title: Trends in gestational choriocarcinoma: a 27-year perspective.
abstract: 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.
  
  
  CONCLUSIONS
  Gestational choriocarcinoma incidence rates have declined and survivals have improved, but blacks continue to have higher incidence and lower survival rates.
authors.affiliation: Department of Obstetrics and Gynecology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131-5286, USA. hsmith@salud.unm.edu
authors.forename: Harriet O
authors.initials: HO
authors.lastname: Smith
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Qualls
authors.forename: Beth A
authors.initials: BA
authors.lastname: Prairie
authors.forename: Luis A
authors.initials: LA
authors.lastname: Padilla
authors.forename: William F
authors.initials: WF
authors.lastname: Rayburn
authors.forename: Charles R
authors.initials: CR
authors.lastname: Key
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002822:Choriocarcinoma / Q000453:epidemiology* / Q000208:ethnology / Q000209:etiology / Q000401:mortality; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D011247:Pregnancy; D016016:Proportional Hazards Models; D012042:Registries; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology; D014594:Uterine Neoplasms / Q000453:epidemiology* / Q000208:ethnology / Q000209:etiology / Q000401:mortality