Epidemiologic pathology of ovarian cancer from the Vaud Cancer Registry, Switzerland

Objective: To provide further information on the descriptive epidemiology and survival of ovarian cancer patients by specific histologic types. Study design: Descriptive epidemiological study. Cases of ovarian cancer registered between 1974 and 1988 in the Vaud Cancer Registry, Switzerland (based on a population of approximately 530,000 inhabitants), were analysed. Results: A total of 649 cases were registered, corresponding to an overall age-standardized (world population) incidence of 9.6/100,000. The most common histotype was serous carcinoma (41%, incidence rate 4.0/100,000), followed by endometrioid (13%), mucinous (12%), clear cell (5%), and undifferentiated carcinomas (3%); 20% of the cases were classified as 'epithelial, unspecified, and 6% were non-epithelial cancers. There was a tendency for the incidence of all epithelial types to rise up to the seventh decade of age, and to level off thereafter. The increases between the ages of 45 and 65 were, however, mostly in serous carcinomas whose proportion of total ovarian epithelial cancer peaked in middle age. Overall, 5-year relative survival was 32%. Survival rate was 32% for serous carcinomas, but was significantly higher for endometrioid (51%) and, among non-epithelial neoplasms, for germ-cell cancers (68%). Survival rates were poor for undifferentiated and 'epithelial, unspecified' carcinomas (16%). Relative survival was systematically higher below age 60 than at age 60 or over. In the two subsequent calendar periods examined (divided according to the approximate time when the use of platinum-based chemotherapy began to spread, i.e., 1982), 5-year relative survival rates were 28% and 36%, respectively (chi1(2) = 6.1, p = 0.02). Conclusion: The present report is a population-based description of the epidemiologic pathology and prognosis of ovarian cancer, and provides evidence of a significant improvement of survival over the past decade. This may be due to changed diagnostic methods (e.g., ultrasonography), improved surgical approach, (platinum-based) chemotherapy, or a combination of all these factors.