Breast Cancer Risk: BMI Matters (Shape, Not So Much)

obese white woman

Summary: A study of predominantly white women finds a larger waist circumference is associated with higher risk of postmenopausal breast cancer, but not beyond its contribution to Body Mass Index (BMI). The study, by American Cancer Society researchers, fails to confirm previous findings that body shape itself is an independent risk factor for breast cancer. The current study appears in the April 2014 issue of Cancer Causes, and Control.

Background: Abdominal obesity is linked to a number of conditions, including heart disease, type II diabetes, and breast and other cancers. Those studies have led to the theory that having an “apple shaped” body, with weight concentrated in the chest and torso, is riskier than having a “pear-shaped” body, with fat concentrated in the hips, thighs and buttocks.

The Evidence: To explore the theory, researchers led by Mia Gadet, PhD, analyzed data from 28,965 women participating in the Cancer Prevention Study II. Among those women there were 1,088 invasive breast cancer cases diagnosed during a median 11.58 years of follow-up. They found a statistically significant positive association between waist circumference and postmenopausal breast cancer risk; however, when they adjusted for BMI, the association disappeared.

“Iif you have a high BMI, regardless if you are pear or apple shaped, you are at higher risk of breast cancer,” said Dr. Gaudet. “Most prior studies on this issue looked at BMI or at waist circumference, but had not looked at them together. This study brings some clarity to the association between obesity and risk of breast cancer.”

Dr. Gaudet says the data could help women focus on what’s important in what has been a confusing array of potential risk factors for breast cancer. “We know being overweight, particularly when the weight gain happened during adulthood, is one of the important modifiable risk factors for breast cancer in post-menopausal women. This new data indicates it’s not what shape you are, it’s what kind of shape you are in that probably ought to be their focus.” I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: Mia M. Gaudet, Brian D. Carter, Alpa V. Patel, Lauren R. Teras, Eric J. Jacobs, Susan M. Gapstur. Waist circumference, body mass index, and postmenopausal breast cancer incidence in the Cancer Prevention Study-II Nutrition Cohort. Cancer Causes & Control, 2014; DOI: 10.1007/s10552-014-0376-4


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s