What is the tissue of origin and pathophysiology of ovarian cancer?

From the Guidelines

Ovarian cancer primarily originates from the epithelial cells, germ cells, and stromal cells of the ovary, with epithelial ovarian cancer being the most common type, accounting for about 90% of cases, and recent evidence suggests that many high-grade serous ovarian cancers may actually originate from the distal fallopian tube. The pathophysiology of ovarian cancer involves genetic mutations that lead to uncontrolled cell growth and division, which may be inherited, such as BRCA1 and BRCA2 gene mutations, or acquired throughout life 1. The disease typically progresses silently, with malignant cells initially growing locally before spreading to the peritoneal cavity and eventually metastasizing to distant organs. As the cancer grows, it can cause ascites, obstruct bowel function, and invade surrounding tissues. The disease often remains undetected until advanced stages because the ovaries are located deep within the pelvis and early symptoms are vague or absent, contributing significantly to the high mortality rate associated with ovarian cancer 1.

Some key points to consider in the pathophysiology and tissue of origin of ovarian cancer include:

• The role of genetic mutations, such as BRCA1 and BRCA2, in the development of ovarian cancer 1
• The potential origin of high-grade serous ovarian cancers from the distal fallopian tube, rather than the ovarian surface epithelium 1
• The importance of early detection and prevention, particularly in women with a family history or genetic predisposition to ovarian cancer 1
• The need for further research into the molecular biology and pathophysiology of ovarian cancer to improve outcomes and develop more effective treatments 1

In terms of the tissue of origin, the distal fallopian tube has been identified as a potential site of origin for high-grade serous ovarian cancers, which are the most common and lethal type of ovarian cancer 1. This has significant implications for our understanding of the disease and the development of effective screening and prevention strategies. Overall, a comprehensive understanding of the tissue of origin and pathophysiology of ovarian cancer is crucial for improving outcomes and reducing mortality from this devastating disease.

From the Research

Tissue of Origin

• Ovarian cancer may arise from any of the histologic portions of the ovary, including the epithelium, stroma, or germ cells 2, 3, 4.
• The most common type of ovarian cancer is high-grade serous carcinoma, which arises from the epithelium of the ovary 2.
• Epithelial ovarian cancer is the most common type, accounting for the majority of ovarian cancers, and arises from the surface epithelium, a single layer of cells that covers the surface of the ovary 3.

Pathophysiology

• The pathogenesis of epithelial ovarian cancer is poorly understood, and efforts at early detection and new therapeutic approaches to reduce mortality have been largely unsuccessful 5.
• Epithelial ovarian cancer is not a single disease but is composed of a diverse group of tumors that can be classified based on distinctive morphologic and molecular genetic features 5.
• Two groups of tumors have been designated: type I, which includes low-grade serous, low-grade endometrioid, clear cell, mucinous, and transitional (Brenner) carcinomas, and type II, which includes conventional high-grade serous carcinoma, undifferentiated carcinoma, and malignant mixed mesodermal tumors (carcinosarcoma) 5.
• Recent studies have provided evidence that some ovarian cancers may originate in other pelvic organs, such as the fallopian tube, and involve the ovary secondarily 5.
• The epidemiology of ovarian cancer shows differences between races and countries due to several factors, including genetic and economic factors 4.