This document discusses the relationship between exercise and cancer. It outlines the mechanisms by which exercise may prevent cancer, including lowering sex hormones and insulin levels. It reviews evidence that physical activity is associated with reduced risks of breast, colon, and other cancers. Exercise may also improve cancer survival rates. However, many cancer survivors do not exercise regularly. The document provides recommendations for an individualized exercise prescription for cancer patients and survivors. Precautions are discussed related to cancer treatments and medications.

1. Cancer and ExerciseCancer and Exercise
B. Elizabeth Delasobera, MDB. Elizabeth Delasobera, MD
Sports Medicine FellowSports Medicine Fellow

2. OutlineOutline
 The mechanism for how exercise canThe mechanism for how exercise can
prevent cancerprevent cancer
 The evidence for exercise and increasedThe evidence for exercise and increased
cancer survivalcancer survival
 The exercise prescription for cancerThe exercise prescription for cancer
patients and survivorspatients and survivors

3. Cancer ReviewCancer Review
 Excessive, uncontrolled cellularExcessive, uncontrolled cellular
proliferation with potential for metastasisproliferation with potential for metastasis
 Symptoms can be local or systemicSymptoms can be local or systemic
 Variety of treatmentsVariety of treatments
Surgery, Radiation, Chemotherapy,Surgery, Radiation, Chemotherapy,
ImmunotherapyImmunotherapy
Designed to attempt remission or cure, or forDesigned to attempt remission or cure, or for
disease control or symptom reliefdisease control or symptom relief

4. Mechanism for CancerMechanism for Cancer
Reduction with ExerciseReduction with Exercise
 Physical activity lowers levels of biologicallyPhysical activity lowers levels of biologically
available sex hormonesavailable sex hormones
Decreased lifetime exposure to endogenousDecreased lifetime exposure to endogenous
sex hormones -> decreased risk of hormone-sex hormones -> decreased risk of hormone-
related cancersrelated cancers
Breast, endometrial, ovaries, prostate, testesBreast, endometrial, ovaries, prostate, testes

5.  Exercise decreases endogenous insulinExercise decreases endogenous insulin
productionproduction
Higher levels of circulating insulin linked withHigher levels of circulating insulin linked with
several cancersseveral cancers
 Exercise associated with decreased levelsExercise associated with decreased levels
of IGFof IGF
High levels of IGF-1 a/w several cancersHigh levels of IGF-1 a/w several cancers
(colon, prostate, breast, lung)(colon, prostate, breast, lung)
Mechanism for CancerMechanism for Cancer
Reduction with ExerciseReduction with Exercise

6. Mechanism for CancerMechanism for Cancer
Reduction with ExerciseReduction with Exercise
 Adiposity and Cancer RiskAdiposity and Cancer Risk
Increased fat associated with increased risk ofIncreased fat associated with increased risk of
cancers of colon, kidney, esophagus,cancers of colon, kidney, esophagus,
endometrium, thyroid, post-menopausal breastendometrium, thyroid, post-menopausal breast
 Physical activity decreases colon transit timePhysical activity decreases colon transit time
 Decreases colonic exposure to carcinogens in stoolDecreases colonic exposure to carcinogens in stool
 Level of physical activity inversely related to levelsLevel of physical activity inversely related to levels
of C-reative proteinof C-reative protein
 NSAID use in physically activeNSAID use in physically active
 NSAID use appears to decrease colon cancer riskNSAID use appears to decrease colon cancer risk

8. The Evidence:The Evidence:
Exercise and Cancer RiskExercise and Cancer Risk
 Breast CancerBreast Cancer
 Invasive Breast Cancer risk decreased by 15%-50%Invasive Breast Cancer risk decreased by 15%-50%
among physically active womenamong physically active women
 Women < 40yo exercising 4 hrs/week or more duringWomen < 40yo exercising 4 hrs/week or more during
reproductive years had 50% risk reductionreproductive years had 50% risk reduction
 Postmenopausal women with higher rates of recreationalPostmenopausal women with higher rates of recreational
activity have lower incidence of breast canceractivity have lower incidence of breast cancer
 Confirmed in over 30 studies in multiple demographic andConfirmed in over 30 studies in multiple demographic and
population groupspopulation groups
 Studies focused solely onStudies focused solely on in situin situ Breast Cancer have shownBreast Cancer have shown
similar reductions in risksimilar reductions in risk
 Estrogren receptor negative cancer seem to be mostEstrogren receptor negative cancer seem to be most
reduced with exercisereduced with exercise
Bernstein L, AACR Education Book 2008:225-231 (2008)

