Epithelial Ovarian Cancer

Introduction
Ovarian cancer is one of the most treatable solid tumors, as the majority will respond temporarily to surgery and cytotoxic agents. The disease, however, frequently persists and recurs, having the highest fatality-to-case ratio of all the gynecologic cancers. Ovarian cancer represents one fourth of the malignancies of the female genital tract, but it is the most common cause of death among women who develop cancers of gynecologic origin. Ovarian carcinomas account for 4% of the total cancers in women in the United States, ranked behind malignant neoplasms of the lung, breast, colon and uterus. In 2003, over 24,400 new cases and 14,300 deaths are expected. Despite these discouraging statistics, improvement in 5-year survival has occurred steadily over the last three decades with more aggressive surgical management and the development of more effective chemotherapy. Five-year survival in the United States has improved significantly (p < .05) from 37% in 1974-76 to 52% in 1992-1998.

Ovarian cancer is a disease of postmenopausal women, with only 10% to 15% discovered in premenopausal patients. The median age for diagnosis of epithelial ovarian cancer, the most common histologic type, is between 60 and 65 years. Less than 1% of epithelial ovarian cancers are found in women less than 30 years of age, and most ovarian malignancies in these younger patients are germ cell tumors. Ovarian cancer occurs sporadically in the population. A strong hereditary component contributes to development of the disease in 10% of cases, but 90% are sporadic. Ovarian cancer is neither a common nor a rare disease. The prevalence of ovarian cancer among postmenopausal women in the United States is 40 per 100,000 or 1 in 2,500. The lifetime risk for a woman to develop ovarian cancer is approximately 1 in 70 (1.4%), compared to 1 in 8 or 9 for breast cancer. The prevalence of ovarian cancer in the general population impacts substantially on strategies for prevention and early detection. In the absence of better markers for increased risk, strategies for prevention must have few serious side effects and screening strategies must be highly specific.

Epidemiologic studies suggest that ovulation is an important co-factor in the development of ovarian cancer. Use of oral contraceptives that suppress ovulation and induce apoptosis in ovarian epithelial cells can reduce the risk of developing ovarian cancer in later life by as much as 50%. In patients with hereditary ovarian cancer who carry mutations of BRCA1 or BRCA2, prophylactic oophorectomy can be considered.

As there are few specific symptoms for early stage disease and there is no generally accepted screening strategy, carcinoma has metastasized beyond the ovary in more than three fourths of patients when epithelial cancer is finally diagnosed. If ovarian cancer is still confined to the ovary, 90% of patients can be cured with conventional surgery and chemotherapy. Many cancers are detected as pelvic masses, although even small tumors confined to the pelvis may have metastasized by the time that they are palpated. About 20% to 30% of ovarian masses found in postmenopausal women are malignant, whereas only 7% of ovarian masses in premenopausal women are malignant. Intense investigation is underway to develop an effective strategy for early detection of ovarian cancer using pelvic ultrasonography and serum/plasma assays that include CA125 and other novel markers. Development of more effective strategies for detection, prevention and treatment has been accelerated by a more and more rapid increase in understanding ovarian cancer at a cellular and molecular level.

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Provided by ArmMed Media
Revision date: July 9, 2011
Last revised: by Dave R. Roger, M.D.