O Brouckaert1, K Van Asten2, A Laenen3, A Soubry4, A Smeets2, I Nevelstreen2, I Vergote2, H Wildiers2, R Paridaens2, E Van Limbergen2, C Weltens2, P Moerman2, G Floris2, P Neven2. 1. Department of Obstetrics and Gynaecology, Jan Yperman Hospital, briekestraat 12, 8900, Ypres, Belgium. Olivier.brouckaert@yperman.net. 2. Multidisciplinary Breast Centre Leuven, University Hospital Leuven, Herestraat 49, 3000, Louvain, Belgium. 3. Department of Electrical Engineering (ESAT-SISTA), Katholieke Universiteit Leuven, Kasteel park Arenberg 10, 3001 LEUVEN, Louvain, Belgium. 4. Epidemiology Research Group, Department of Public Health and Primary Care, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucyijnenvoer 35 blok d, box 7001, 3000, Louvain, Belgium.
Abstract
PURPOSE: Evidence suggests that premenopausal obesity decreases and postmenopausal obesity increases breast cancer risk. Because it is not well known whether this is subtype dependent, we studied the association between body mass index (BMI) and age at breast cancer diagnosis, or the probability of being diagnosed with a specific breast cancer phenotype, by menopausal status. METHODS: All patients with non-metastatic operable breast cancer from the University Hospital Leuven diagnosed between January 1, 2000 and December 31, 2013 were included (n = 7020) in this cross-sectional study. Linear models and logistic regression were used for statistical analysis. Allowing correction for age-related BMI-increase, we used the age-adjusted BMI score which equals the difference between a patient's BMI score and the population-average BMI score corresponding to the patient's age category. RESULTS: The quadratic relationship between the age-adjusted BMI and age at breast cancer diagnosis (p = 0.0207) interacted with menopausal status (p < 0.0001); increased age at breast cancer diagnosis was observed with above-average BMI scores in postmenopausal women, and with below-average BMI scores in premenopausal women. BMI was linearly related to the probabilities of Luminal B and HER2-like breast cancer phenotypes, but only in postmenopausal women. The relative changes in probabilities between both these subtypes mirrored each other. CONCLUSION: BMI associates differently before and after menopause with age at breast cancer diagnosis and with the probability that breast cancer belongs to a certain phenotype. The opposite effect of increasing BMI on relative frequencies of Luminal B and HER2-like breast cancers suggests a common origin.
PURPOSE: Evidence suggests that premenopausal obesity decreases and postmenopausal obesity increases breast cancer risk. Because it is not well known whether this is subtype dependent, we studied the association between body mass index (BMI) and age at breast cancer diagnosis, or the probability of being diagnosed with a specific breast cancer phenotype, by menopausal status. METHODS: All patients with non-metastatic operable breast cancer from the University Hospital Leuven diagnosed between January 1, 2000 and December 31, 2013 were included (n = 7020) in this cross-sectional study. Linear models and logistic regression were used for statistical analysis. Allowing correction for age-related BMI-increase, we used the age-adjusted BMI score which equals the difference between a patient's BMI score and the population-average BMI score corresponding to the patient's age category. RESULTS: The quadratic relationship between the age-adjusted BMI and age at breast cancer diagnosis (p = 0.0207) interacted with menopausal status (p < 0.0001); increased age at breast cancer diagnosis was observed with above-average BMI scores in postmenopausal women, and with below-average BMI scores in premenopausal women. BMI was linearly related to the probabilities of Luminal B and HER2-like breast cancer phenotypes, but only in postmenopausal women. The relative changes in probabilities between both these subtypes mirrored each other. CONCLUSION: BMI associates differently before and after menopause with age at breast cancer diagnosis and with the probability that breast cancer belongs to a certain phenotype. The opposite effect of increasing BMI on relative frequencies of Luminal B and HER2-like breast cancers suggests a common origin.
Entities:
Keywords:
Age at diagnosis; BMI; Body mass index; Breast cancer; Obesity; Subtype
Authors: Rebecca Troisi; Anne Gulbech Ording; Tom Grotmol; Ingrid Glimelius; Anders Engeland; Mika Gissler; Britton Trabert; Anders Ekbom; Laura Madanat-Harjuoja; Henrik Toft Sørensen; Steinar Tretli; Tone Bjørge Journal: Int J Cancer Date: 2018-08-10 Impact factor: 7.396