Trends and differentials in ovarian cancer: incidence, mortality and survival experience.

Ovarian cancer was reported to be increasing in the 1970s. A continuously increasing trend has been anticipated for quite some time and an observation of international trends and differentials in the mortality, morbidity and survival from ovarian cancer is provided. Recent data on mortality and morbidity were obtained from the WHO and IARC data banks. Globally, ovarian cancer had moderate or relatively low rates for both mortality (1.5-10 per 100,000) and incidence (4-15 per 100,000), using standardized (world) rates. The ranges were the narrowest among all major cancers. The observed pattern of long-term trends was classified into three types: 1) increase followed by a plateau, then a decrease, 2) steady increase, and 3) uncertain. The rate was seen to be fairly high in the first group and still low in the second while it fluctuated in the third. A decrease of the rates in younger age-groups has extended to upper age-groups in countries with the first type of trend. Germ-cell tumours appeared more frequently in younger ages and low-incidence areas, while the common "epithelial" cancers were more apparent in older age-groups and high-incidence areas. The geographical differences seem to be smaller for germ cell carcinomas than the common "epithelial" carcinomas which may be associated more with environmental risk factors. Five-year survival rates improved to a range of 25-41% in the latter half of the 1970s.