Impact of sarcopenia on the prognosis and treatment toxicities in patients diagnosed with cancer

Purpose of review: High-resolution computed tomography (CT) imaging routinely performed for cancer follow-up provides valuable information on body composition. The influence of body composition on outcomes and the occurrence of toxicities can therefore be explored in cancer patients. This review describes recent findings regarding the prognostic impact of skeletal muscle mass (SMM) on chemotherapy toxicity. Recent findings: The higher risk of toxicity associated with low SMM (i.e. sarcopenia) was first described for 5-fluorouracil-based chemotherapy toxicity in colon cancer patients before being increasingly studied, not only in the case of body surface area-adapted chemotherapy in breast cancer but also in various cancers treated with targeted therapies. The underlying mechanisms are still being debated; sarcopenia could act on pharmacokinetic parameters and/or sarcopenic patients could be more susceptible to adverse medical events including chemotherapy toxicity. Summary: Evidence for a strong link between sarcopenia and chemotherapy toxicity is increasing. SMM may not be the only body composition parameter involved. Muscle function assessed by measuring muscle density and the BMI could be of interest. The ultimate purpose is to better identify patients at higher risk of toxicity and to reduce toxicity through body composition-based dosing.