title: Risk factors for hormone receptor-defined breast cancer in postmenopausal women.
abstract: The effect of classic breast cancer risk factors on hormone receptor-defined breast cancer is not fully clarified. We explored these associations in a Swedish population-based study. Postmenopausal women ages 50 to 74 years, diagnosed with invasive breast cancer during 1993 to 1995, were compared with 3,065 age frequency-matched controls. We identified 332 estrogen receptor (ER-) and progesterone receptor (PR-) negative, 286 ER+PR-, 71 ER-PR+, 1,165 ER+PR+, and 789 tumors with unknown receptor status. Unconditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI). Women ages >or=30 years, compared with those ages 20 to 24 years at first birth, were at an increased risk of ER+PR+ tumors (OR, 1.5; 95% CI, 1.2-1.8) but not ER-PR- tumors (OR, 1.1; 95% CI, 0.8-1.6). Women who gained >or=30 kg in weight during adulthood had an approximately 3-fold increased relative risk of ER+PR+ tumors (OR, 2.7; 95% CI, 1.9-3.8), but no risk increase of ER-PR- tumors (OR, 1.0; 95% CI, 0.5-2.1), compared with women who gained <10 kg. Compared with never users, women who used menopausal estrogen-progestin therapy for at least 5 years were at increased risk of ER+PR+ tumors (OR, 3.0; 95% CI, 2.1-4.1) but not ER-PR- tumors (OR, 1.3; 95% CI, 0.7-2.5). In conclusion, other risk factors were similarly related to breast cancer regardless of receptor status, but high age at first birth, substantial weight gain in adult age, and use of menopausal estrogen-progestin therapy were more strongly related to receptor-positive breast cancer than receptor-negative breast cancer.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, P.O. Box 281, SE-171 77 Stockholm, Sweden. lena.u.rosenberg@ki.se
authors.forename: Lena U
authors.initials: LU
authors.lastname: Rosenberg
authors.forename: Kristjana
authors.initials: K
authors.lastname: Einarsdóttir
authors.forename: Erika Isaksson
authors.initials: EI
authors.lastname: Friman
authors.forename: Sara
authors.initials: S
authors.lastname: Wedrén
authors.forename: Paul W
authors.initials: PW
authors.lastname: Dickman
authors.forename: Per
authors.initials: P
authors.lastname: Hall
authors.forename: Cecilia
authors.initials: C
authors.lastname: Magnusson
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000453:epidemiology / Q000378:metabolism*; D018275:Carcinoma, Lobular / Q000453:epidemiology / Q000378:metabolism*; D016022:Case-Control Studies; D004967:Estrogens / Q000627:therapeutic use; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D011372:Progestins / Q000627:therapeutic use; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D015430:Weight Gain
chemical_list: D004967:Estrogens; D011372:Progestins; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone