Physical Activity Reduces Breast Cancer Risk

Effect of Physical Activity on Women at Increased Risk of
Breast Cancer: Results from the E3N Cohort Study

Bertrand Tehard,1 Christine M. Friedenreich,2,3 Jean-Michel Oppert,4
and Francoise Clavel-Chapelon1
1Institut National de la Sante et de la Recherche Medicale, Institut Gustave Roussy, Villejuif, France; 2Division of Population Health and
Information, Alberta Cancer Board, Calgary, Alberta, Canada; 3IARC, Lyon, France; and 4Department of Nutrition,
Hoˆtel-Dieu Hospital, University Pierre-et-Marie Curie, Paris, France

... We analyzed the relation between physical activity
and breast cancer incidence between 1990 and 2002
(n = 3,424 cases), among 90,509 women of the French E3N
cohort, ages between 40 and 65 years in 1990. ...
Results: A linear decrease in risk of breast cancer was
observed with increasing amounts of moderate (Ptrend <>>>>>>>>>>>>>>>>>>>>>>>>>

BrooklynDodger(s) comments: The Dodger(s)'s interest in this paper was how physical activity of industrial work, by reducing breast cancer risk, reduces the chances of observing effects of industrial chemicals on breast cancer.

How were the investigators allowed to ignore physical activity at work in this study?

The E3N cohort is composed of 98,995 women living in France,
who are insured with the Mutuelle Ge´ne´rale de l’Education
Nationale, a national health insurance scheme primarily
covering teachers.

So, they all did similar work, except for gym teachers.

The median in this cohort was about 42 MET-h/week, while the bottom of the fourth quartile was 58 MET-h/week.

How does that translate to industrial work? The Dodger(s) need to figure out what METs are in relation to industrial worl