Introduction: Primary carcinoma of the ovary is the fourth most common cancer among women in developed countries. In 1999, almost 7,000 new cases were reported in the United Kingdom, which equates to a lifetime risk for women of 2%. Ovarian cancer is also the most common cause of death from a gynaecological malignancy – there are about 4,500 deaths from the disease in the UK every year . Worldwide, ovarian cancer incidence rates vary widely between different geographic regions and ethnic groups. The highest incidence is in Northern Europe; the lowest incidence is in Japan (Fig. 1.1). As with other cancers, there are notable increases in risk in populations that migrate from a country with low risk to a country of higher risk, indicating a possible role for dietary and environmental factors. The purpose of this article is to review the epidemiological, lifestyle and genetic factors that may be responsible for the variations in ovarian cancer risks. Genetic Epidemiology Familial Risks The most significant risk factor for ovarian cancer is a family history of the disease. A meta-analysis of data from 15 case-control and cohort studies estimated that the relative risk of developing ovarian cancer for women with a single first-degree relative affected with ovarian cancer is 3.1 (95% CI = 2.6–3.7) . Based on ovarian cancer incidence rates typical in northern Europe and North America, this risk equates to a cumulative risk of 4% by age 70. This risk estimate represents an average across all ages.
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