Muscle Loss and Increased Fat Negatively Affect the Course of Breast Cancer

JAMA Oncologypublished a study on 5 April showing that sarcopenia (muscle loss) and adiposity (fat accumulation)significantly affect the course of disease in nonmetastatic breast cancer patients. Developing effective strategies to address this is important for cancer prevention and treatment.

What Are Sarcopenia and Adiposity?

Sarcopenia is muscle loss and weakening of muscle strength, particularly with aging. Adiposity is increased body fat mass, often accompanying sarcopenia and playing an important role in the development of metabolic syndrome and cardiovascular diseases.

Sarcopenia and adiposity cause reduced strength, loss of resistance, exhaustion and frequent falls. Regular exercise, an active lifestyle and an appropriate protein-carbohydrate balance are lifestyle choices preventing sarcopenia and adiposity. These are also now well-established ways of protecting against cancer, diabetes and cardiovascular disorders.

Study Details:

The method most commonly used to help understand the relationship between body composition and cancer effects is body mass index (BMI). As many now know, BMI is calculated from weight and height. It therefore has important shortcomings, such as not considering muscle content or body fat. In this respect, it was considered inadequate for assessing life expectancy in cancer patients.

Earlier studies used computed tomography (CT) to identify sarcopenia and accompanying high fat levels in certain diseases, finding associations with higher mortality. However, assessing body mass together with these parameters and their effects on cancer prognosis had not been fully understood.

Researchers collected data from 2 cancer centers on women diagnosed between January 2000 and December 2013 with stage II or III breast cancer, a total of 3241 women. All patients, followed for a median of 6 years, had BMI above 18.5 at the time of CT. No scans were performed specifically for this study; existing diagnostic CTs on which muscle could be assessed were used.

Analysis identified radiological evidence of sarcopenia in 1086 (% 34) patients.

Patients with sarcopenia had higher mortality than those without it. Overall mortality was also higher in patients with the greatest total fat tissue.

Patients with both sarcopenia and the greatest fat tissue had the highest risk of death.

No noteworthy relationship was found between BMI and overall survival, and BMI had no prognostic value in assessing survival.

Researchers, in conclusion, identify both sarcopenia (muscle loss) and adiposity (fat accumulation) as modifiable risk factors in breast cancer patients. This study suggests that lifestyle changes increasing muscle mass and reducing fat, such as losing excess weight, resistance training or a proportionately protein-rich diet, may improve outcomes. Moreover, in the era of precision medicine , muscle and fat measurements will help guide treatment plans and interventions to improve survival outcomes.

YOU MAY BE INTERESTED

• Advances in Breast Cancer Treatment—2017 and 2018
• Why Does a Patient with Recurrent Breast Cancer Become Angry with Their Doctor?
• Recommendations for Menopausal Symptoms After Breast Cancer