title: A case-control study of reproductive factors and renal cell carcinoma among black and white women in the United States.
abstract: OBJECTIVE
  Renal cell carcinoma (RCC) incidence is higher among blacks than whites in the United States and has been associated with the frequency and timing of childbirth among women in some epidemiologic studies. We investigated whether reproductive factors are associated with RCC, overall and by race, within a population-based case-control study.
  
  
  METHODS
  Between 2002 and 2007, 497 female cases of incident RCC (136 black, 361 white) and 546 female controls (273 black, 273 white) within the Detroit and Chicago metropolitan areas were enrolled. Information on reproductive history and other factors was collected through in-person interviews. Multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CI) were computed using unconditional logistic regression.
  
  
  RESULTS
  Reduced RCC risk was observed among women aged ≥30 years at first live birth, relative to an age of <20 years (OR 0.5, 95% CI 0.3-0.9). This association was present among both white (OR 0.4, 95% CI 0.2-0.9) and, though not statistically significant, black women (OR 0.6, 95% CI 0.2-1.8). In analyses restricted to clear cell adenocarcinoma, the most common RCC histological subtype, the association was particularly strong (OR 0.3, 95% CI 0.2-0.8). We did not observe clear evidence of association with RCC for other reproductive factors.
  
  
  CONCLUSIONS
  Our findings further support an association between late maternal age at first birth and reduced RCC risk, and suggest that the association may be particularly strong for clear cell adenocarcinoma.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health/DHHS, 6120 Executive Boulevard, Bethesda, MD 20892-7240, USA. purduem@mail.nih.gov
authors.forename: Mark P
authors.initials: MP
authors.lastname: Purdue
authors.forename: Joanne S
authors.initials: JS
authors.lastname: Colt
authors.forename: Barry
authors.initials: B
authors.lastname: Graubard
authors.forename: Faith
authors.initials: F
authors.lastname: Davis
authors.forename: Julie J
authors.initials: JJ
authors.lastname: Ruterbusch
authors.forename: Ralph
authors.initials: R
authors.lastname: Digaetano
authors.forename: Sara
authors.initials: S
authors.lastname: Karami
authors.forename: Sholom
authors.initials: S
authors.lastname: Wacholder
authors.forename: Kendra
authors.initials: K
authors.lastname: Schwartz
authors.forename: Wong-Ho
authors.initials: WH
authors.lastname: Chow
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000453:epidemiology* / Q000208:ethnology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007680:Kidney Neoplasms / Q000453:epidemiology* / Q000208:ethnology*; D008875:Middle Aged; D017584:Reproductive History; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D044465:White People; D055815:Young Adult