Dr. Jasmine McDonald of Columbia University's Mailman School of Public Health explains environmental impacts on breast cancer occurrence.

1. THE ENVIRONMENT AND
BREAST CANCER: WHAT
WE KNOW ABOUT RISK
AND PREVENTION
Jasmine A. McDonald, PhD
Department of Epidemiology
Mailman School of Public Health
Columbia University

2. EPIDEMIOLOGY OF
BREAST CANCER

3. Lindsey A. Torre et al. Cancer Epidemiol Biomarkers Prev 2016;25:16-27
*Excludes basal and squamous cell skin cancers and in situ carcinomas except urinary bladder.
Source: American Cancer Society, 2018.
BREAST CANCER IS THE MOST COMMONLY DIAGNOSED
CANCER IN WOMEN IN THE U.S. AND MOST OF THE
WORLD REGIONS

4. age 50 and
over
(Developing)
28%
age 50 and
over;
(Developed)
39%
age <50;
(Developing)
23%
age <50;
(Developed)
10%
Lancet Oncology Volume 378, Issue 9801, 22 October 2011
GLOBAL BURDEN OF BREAST CANCER
 Global breast cancer incidence increased
from 641 000 in 1980 to 1,643 000 in
2010, an annual rate of increase of 3.1%.
 1/3 of global breast cancer cases
diagnosed are under 50 years.
 Pregnancy-related breast cancer
 Even women without family history, their
children now have a family history.
Percentage of Total Global Breast Cancer
Deaths by Age

5. LIFETIME RISK OF BREAST
CANCER
 A woman living in the US has a 12.4 lifetime
risk of being diagnosed with breast cancer
OR
 1 in 8 women will be diagnosed with cancer
of the breast during their lifetime.
https://seer.cancer.gov/statfacts/html/breast.html

6. PREVENTING BREAST
CANCER

7. NAVIGATING BREAST CANCER PREVENTION WITHIN A
MULTILEVEL MODEL
Inherited Genes
Somatic Genome
Individual
Biologic
Physical and Social
Environment
Health Policy
Environment
Levels of Etiology
Modified from Lynch and Rebbeck CEBP 2013; Webb, Suglia, and Tehranifar Curr Diab Rep 2013
Risk Assessment
Detection
Diagnosis
Treatment
1°,2°,3°Prevention
Survivorship
Levels of InterventionLevels of Carcinogenesis
Initiation
Promotion
Progression
Metastasis
Lifecourse
Conception
Lifecourse
Death

8. LEVELS OF PREVENTION
Tertiary
Prevention
People with a
health problem
Secondary
Prevention
People at risk
of a health
problem
Primary
Prevention
Healthy
Populations
• Health promotion
• Identification &
protection against risk
factors
• Screening
• Early
diagnosis
• Treatment
• Rehabilitation
• Improving quality of life
Adapted from: https://cursos.campusvirtualsp.org/mod/tab/view.php?id=23157

10. BREAST CANCER RISK FACTORS
< 1 Fold
(Protective Factors)
1-2 Fold > 2 Fold
NSAIDs
Tamoxifen
Physical Activity
Early Menarche
Never Pregnant
Never Breastfed
Late Age at First Birth
Late Menopause
Hormone Use (HRT, OC)
Overweight
Alcohol
Family History
Benign Breast
Disease
Mammographic
Density
Personal History of
Breast Cancer
Radiation

11. Runowicz et al JCO 2016, 34, 611-635
AMERICAN CANCER SOCIETY/AMERICAN SOCIETY
OF CLINICAL ONCOLOGY BREAST CANCER
SURVIVORSHIP CARE GUIDELINE

12. WORLD CANCER RESEARCH
FUND RECOMMENDATIONS
 Be as lean as possible without becoming underweight.
 Be physically active for at least 30 minutes every day.
 Limit consumption of energy-dense foods (foods high in fats and/or added
sugars and/or low in fiber) and avoid sugary drinks.
 Eat more of a variety of vegetables, fruits, whole grains, and pulses (beans).
 Limit consumption of red meats (such as beef, pork and lamb) and avoid
processed meats (such as sausage, bacon).
 If consumed at all, limit alcoholic drinks to 1 a day for women.
 Limit consumption of salty foods and foods processed with salt (sodium).
 Don’t use supplements to protect against cancer.
http://www.wcrf.org/cancer_research/expert_report/recommendations.php

13. MAINTAIN A HEALTHY WEIGHT
Evidence suggest a link between having a
healthy BMI – before and after diagnosis –
and survival.

14. BODY FAT BEFORE BREAST CANCER DIAGNOSIS AND
MORTALITY: VISUALIZING EVIDENCE
World Cancer Research Fund
International/American Institute for
Cancer Research Continuous
Update Project Report: Diet,
Nutrition, Physical Activity, and
Breast Cancer Survivors. 2014.
Available at:
www.wcrf.org/sites/default/files/Brea
st-Cancer-Survivors-2014-
Report.pdf

15. World Cancer Research
Fund
International/American
Institute for Cancer
Research Continuous
Update Project Report:
Diet, Nutrition, Physical
Activity, and Breast
Cancer Survivors. 2014.
Available at:
www.wcrf.org/sites/default/
files/Breast-Cancer-
Survivors-2014-Report.pdf
BODY FAT AFTER BREAST CANCER DIAGNOSIS AND
MORTALITY: VISUALIZING EVIDENCE