9. The Evidence:The Evidence:
Exercise and Cancer RiskExercise and Cancer Risk
 Breast CancerBreast Cancer
 Greatest reduction is risk found with exercise duringGreatest reduction is risk found with exercise during
reproductive years, strenuous activity, at least 5 hoursreproductive years, strenuous activity, at least 5 hours
per weekper week
 Estrogen receptor-negative Breast Cancer respondsEstrogen receptor-negative Breast Cancer responds
better to exercise than receptor-positive cancerbetter to exercise than receptor-positive cancer
 Meta-analysis revealed a dose-response relationshipMeta-analysis revealed a dose-response relationship
of 6% decrease in relative risk for each additionalof 6% decrease in relative risk for each additional
hour of physical activity per weekhour of physical activity per week
Monninkhof EM, et al. Epidemiol 2007;18:137–57.Monninkhof EM, et al. Epidemiol 2007;18:137–57.
Bernstein L, AACR Education Book 2008:225-231 (2008)

10. The Evidence:The Evidence:
Exercise and Cancer SurvivalExercise and Cancer Survival
 Breast Cancer Survival Meta-AnalysisBreast Cancer Survival Meta-Analysis
24% - 67% reduction in total deaths and 50%24% - 67% reduction in total deaths and 50%
reduction in breast cancer recurrence inreduction in breast cancer recurrence in
women who are physically activewomen who are physically active
Best effect in women who underwentBest effect in women who underwent
equivalent of brisk walking 3h per weekequivalent of brisk walking 3h per week
Effect observed in pre and post-menopausal,Effect observed in pre and post-menopausal,
overweight and normal weight women, andoverweight and normal weight women, and
those with stage I-III diseasethose with stage I-III disease

11. The Evidence:The Evidence:
Exercise and Cancer RiskExercise and Cancer Risk
 Colon CancerColon Cancer
 43 out of 51 studies demonstrated decreased risk of43 out of 51 studies demonstrated decreased risk of
colon cancer in the most physically active participantscolon cancer in the most physically active participants
 Risk reduction averaged 40%-50%, up to 70%Risk reduction averaged 40%-50%, up to 70%
 Consistent risk reduction despite differing studyConsistent risk reduction despite differing study
designs and populations and types of exercisedesigns and populations and types of exercise
 Greater effect in men vs. womenGreater effect in men vs. women
 Hormone supplementation in postmenopausal women alsoHormone supplementation in postmenopausal women also
has protective effecthas protective effect
 Unclear exercise effect on rectal cancerUnclear exercise effect on rectal cancer
Bernstein L, AACR Education Book 2008:225-231 (2008)
Friedenreich CM, et al. J Nutr 132:3456-3464, 2002.

12. The Evidence:The Evidence:
Exercise and Cancer SurvivalExercise and Cancer Survival
 Colon cancer survivalColon cancer survival
3h per week of moderate physical activity3h per week of moderate physical activity
after colon cancer diagnosis:after colon cancer diagnosis:
39%-59% decreased risk of colon cancer death39%-59% decreased risk of colon cancer death
50%-63% decreased risk of total death50%-63% decreased risk of total death
Effect essentially unchanged across age, sex, BMI,Effect essentially unchanged across age, sex, BMI,
disease stage, age at diagnosisdisease stage, age at diagnosis
 Meyerhardt JA, et al.Meyerhardt JA, et al. J Clin OncolJ Clin Oncol 2006;2006;2424:3535–41:3535–41

13. The Evidence:The Evidence:
Exercise and Cancer PreventionExercise and Cancer Prevention
 Prostate CancerProstate Cancer
Less consistent data, risk reduction averagedLess consistent data, risk reduction averaged
10% - 30%10% - 30%
Poor understanding of natural history ofPoor understanding of natural history of
Prostate CancerProstate Cancer
Exercise can also reduce risk of BPHExercise can also reduce risk of BPH
Exercise lowers severity of disease andExercise lowers severity of disease and
fatalities from prostate cancerfatalities from prostate cancer
Likely that very high level of exertion early inLikely that very high level of exertion early in
life needed to influence implicated hormoneslife needed to influence implicated hormones
Bernstein L, AACR Education Book 2008:225-231 (2008)
Friedenreich CM, et al. J Nutr 132:3456-3464, 2002.

