FitDay Discussion Boards - Breast Cancer Risk Reduced in Women Who Exercise 10 Hrs./Week

This was in my inbox this morning: interesting...

The journal *Cancer* has scheduled an article for publication in a future
issue: "Fat or fit: The joint effects of physical activity, weight gain, and
body size on breast cancer risk."

The authors are Lauren E. McCullough MSPH1,?,*, Sybil M. Eng PhD, MPH2,
Patrick T. Bradshaw PhD1, Rebecca J. Cleveland PhD3, Susan L. Teitelbaum
PhD4, Alfred I. Neugut MD, PhD2,5, & Marilie D. Gammon PhD1.

Here's the abstract:

BACKGROUND:

Although physical activity reduces breast cancer risk, issues critical to
providing clear public health messages remain to be elucidated. These
include the minimum duration and intensity necessary for risk reduction and
the optimal time period for occurrence, as well as subgroup effects,
particularly with regard to tumor heterogeneity and body size.

METHODS:

This study investigated the relationship between recreational physical
activity (RPA) and breast cancer risk, in addition to characterizing the
joint effects of activity level, weight gain, and body size, through use of
a population-based sample of 1504 cases (N = 233 in situ, N = 1271 invasive)
and 1555 controls (aged 20-98 years) from the Long Island Breast Cancer
Study Project, in Long Island, New York.

RESULTS:

A nonlinear dose-response association was observed between breast cancer
risk and RPA during the reproductive period and after menopause. Women in
the third quartile of activity experienced the greatest benefit with an
approximate 30% risk reduction for reproductive (odds ratio = 0.67; 95%
confidence interval = 0.48-0.94) and postmenopausal activity (odds ratio =
0.70; 95% confidence interval = 0.52-0.95). Little to no difference was
observed regarding intensity of activity or hormone receptor status. Joint
assessment of RPA, weight gain, and body size revealed that women with
unfavorable energy balance profiles were at increased breast cancer risk. A
significant multiplicative interaction was observed between RPA and adult
weight gain (P = .033).

CONCLUSIONS:

RPA at any intensity level during the reproductive and postmenopausal years
have the greatest benefit for reducing breast cancer risk. Substantial
postmenopausal weight gain may eliminate the benefits of regular activity.

The article is online at:
<http://bit.ly/KenPopeExerciseAndBreastCancerRisk>