Measures of severe skeletal muscle loss, or sarcopenia, are associated with toxicity outcomes and survival in patients with metastatic breast cancer receiving first-line taxane-based chemotherapy, a study published in the journal Clinical Cancer Research has shown.1

Previous research has demonstrated that severe sarcopenia is associated with reduced survival and increased toxicity; however, it remains unclear as to which measures of skeletal muscle loss are specifically correlated with poor outcomes in patients receiving first-line taxane-based chemotherapy.

For the study, investigators analyzed CT images taken for the evaluation of disease burden, skeletal muscle area, and skeletal muscle density that were measures at the third lumbar vertebrae from 40 patients with metastatic breast cancer. Sarcopenia was defined as Skeletal Muscle Index less than 41.


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Results showed that, of those, 58% were sarcopenic. Researchers observed grade 3 to 4 toxicity in 57% of sarcopenic patients compared with 18% of nonsarcopenic patients (P =.02).

In addition, toxicity-related hospitalizations (39% vs 0%; P =.005) and any adverse events (74% vs 35%; P =.02) were higher in patients with sarcopenia vs those without sarcopenia.

Low Skeletal Muscle Gauge, which was determined by multiplying Skeletal Muscle Index and skeletal muscle density, was associated with grade 3 to 4 toxicity (P =.04), hospitalization (P =.01), and time to treatment failure (P =.03).

There was also a borderline significant association between low Skeletal Muscle Gauge and any adverse event (P =.06), as well as overall survival (P =.07).

“Further studies are needed to explore how routinely obtained CT scans can be used to individualize dosing and improve treatment planning,” the authors conclude.

Reference

1. Shachar SS, Deal AM, Weinberg M, et al. Skeletal muscle measures as predictors of toxicity, hospitalization, and survival in patients with metastatic breast cancer receiving taxane based chemotherapy. Clin Cancer Res. 2016 Aug 3. doi: 10.1158/1078-0432.CCR-16-0940. [Epub ahead of print]