Muscling away cancer

People with more lean muscle mass may have an advantage when it comes to fighting cancer, new research suggests.

The study, published in the medical journal Lancet Oncology, is the latest to suggest a patient’s body composition may play a role in cancer survival rates. Researchers from the University of Alberta used body scan imaging to study 250 obese cancer patients. The scans showed that 15 percent of the cancer patients had very low muscle mass relative to their weight.

The obese patients with the lower levels of lean muscle mass lived an average of 10 months less than patients with more muscle mass, even after controlling for other variables like cancer stage and severity.

Other studies have shown that people who exercise have lower rates of some types of cancer. Although the study suggests that higher levels of lean muscle mass help the body better

cope with cancer, it’s not clear whether lifting weights prior to or after a diagnosis would improve a patient’s odds for surviving the disease. “That would be the next experiment,” said Dr. Vickie Baracos, a professor of oncology and adjunct professor of human nutrition at the University of Alberta, and lead author on the study. “This intervention has not been tested.”

The data also raise questions about whether body composition should be considered as doctors make treatment decisions and assess a patient’s prognosis. A patient with very low lean body mass, for instance, may be given a more tailored dose of chemotherapy, Dr. Baracos said.

Patients who have been treated for cancer should talk to their doctor before embarking on any exercise routine. For instance, patients who have undergone lymph node removal are at risk for a severe swelling disorder called lymphedema and may be advised against lifting weights.