14. The Evidence:The Evidence:
Exercise and Cancer PreventionExercise and Cancer Prevention
 Endometrial CancerEndometrial Cancer
Strong association with Breast CancerStrong association with Breast Cancer
Fewer/lower quality studiesFewer/lower quality studies
Majority still show decreased risk of endometrialMajority still show decreased risk of endometrial
cancer with increased physical activitycancer with increased physical activity
 Risk Reduction varied: 0 – 90%, average 30% - 40%Risk Reduction varied: 0 – 90%, average 30% - 40%
Majority of studies show dose response effectMajority of studies show dose response effect
Bernstein L, AACR Education Book 2008:225-231 (2008)
Friedenreich CM, et al. J Nutr 132:3456-3464, 2002.

15. The Evidence:The Evidence:
Exercise and Cancer PreventionExercise and Cancer Prevention
 Lung CancerLung Cancer
Physical activityPhysical activity probablyprobably decreases risk ofdecreases risk of
lung cancer, but effect not well-establishedlung cancer, but effect not well-established
Meta-analysis shows 13% risk reduction withMeta-analysis shows 13% risk reduction with
moderate recreational physical activity andmoderate recreational physical activity and
30% decreased risk with strenuous activity30% decreased risk with strenuous activity
Studies may not reflect differences in smokingStudies may not reflect differences in smoking
habitshabits
Tardon A, et al. Cancer Causes Control 2005;16:389–97.Tardon A, et al. Cancer Causes Control 2005;16:389–97.

16. The Evidence:The Evidence:
Exercise and Cancer PreventionExercise and Cancer Prevention
 Limited and/or insufficient evidence:Limited and/or insufficient evidence:
Ovarian CancerOvarian Cancer
Testicular CancerTesticular Cancer
Renal Cell CancerRenal Cell Cancer
Pancreatic CancerPancreatic Cancer
Thyroid CancerThyroid Cancer
MelanomaMelanoma

17. Survivors and ObesitySurvivors and Obesity
 Improvements in treatment means more survivorsImprovements in treatment means more survivors
 11 million cancer survivors in US alone11 million cancer survivors in US alone
 Obesity and a sedentary lifestyle prevalent amongObesity and a sedentary lifestyle prevalent among
cancer survivors (Irwin ML,cancer survivors (Irwin ML, BJSMBJSM 2009;2009;4343:32-38):32-38)
 Higher than general populationHigher than general population
 Increases risk of cancer recurrence and deathIncreases risk of cancer recurrence and death
 In breast cancer survivors, obesity assoc w/ 50%In breast cancer survivors, obesity assoc w/ 50%
increase in cancer recurrence and death (Kroenkeincrease in cancer recurrence and death (Kroenke
CH, et al.CH, et al. J Clin OncolJ Clin Oncol 2005;2005;2323:1370–8):1370–8)
 Cancer survivors die from non-cancer related CVDCancer survivors die from non-cancer related CVD
and DM2 at a higher rate than the generaland DM2 at a higher rate than the general
populationpopulation

18. So Are Cancer Pts Exercising?So Are Cancer Pts Exercising?
 Despite these well documented dramaticDespite these well documented dramatic
effects, the great majority of cancereffects, the great majority of cancer
survivors do not participate in regularsurvivors do not participate in regular
physical activityphysical activity
 Many cancer survivors decrease theirMany cancer survivors decrease their
physical activity after diagnosisphysical activity after diagnosis
 Women with breast cancer exercise, onWomen with breast cancer exercise, on
average, 2 hours less per week 1 yearaverage, 2 hours less per week 1 year
after diagnosis than pre-diagnosis.after diagnosis than pre-diagnosis.

