Number of risky lifestyle behaviors and breast cancer risk
File(s)
Author(s)
Type
Journal Article
Abstract
Background
Lifestyle factors are associated with overall breast cancer risk, but less is known about their associations, alone or jointly, with risk of specific breast cancer subtypes.
Methods
We conducted a case–control subjects study nested within a cohort of women who participated in the Norwegian Breast Cancer Screening Program during 2006–2014 to examine associations between risky lifestyle factors and breast cancer risk. In all, 4402 breast cancer cases subjects with information on risk factors and hormone receptor status were identified. Conditional logistic regression was used to estimate odds ratios (ORs), with 95% confidence intervals (CIs), in relation to five risky lifestyle factors: body mass index (BMI) of 25 kg/m² or greater, three or more glasses of alcoholic beverages per week, ever smoking, fewer than four hours of physical activity per week, and ever use of menopausal hormone therapy. Analyses were adjusted for education, age at menarche, number of pregnancies, and menopausal status. All statistical tests were two-sided.
Results
Compared with women with no risky lifestyle behaviors, those with five had 85% (OR = 1.85, 95% CI = 1.42 to 2.42, Ptrend < .0001) increased risk of breast cancer overall. This association was limited to luminal A–like (OR = 2.20, 95% CI = 1.55 to 3.12, Ptrend < .0001) and luminal B–like human epidermal growth factor receptor 2 (HER2)–positive (OR = 1.66, 95% CI = 0.61 to 4.54, Ptrend < .004) subtypes. Number of risky lifestyle factors was not associated with increased risk of luminal B–like HER2-negative, HER2-positive, or triple-negative subtypes (Ptrend > .18 for all).
Conclusions
Number of risky lifestyle factors was positively associated with increased risk for luminal A–like and luminal B–like HER2-positive breast cancer.
Lifestyle factors are associated with overall breast cancer risk, but less is known about their associations, alone or jointly, with risk of specific breast cancer subtypes.
Methods
We conducted a case–control subjects study nested within a cohort of women who participated in the Norwegian Breast Cancer Screening Program during 2006–2014 to examine associations between risky lifestyle factors and breast cancer risk. In all, 4402 breast cancer cases subjects with information on risk factors and hormone receptor status were identified. Conditional logistic regression was used to estimate odds ratios (ORs), with 95% confidence intervals (CIs), in relation to five risky lifestyle factors: body mass index (BMI) of 25 kg/m² or greater, three or more glasses of alcoholic beverages per week, ever smoking, fewer than four hours of physical activity per week, and ever use of menopausal hormone therapy. Analyses were adjusted for education, age at menarche, number of pregnancies, and menopausal status. All statistical tests were two-sided.
Results
Compared with women with no risky lifestyle behaviors, those with five had 85% (OR = 1.85, 95% CI = 1.42 to 2.42, Ptrend < .0001) increased risk of breast cancer overall. This association was limited to luminal A–like (OR = 2.20, 95% CI = 1.55 to 3.12, Ptrend < .0001) and luminal B–like human epidermal growth factor receptor 2 (HER2)–positive (OR = 1.66, 95% CI = 0.61 to 4.54, Ptrend < .004) subtypes. Number of risky lifestyle factors was not associated with increased risk of luminal B–like HER2-negative, HER2-positive, or triple-negative subtypes (Ptrend > .18 for all).
Conclusions
Number of risky lifestyle factors was positively associated with increased risk for luminal A–like and luminal B–like HER2-positive breast cancer.
Date Issued
2018-07-01
Date Acceptance
2018-06-05
Citation
JNCI Cancer Spectrum, 2018, 2 (3), pp.1-8
ISSN
2515-5091
Publisher
Oxford University Press
Start Page
1
End Page
8
Journal / Book Title
JNCI Cancer Spectrum
Volume
2
Issue
3
Copyright Statement
© The Author(s) 2018. Published by Oxford University Press.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
License URL
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000495716300016&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Life Sciences & Biomedicine
Oncology
HORMONE-REPLACEMENT THERAPY
CORONARY-HEART-DISEASE
CIGARETTE-SMOKING
RECEPTOR STATUS
ALCOHOL-CONSUMPTION
PRIMARY PREVENTION
PHYSICAL-ACTIVITY
ACTIVE SMOKING
WOMEN
ESTROGEN
Publication Status
Published
Article Number
ARTN pky030
Date Publish Online
2018-07-19