More and more studies are showing that low muscle mass, called sarcopenia by doctors, is linked to worse outcomes, worse survival, and more side effects from cancer treatment.
A study looking specifically at women diagnosed with stage II or stage III breast cancer found that women with low muscle mass had a higher risk of dying from breast cancer or any other cause.
The study was published online on April 5, 2018 by JAMA Oncology. Read the abstract of “Association of Muscle and Adiposity Measured by Computed Tomography With Survival in Patients With Nonmetastatic Breast Cancer.”
The study included 3,241 women who were diagnosed with stage II or stage III breast cancer at Kaiser Permanente of Northern California or the Dana-Farber Cancer Institute between January 2000 and December 2013. The women ranged in age from 18 to 80 years and follow-up time was about 6 years.
Using CT scans that were done as part of the women’s medical care, the researchers looked for any links between low muscle mass, low muscle quality, and excess fat, and breast cancer outcomes and survival.
The CT scans showed that:
- 1,086 women (34%) had low muscle mass
- 1,199 women (37%) had low muscle quality
Women with low muscle mass were about 40% more likely to die from breast cancer or another health issue than women who didn’t have low muscle mass.
Low muscle quality was not associated with survival.
Women with the highest amounts of fatty tissue were more likely to die from breast cancer or any other cause than women with the lowest levels of fatty tissue.
Women who had both low muscle mass and the highest levels of fatty tissue had the worst survival rates. Using these two measurements was much better than body mass index (BMI) in predicting survival. In this study, there was no link between BMI and survival.
Women with low muscle mass were more likely to be white and Asian. Black and Hispanic women were less likely to have low muscle mass.
All these differences were statistically significant, which means they were likely due to low muscle mass and high levels of fatty tissue and not just because of chance.
"I was surprised by how high the prevalence of sarcopenia was in breast cancer patients with nonmetastatic disease, who in general have good survival," said lead researcher Bette Caan, of Kaiser Permanente, in an interview. "It is well known that patients with advanced cancer have muscle loss, but that sarcopenia can occur in so many patients earlier in the cancer process is not well appreciated.
"Evaluating body composition is not part of a standard workup currently, but automated software is available to assess body composition, and radiologists who examine CT scans for diagnosis and surveillance could quickly identify persons with sarcopenia once the appropriate software is installed," she continued. "Many -- but not all -- breast cancer patients receive CT scans at diagnosis, and the percentage that receive scans increases with cancer stage."
This study highlights the benefits of keeping yourself healthy before, during, and after breast cancer treatment.
If you’re busy with work, household chores, and family matters, finding time to exercise almost every day can be hard. Exercising also can be nearly impossible if you’re recovering from breast cancer treatment or having painful side effects. Still, it’s worth your while to make time to move.
It can help to break up your exercise into 20- or 30-minute sessions that add up to about 5 or more hours per week. Walking is a great way to start. Maybe you walk 30 minutes before going to work and 30 minutes on your lunch break. You can add a few more minutes by parking farther away from your building or taking mass transit. Or you can make plans to walk with a friend after work -- you’re more likely to stick with exercise if someone else is counting on you. Plus, you can socialize at the same time.
Visit the Breastcancer.org Exercise section for tips on exercising safely and how to stick to an exercise routine.