20. Recs for Exercising with CancerRecs for Exercising with Cancer
 Goal is to preserve and possibly improveGoal is to preserve and possibly improve
functionfunction
 Must be individualizedMust be individualized
Tailor to level of functionTailor to level of function
Accommodate for periods of increased fatigueAccommodate for periods of increased fatigue
and cycles of treatmentand cycles of treatment
 Make exercise an integral part of everydayMake exercise an integral part of everyday
lifelife

21. Recs for Exercising with CancerRecs for Exercising with Cancer
 30-50% of breast cancer deaths among30-50% of breast cancer deaths among
post-menopausal women can bepost-menopausal women can be
attributed to being overweightattributed to being overweight
 Cancer survivors die of non-cancerCancer survivors die of non-cancer
causes at a higher rate than persons incauses at a higher rate than persons in
the general population (CV dz, DM, etc)the general population (CV dz, DM, etc)

22. Recs for Exercising with CancerRecs for Exercising with Cancer
 Special Considerations for Cancer andSpecial Considerations for Cancer and
Exercise:Exercise:
Cancer treatment can cause osteoporosis;Cancer treatment can cause osteoporosis;
bony metastases may weaken bone = higherbony metastases may weaken bone = higher
risk of pathologic fracturerisk of pathologic fracture
Be aware of Hickman cathethers, Port-a-Be aware of Hickman cathethers, Port-a-
caths, other access linescaths, other access lines
If platlet count is below 50k, consider risk ofIf platlet count is below 50k, consider risk of
bleedingbleeding
Consider concomitant effects of CVD andConsider concomitant effects of CVD and
anemiaanemia

23. Recs for Exercising with CancerRecs for Exercising with Cancer
 Medications That Can Effect Exercise Tolerance:Medications That Can Effect Exercise Tolerance:
 Glucocorticoids: may cause muscle weakness andGlucocorticoids: may cause muscle weakness and
wastingwasting
 Growth factors: may cause bone painGrowth factors: may cause bone pain
 Chemotherapy: may cause anemia, fatigue, and nausea;Chemotherapy: may cause anemia, fatigue, and nausea;
possibly myopathies and neuropathiespossibly myopathies and neuropathies
 Anthracyclines can cause cardiomyopathy, heart failure andAnthracyclines can cause cardiomyopathy, heart failure and
coronary vasospasmcoronary vasospasm
 Radiation: may cause skin breakdown, muscle and jointRadiation: may cause skin breakdown, muscle and joint
constriction, and cardiopulmonary fibrosisconstriction, and cardiopulmonary fibrosis

24. Recs for Exercising with CancerRecs for Exercising with Cancer

25. Recs for Exercising with CancerRecs for Exercising with Cancer
 American Cancer Society Recs:American Cancer Society Recs:
While getting adjuvant treatment recs 3-5While getting adjuvant treatment recs 3-5
days/week for 20-30 mins tailored to fitnessdays/week for 20-30 mins tailored to fitness
level and tx side effects (ex, walking, resistancelevel and tx side effects (ex, walking, resistance
training, yoga)training, yoga)
Survivors use ACSM sports prescriptionSurvivors use ACSM sports prescription
guidelines (keep in mind any limitations basedguidelines (keep in mind any limitations based
on prior slides)on prior slides)

26. Recs for Exercising with CancerRecs for Exercising with Cancer
 Things to Keep in Mind with Return toThings to Keep in Mind with Return to
Sport:Sport:
Immunocompromised? (neutropenia, on chemo,Immunocompromised? (neutropenia, on chemo,
etc)etc)
At risk of bleeding? (platlet count, coags, meds)At risk of bleeding? (platlet count, coags, meds)
At risk of CV issues? (meds)At risk of CV issues? (meds)
““Neck check”Neck check”

28. SummarySummary
 Multiple biologic explanations for benefitsMultiple biologic explanations for benefits
of exercise with respect to cancer riskof exercise with respect to cancer risk
reduction and survivalreduction and survival
 Exercise and Cancer PreventionExercise and Cancer Prevention
Convincing evidence for increased activityConvincing evidence for increased activity
and prevention of colon, breast, and prostateand prevention of colon, breast, and prostate
cancercancer
Probable evidence for endometrial and lungProbable evidence for endometrial and lung
cancercancer
Insufficient evidence for all othersInsufficient evidence for all others

29. SummarySummary
 Exercise and Cancer SurvivalExercise and Cancer Survival
 Increasing numbers of survivors in populationIncreasing numbers of survivors in population
 Decreasing physical activity among survivorsDecreasing physical activity among survivors
 Increased physical activity significantly lowers cancerIncreased physical activity significantly lowers cancer
recurrence and total death in survivorsrecurrence and total death in survivors
 Exercise PrescriptionExercise Prescription
 Must be individualizedMust be individualized
 Many confounding factors (be aware of meds andMany confounding factors (be aware of meds and
side effects)side effects)
 Keep it simple, make it regular, progress graduallyKeep it simple, make it regular, progress gradually