Ovarian cancer is a disease in which malignant (cancer) cells form in the ovaries.
The ovaries are a pair of organs in the female reproductive system. They are in the pelvis, one on each side of the uterus (the hollow, pear-shaped organ where a fetus grows). Each ovary is about the size and shape of an almond. The ovaries make eggs and female hormones (chemicals that control the way certain cells or organs work in the body).Anatomy of the female reproductive system. The organs in the female reproductive...
Several malignancies arise from the ovary. Epithelial carcinoma of the ovary is one of the most common gynecologic malignancies and the fifth most frequent cause of cancer death in women, with 50% of all cases occurring in women older than 65 years. Approximately 5% to 10% of ovarian cancers are familial, and three distinct hereditary patterns have been identified: ovarian cancer alone, ovarian and breast cancers, or ovarian and colon cancers. The most important risk factor for ovarian cancer is a family history of a first-degree relative (e.g., mother, daughter, or sister) with the disease. The highest risk appears in women with two or more first-degree relatives with ovarian cancer. The risk is somewhat less for women with one first-degree and one second-degree relative (grandmother or aunt) with ovarian cancer.
In most families affected with the breast and ovarian cancer syndrome or site-specific ovarian cancer, genetic linkage has been found to the BRCA1 locus on chromosome 17q21.[5,6,7]BRCA2, also responsible for some instances of inherited ovarian and breast cancer, has been mapped by genetic linkage to chromosome 13q12. The lifetime risk for developing ovarian cancer in patients harboring germline mutations in BRCA1 is substantially increased over the general population.[9,10] Two retrospective studies of patients with germline mutations in BRCA1 suggest that these women have improved survival compared with BRCA1 mutation-negative women.[11,12][Level of evidence: 3iiiA] The majority of women with a BRCA1 mutation probably have family members with a history of ovarian and/or breast cancer; therefore, these women may have been more vigilant and inclined to participate in cancer screening programs that may have led to earlier detection.
For women at increased risk, prophylactic oophorectomy may be considered after the age of 35 if childbearing is complete. In a family-based study among women with BRCA1 or BRCA2 mutations, of the 259 women who had undergone bilateral prophylactic oophorectomy, two of them (0.8%) developed subsequent papillary serous peritoneal carcinoma, and six of them (2.8%) had stage I ovarian cancer at the time of surgery. Of the 292 matched controls, 20% who did not have prophylactic surgery developed ovarian cancer. Prophylactic surgery was associated with a higher than 90% reduction in the risk of ovarian cancer (relative risk [RR], 0.04; 95% confidence interval [CI], 0.01–0.16), with an average follow-up of 9 years; however, family-based studies may be associated with biases resulting from case selection and other factors that may influence the estimate of benefit. (Refer to the Evidence of Benefit section in the PDQ summary on Ovarian Cancer Prevention for more information.)