1. Diet, Exercise, and Cancer Risk
Diane Baer Wilson, EdD, MS, RD
Associate Professor Division of Quality Healthcare
Department of Internal Medicine
Co-Director Cancer Prevention and Control
Massey Cancer Center
Virginia Commonwealth University
I am delighted to be here to share a bit about the work I am doing in SC related to nutrition and cancer prevention.
Have been involved in this area of research for the last five years when Dr Dan Nixon brought a focus on the role of nutrition in cancer when he arrived at MUSC.
CCFellows

2. Today’s objectives
Examine dietary-related factors and physical activity related to cancer risk
Discuss dietary fat as a model for dietary studies related to cancer risk
Review nutrition measurement methods
Examine recent research related to BMI and breast cancer

3. the trigger.” Elliott Joslyn, MD
“Genes load the gun. Lifestyle pulls
the trigger.” Elliott Joslyn, MD

4. 11 11

5. Cancer risk factors Age Family history Hormone exposure …… …… ……
…… …… ……
Tobacco use
Diet/exercise
Environmental exposures
Alcohol Intake

6. Cancer Risk Factors: Nutrition
Top Issues:
Energy Balance
Weight
Exercise
Nutrient Composition
Dietary Fat
Fruit/Vegetables
Fiber
Soy

7. Understanding dietary fat/cancer hypotheses
Nutrition relatively recent area of cancer research
Research seeds:
Correlational
Animal research
Cross sectional
RCT

8. Fat intake/breast cancer, Carroll, 1975.

9. Dietary Fat/Breast Cancer Animal studies
Proportionate level of tumor growth recorded in laboratory rats related to level of dietary fat fed animals over designated period of time.
( ’s)

10. Dietary Fat/Breast Cancer
Human studies
Cross sectional
Nurses Health Study-Willett, et al, 2000.

11. Dietary Fat/Breast Cancer Randomized Clinical Trial
“Low-fat Dietary Patterns and Risk of Invasive Breast Cancer”
The Women’s Health Initiative Randomized Controlled Dietary Modification Trial
Prentice, Caan, Chlewbowski, et al. JAMA
2006;295: (2/8/06)

12. Participant Flow in the Dietary Modification Component of the Women's Health Initiative
Prentice, R. L. et al. JAMA 2006;295:
Copyright restrictions may apply.

13. Baseline Demographics of Participants in Women's Health Initiative Dietary Modification Trial*
Prentice, R. L. et al. JAMA 2006;295:
Copyright restrictions may apply.

14. Nutrient Consumption Estimates and Body Weight at Baseline and Year 1
Prentice, R. L. et al. JAMA 2006;295:
Copyright restrictions may apply.

15. Blood Biomarkers for Baseline and Year 3*
Prentice, R. L. et al. JAMA 2006;295:
Copyright restrictions may apply.

16. Risk of Invasive Breast Cancer and Other Major Clinical Outcomes
Prentice, R. L. et al. JAMA 2006;295:
Copyright restrictions may apply.

17. Breast Cancer Risk by Baseline Dietary Factors
Prentice, R. L. et al. JAMA 2006;295:
Copyright restrictions may apply.

18. Breast Cancer Risk Based on Baseline Demographics, Medical History, and Health Behavior Variables
Prentice, R. L. et al. JAMA 2006;295:
Copyright restrictions may apply.

19. The American view of nutrition information

20. Dietary Assessment Twenty-four hour dietary recall
Food frequency questionnaire
Diet record
Diet history

21. Data Collection Methods
24 hour recall method
Most common method used for national dietary surveys
Information on everything consumed over past 24 hours-relies on memory
Trained interviewers
non-judgmental
neutral

22. Food Record Method
Detailed record of all foods consumed on one or more days at time consumed
Less dependent on memory
Face to face training on completeness and accuracy essential
Accurate portion reporting essential
Final record reviewed by professional

23. Food frequency questionnaires
Food frequency surveys most common measurement method in nutrition epi research
Average intake, “usual” intake
Easy to complete
Foods, clarity, format important

24. Approaches for Evaluating Dietary Questionnaires
Compare mean of nutrient intake
Proportion of intake accounted for
Reproducibility
Validity
Compare to biochemical indicator
Compare to physiologic indicator
Ability to predict disease

25. Food Recalls/Records Foods Recalls and Records
Based on specific foods consumed
Attempt to get data on one’s “true intake”, open-ended
Can be representative if enough days tested
Best method for comparing intake to recommendations
Most used to validate FFQ

26. Designing and Administering Questionnaires
Motivated subjects
Clear instructions
Correct foods
Standardized procedures
Interview or telephone
Portion sizes?

27. Determining best method
Individual intake or group mean?
Actual intake or relative ranking?
Open-ended method or structured list?
Age limitations?
Literacy considerations?

28. Overweight and breast cancer
Women who are overweight are more likely to:
Develop breast cancer
Be diagnosed at a later stage
Have higher mortality rates

29. Overweight and Breast Cancer
Review of 26 studies examining the association of pre-morbid weight or weight at diagnosis with recurrent disease or survival (Rock and Wahnefried, 2002)
17 found increased BMI significantly associated with increased risk of death
2 null findings
7 inverse findings

30. Overweight and Breast Cancer
Weight gain and increased risk
Obesity increases peptide hormones-insulin and steroid hormones-estrogen
Heaviest women have 3x level of estrogen than lean women without HRT
Obesity increases risk of death from breast cancer about as much as mammography reduces it.

