title: Human chorionic gonadotropin in pregnancy and maternal risk of breast cancer.
abstract: Full-term pregnancies are associated with long-term reductions in maternal risk of breast cancer, but the biological determinants of the protection are unknown. Experimental observations suggest that human chorionic gonadotropin (hCG), a major hormone of pregnancy, could play a role in this association. A case-control study (242 cases and 450 controls) nested within the Northern Sweden Maternity Cohort included women who had donated a blood sample during the first trimester of a first full-term pregnancy. Total hCG was determined on Immulite 2000 analyzer. Odds ratios (OR) and 95% confidence intervals (CI) were estimated through conditional logistic regression. Maternal breast cancer risk decreased with increasing hCG (upper tertile OR, 0.67; CI, 0.46-0.99), especially for pregnancies before age 25 (upper tertile OR, 0.41; CI, 0.21-0.80). The association diverged according to age at diagnosis: risk was reduced after age 40 (upper tertile OR, 0.60; CI, 0.39-0.91) and seemed to increase before age 40 (upper tertile OR, 1.78; CI, 0.72-4.38). Risk was reduced among those diagnosed 10 years or longer after blood draw (upper tertile OR, 0.60; CI, 0.40-0.90), but not so among those diagnosed within 10 years (upper tertile OR, 4.33; CI, 0.86-21.7). These observations suggest that the association between pregnancy hCG and subsequent maternal risk of breast cancer is modified by age at diagnosis. Although the hormone seems to be a determinant of the reduced risk around or after age 50, it might not confer protection against, or it could even increase the risk of, cancers diagnosed in the years immediately following pregnancy.
authors: Department of Obstetrics and Gynecology, NYU Cancer Institute, NYU School of Medicine, New York, NY, USA. paolo.toniolo@nyumc.org
authors: Paolo
authors: P
authors: Toniolo
authors: Kjell
authors: K
authors: Grankvist
authors: Marianne
authors: M
authors: Wulff
authors: Tianhui
authors: T
authors: Chen
authors: Robert
authors: R
authors: Johansson
authors: Helena
authors: H
authors: Schock
authors: Per
authors: P
authors: Lenner
authors: Göran
authors: G
authors: Hallmans
authors: Matti
authors: M
authors: Lehtinen
authors: Rudolf
authors: R
authors: Kaaks
authors: Göran
authors: G
authors: Wadell
authors: Anne
authors: A
authors: Zeleniuch-Jacquotte
authors: Eva
authors: E
authors: Lundin
authors: Annekatrin
authors: A
authors: Lukanova
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001943:Breast Neoplasms / Q000097:blood* / Q000517:prevention & control; D016022:Case-Control Studies; D006063:Chorionic Gonadotropin / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D055815:Young Adult
chemical_list: D006063:Chorionic Gonadotropin