Physical Activity and Reduction of Breast

Cancer Risk

Physical Activity vs. Exercise

Physical Activity• Any form of movement

using skeletal muscles.• Movement required for

daily life.– Occupational physical activity

• Activities done for enjoyment.

Exercise• Physical training

– Recreational physical activity

• Aerobic or anaerobic• Higher intensities

Benefits of Physical Activity

• Physical activity can help maintain and/or reduce weight

• It helps to maintain and/or reduce body mass index (BMI) – Underweight < 18.5– Normal = 18.5- 24.9– Overweight = 25.0-29.9– Obesity > 30

Benefits Continued

• Helps us burn excess calories instead of turning into fat

• Increases lean muscle• Helps retain and strengthen bone • Strengthens the immune system• Enhances mental and emotional well being

Definitions

• Risk- The likelihood of developing cancer based on lifestyle choices and family history

• Prevention- Lifestyle choices to reduce the risk of cancer

• Recurrence- The return of cancer after treatment

Pre vs. Postmenopausal Breast Cancer

Premenopausal• Occurs in younger women• Often linked to genetic

predisposition• Typically more severe and

harder to treat

Postmenopausal• More common form• Linked to younger age of

menarche and older age menopause

• Higher risk with no or few children, or older age of first birth

• Strongly linked to obesity after mid-life

Color on Map Interval

Light green 99.9 to 116.8

Medium green 116.9 to 122.5

Medium blue 122.6 to 124.8

Dark blue 124.9 to 139.2

Light Grey Did not meet USCS data quality criteria

†Source: U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999–2007 Incidence and Mortality Web-based Report. Atlanta (GA): Department of Health and Human Services, Centers for Disease Control and Prevention, and National Cancer Institute; 2010. Available at: http://www.cdc.gov/uscs.

Rates are per 100,000 and are age-adjusted to the 2000 U.S. standard population.

Female Breast Cancer Incidence Rates* by State, 2007

American Institute for Cancer Research Summary

• Increased amounts of physical activity reduce risk of breast cancer.

• Stronger for postmenopausal women

Physical Activity and Risk of Breast Cancer Among Postmenopausal

Women• Objective

– Examine the associations of physical activity with breast cancer risk among postmenopausal women

• long-term activity• recent activity• change in activity• specific types of activity

Study Design

• Nurses Health Study - 95,396 postmenopausal women

• Questionnaire in 1986 – time per week spent doing physical activities

• 7 more questionnaires over next 20 years• Reports of breast cancer confirmed through

medical records

Results

• Moderate physical activity may reduce postmenopausal breast cancer risk

• 5 hours per week of brisk walking was sufficient to reduce the risk of breast cancer

• An increase in activity after menopause may be beneficial

Take Home

• Moderate physical activity like walking reduces breast cancer risk

• More exercise further reduces risk• Physical activity reduces risk in women with a

family history of breast cancer

The evidence is strong that a lifestyle including regular

physical activity and maintaining a healthy weight reduces breast cancer risk for women of all ages

The American College of Sports Medicine and the American Heart Association

recommend

30 minutes of moderately intense aerobic exercise 5 days a week

andstrength- training exercises twice a week

Summary

• Physical activity has many benefits – Maintains healthy weight

• Physical activity reduces cancer risk – moderate is good but vigorous is better– Daily and consistent