33. Breast Cancer Survivorship
With early diagnosis, the survival rate has significantly increased
22% of all cancer survivors are breast cancer survivors
Breast cancer survivors comprise the largest proportion of cancer survivors
Survival rate is lalargely due to diagnosis occurring at a local stage, associate with a 96% 5 year survival rate

34. Weight Gain Weight gain
60% of women report weight gain after diagnosis
more prevalent:
premenopausal at diagnosis
received adjuvant chemotherapy
in African Americans
caloric intake

35. Reasons for weight gain:
Likely to be at least “peri menopausal”
Being told to “keep your strength up” during therapy
Comfort foods
Less exercise
Needs more research….

36. Exercise Type of exercise Breast cancer
Walking vs. more rigorous forms
Breast cancer
Multi beneficial
Mental, physical, emotional
Integration

37. Addressing weight gain in African American breast cancer survivors
African American women have higher mortality from breast cancer when compared to Caucasian women
Some 60% of all women report gaining weight after being diagnosed with breast cancer. However, African American women are especially at risk for this weight gain, after diagnosis of breast cancer, placing them at greater risk for cancer recurrence and shorter survival time.

38. Testing an exercise intervention in African American breast cancer survivors (Study 1)
Study Aim: Determine the feasibility and impact of a cognitive, behavioral theory-based walking intervention, Walking Counts! in a sample of AA breast cancer survivors.
Feasibility: Attendance, compliance, process measures
Outcomes: Integration of regular exercise (steps/day)
change in BMI, waist, hip, forearm circumferences, body fat %, blood pressure, attitude toward exercise and cancer stress.

39. Walking Counts!-Methods
Eligibility:
Breast cancer diagnosis
>3 months past cancer treatment
Mobile
<70 years old
Description of the intervention:
Health Belief Model
Eight week community-based, 75 minute sessions
Benefits, barriers, relationship to cancer risk,
Personal assessment/problem solving
Pedometers, scheduling, and tracking of steps/day
Wilson et al; Preventing Chronic Disease 2005

40. Walking Counts!-Results
Feasibility
Attendance-70% attended > 7 sessions
Retention: 92% retained
1 dropped after enrollment due to scheduling
1 recurred
Pedometers
Steps only mode
25% needed replacement

41. Walking Counts!-Results
Characteristics of the Sample
(n=22)
Age (yrs)
55 (39 – 66)
Weight (lbs)
191 (142 – 271)
BMI (kg/m2)
32.7 (25.2 – 47.2)
Education: (%)
< high school
High school graduate
Post high school
4.5
90.9
Marital Status: (%)
Married
Single/Divorced/Widowed 50

42. Characteristics of the Sample
Menopausal Status (%)
Pre
Post
13.6
86.4
Time Since Diagnosis: (%)
1-6 years
7-10 years
More than 10 years
59.1
27.3
Type of Treatment: (%)
Chemotherapy
Radiation therapy
Both
Neither
18.2
45.5
Tamoxifen: (%) Yes No
22.7
77.3
Alcohol: (%) Yes
72.7
Smoking: (%) Yes
9.1
90.9

43. Walking Counts! Pre/Post Measures
Baseline (N=22) Change p value*
Anthropometric measures:
Steps/day <0.001
BMI (kg/m2)
Weight (lb.)
Body Fat (%)
Waist circumference (in.)
Hip circumference (in.)
Arm circumference (in.)
Systolic B/P (mm Hg)
Diastolic B/P(mm Hg)
Waist to Hip ratio
Attitudinal measures:
Exercise Attitude Total
Cancer Stress Total
* Paired “t-test” for difference in group means.

44. Steps/day at Baseline, Post and 3 Month Post Intervention
p<.001 B/P***, p=.001*** B/3mth

45. Other research addressing obesity
Nutrigenomics: Studies to help understand the mechanism by which genes may influence chronic disease risk related to nutrients and obesity

46. Genes and obesity in breast cancer
Study Aim: Measure breast cancer gene expression profiles and analyze differences in tumor gene expression according to ethnicity in lean (BMI <25) and overweight (BMI >30) women
Methods: Using tissue samples taken at diagnosis of breast cancer, we will study microarray expression of selected genes in 100 AA and 100 Caucasian women.
Co-variates, include menopausal status, serum markers for insulin resistance and obesity, dietary intake and level of physical activity
Implications: Study results may help to identify molecular changes and or genetic pathways in lean vs overweight women that contribute to breast cancer outcomes.
(O’Connell P, Penberthy L, Wilson DB, Dumur K)

47. Other dietary trials: Women’s Intervention Nutrition Study (WINS)
Tests effect of low-fat intervention on recurrence in 2500 breast cancer survivors
Women’s Healthy Eating and Living intervention
3,109 survivors tests increased fr/veg intake, low fat, high fiber on progression of disease

48. Other nutrition areas of interest:

49. Soy Dual roles-low vs high levels Food sources only
Soy protein 25 g/day
Isoflavones-genistein
Avoid supplements

51. Omega-3 fatty acids Slow growth of tumors in animals
May increase efficacy of chemopreventive agents
Cold water fish-
Variable even within fish types
Flax seed
Canola oil

52. Supplements
Cancer patients start consuming more supplements and herbal products after diagnosis
Health claims on labels are not all official terms
Watch the research-many products are in trials

53. What to eat? Emphasize plant based foods
Eat 5-10 servings of fruits/vegetables
chemopreventive constituents
fiber
antioxidants
Eat less red-meat
Pay attention to type of fat
Don’t eliminate fat
Eat more fish

54. Summary
Nutrient driven hypotheses have significant measurement threats to validity
Providing the public with sound nutritional guidelines requires a thorough examination of “the evidence”
The evidence for the role of obesity and that for the role of exercise are among the strongest for providing advice to the public
Much more scientific research is needed to better understand the role of macro and micro nutrients related to specific cancer risk.

55. “Nutrition is one of the most significant determinants of health and one of the most modifiable.” The US Surgeon General