The epidemiology of ovarian cancer.

Ovarian cancer is the second most common cancer of the female reproductive system and the leading cause of death from gynecologic malignancies. In 1995, 26,600 women will be diagnosed with ovarian cancer in the U.S., and 14,500 women will die from the disease. Between 1986-1900, the overall age-adjusted incidence was 14.3/100,000 women; mortality was 7.8/100,000 women. Ovarian cancer, rare before age 40, increases steeply thereafter and peaks at ages 65-75. Incidence and mortality rates are higher among white women than among African-American women. Over the last three decades, ovarian cancer incidence has remained stable in high-risk countries, while an increasing trend has been reported in low-risk countries. Despite recent advancements in treatment, the overall five-year survival rates continues to be low (39%). Over 70% of ovarian tumors are diagnosed when regional or distant involvement has already occurred, causing survival rates to remain stable. The etiology of ovarian cancer is poorly understood. Most studies have focused on the epidemiology of invasive epithelial ovarian tumors, while few have explored the epidemiology of epithelial tumors of low malignant potential and nonepithelial tumors. Factors associated with an increased risk for invasive epithelial ovarian cancer include age, race, nulliparity, family history of ovarian cancer, and history of endometrial or breast cancer. Factors associated with a reduced risk are history of one or more full-term pregnancies, use of oral contraceptives, history of breast feeding, tubal ligation, and hysterectomy. Other factors such as infertility drugs, hormone replacement therapy, age at menarche, age at menopause, dietary factors, lactose intolerance, talc use, coffee and alcohol consumption have been suggested, but their role is still inconclusive.