Prediagnostic body size and breast cancer survival in the E3N cohort study

• Published in: International journal of cancer Vol. 139; no. 5; pp. 1053 - 1064
• Main Authors: His, Mathilde, Fagherazzi, Guy, Mesrine, Sylvie, Boutron‐Ruault, Marie‐Christine, Clavel‐Chapelon, Françoise, Dossus, Laure
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.09.2016
• Subjects: Adiposity; Body mass index; Body Size; Body Weights and Measures; Breast cancer; breast cancer survival; Breast Neoplasms - diagnosis; Breast Neoplasms - epidemiology; Breast Neoplasms - mortality; Cancer; Confounding Factors (Epidemiology); disease‐free survival; Female; Health risk assessment; Humans; Mammography; Medical prognosis; Medical research; mortality; Neoplasm Grading; Neoplasm Staging; obesity; Population Surveillance; Proportional Hazards Models; Prospective Studies; Risk Factors; Surveys and Questionnaires; Survival Analysis; Survival Rate; mortality; adiposity; disease-free survival; breast cancer survival; obesity
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.30158

Obesity has been associated with poor breast cancer prognosis, however most studies have focused on body mass index (BMI) and few have considered the distribution of adipose tissue. We investigated associations between prediagnostic adiposity and breast cancer survival, considering BMI, waist and hip circumferences (WC and HC), and waist‐to‐hip ratio (WHR). Analyses included 3,006 women from the French E3N prospective cohort study diagnosed with primary invasive breast cancer between 1995 and 2008. We investigated overall, breast cancer‐specific, and disease‐free survival, overall and according to stage, menopausal and hormonal status and year of diagnosis, using Cox proportional hazard models adjusted for tumor characteristics and lifestyle risk factors. Women with a prediagnostic HC > 100 cm were at increased risk of death from all causes (hazard ratio (HR)>100vs < 95 cm = 1.38, 95% Confidence Interval (CI) = 1.02–1.86, Ptrend = 0.02) and from breast cancer (HR>100vs < 95 cm = 1.50, CI = 1.03–2.17, Ptrend = 0.03), and of second invasive cancer event (HR>100vs < 95 cm = 1.36, CI = 1.11–1.67, Ptrend = 0.002), compared to those with HC <95 cm. Associations were stronger after adjustment for BMI. BMI, WC and WHR were not associated with survival after breast cancer. Our study underlines the importance of going beyond BMI when studying the association between adiposity and breast cancer survival. Further studies should be conducted to confirm our results on hip circumference. What's new? If you're fat, you're less likely to survive breast cancer—but does it matter where that fat is on your body? Perhaps, according to a new report. These authors noted that previous work only considers the patient's BMI when studying prognosis. This study tested hip and waist circumference as well. They discovered that women with larger hip circumference had greater risk of death from all causes and from breast cancer, and of second invasive cancer than had women with smaller hips. No association was found with waist circumference or BMI, suggesting there's more to the story than BMI when it comes to cancer survival.