Sarcopenia as a risk factor of severe laboratory adverse events in breast cancer patients receiving perioperative epirubicin plus cyclophosphamide therapy.

PURPOSE: Sarcopenia has been reported to be associated with higher mortality and increased toxicity of chemotherapy in breast cancer patients. However, evidence from Asian countries is scarce. Here, we investigated the association between sarcopenia and the frequency of severe laboratory adverse events due to perioperative chemotherapy in Japanese breast cancer patients. METHODS: Eighty-two patients with breast cancer receiving perioperative epirubicin plus cyclophosphamide therapy were evaluated. Skeletal muscle of the cross-sectional area at the third lumbar vertebra was measured by computed tomography, and sarcopenia was defined as skeletal muscle index < 40 cm2/m2. Laboratory toxicity during all cycles of perioperative chemotherapy was assessed. The study endpoint was the frequency of severe (grade 3 or more) laboratory adverse events. RESULTS: Overall, 10 patients (12.2%) were classified as sarcopenic. The frequency of severe laboratory adverse events was 28.0%, and this was significantly higher in sarcopenic patients compared to non-sarcopenic patients (70% vs. 22.2%, odds ratio 7.9 (95% CI, 1.6-52.8), p = 0.004). Neither of body weight, body mass index, area of visceral adipose tissue, subcutaneous adipose tissue, nor skeletal muscle density was significantly associated with the frequency of severe laboratory adverse events. CONCLUSION: Sarcopenia was a significant risk factor of severe laboratory toxicity in breast cancer patients receiving perioperative epirubicin plus cyclophosphamide therapy. This finding raises the potential use of body composition assessment to predict the risk of chemotherapy toxicity and determine an individualized treatment strategy.