The low cross-sectional muscle index at the third cervical vertebra is a marker for sarcopenia in patients with laryngopharyngeal cancer

Muscle loss and sarcopenia play a significant role in head and neck cancer. In this study, the value of C3 cross-sectional skeletal muscle index was investigated to evaluate sarcopenia. Seventy-four patients were included in this retrospective study. Skeletal muscle index (SMI) was calculated using the paracervical muscles at the level of the third cervical vertebra. Survival rates and toxicities were compared. The 3-year overall survival rates were 33.3% in patients with low SMI (≤44.79) and 63.9% in patients with high SMI (>44.79) (P < 0.01). The 3-year progression-free survival rates were 25.9% in patients with low SMI and 63.2% in patients with high SMI (P < 0.01). Multivariate analyses found that advanced age (>65) was associated with a 2.9-fold increased risk of death and low SMI was associated with a 3.9-fold increased risk of death. Low SMI is associated with prolonged treatment time, increased toxicity, and decreased survival.