THE OVERLOOKED ROLE OF PHYSICAL ACTIVITY
IN THE PREVENTION AND TREATMENT OF CANCER.

By Dr. Martin Collis

Physical activity is the friend of the body/mind. Inactivity is an ally of disease. In the past few years we have seen with inconvertible clarity the fact that lack of movement is linked to many of the major diseases that kill and disable us. The truth knocks on our doors, whispers in our collective ear, shines from the print of our books and computers and we say, "Go away, I'm looking for the truth." We recline on our Lazy Boys, our fingers read the buttons of the remote control like Braille and hour and after hour we watch murders and mayhem and the 24/7 tabloid tattoo of CNN with sports scores and regional temperatures scrolling beneath. We await the next 'medical miracle' which will save our bloated bodies and the popular press gives us hope.

We read that Dr. Saunders Williams of the Duke University School of Medicine has developed a pill that builds strength and endurance in the muscles of mice. Using the Mice and Men approach it is not hard to extend the premise of this research so that we will soon have muscle pills for the human species to be washed down with beer or soft drinks while changing channels.

So reads another headline about the same story, and people live their lives in pursuit of the loophole and die of heart disease, stroke, diabetes and cancer.

The beneficial relationship between exercise and cancer is less clear than between the exercise and heart disease, stroke and diabetes. It's not hard to see why. There are many different cancers whose etiology is complex and often unknown. We do know that cancers can be triggered by genetics, cigarette smoke, stress, asbestos, fiberglass, diesel fuel, sunlight, radiation, preservatives, pollution and pesticides. There was an old rock song that featured the lyric, "Everything causes cancer." and at times it seems that way. With multiple cancers and multiple causes it's not surprising that it has been challenging to see a statistically clear positive relationship between:

1. Physical activity and the prevention of cancer.
2. Physical activity as part of a successful treatment regimen for cancer.

Another reason for the lack of clarity is the way in which many research studies have chosen to measure or record 'physical activity.'

In the past two years I've participated in three important conferences that concerned the linkage between physical activity and cancer.

In point form here is a summary of some of the current knowledge and thinking regarding the relationships between exercise and the prevention and treatment of cancer.

Data from Analysis of Multiple Studies.

• There is a 40% to 50% reduction in colon cancer incidence in active compared with sedentary individuals.
• There is a 30% to 40% reduction in breast cancer incidence among women engaging in three or more hours/week of regular vigorous activity.
• There are less strong associations (about 20%) between inactivity and prostate cancer.
• In 1997 the American Institute for Cancer Research combined with the World Cancer Research Fund to study 4,500 scientific studies involving associations between diet and physical activity level on one hand and cancer risk on the other. The findings of the 16 scientists who conducted the study indicated a general association between inactivity and increased overall cancer risk. Obesity, often linked to inactivity, increased the risk of cancer of the kidney, endometrium, breast, bladder, colon and rectum.

Data from Large Number Individual Studies.

• In the Harvard Alumni Study of 5,398 women, non-athletes had 2.5x as many cancers of the reproductive system (uterus, ovaries, cervix and vagina) as athletes and 2x as many breast cancers.
• Barlow, Blair et al. followed 22,000 men for 10 years and found unfit subjects were 2.6x more likely to die of cancer than fit subjects.
• In the journal 'Cancer' 2002; 94 Fairey and Courney note that a majority of studies show significant positive changes in immune system markers with regular exercise. They state that this may well point to exercise as a method for reducing the risk of cancer recurrence and improving survival times."

Writing for 'Well' I try to avoid citing long lists of studies, but in this case I think it is important to show that there are convincing data showing that physical activity is a significant factor in cancer prevention. The truth is that regular physical activity is almost certainly more beneficial than the studies indicate.

Most of the larger number epidemiological studies use questionnaires to assess people's physical activity level. In the past many of the questions regarding exercise have been vague and the answers hard to classify. People overestimate the amount of exercise they do, or to put it bluntly, people lie to themselves and the researchers. There have now been a number of studies in which subjects responded to a questionnaire about their physical activity and then had their cardio-respiratory fitness (CRF) objectively measured on a treadmill or cycle ergometer. In every study I have seen correlation between exercise and disease jumped when actual measured data were used. In some cancer studies the results went from showing no relationship between physical activity and cancer prevention (questionnaire responses) to a strong statistical relationship. (Objective measure of CRF). In the April 2002 Tufts Health and Nutrition Letter there is a report on a study by Dr. G. Duncan in which he says, 'people think they are pushing themselves harder than they are.' In this study, the subjects wore heart rate monitors and were also asked questions about their exercise intensity. Almost half the participants, who averaged in their late 40's, thought they exercised at least 'moderately.' But only 15% actually did.

