Prognostic value of pretreatment temporal muscle thickness after curative surgery for oral cavity squamous cell carcinoma.

Background: Sarcopenia is a poor prognostic factor in various diseases. Temporal muscle thickness (TMT) has been reported to be associated with sarcopenia. We investigated the prognostic value of TMT in patients with oral squamous cell carcinoma.

Methods: This study included 61 patients with oral squamous cell carcinoma. Two board-certified otolaryngologists measured TMT based on pre-treatment CT. The following sex-specific TMT cut-off values were used in accordance with previous reports: ≤ 6.3 mm in men, and ≤ 5.2 mm in women. We classified patients into normal TMT group and low TMT group according to the cutoff values. The correlation between the TMT measurements of the two readers was tested using the interclass correlation coefficient (ICC). Cox regression models were used to verify the association between TMT and prognostic factors.

Results: The low TMT group had a significantly lower BMI than the normal TMT group. Patients with low TMT at baseline had a significantly higher risk of death than those with normal TMT (hazard ratio 4.51; 95% confidence interval [CI] 1.49-13.61; p = 0.0076). There were no significant differences in disease-specific survival between the two groups. The correlation between the two evaluators' TMT measurements was excellent (ICC 0.988, 95% CI 0.981-0.933).

Conclusions: Sex-specific TMT was associated with overall survival in patients with oral squamous cell carcinoma. TMT is easy to assess and its measurement is consistent between evaluators.