Table Breast Cancer Studies
Benefits of maintaining a healthy weight
Prevention:
| Study | Characteristic | % risk increase |
| Meta Analysis | Obese at time of diagnosis | +30% higher risk of dying of BC or other causes |
Maintain a healthy weight
| Study | Weight gain after diagnosis | Increase in risk of recurrence | Increase in risk of death from any cause | Notes |
| NHS | Ave.weight gain of 6 lbs | 1.4 x risk of recurrence
or |
Women who were at a normal weight at diagnosis were more heavily impacted by weight gain after diagnosis
|
|
| NHS | Ave. weight gain of 17 lbs | 1.53 x risk or | Women at normal wt. at diagnosis more impacted | |
| NHS | Highest weight gain | 1.6x risk
or |
Women at normal wt. at diagnosis more impacted | |
| CWLS | For each 11 lbs of weight gained | +13% increased risk of death from any cause (higher for risk of dying from heart disease) | ||
| Long Island
Study |
Gaining more than 10% of body weight | 2.5x risk of dying from breast cancer or other causes |
Note: It is not known at this time how weight loss after diagnosis would affect women who were overweight at the time of diagnosis.
Exercise reduces your risk of recurrence, risk of death from breast cancer, risk of death from any cause
| Study | Exercise
|
How much reduction of risk? | |||
| NHS | >3 MET hrs/wk | 40% reduction in death due to BC; 35% reduction in death from any cause | >9 MET hrs/wk of moderate exercise | 92% 10 year survival rate
(compare to 86% for <3 MET hrs) 6%absolute survival benefit |
|
| CWLS | Each increase of 5 MET hrs/wk of moderate exercise | Relative risk of death lowered by 15% | Effect not found for vigorous exercise | ||
| HEAL | Exercising 2 years after diagnosis | Reduction of risk by 2/3 | Inactive before diagnosis, but exercised after | Reduction of risk by 45% | Those who had stopped exercising increased risk of death x 4 |
| WHI | >/= 9 MET hours | 39% lower risk from BC; 46% lower risk death from any cause | |||
| ABCPP | 10 MET hours | Risk of recurrence decreased by 24%; death from bc reduced by 25%; all cause death reduced by 27% | |||
| 2011 Meta | Above 3 MET hrs/wk | Reduced risk of recurrence by 24%, Reduced risk of death from BC 34 %, Death from any cause 41% |
Exercise after diagnosis reduced risk of recurrence, death from breast cancer, death from any cause
| Study | MET hrs | Equivalent to walking at a pace of 2.5 mph | Reduced
risk of recurrence |
Reduced
Risk of death from BC |
Reduced Risk of death from any cause | 10 yr
survival rate |
Notes |
| NHS | > 3 MET hrs/wk | Walking more than an hour per week | -40% | -35% | |||
| NHS | >9 MET hrs/wk of moderate exercise | Walking more than 3 hours per week | 92% 10 year survival rate | For every 100 women | |||
| NHS | < 3 MET hrs/wk | Walking less than an hour per week | 86% 10 year survival rate | ||||
| CWLS | Each increase of 5 MET hrs/wk moderate exercise | Each increase of
1 hr. 40 min |
-15% | Effect not seen for increase in vigorous exercise | |||
| HEAL | At least 9 MET hrs/wk? | At least 3 hrs/wk of moderate walking | -66% | Looked at outcome 2 years after diagnosis | |||
| WHI | >/=9 MET hrs/wk | At least 3 hrs/wk | -39% | -40% | |||
| ABCPP | 10 MET hrs/wk | 3 hrs 20 min | -24% | -25% | -27% | ||
| 2011 Meta | More than 2.8 MET hours | Approx 1 hr walking per week or more | -24% | -34% | -41% |
*walking 2.5 mph on a firm, level surface is 3 METs so 1 hr. x 3 METs= 3 MET hours
https://sites.google.com/site/compendiumofphysicalactivities/Activity-Categories/walking
For other activities:
https://sites.google.com/site/compendiumofphysicalactivities/Activity-Categories
What the heck is a MET hour?
MET stands for Metabolic Equivalent Task. In practical terms, it is a standardized way for researchers and others to compare the amount of energy expended in various activities. ( It’s technically more complicated than that.)
1 MET is the amount of energy you expend when you are sitting.
If you do an exercise that is 6 METs, you are expending 6x the energy you would expend sitting. If you do an activity that is 3 METS, you are expending 3x the energy you would expend sitting.
A MET hour is the time spent on an activity x the MET value of the activity. So given that walking at a 2.5 mph is 3 METS, then doing it for 1 hour is 3 METs x 1 hour= 3 MET hours. If you walked at that pace for 2 hours, it would be 3 METs x 2 hours= 6 MET hours.
