Breast Cancer Survival Higher For Patients Who Build Muscle, Study Finds

Mia Lorenzo

Breast cancer patients may be focusing more on treatment than any other thing, but a new study published in the peer-reviewed journal JAMA Oncology suggests that building muscles increase the chances of survival.

Losing muscle is one of the consequences of weight loss which is common among sick individuals, including those who are suffering from cancer. Sarcopenia, the medical term for low muscle mass, also happens as a person grows old and there seems to be a relationship between treatment outcome and losing muscles.

Better Caan, a senior research scientist in Kaiser Permanente's Northern California Division, explained the premise of the study to Medscape Medical News as follows.

"In this population of women who have nonmetastatic early-stage breast cancer, we've demonstrated that if they lose weight, they have worse survival and we hypothesized that this was due to muscle loss."

To measure the correlation between gaining muscle and mortality, researchers studied 3,241 breast cancer patients, 34 percent of which experienced sarcopenia and had higher chances of mortality compared to other patients. Patients with high adipose tissue also faced higher mortality rates than the rest of the population.

Three body composition indexes were assessed: total adipose tissue, sarcopenia, and low muscle radio-density. The study used Body Mass Index and CT scan for the study, and they found out that BMI alone does not predict survival outcome.

A study published in 2017 in the International Journal of Epidemiology revealed the increasing evidence of reduced survival for women with breast cancer and elevated BMI. The said study involved 36,210 individuals concluded a causal effect between reduced survival and increased BMI in estrogen receptor positive cases but not in ER-negative cases.

"Our findings are likely generalizable across many other nonmetastatic cancers because the associations with muscle and improved survival for those with metastatic cancer has been observed across a variety of solid tumors."