Sloan Kettering’s Quest to Prove Exercise Can Inhibit Cancer
Dr. Lee Jones and his team at Memorial Sloan Kettering Cancer Center in New York are studying whether an exercise regimen can inhibit the spread of cancer and help prevent its recurrence. From left, Dr. Jones, Marsha Patel, John Sasso and Kristen Aufiero. Photo: Memorial Sloan Kettering Cancer Center
By Lucette Lagnado
Researchers are testing an intriguing new weapon for patients battling cancer: rigorous physical exercise.
Studies and clinical trials at Memorial Sloan Kettering Cancer Center in New York City aim to find out if a regimen of exercise training can inhibit or delay the spread of a malignant tumor and help prevent its recurrence. An early-stage trial currently under way involves 72 women with stage 4 breast cancer, which has spread to other parts of the body and is generally considered incurable.
Scientists say the research, part of an emerging field known as exercise oncology, could take years to prove a link between exercise and cancer. If successful, they hope exercise someday will become a standard of care in cancer treatment, along with conventional therapies such as surgery, radiation and chemotherapy.
ENLARGE
Kristen Bouderau, who has stage 4 breast cancer, is supervised by an exercise physiologist as she walks on a treadmill at various intensities and duration for 30 to 60 minutes, three times a week for 12 weeks as part of a trial at Memorial Sloan Kettering.Photo: Caitlin Hool for Memorial Sloan Kettering Cancer Center
Previous studies have found, for example, that breast-cancer patients who exercise have a lower risk of recurrence and are less likely to die from their disease than women who are inactive. But the findings, from observational studies, aren’t definitive, experts say. Exercise also has been shown to help some cancer patients tolerate the debilitating effects of chemo and radiation treatments.
The new research at Sloan Kettering includes randomized, controlled studies—considered the gold standard for scientific inquiry—seeking to prove that exercise can alter the biology of a tumor, thereby inhibiting or slowing its growth, says Lee Jones, who is leading the Sloan Kettering effort.
Dr. Jones, an exercise scientist with Sloan Kettering’s Cardiology Service, whose research has focused on oncology, says studies with animals suggest the idea of reversing tumor growth with exercise may be possible. A study he co-authored, published last year in the Journal of the National Cancer Institute, found that “exercise statistically significantly reduced tumor growth” in mice with breast cancer.
Some doctors caution that some cancer patients can’t tolerate even moderate exercise. Chemo drugs can take a heavy toll on the body, for example, and cancers that metastasize to the bones could raise the risk of fractures, says Anne McTiernan,a doctor and researcher at the Fred Hutchinson Cancer Center in Seattle.
Still, Dr. McTiernan says previous research has made her optimistic that physical activity can affect tumor behavior and may lower cancer recurrence, though more research needs to be done.
There is “no question” that exercise is important to overall health, but data showing it can combat or prevent cancer is “poorly supported,” says Daniel Hayes, an oncologist and professor of breast-cancer research at the University of Michigan Comprehensive Cancer Center in Ann Arbor. Dr. Hayes, who is the incoming president of the American Society of Clinical Oncology, says he supports further research, but emphasizes “the importance of not abandoning standard treatments in hopes that diet and exercise will replace them.”
In the trial of stage 4 breast-cancer patients, a total of 72 women, who are also receiving standard cancer treatments, have been randomly assigned to either 12 weeks of rigorous, structured exercise, or to a gentler program of stretching. Fifty women have so far completed the trial. The early-stage study is meant to determine if the women are safely able to tolerate the workout, done on a treadmill. Results are expected later this year, Dr. Jones says.
Patients are initially tested to establish their baseline capacity, which helps determine the duration and intensity of their workouts. Members of the research team monitor the patients’ vital signs during the workout and stretching sessions.
Dr. Jones says he hopes to move on to a phase 2 randomized trial to test whether women who do intense exercise show improvement. Signs could include a tumor remaining stable for a longer time, better overall patient survival or improved quality of life. Conclusive evidence on whether exercise can inhibit cancer’s progression could take as long as 15 years to gather, he says.
Leslie Plush completed Sloan Kettering’s phase I trial of exercise and cancer last year. Ms. Plush, who got married a few months ago, says she found herself on New Year’s Eve wishing that ‘my life was going to be good and I was going to be healthy.’ Photo: Leslie Plush
Patients with stage 4, metastatic breast cancer have an average life expectancy of about three years from the time of diagnosis, although some women live much longer.
Kristen Bouderau, a costume designer in New York City, was diagnosed in 2012 with metastatic breast cancer that spread to her spine. The 50-year-old gets weekly chemo treatments. She also works out at a Sloan Kettering rehab facility three times a week as part of Dr. Jones’s exercise trial. An exercise physiologist stands at her side monitoring her pulse and breathing and takes her blood pressure every five minutes to make sure she is tolerating the exercise.
After 11 minutes on the treadmill, Ms. Bouderau is chipper but a bit out of breath. “I haven’t burned off half a bagel yet,” she jokes. She is hopeful the workout will help her. “I want to be here for my 12-year-old [daughter]. I would like to be here when she is 18.”
Dr. Jones says his team carefully tells participants the study isn’t designed to help with their cancer, that it isn’t known if it will.
It isn’t clear how exercise might work in the body to affect a tumor. One theory is that physical activity can reduce levels of insulin and other factors that have been linked to greater cancer risk. Exercise also can boost the immune system, and it might affect the environment in which the cancer is growing. “Cancer doesn’t grow in a vacuum, and what is around the tumor can either support its growth or can inhibit it,” says Jennifer Ligibel, an oncologist at Dana-Farber Cancer Institute.
“Twenty years ago when I was in training we thought that people with cancer, we needed to give them more rest. [Now] we realize that physical activity can be part of the treatment,” says Ernest Hawk, vice president of cancer prevention at MD Anderson Cancer Center in Houston, who helps lead prevention efforts at the American Association for Cancer Research.
Karen Cadoo, an oncologist at Sloan Kettering who specializes in ovarian cancer, is working with Dr. Jones on another experiment to see if a regimen of exercise can help a group of her patients cope with the side effects of chemotherapy. Typically, 50% of women with ovarian cancer who are prescribed intense chemotherapy aren’t able to finish the treatment because of such side effects as persistent nausea or extreme fatigue, she says. Since patients who tolerate more rounds of the strong chemo have better outcomes, exercise could perhaps help improve their survival, Dr. Cadoo says.
Animal studies Dr. Jones is running in basement laboratories at Sloan Kettering also are investigating whether physical activity can delay or prevent the spread of cancer. In one experiment, groups of zebrafish swim three hours a day against different strength currents in special tanks known as swim tunnels. The zebrafish have metastatic melanoma, and because they are translucent, the cancer shows up as a little black blemish.
In another experiment, groups of mice at risk for breast cancer are racing on treadmills to test whether exercise, and how much, will keep them from developing a malignancy or delay its onset.
Leslie Plush, 50, has been getting various treatments for her stage 4 metastatic breast cancer. She also completed Dr. Jones’s phase I trial last year. Ms. Plush, a decorative artist in New York City, says she continues to exercise at home and finds she can walk faster and is less out of breath.
Ms. Plush, who got married a few months ago, says she found herself on New Year’s Eve wishing that “my life was going to be good and I was going to be healthy.” She hopes the exercise regimen and other treatments will help stave off her cancer. Her new husband “has been there for me through it all,” she says. Now she would like to be there for him “as much as possible and for as long as possible.”
Write to Lucette Lagnado at lucette.lagnado@wsj.com
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