What would Hiawatha think?

Jacob Schor ND FABNO

November 5, 2008


I spend several early morning hours each week in the weight room of the Hiawatha Davis Recreation Center, one the neighborhood centers funded by the City of Denver. This center used to be called Skyline but was renamed in honor of Hiawatha Davis who died of prostate cancer in May 2000. 

Hiawatha Davis was born on April 30, 1944 and grew up in the Denver neighborhoods that he went on to serve for three decades as our representative on the Denver City Council.  He was a graduate of Manual High School, and studied economics at the University of Colorado.

During the Vietnam era, Davis something of a rabble rouser, working as a community activist and organizer in the San Francisco area and getting arrested as a draft resister. . Though sentenced to eighteen months in prison, he was pardoned by Gerald Ford, thanks, in part, to his community involvement, which entailed training Vista volunteers to work in underprivileged communities, managing youth centers, and directing the Neighborhood Programs for Denver Opportunity.  Elected to the Denver City Council in 1983 and Davis served on the council until his death.

I did not have the privilege of knowing Davis in his younger years; by the time I met him, he had grown into a gracious gentleman.

I am thinking of Hiawatha this morning.  I should be thinking of him I guess because of the election results, but I hadn’t thought of the election and race issues until I typed the prior line.  I’m sorry, as Hiawatha was someone who would appreciate yesterday’s election.  Rather, I’m thinking of Hiawatha because I’ve been reviewing research on the benefit exercise provides to cancer patients.

Despite the party atmosphere at the gym this morning, there is a rumor going around that budget cuts threaten to reduce the services provided at the center named in Hiawatha’s memory.

Over the last several years a number of startling papers have been published on the benefit exercise has on cancer.  Startling because few would guess the effect would be so great.  Hiawatha Davis being the intelligent gentleman he was would have seen the importance and implications of the current science.

Back in August 2006, the Journal of Clinical Oncology (JCO) reported that exercise could cut risk of dying in patients with advanced colon cancer by almost half.  The researchers watched 832 patients with stage III colon cancer.  Patients reported on physical activities approximately 6 months after finishing treatment and were observed for recurrence or death.  The patients who exercised the most had an “adjusted hazard ratio for disease-free survival of 0.51.” Translated into English, the people who exercised decreased their chance having cancer come back by almost.

Another JCO paper from the same month, observed 573 women with stage I to III colorectal cancer, and tracked if the cancer killed them or something else did and compared these statistics with how much they exercised.  The women who exercised decreased their overall risk of dying from cancer by 61% and from all causes by 57%. How physically active the women were before they were diagnosed with cancer didn’t matter. Increasing physical activity after diagnosis was what had the greatest effect. 

A larger December 2007 article in the International Journal of Cancer also looked at women and colon cancer.   This study analyzed the risk of colon cancer in 79,295 women.  Between the start of the study in 1986 and when it finished in 2002, 547 cases of colon cancer were diagnosed in the group. The women who exercised had a 23% lower risk of developing colon cancer than women who didn’t.  The more hours spent in physical activity the lower the risk.  Women who exercised more than 4 hours a week had a 40% lower risk of colon cancer than those exercising less than an hour a week. 

A number of new papers on this weight, exercise and cancer business were presented at this years annual meeting of the American Society of Clinical Oncology (ASCO).  Several studies focused on Body Mass Index (BMI).  BMI is simply the ratio between belly and hip circumference.  The bigger your belly in compared to your hips the worse your cancer risk.

Larger BMI  means larger risk for cancer, all types of cancer, including breast cancer. 

Information presented at ASCO tell us that breast cancer patients can survive longer without disease and live longer overall simply by losing weight and reducing their BMI.  Reducing BMI improves response to cancer treatment and reduces complications.   The data show that even brisk walking provides a survival benefit for breast cancer patients

Obesity clearly leads to worse outcomes in breast cancer.  Litton and colleagues at MD Anderson, writing in JCO, compared BMI and response to chemotherapy in 1169 women treated for breast cancer between 1990 and 2004. Chemotherapy was more likely to shrink tumors in normal weight patients than in heavy patients. Obese patients had fewer hormone-dependant tumors and more stage 3-4 tumors; these are all bad things to have and result in worse overall survival 4 years later.