The American Cancer Society estimates that if everybody exercised and controlled their weight, the number of Americans who die of cancer would drop by about one third. About an equal number of new cases would be prevented.

Physical Activity and Cancer Treatment

Cancer can be like high speed aging, and the treatment of cancer can be so debilitating that it becomes a risk factor itself. Chemo and radiation therapy can leave the patient nauseous, bone tired, with their immune system compromised and their hemoglobin way down. My wife, Nancy, works with many cancer patients whom she describes as 'being blindsided by fatigue.' Not surprisingly, people in this condition often take to their beds and try to eat easily digestible foods. But bed-rest can compound the problems the body is already facing with the cancer treatments. After 72 hours in bed, glucose tolerance can look like diabetes, blood coagulation increases, leading to dangers of clotting, muscles atrophy and osteoporosis begins. Also, the mind is getting a message from the body, which is immobile and horizontal, that there are major problems. It is important that physicians council their patients on the value of maintaining some form of physical activity during treatment if possible. The fatigue can be ameliorated by the use of Eprex and other drugs that elevate hemoglobin. Drugs such as Neupogen, which helps increase the white blood cell count, can boost the immune system.

The research on exercise as part of cancer treatment is not extensive, but is growing. Schwartz et al. in an article titled 'Fatigue, Breast Cancer and Chemotherapy' reported that far from increasing fatigue, exercise seemed to do the opposite. They note that, "Exercise seemed to change the perception of fatigue and its intensity.' These findings were echoed in the May 2002 'Consumer Reports on Health' in an article titled 'Exercise Fights Chemo. Fatigue.' A study, at the Oregon Cancer Center, of women undergoing breast cancer treatment found women felt 14 – 35% less fatigued on the days on which they did the recommended 15 – 30 minutes moderate exercise. Roanne Segal's work at the Ottawa Regional Cancer Center now has good data on the effectiveness of exercise during treatment, and she makes some interesting distinctions with different exercise regimens for different types of treatment.

1. Cytotoxic therapies – Cardio-vascular fitness.
2. Intensive radiotherapy – Flexibility.
3. Hormone based treatments such as Tamoxifin - Programs to improve body composition.

These are not exclusive to each type of treatment, but remind us that one exercise program does not fit all. Courneya and Friedenreich summarized 24 empirical studies and noted that physical activity led to improvements in cardio-respiratory fitness, muscle strength and body composition. People were less fatigued and nausea was more manageable. Quality of life improved, as did self-esteem, general morale and ability to deal with depression.

The ever macho and remarkable Lance Armstrong in his book 'It's Not About the Bike' says, "During those first weeks of chemo I had to keep moving. 'Move' I told myself. I would get up, throw up, put on my Walkman and walk." It is worth noting that during treatments Armstrong refused hospital food saying that his body needed only high quality nutrition in order to fight cancer. The finest line in the book is his comment about the importance of belief. He wasn't religious but said, "I believed in belief for its own shining sake."

One of my heroes, George Sheehan, a physician/runner, who died of prostate cancer that metastasized into the bone, wrote about his cancer in 'Going the Distance.' (Which he referred to as 'my death book'?) "The patient's responsibility is to follow a lifestyle that will add hours to their day. To follow a program that gives meaning and purpose to their final years, no matter how few they may be."

The Goldilocks Principle

How much exercise is appropriate to help prevent cancer? Not too little, not too much, but just right. Too little exercise, as we have pointed out, is associated with sickness. Too much, or exercise at too high an intensity, could possibly cause DNA damage and an increase in free radicals, both of which are associated with cancer. (I should add that the benefits associated with a high performance lifestyle far, far outweigh the rather remote possibility of cancerous cell damage.) The American Cancer Society Guidelines suggest the following.

