Toth’s NCI Grant Will Test Muscle-rebuilding Strategy in Breast Cancer Patients

April 25, 2016 by Carolyn Shapiro

He’s not a personal trainer, but University of Vermont Associate Professor of Medicine Michael Toth, Ph.D., has an idea for counteracting the muscle loss that commonly occurs in cancer patients. What causes this loss in muscle loss – or atrophy – with cancer and its treatment is still not known, but Toth believes that the reduction in physical activity during cancer treatment may be an important factor.

Michael Toth, Ph.D., UVM Associate Professor of Medicine. (Photo: COM Design & Photography)

He’s not a personal trainer, but University of Vermont Associate Professor of Medicine Michael Toth, Ph.D., has an idea for counteracting the muscle loss that commonly occurs in cancer patients. What causes this loss in muscle loss – or atrophy – with cancer and its treatment is still not known, but Toth believes that the reduction in physical activity during cancer treatment may be an important factor. 

Fatigue is a common side effect of cancer and its treatments. Patients undergoing chemotherapy, radiation therapy or the combination of these treatments report that fatigue is “one of the most distressing side effects of their treatment,” says Toth, in some cases being so severe that it can force patients to alter their treatment. It also makes them about 50 percent less physically active than before their treatment, he adds, which can drive muscle atrophy and weakness and even more inactivity, in a disabling downward spiral.

In an effort to break this cycle, Toth, an expert in muscle physiology, and his research team will utilize a new two-year grant from the National Cancer Institute to study whether neuromuscular electrical stimulation (NMES) can help combat the effects of muscle atrophy in breast cancer patients. NMES is used most often in orthopedic injuries to prevent muscle atrophy. The women in the study who get this therapeutic device can use it at home while they relax.

“You can just sit there and it will contract your muscles for you,” says Toth, who doesn’t suggest this approach for most people, but maintains that “it may be an effective surrogate for exercise in those patients who can’t participate in a program at a traditional training facility.”

The study’s goal is to enroll 24 women with breast cancer. Half of the participants will receive a NMES device, which attaches to the thigh via electrodes and sends an electrical current that makes the muscle contract. Over two months, Toth and his team will measure each patient’s muscle size and function – taking a biopsy of the muscle to dissect the fibers and test them for their size and strength.

“These types of measurements at the cellular level are pivotal to demonstrating an effect of NMES over such a short period of time,” Toth says, because they are far more sensitive than traditional measurements of muscle size and strength.

After the completion of this two-year exploratory grant, he hopes to use the results to provide the foundation for a larger, controlled clinical trial.

Toth, whose research focuses on chronic muscle disuse, turned his attention to cancer a few years ago and began working with Kim Dittus, M.D., Ph.D., UVM oncologist and medical director of the Steps to Wellness oncology rehabilitation program. The two researchers, both members of the University of Vermont Cancer Center, saw the same kind of muscle loss in cancer patients as had been observed in other diseases and wanted to find a way to extend the benefits of exercise to cancer patients during their treatment.

With cancer patients, it’s a challenge to lure them to rehabilitation when they already feel exhausted. That’s why it’s critical to focus on the NMES at-home therapy with these patients, says Toth, who admits that “We probably won’t completely eliminate their fatigue, but we hope to prevent the effects of fatigue on their muscles, which likely worsens their fatigue.” With more people now living many years following cancer treatment, the therapy might also mitigate the long-term effects of cancer on their overall health.

Ideally, the study will indicate the potential benefit of NMES as an intervention for oncologists to use to prevent muscle deterioration in their patients. “What we’re trying to do is lessen the burden of the disease,” Toth says.