Patients with higher BMI have larger breast tumors, more positive lymph nodes, and worse tumor stage and grade.  Danish researchers made these conclusions after evaluated BMI in 4,917 women diagnosed with breast cancer between 2001 and 2004. Losing the extra belly weight and reducing BMI is good for cancer patients.

So is exercise. In another new ASCO paper, Irwin and his colleagues asked whether walking makes a difference in survival. They observed 933 women with breast cancer who were part of the Health, Eating, Activity and Lifestyle Study.  The researchers found an association between pre and post-diagnosis physical activity and mortality.  

Compared with women who were inactive both before and after diagnosis, women who increased physical activity after diagnosis had a 45% lower risk of death.  Women who decreased physical activity after diagnosis had a four-fold greater risk of death.  

This is intense to contemplate. Do the math; the difference in risk between women who increase their exercise after diagnosis and those who decrease their exercise is 8-fold. 

Compare this with standard treatments for breast cancer.  Typical estimates are that chemotherapy reduces risk of death by 10-20% and radiation therapy by 70%.   Getting women diagnosed with breast cancer to exercise may prove to be as effective (or maybe even more effective) than standard treatments.  Given current knowledge we need to focus on increasing fitness and exercise programs both to prevent and treat cancer.  Exercise generally makes people feel better.  Few would say the same about chemotherapy.

As a community we should be opening more recreational centers and finding new ways to encourage physical activity.  Closing down accessibility to existing facilities, though seemingly sensible due to decreasing restraints, in the long run will cost us all more both in money and loss of life.  Hiawatha Davis spent his life working to better his community.  I can only guess what he would think about these staffing cuts.



Impact of physical activity on cancer recurrence and survival in patients with stage III colon cancer: findings from CALGB 89803. J Clin Oncol. 2006 Aug 1;24(22):3535-41.


PURPOSE: Regular physical activity reduces the risk of developing colon cancer, however, its influence on patients with established disease is unknown.

PATIENTS AND METHODS: We conducted a prospective observational study of 832 patients with stage III colon cancer enrolled in a randomized adjuvant chemotherapy trial.

Patients reported on various recreational physical activities approximately 6 months after completion of therapy and were observed for recurrence or death. To minimize bias by occult recurrence, we excluded patients who experienced recurrence or died within 90 days of their physical activity assessment.

RESULTS: Compared with patients engaged in less than three metabolic equivalent task (MET) -hours per week of physical activity, the adjusted hazard ratio for disease-free  survival was 0.51 (95% CI, 0.26 to 0.97) for 18 to 26.9 MET-hours per week and 0.55 (95% CI, 0.33 to 0.91) for 27 or more MET-hours per week. The adjusted P for trend was .01. Postdiagnosis activity was associated with similar improvements in recurrence-free survival (P for trend = .03) and overall survival (P for trend =  .01). The benefit associated with physical activity was not significantly modified by sex, body mass index, number of positive lymph nodes, age, baseline performance status, or chemotherapy received. Moreover, the benefit remained unchanged even after excluding participants who developed cancer recurrence or died within 6 months of activity assessment.

CONCLUSION: Beyond surgical resection and postoperative adjuvant chemotherapy for stage III colon cancer, for patients who survive and are recurrence free approximately 6 months after adjuvant chemotherapy, physical activity appears to reduce the risk of cancer recurrence and mortality. PMID: 16822843

 Physical activity and survival after colorectal cancer diagnosis. J Clin Oncol. 2006 Aug 1;24(22):3527-34.


PURPOSE: Physically active individuals have a lower risk of developing colorectal cancer but the influence of exercise on cancer survival is unknown.

