Women with more muscle mass are more likely to survive stage 2 or 3 breast cancer, a new study suggests.
A team of researchers compared patients who had sarcopenia when they were diagnosed with Stage 2 or 3 breast cancer with those who did not, Forbes reports. Sarcopenia is a medical condition that basically means “muscle deficiency” or lack of muscle.
According to the National Institutes of Health, many kinds of cancer can lead to muscle loss, though the exact reasons are unclear. Stage 2 or 3 breast cancer is cancer that has developed, but has not yet spread to other parts of the body far from the breast.
Researchers from Kaiser Permanente, the University of Alberta, Canada, and the Dana Farber Cancer Institute examined the records of 3,241 women who were initially diagnosed at Kaiser Permanente of Northern California or Dana Farber Cancer Institute between January 2000 and December 2013. All of the patients had CT scans of their abdomens when they were diagnosed with breast cancer. The scans allowed the team to determine which patients had sarcopenia, and provided an estimate of fat volume in their bodies.
The scientists defined sarcopenia as having skeletal muscle index that is less than 40, calculating the index by looking at the CT cross section of the abdomen. The team then reviewed the patients’ medical records to see whether they had survived.
Their main finding was that about one-third of the patients had sarcopenia during their first CT scan. Those who had muscle deficiency were 41% more likely to have died later on versus those who did not have sarcopenia.
In addition, those who had more fat in their bodies were also more likely to have died. Patients who had both sarcopenia and a high amount of body fat were 89% more likely to have died.
The theory is that muscle could be a stockpile of energy of sorts, wherein having more at the start of diagnosis could help a patient weather the storm of losing muscle mass to cancer. In addition, those who have more muscle mass could also be living healthier lifestyles, which could be helping them survive the disease.
The study was published in JAMA Oncology.