title: Ovarian cancer risk is reduced by prolonged lactation: a case-control study in southern China.
abstract: BACKGROUND
  Ovarian cancer is an important neoplasm that is difficult to diagnose and treat; therefore, prevention is the preferable strategy. Growing evidence indicates a protective effect of breastfeeding on ovarian cancer risk.
  
  
  OBJECTIVE
  The objective was to investigate the association between lactation and the risk of ovarian cancer among southern Chinese women.
  
  
  METHODS
  A case-control study was undertaken in Guangzhou, Guangdong Province, between August 2006 and July 2008. A validated and reliable questionnaire was used to obtain information on the months of lactation and number of children breastfed in a sample of 493 incident ovarian cancer patients and 472 hospital-based controls (mean age: 59 y). Logistic regression analyses were performed to assess the association between breastfeeding and the risk of ovarian cancer.
  
  
  RESULTS
  Significant inverse dose-response relations were found for both duration of lactation and the number of children breastfed. The adjusted ORs were 0.09 (95% CI: 0.04, 0.19) for women with ≥31 mo of total lactation and those with ≤10 mo of lactation and 0.38 (95% CI: 0.27, 0.55) for women with ≥3 children breastfed compared with those with one child breastfed.
  
  
  CONCLUSIONS
  Prolonged lactation is associated with a lower risk of ovarian cancer in parous Chinese women.
authors.affiliation: School of Public Health, Curtin University, Perth, Australia.
authors.forename: Dada
authors.initials: D
authors.lastname: Su
authors.forename: Maria
authors.initials: M
authors.lastname: Pasalich
authors.forename: Andy H
authors.initials: AH
authors.lastname: Lee
authors.forename: Colin W
authors.initials: CW
authors.lastname: Binns
mesh_terms: D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D005260:Female; D006779:Hospitals, Public; D006801:Humans; D015994:Incidence; D007774:Lactation; D016015:Logistic Models; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000453:epidemiology / Q000517:prevention & control; D010051:Ovarian Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D012306:Risk; D011795:Surveys and Questionnaires; D013997:Time Factors