title: Breast-feeding the last born child and risk of ovarian cancer.
abstract: Conflicting reports regarding the relationship between breast-feeding and ovarian cancer risk suggest a possible influence of patterns of breast-feeding. We used logistic regression to examine breast-feeding in a large population of parous women who participated in a case-control study of ovarian cancer in New Hampshire and MA, USA. Risk of ovarian cancer was reduced in parous women who ever breast-fed (OR: 0.75; 95% CI: 0.62, 0.92), but evidence was limited for an influence of duration of breast-feeding and the number of children breast-fed. Compared to never breast-feeding, inverse associations were seen for breast-feeding all children (OR: 0.72; 95% CI: 0.58, 0.91) and for breast-feeding some children when the last born child was breast-fed (OR: 0.58; 95% CI: 0.37, 0.91). There was little evidence of reduced risk for those who breast-fed some children when the last born child was not breast-fed (OR: 0.91; 95% CI: 0.66, 1.26). Similar findings were noted in women with exactly two children and in those with two or more children. The protective influence of breast-feeding on ovarian cancer risk may be limited to women who breast-feed their last born child. These findings, which require confirmation by future studies, imply that breast-feeding resets pregnancy-related states that mediate ovarian cancer risk.
authors.affiliation: Department of Community & Family Medicine, Dartmouth Medical School, Lebanon, NH 03756, USA. Linda.titus-ernstoff@dartmouth.edu
authors.forename: Linda
authors.initials: L
authors.lastname: Titus-Ernstoff
authors.forename: Judy R
authors.initials: JR
authors.lastname: Rees
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Terry
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Cramer
mesh_terms: D001942:Breast Feeding / Q000706:statistics & numerical data*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D009513:New Hampshire / Q000453:epidemiology; D010051:Ovarian Neoplasms / Q000453:epidemiology*; D010298:Parity; D011247:Pregnancy; D011379:Prognosis; D018570:Risk Assessment / Q000706:statistics & numerical data