PATIENTS AND METHODS: By a prospective, observational study of 573 women with stage I to III colorectal cancer, we studied colorectal cancer-specific and overall mortality according to predefined physical activity categories before and after diagnosis and by change in activity after diagnosis. To minimize bias by occult recurrences, we excluded women who died within 6 months of their postdiagnosis physical activity assessment.

RESULTS: Increasing levels of exercise after diagnosis of nonmetastatic colorectal cancer reduced cancer-specific mortality (P for trend = .008) and overall mortality (P for trend = .003). Compared with women who engaged in less than 3 metabolic equivalent task [MET] -hours per week of physical activity, those engaging in at least 18 MET-hours per week had an adjusted hazard ratio for colorectal cancer-specific mortality of 0.39 (95% CI, 0.18 to 0.82) and an adjusted hazard ratio for overall mortality of 0.43 (95% CI, 0.25 to 0.74). These results remained unchanged even after excluding women who died within 12 and 24 months of activity assessment. Prediagnosis physical activity was not predictive of mortality. Women who increased their activity (when comparing prediagnosis to postdiagnosis values) had a hazard ratio of 0.48  (95% CI, 0.24 to 0.97) for colorectal cancer deaths and a hazard ratio of 0.51 (95% CI, 0.30 to 0.85) for any-cause death, compared with those with no change in activity.

CONCLUSION: Recreational physical activity after the diagnosis of stages I to III colorectal cancer may reduce the risk of colorectal cancer-specific and overall mortality. PMID: 16822844

COMMENT: So the conclusion is broadened to colorectal cancer with stages I to III.  Note it was an increase in physical activity that provided benefit.

Leisure-time physical activity patterns and risk of colon cancer in women.

Int J Cancer. 2007 Dec 15;121(12):2776-81.

ABSTRACT: Although physical activity has been consistently associated with lower risk of colon cancer, many details of the relationship remain unclear. We assessed the relation between physical activity and risk of colon cancer in 79,295 women aged 40-65 who were free of cancer, ulcerative colitis and Crohn's disease and who reported their leisure-time physical activity in 1986; 547 cases were identified through 2002. Women who expended more than 21.5 metabolic equivalent hr/week of physical activity had a relative risk (RR) of colon cancer of 0.77 (95% CI 0.58-1.01), compared to women who expended <2 metabolic equivalent hr/week. The association was stronger for distal than proximal tumors. Among women whose only reported activity was walking, there was a decreased risk of colon cancer in women walking 1-1.9 hr/week (RR = 0.69, 95% CI 0.47-1.03) compared to those who did not walk. Results were similar for increased amounts of walking, but there was no evidence of a dose response relation. Among women who participated in moderate or vigorous activity, increasing hours of activity were also associated with a decreased risk of colon cancer (p for trend = 0.01); women exercising >4 hr/week had a 40% lower risk of colon cancer than those exercising <1 hr/week (RR = 0.56, 95%CI 0.33-0.94). Long-term physical activity was not associated with risk of colon cancer, but the number of cases was small. A significant inverse association exists between physical activity, including that of moderate intensity, such as walking, and risk of colon cancer in women that is more pronounced for distal tumors. (c) 2007 Wiley-Liss, Inc. PMCID: PMC2291204, PMID: 17722094

Litton et al. Relationship Between Obesity and Pathologic Response to Neoadjuvant Chemotherapy Among Women With Operable Breast Cancer. J Clin Oncol 26:4072-4077J

Jensen A. R.  al. The relation between Body Mass Index, comorbidity, choice of surgery, and prognostic factors in early breast cancer - Data from a nation-wide Danish cohort

Irwin ML et al. Influence of Pre- and Postdiagnosis Physical Activity on Mortality in Breast Cancer Survivors: The Health, Eating, Activity, and Lifestyle StudyML J Clin Oncol 26:3958-3964