• Adults: engage in at least moderate activity for 30 minutes or more on 5 or more days of the week; 45 minutes or more of moderate to vigorous activity on 5 or more days per week may further enhance reductions in the risk of breast and colon cancer.
• Children and adolescents: engage in at least 60 minutes per day of moderate-to-vigorous physical activity at least 5 days per week.
• During treatment do what you can, but try to do something despite your tiredness.

The Mechanisms. Why does exercise reduce the incidence of cancer?

The mechanisms by which regular exercise prevents cancers are not clear-cut. There are many cancers and there are probably many reasons why exercise plays a role in cancer prevention and recovery. The most simplistic is that the human body/mind is designed to move and that opportunistic disease flourishes where there is little movement. (This is simple, but as Schweitzer reminded us, we can progress from naïve simplicity to profound simplicity.) Physical activity is a known stress reducer (Remember the 3 A's Activity Absorbs Anxiety). Exercise increases immune cell function (e.g. T lymphocytes, natural killers cells, and macrophages). Exercise helps weight control and overweight is associated with cancer. The strong relationship between exercise and a decrease in colon cancer might be associated with enhanced transit time in the gut, lower insulin levels and altered bile acid metabolism.

There is much we don't know and much to be learned, and we certainly can't wait to take action until, 'all the information is in.' It never will be. Since Richard Nixon declared his 'War on Cancer' in 1971 some 30 billion dollars has been spent. (If 30 billion over 30 years sounds like a lot of money, it is less than the fast food industry spends in one year on promotion. Is it any wonder we're struggling to influence people's lifestyle and eating habits.) I didn't like Richard Nixon and I don't like military metaphors in dealing with a disease like cancer. Jeanette Rankin's famous comment is that, "You can no more win a war than you can win an earthquake." Decreasing the incidence and deaths from cancer requires finesse, patience and cultural shifts, not a war. One of the challenging questions is, how to make the most effective use of the billions of dollars obtained to help lead to a major decrease in both the incidence of cancer and deaths from cancer. There are four major areas where money can be spent namely, basic research, diagnosis, treatment and prevention. A figure one often hears is that more than 70% of cancers have their origins in lifestyle. This being so, I feel there is a strong case to be made for allocating a greater percentage of the cancer dollars to programs of prevention, lifestyle and public health.

Like the wars in Vietnam and Afghanistan and the War on Drugs, the War on Cancer can drag on and yield some statistics, which are hard to justify at first glance. In 1971, the year the war was declared, 335,000 Americans died of cancer, 25 years, and $25 billion later in 1996, 547,000 Americans died of cancer. (Close to the number of Americans that died fighting for their country in the 20th century.) It is often said that more people make a living from cancer than die from it. There has probably been far too much emphasis on discovering 'the magic bullet' and the big money corporate cure rather than helping create an environment and a cultural lifestyle which is not a good host for cancer.

Cancer is the number one cause of death in children from 1 – 14 years and in women aged 35 – 75. In the past half century breast cancer has increased 60% and prostate cancer 200% and the overall incidence of cancer seems to be growing in all age groups.

The news is not all bad however. Although the incidence of cancer is up, deaths from cancer have been declining for the past few years since 1998. This reflects earlier detection and more effective treatment. There are now about 8 million cancer survivors in the U.S.A. and since 1971 overall survival rates have nearly doubled. Childhood leukemia and Hodgkins disease have been major success stories. With the decrease in smoking, lung cancer is on the decline, a decline that will continue if we make smoking less and less socially acceptable. There are real breakthroughs in understanding the molecular and genetic processes of the cancer cell.

Leading epidemiologist, J.C. Bailar of University of Chicago, sums things up by saying, "I think it's foolish to think that some day we'll find cures for cancer. We cannot base national strategy on that kind of hope." He feels we must make prevention a top priority, while continuing work to try to pin point causation.