16. Systematic review on diet, nutrition, physical activity and survval and second cancer in breast cancer
survivors. World Cancer Research Foundation; 2014
BODY FAT AFTER BREAST CANCER DIAGNOSIS AND
2ND BC: VISUALIZING EVIDENCE

17. Playdon et al; J Natl Cancer Inst. 2015 Dec; 107(12): djv275.
WEIGHT GAIN AFTER BC DIAGNOSIS AND MORTALITY

18. PHYSICAL ACTIVITY
Evidence shows that women who are
physically active – both before and after
diagnosis – have a greater chance of
surviving breast cancer

19. WORLD CANCER RESEARCH
FUND RECOMMENDATIONS
 Be as lean as possible without becoming underweight.
 Be physically active for at least 30 minutes every day.
 Limit consumption of energy-dense foods (foods high in fats and/or added
sugars and/or low in fiber) and avoid sugary drinks.
 Eat more of a variety of vegetables, fruits, whole grains, and pulses (beans).
 Limit consumption of red meats (such as beef, pork and lamb) and avoid
processed meats (such as sausage, bacon).
 If consumed at all, limit alcoholic drinks to 1 a day for women.
 Limit consumption of salty foods and foods processed with salt (sodium).
 Don’t use supplements to protect against cancer.
http://www.wcrf.org/cancer_research/expert_report/recommendations.php

20. PHYSICAL ACTIVITY AND CANCER
RISK - MECHANISM
 Reduction in body fat
 Enhanced antioxidant defense
 Decreases in reproductive hormones
 Enhanced immunity
 Change in insulin resistance and IGF-1 pathway

21. DIET &
NUTRITION
Good nutrition may reduce the
incidence of breast cancer and the risk
of breast cancer progression or
recurrence.

22. WORLD CANCER RESEARCH
FUND RECOMMENDATIONS
 Be as lean as possible without becoming underweight.
 Be physically active for at least 30 minutes every day.
 Limit consumption of energy-dense foods (foods high in fats and/or added
sugars and/or low in fiber) and avoid sugary drinks.
 Eat more of a variety of vegetables, fruits, whole grains, and pulses (beans).
 Limit consumption of red meats (such as beef, pork and lamb) and avoid
processed meats (such as sausage, bacon).
 If consumed at all, limit alcoholic drinks to 1 a day for women.
 Limit consumption of salty foods and foods processed with salt (sodium).
 Don’t use supplements to protect against cancer.
http://www.wcrf.org/cancer_research/expert_report/recommendations.php

23. ALCOHOL INTAKE

25. ALCOHOL INTAKE 101
12.8-15.4 grams10.8-13.9 grams 14.0-15.1 grams
≤1 drink/day = ≤12.5 grams EtOH/day = ≤7 drinks/week = Light/Moderate
>1 drink/day = >12.5 grams EtOH/day = >7 drinks/week = Heavy
“Low Risk” Drinking
One "standard" drink contains roughly 14 grams of pure alcohol:
“At Risk” Drinking

26. ALCOHOL AND BREAST CANCER: DOSE-
RISK RELATIONSHIP
Hamajima N et. al. Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological
studies, including 58,515 women with breast cancer and 95,067 women without the disease. BJC. 2002;87(11):1234-45.

27. ALCOHOL INTAKE AND BREAST CANCER
SURVIVORS
 Some findings suggest breast cancer survivors who drink
alcohol after diagnosis have an increased risk of
recurrence and breast cancer mortality (death from
breast cancer).
 Other studies have shown no difference in recurrence or
breast cancer mortality between survivors who drink
alcohol in moderation (less than 1 drink a day for women)
and survivors who are non-drinkers.
 Excessive alcohol drinking has no health benefits, only
health risks.

28. Systematic review on diet, nutrition, physical activity and survival and second cancer in breast cancer
survivors. World Cancer Research Foundation; 2014
DOSE RESPONSE ALCOHOL AFTER BREAST
CANCER DIAGNOSIS AND 2ND BC

29. • 3 clinic-based sites
• Cases: local hospitals,
organizations, support groups
• Controls: Random digit dialing
• 3 population-based sites
• Cases: Cancer registries
• Controls: Random digit dialing
• Follow-up started in 2007
THE BREAST CANCER FAMILY REGISTRY
(BCFR)

30. Zeinomar N, Thai A, Cloud AJ, McDonald JA, Liao Y, et al. PLOS ONE 2017.
LIFETIME ALCOHOL INTAKE NOT ASSOCIATED WITH BREAST
CANCER MORTALITY IN A HIGH RISK COHORT

31. Zeinomar N, Thai A, Cloud AJ, McDonald JA, Liao Y, et al. PLOS ONE 2017.
LIFETIME ALCOHOL INTAKE & BREAST CANCER MORTALITY
BY AGE

32. SUMMARY: RISK OF BREAST CANCER
IS MODIFIABLE
 Lower body fat can reduce risk of BC diagnosis and
mortality.
 Women who are physically active have a greater chance
of surviving BC.
 A diet high in fruits, vegetables and whole grains and low
in saturated fat is recommended.
 Consuming even 1-2 alcoholic drinks/day can increase the
risk of BC diagnosis.

33. ONLINE RESOURCES
 American Cancer Society http://www.cancer.org/
 National Cancer Institute http://www.cancer.gov/
 WCRF Recommendations http://www.aicr.org/can-
prevent/what-you-can-do/10-recommendations.html
 Live Strong Foundation http://www.livestrong.org/
 Your Disease Risk
http://www.yourdiseaserisk.wustl.edu/english/index.htm

34. THANK YOU!