells, along with a wide range of bioactive soluble factors, several of which stimulate the EGF-receptor (EGFR). Elevated EGFR is associated with less favorable disease outcome in ovarian cancer, related in part to EGFR activation of signaling cascades that lead to enhanced matrix metalloproteinase expression and/or function. The available data suggest that modulating the expression or activity of the EGFR and/or matrix metalloproteinases offers opportunity for targeted intervention in patients with metastatic disease.
KeywordsEGF-receptor; invasion; metastasis; MMP-9; MT1-MMP/MMP-14; ovarian carcinoma Epithelial ovarian carcinoma (EOC) is the leading cause of death from gynecologic malignancy, resulting in 15,520 deaths in the USA in 2008 [201]. When disease is confined to the ovary, 5-year survival is greater than 90%. Unfortunately, the majority of women with EOC are diagnosed with already disseminated intra-abdominal disease and have a low 5-year survival rate of less than 20%. Thus, while early detection is a pressing clinical problem, analysis of factors that promote metastatic dissemination can ultimately improve the survival of women with ovarian cancer.
Ovarian tumor microenvironmentA dualistic model for ovarian tumorigenesis has been proposed that is characterized by specific genetic alterations and unique molecular signatures [1][2][3]. In this classification system, lowgrade carcinomas are often confined to the ovary, arise from a recognized precursor lesion, â Author (Figure 1) [9][10][11]. These shed tumor cells may also block peritoneal lymphatics [12], contributing to the accumulation of peritoneal ascites, which can further facilitate metastatic implantation. Single cells and MCAs adhere to peritoneal mesothelium, where upon adhesive interactions and localized proteolysis enable anchoring of proliferative secondary lesions [9,10]. An exception is found in atypical proliferative serous tumors or micropapillary proliferative serous tumors (grouped as 'borderline' or 'low malignant potential'), the prognosis of which requires evaluation of peritoneal implants that often accompany these tumors. While patients with 'noninvasive implants' have a 10-year survival of practically 100%, a 34% mortality within 7 years is observed for those patients with invasive implants [12].An unique microenvironmental niche is thereby established in the peritoneal cavity, comprised of tumor cells, inflammatory cells and a plethora of soluble factors secreted by -or in response to -tumor cells, including growth factors, inflammatory mediators, bioactive lipids and proteolytic enzymes [13][14][15][16][17][18][19][20]. In addition, products of matrix invasion or partially resolved fibrosis, as well as shed...