I agree with Dr. Bailar about the primacy of prevention and identifying the causes of cancer, but I feel he is a bit cavalier in his comments about discovering cures. Thirty five years ago as a student at Stanford I remember being puzzled by one of my old professors, Nobel Laureate Joshua Lederberg, who spoke briefly of the possibility of viruses being used to treat cancer. There have always been rumors about people whose tumors regressed when they had the flu or other viral infection, and now there seems to be growing substance to the paradoxical situation in which one disease fights another, although the principle of antibiotics is not too dissimilar from this. Work is now going on at the Ottawa Regional Cancer Center, Stanford University, Harvard and Duke, and many other institutions in which animals with cancerous tumors are being infected with a variety of viruses from herpes to the common cold. Speaking of tumor cells, Dr. Bell of the University of Ottawa notes, "They have thrown out genes that inhibit their growth, but at the same time they've thrown out their anti-viral programming."

Human trials are now underway. Michael Wosnick, director of research at the National Cancer Institute of Canada noted, "all logic says it should work." Dr. Bell has said, "I think we're going to find out that some viruses are going to be good at targeting some cancers, and that other viruses will get other cancers." The drawback of using viruses to attack tumors is that it has to be an on-going treatment and the patient will experience symptoms from the virus. However, that seems to be a price worth paying if cancer can be transformed from a killer into a manageable chronic disease.

As Emily Dickinson told us.

"Hope is the thing with feathers
That perches on the soul
And sings the song
Without the words
And never stops at all."

I believe that many of the answers lie outside the walls of the hospitals and research labs and that any initiative to rein in cancer will be doomed to failure unless we provide enormous human and fiscal resources to address lifestyle and environmental issues. My local bank sponsors a fundraiser for breast cancer titled 'Run for the Cure', which is an interesting double entendre. You can run 10K and raise some money for research, or jog on your own and literally run away from a sedentary disease inducing lifestyle.

The final word is that exercise does not stop with the cure, or when cancer goes into remission. Having been struck by the 2 by 4 of a cancer diagnosis and recovered, now is the time, not to 'put your affairs in order' but to put your life in order. Become the person you want to be, eat well, look very carefully at stressful jobs and situations and above all, move. As I've noted before, the key word in the human potential movement is 'movement.' Buy a bike, join a fitness club, get a pedometer for a step by step recovery. The possibilities are limitless. In the Fall 1999 edition of 'Well', Dino Asproloupos wrote about 10 teams of breast cancer survivors who were paddling in the Alcan Dragon Boat Festival in front of 40,000 spectators. The group known as 'Abreast in a Boat' has been featured on TV and many magazines and has helped re-shape the way physicians prescribe physical fitness activities to breast cancer survivors.

Funny how he always suggests exercise.

C.A.N.C.E.R.

There are many similarities between the lifestyle and mindset for cancer prevention and cancer treatment. These can be summed up by the acronym C.A.N.C.E.R.

C. Choice
Whatever the situation, you can choose to react or respond. The choice might be between a rock and a hard place, but it is still a choice. You can choose to accept a situation or you can choose to try and change it. You can always choose to nurture your sense of humor, which is a built in survival device.

A. Attitude
Attitude is the paintbrush of the mind. Success in real estate is defined as 'location, location, location'. Success in life is attitude, attitude, attitude.

The greatest discovery of my generation is that human beings can alter their lives by altering their attitudes of mind.
- William James

N. Nutrition
Eat plenty of natural complex carbohydrates and fiber (e.g. fruits, vegetables, grains and nuts). Go for a rainbow diet with multiple colors everyday. Numerous health enhancing phytonutrients are found in colored fruits and veggies. (see 'Well' Spring 2001 or 'The Little Book of Lifestyle Artistry.')

C. Control of Stress
We are good at being human doings, but need to be human beings as well. Seek relaxation through meditation or massage, yoga, progressive muscle relaxation, or whatever turns you off. Don't just do something, sit there. ("Calm Down" is a superb breath centered guided meditation CD by Nancy Wardle, MD)

E. Exercise
Make sure purposeful movement is a part of your day. I really like the 10,000 steps concept (see 'Well' Spring and Summer 2002, '10,000 Steps' articles). Exercise is the generic medicine, what sort of play you choose is just your brand preference. (see 'Well' Spring 2000 'Exercise' article)

R. Relationships
Loneliness is a major risk factor for cancer and many other diseases. Find ways to give and receive love, and make sure you have a loving relationship with yourself. If you find yourself spending a lot of time with negative and depressed people, consider weeding your social garden. As Dean Ornish notes, "There is a scientific basis for the healing power of intimacy.

