Skeletal Muscle Mass, Composition Is Predictive of Treatment-Related Toxicity in Breast Cancer
Lean muscle mass
A new tool to measure the quality and quantity of skeletal muscle predicted chemotherapy toxicity in patients with early-stage breast cancer. Low measures of muscle quality and quantity was associated with serious side effects from chemotherapy and increased hospitalizations.1
Chemotherapy is the standard treatment for many cancers, but it can have many side effects. Researchers developed this tool to better predict which patients would experience toxicity and to predict the extent to which they would experience side effects. The tool can also help determine appropriate drug doses.
Body surface area, the formula currently used to determine chemotherapy dose, is not predictive of treatment-related toxicity, explained Shlomit Strulov Shachar, MD, of University of North Carolina at Chapel Hill Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina, and Division of Oncology, Rambam Health Care Campus, Haifa, Israel.
"This study supports the concept that body composition may be more sensitive than the formula that has been used for decades to dose chemotherapy."
Previous research indicated that sarcopenia is correlated with poor overall survival in patients with solid tumors. However, less is known about the effects of muscle mass and composition on chemotherapy toxicity in patients with early-stage breast cancer.
This study examined medical data from 151 patients treated for early-stage breast cancer at the North Carolina Cancer Hospital between 2008 and 2013. In total, 50 patients experienced serious toxicities from chemotherapy.
Researchers assessed available abdominal CT scans for each patient to determine fat and muscle composition. Measurements of muscle quality and quantity included measurements of indirect fat content and allowed the development of a skeletal muscle gauge.
Serious toxicities included hospitalizations, gastrointestinal complications such as nausea and vomiting, depletion of types of blood cells, and peripheral neuropathy. Patients with low muscle quality and quantity were more likely to experience blood-related toxicities, gastrointestinal complications, and neuropathy.
These patients were also twice as likely to be hospitalized after researchers adjusted for age and body surface area.
Skeletal muscle gauge was the most predictive of toxicity compared with other measurements of body composition such as body mass index.
These study findings could assist clinicians in determining the optimal chemotherapy dose for patients. Optimized doses could reduce the risk of side effects from treatment.