Trends in gestational choriocarcinoma: a 27-year perspective.

Objective: To evaluate trends in incidence and survival rates for gestational choriocarcinoma with the use of population-based data.

Methods: Overall and 5-year average age-adjusted incidence rates were computed with the Surveillance, Epidemiology, and End Results program public-use database. Differences by age at diagnosis, race, stage, registry, and over calendar time were compared by Poisson regression, and survival censored for deaths other than choriocarcinoma by log-rank tests and Cox's proportional hazard ratios.

Results: Between 1973 and 1999, 450 cases were recorded. The annualized age-adjusted incidence rate for choriocarcinoma was 0.133 per 100,000 woman-years and decreased by 49.7% (2.8% per year). By race (whites, blacks, and others), incidence rates declined by 62.3%, 27.2%, and 54.3%, respectively. In the Poisson model evaluating incidence rates, age, race, registry, and stage were significant main effects. Compared with whites, the relative risk was higher for blacks (2.14, 95% confidence interval [CI] 1.60, 2.86) and others (2.30, 95% CI 1.67, 3.18). Rates were highest in Utah and lowest in Iowa. By age at diagnosis, rates were higher in 20-39-year-olds. The 5-year relative survival rate was 89.5%. Censored survival was significantly lower among blacks (whites 92.4%, blacks 84.9%, others 87.1%, P = .045), for advanced disease (localized 94.5%, regional 92.9%, distant 87.1%, P = .02), and with increasing age at diagnosis (P = .017). Age and calendar time significantly influenced censored survival independent of stage and registry.

Conclusion: Gestational choriocarcinoma incidence rates have declined and survivals have improved, but blacks continue to have higher incidence and lower survival rates.