Fund Raising for Cancer.
From the Ridiculous to the Sublime.

There has to be a better advertising placement for raising money to "conquer" cancer than a matchbook cover. But this old matchbook reminded people "every 3 minutes someone dies of cancer" and "guard those you love."

A few months back I addressed the staff of the Bone Marrow Transplant and Leukemia Unit of Vancouver General Hospital. One of their many successful patients was Adella Krall whose daughter, Diana, is one of the great jazz divas in the world. In one of those 'everybody wins' situations, each year Diana gives an exclusive performance to raise funds for the BMT Unit. Diana gets to support her mother, Adella was able to provide financial support for the hospital and people like Nancy and me get to spend a pretty special evening listening to Diana in a very intimate setting. I am always amazed at how a middle class white girl from Nanaimo can inhabit those bleak, desperate songs that make up some of the standards of jazz. But when Diana sang "Cry Me A River" she was tapping into some of those universal feelings of pain we've all experienced. The BMT Unit was able to raise over a quarter of a million dollars, and best of all, Adella was able to sit and listen to her daughter.

As a sad addendum to this, Adella Krall died very recently at age 60. I knew her when she was a teacher in Nanaimo and had a good conversation with her at Diana's evening. She was first diagnosed with multiple myeloma in 1996 and seemed to respond well to her bone marrow transplant and went back to teaching for a while, but she had a relapse in 2000 and underwent a second transplant in Sept. 2001. Cancer is a roller coaster disease in which apparent gains can be suddenly snatched away. We all wish she could have lived longer, but here is little doubt her treatment gave her a bonus six years and enabled her to watch her daughter grow into a beautiful woman and world star. Now there will be an extra poignancy when Diana sings 'Cry Me A River'.

One of my favorite detective writers is T. Jefferson Parker who has experienced the trauma of cancer within his own family. His new novel 'Black Water' features a spurious cancer cure, but in a previous novel 'Summer of Fear' he writes some very compelling segments about someone facing the reality of cancer.

"It was cancer. And I'll tell you something - I hate it. I even hate the word cancer, the way it hisses off our tongues, so eager to be said. I didn't create it, no matter what these…these…these bliss ninnies try to make me believe. They're selling snake oil in a New Age wrapper, that's all. They're in the cancer business, the phony-hope trade. I'll take the rap for almost anything - I'm a Mexican and a Catholic, right? But I refuse to take the blame anymore for this. I'm going to win; I'm going to beat this thing. Damn those people, those…parasites. Russ, what is it with this country? We think we control the whole world and everything on it - and beyond that, the moon, all the way from the heavens down to the metastatic level of the cells in our bodies. Where did we ever get so arrogant to believe that? Did it do any good? What did it get us but a place stripped of the people and animals who used to live here, a sky full of satellites and floating junk, a nation full of people who believe they can cure cancer by eating right? How can we be so arrogant to believe that cancer is our own fault? I want to live, Russ. I'm going to beat this thing. But I'm not going to accept responsibility for what's happened. I feel invaded. I feel cheated. I love you and I love life, but I hate what's happened to me. I'm going to fight with the tools I've got - love and hate. That's what I've got for weapons. You know what cancer is? Cancer is little cells growing where they shouldn't. Nobody knows why they start or how to stop them, but nobody can cure a cold, either. Cancer is not a symptom. Cancer is not a metaphor. It is not a theme. Mailer said that cancer is the growth of madness denied. Mailer is full of shit. The only thing cancer is for sure is bad luck. It's a vicious little bastard and I want it out of me. This is not a journey into myself to discover my secret desire to die."

I don't necessarily agree with all the sentiments, but it's a good reflection of the anger, frustration and desperation that cancer can provoke in a person.

Major Sources

1. Draft of proceedings of the 'Physical Activity and Cancer Conference' in Dallas, TX. Principal author Rachel Ballard-Barbash.
2. Proceedings of 'Living Well With Cancer Conference' in Vancouver, BC.
3. Proceedings of 'Promoting Nutrition and Physical Activity to Reduce Cancer Risk' in Atlanta, GA.
4. American Institute of Cancer Research press release, August 14, 1999.
5. Websites of American Cancer Society, National Cancer Institute, and Canadian Cancer Society.