Risk Factors for Hormone Receptor-Defined Breast Cancer in Postmenopausal Women

• Published in: Cancer epidemiology, biomarkers & prevention Vol. 15; no. 12; pp. 2482 - 2488
• Main Authors: ROSENBERG, Lena U, EINARSDOTTIR, Kristjana, FRIMAN, Erika Isaksson, WEDREN, Sara, DICKMAN, Paul W, HALL, Per, MAGNUSSON, Cecilia
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01-12-2006
• Subjects: Aged; Biological and medical sciences; breast cancer; Breast Neoplasms - epidemiology; Breast Neoplasms - metabolism; Carcinoma, Ductal, Breast - epidemiology; Carcinoma, Ductal, Breast - metabolism; Carcinoma, Lobular - epidemiology; Carcinoma, Lobular - metabolism; Case-Control Studies; epidemiology; estrogen receptor; Estrogens - therapeutic use; Female; Gynecology. Andrology. Obstetrics; Hormone Replacement Therapy; Humans; Mammary gland diseases; Medical sciences; Medicin och hälsovetenskap; Middle Aged; Postmenopause; progesterone receptor; Progestins - therapeutic use; Receptors, Estrogen - metabolism; Receptors, Progesterone - metabolism; risk factor; Risk Factors; Sweden - epidemiology; Tumors; Weight Gain; Sweden; Europe; Human; Anthropometry; Breast cancer; Malignant tumor; Epidemiology; Mammary gland diseases; Reproduction; Cancerology; Risk factor; Postmenopause; Adult; Female; Hormone replacement therapy; Public health; Hormonal receptor
• ISSN: 1055-9965; 1538-7755
• DOI: 10.1158/1055-9965.EPI-06-0489

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 ≥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 ≥30 kg in weight during adulthood had an ∼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. (Cancer Epidemiol
Biomarkers Prev 2006;15(12):2482–8)