title: Cancer risk associated with early and late maternal age at first birth.
abstract: OBJECTIVE
  This paper provides a review of the literature associating maternal age at first birth and cancer. Potential mechanisms explaining associations between maternal age at first birth and cancer are also discussed.
  
  
  METHODS
  Systematic review of English language literature using searches on established databases (e.g., Medline, Popline) and the references of materials identified in these databases.
  
  
  RESULTS
  Older age (typically defined as 35 years or older) at first birth is associated with increased risk of breast and brain cancers. Conversely, younger age (typically defined as 19 years or younger) at first birth is associated with an increased risk of cervical and endometrial cancers. There is an unclear correlation between maternal age at first birth and site-specific malignancies such as ovarian, colorectal, thyroid, pancreatic, and kidney cancers. Causal mechanisms linking age at first birth and cancer were identified and reported for breast, brain, cervical, and endometrial cancers.
  
  
  CONCLUSIONS
  Older age at first birth increases the risk for breast and brain cancers but decreases the risk of cervical and endometrial cancers.
authors.affiliation: Department of Health Science, College of Health and Human Performance, 229-A Richards Building, Brigham Young University, Provo, UT 84602, USA. Ray_Merrill@byu.edu
authors.forename: Ray M
authors.initials: RM
authors.lastname: Merrill
authors.forename: Stephanie
authors.initials: S
authors.lastname: Fugal
authors.forename: Lelinneth B
authors.initials: LB
authors.lastname: Novilla
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Raphael
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000453:epidemiology; D001943:Breast Neoplasms / Q000453:epidemiology; D015179:Colorectal Neoplasms / Q000453:epidemiology; D005260:Female; D005833:Genital Neoplasms, Female / Q000453:epidemiology; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D011247:Pregnancy; D012307:Risk Factors