title: Incidence and outcomes of pregnancy-associated cancer in Australia, 1994-2008: a population-based linkage study.
abstract: OBJECTIVE
  To determine trends in pregnancy-associated cancer and associations between maternal cancer and pregnancy outcomes.
  
  
  METHODS
  Population-based cohort study.
  
  
  METHODS
  New South Wales, Australia, 1994-2008.
  
  
  METHODS
  A total of 781 907 women and their 1 309 501 maternities.
  
  
  METHODS
  Cancer and maternal information were obtained from linked cancer registry, birth and hospital records for the entire population. Generalised estimating equations with a logit link were used to examine associations between cancer risk factors and pregnancy outcomes.
  
  
  METHODS
  Incidence of pregnancy-associated cancer (diagnosis during pregnancy or within 12 months of delivery), maternal morbidities, preterm birth, and small- and large-for-gestational-age (LGA).
  
  
  RESULTS
  A total of 1798 new cancer diagnoses were identified, including 499 during pregnancy and 1299 postpartum. From 1994 to 2007, the crude incidence rate of pregnancy-associated cancer increased from 112.3 to 191.5 per 100 000 maternities (P < 0.001), and only 14% of the increase was explained by increasing maternal age. Cancer diagnosis was more common than expected in women aged 15-44 years (observed-to-expected ratio 1.49; 95% CI 1.42-1.56). Cancers were predominantly melanoma (33.3%) and breast cancer (21.0%). Women with cancer diagnosed during pregnancy had high rates of labour induction (28.5%), caesarean section (40.0%) and planned preterm birth (19.7%). Novel findings included a cancer association with multiple pregnancies (adjusted odds ratio 1.52, 95% CI 1.13-2.05) and LGA (aOR 1.47, 95% CI 1.14-1.89).
  
  
  CONCLUSIONS
  Pregnancy-associated cancers have increased, and this increase is only partially explained by increasing maternal age. Pregnancy increases women's interaction with health services and the possibility for diagnosis, but may also influence tumour growth.
authors.affiliation: Clinical and Population Perinatal Health Research, Kolling Institute of Medical Research, University of Sydney, Sydney, NSW, Australia.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Lee
authors.forename: C L
authors.initials: CL
authors.lastname: Roberts
authors.forename: T
authors.initials: T
authors.lastname: Dobbins
authors.forename: E
authors.initials: E
authors.lastname: Stavrou
authors.forename: K
authors.initials: K
authors.lastname: Black
authors.forename: J
authors.initials: J
authors.lastname: Morris
authors.forename: J
authors.initials: J
authors.lastname: Young
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D005260:Female; D005320:Fetal Macrosomia / Q000209:etiology; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D016015:Logistic Models; D008423:Maternal Age; D008498:Medical Record Linkage; D009517:New South Wales / Q000453:epidemiology; D016017:Odds Ratio; D016012:Poisson Distribution; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000453:epidemiology* / Q000209:etiology; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000209:etiology; D012042:Registries; D012307:Risk Factors; D055815:Young Adult