A decline in weight and attrition of muscle in colorectal cancer patients receiving chemotherapy with bevacizumab

Weight loss and muscle wasting are of critical importance to cancer patients because of their negative effects on survival, functional status, and tolerability of chemotherapy. Because previous data suggest vascular endothelial growth factor receptor inhibitors disrupt skeletal muscle pathways, such as PI3K and AKT, the current study explored weight loss and muscle wasting in colorectal cancer patients treated with bevacizumab. Patients were assessed for serial weight and radiographic changes in skeletal muscle at baseline and again within 3 months of starting cancer therapy. Computed tomography scans were used to assess muscle. Fifty-seven patients are the focus on this report. These patients manifested a decline in mean weight from 85 to 83 kilograms (P = 0.002). Mean skeletal muscle area at the L3 vertebral level dropped from 148 cm² to 145 cm² (P = 0.02). This drop in weight and skeletal muscle occurred independently of cancer progression. No statistically significant differences in survival were observed based on loss of weight or skeletal muscle. Colorectal cancer patients prescribed bevacizumab appear to lose weight and muscle over a few months even in the absence of cancer progression.