Waist-to-Hip Ratio and Breast Cancer Mortality

• Published in: American journal of epidemiology Vol. 158; no. 10; pp. 963 - 968
• Main Authors: Borugian, Marilyn J., Sheps, Samuel B., Kim-Sing, Charmaine, Olivotto, Ivo A., Van Patten, Cheri, Dunn, Bruce P., Coldman, Andrew J., Potter, John D., Gallagher, Richard P., Hislop, T. Gregory
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 15-11-2003; Oxford Publishing Limited (England)
• Subjects: Adult; Aged; Antineoplastic Agents - therapeutic use; Biological and medical sciences; Body Constitution; Body Mass Index; Breast cancer; breast neoplasms; Breast Neoplasms - etiology; Breast Neoplasms - metabolism; Breast Neoplasms - mortality; Breast Neoplasms - therapy; British Columbia - epidemiology; confidence interval; Energy Intake; estrogen; estrogen receptor; Exercise; Female; Gynecology. Andrology. Obstetrics; Humans; Hyperinsulinism - complications; Hyperinsulinism - metabolism; Insulin Resistance; Mammary gland diseases; Medical sciences; Middle Aged; mortality; Obesity - complications; Obesity - diagnosis; Obesity - metabolism; Population Surveillance; Postmenopause; Predictive Value of Tests; Premenopause; Prognosis; Proportional Hazards Models; Prospective Studies; receptors; Receptors, Estrogen - analysis; Risk Factors; Survival Analysis; Tamoxifen - therapeutic use; Tumors; waist-to-hip ratio; WHR; British Columbia; Human; Mammary gland diseases; estrogen; Prognosis; Mortality; body constitution; breast neoplasms; insulin resistance; mortality; receptors; Female; Mammary gland; Malignant tumor; Waist hip ratio; Epidemiology; Public health
• ISSN: 0002-9262; 1476-6256; 0002-9262
• DOI: 10.1093/aje/kwg236

High insulin levels have been associated with increased risk of breast cancer and poorer survival after a breast cancer diagnosis. Waist-to-hip ratio (WHR) is a marker for insulin resistance and hyperinsulinemia. In this study, the authors tested the hypothesis that elevated WHR is directly related to breast cancer mortality. For identification of modifiable factors affecting survival, data were collected on 603 patients with incident breast cancer who visited the Vancouver Cancer Centre of the British Columbia Cancer Agency (Vancouver, British Columbia, Canada) in 1991–1992, including body measurements and information on demographic, medical, reproductive, and dietary factors. These patients were followed for up to 10 years. Cox proportional hazards regression models were used to relate the variables to breast cancer mortality (n = 112). After adjustment for age, body mass index, family history, estrogen receptor (ER) status, tumor stage at diagnosis, and systemic treatment (chemotherapy or tamoxifen), WHR was directly related to breast cancer mortality in postmenopausal women (for highest quartile vs. lowest, relative risk = 3.3, 95% confidence interval: 1.1, 10.4) but not in premenopausal women (relative risk = 1.2, 95% confidence interval: 0.4, 3.4). Stratification according to ER status showed that the increased mortality was restricted to ER-positive postmenopausal women. Elevated WHR was confirmed as a predictor of breast cancer mortality, with menopausal status and ER status at diagnosis found to be important modifiers of that relation.