Could exercise and mindfulness slow the growth of breast cancer tumors? A study by Yale's medical and public health schools now under way in partnership with the Dana-Farber Cancer Institute aims to answer that question.
Researchers at the Breast Center at Smilow Cancer Hospital at Yale-New Haven, the Yale School of Public Health and the Dana-Farber Cancer Institute, a Boston-based affiliate of Harvard Medical School, are conducting a preclinical trial to compare the effects of exercise and mindfulness on breast cancer patients — during the window between diagnosis and surgery.
The study is exploring how much of a positive effect exercise and mindfulness — a therapeutic stress-reduction technique being used as a control in the study — could have on the immune system, which then might have a biologic effect on cancer, said Dr. Anees Chagpar, the Breast Center's director and a co-investigator on the study.
"We don't know that it will actually shrink the cancer or have an effect on the cancer at a more molecular, a more cellular level," Chagpar said. "We're looking at how it affects the immune system, which then may make the cancer potentially less aggressive or may help the body to have a response to these cancers."
Dr. Melinda Irwin, co-principal investigator on the study and an associate professor of epidemiology with the Yale School of Public Health, said observational studies since 1994 have shown that physical activity lowers the risk of developing breast cancer, though no research using randomized subjects and a control group has been done to conclusively prove that.
Nor have any studies been done on the effect of exercise once breast cancer has already developed, Irwin added.
"Because our early detection is being improved, more women are being diagnosed, and we need to figure out how to lower the risk of recurrence and mortality," Irwin said. "Treatments are being improved, but what is something we can tell women to do that also lowers the risk?"
Medical oncologists with both cancer centers are recruiting 50 women who have been diagnosed with breast cancer. The women are randomly put into one of two groups of 25: Those in one group are assigned to a trainer and given a gym membership, and those in the other get a series of books and tapes on mindfulness.
A tissue sample is taken from each patient at the time of the diagnosis. Before the mastectomy or lumpectomy, patients then work with a trainer on Irwin's research team or are given books and a CD on stress reduction strategies to prepare them for the surgery.
Those assigned to the exercise group must spend a total of 150 minutes a week exercising. Two days of the week, they meet with a trainer for resistance training where their heart rate, walking speed and timing are measured. They are free to fulfill the remainder of the 150 minutes on aerobic exercises throughout the week.
At surgery time, the researchers take a tissue sample of the tumor to assess any change in the cancer cells, such as whether the growth of the cells has slowed.
Only women who are not already physically active are eligible for the study, but that makes up about 80 percent of women diagnosed, Irwin said.
Chagpar, Irwin and Dr. Jennifer Ligibel, principal investigator, who is an assistant professor at Harvard Medical School and a medical oncologist with Dana-Farber's Susan F. Smith Center for Women's Cancers, are still recruiting participants for the study, which is being funded with a $1 million grant from the Society for Women's Health Research and Susan G. Komen for the Cure.
Irwin and Ligibel have been studying the concept of physical activity and stress reduction on breast cancer since the late 1990s and early 2000s, respectively.
Patients Often Reluctant To Work Out
"There's a perception on the part of many patients that exercise increases the stress and demands on the body during the time where they are going through the stress and psychological stress of the new diagnosis, or undergoing treatment, and the potential impact of the disease," Salner said.
"What we've really learned through patient studies and personal experience is just the opposite happens," he said. "People really gain extra energy and vitality as a result of some physical activity. It's as significant as the medications they might take."
While the benefits of exercise in preventing breast cancer and helping with recovery are widely accepted, for many breast cancer patients exercising is easier said than done.
Even for patients who appear healthy, symptoms can include fatigue, nausea, vomiting and nerve damage that results in numbness or abnormal sensations in the hands and feet, said Dr. Jeffrey D. White, director of the National Cancer Institute's Office of Cancer Complementary and Alternative Medicine.