Abstract
Background
Sarcopenia is a well-established prognostic factor in patients with malignancies, with the muscle index serving as a key parameter in evaluating sarcopenia. However, the relationship between the pectoralis muscle index (PMI) determined by preoperative computed tomography (CT) and recurrence-free survival (RFS), as well as distant metastasis-free survival (DMFS), remains unclear in patients with early-stage non-small cell lung cancer (NSCLC).
Methods
Consecutive patients who underwent curative-intent resection for stage I to IIIA NSCLC between 2013 and 2018 at a cancer center were retrospectively identified. The Cox proportional hazard model was employed to analyze the correlation between PMI and survival, with subgroup analyses conducted to explore potential heterogeneity among different subgroups. Finally, the relative influence of each parameter was compared using a gradient boosting model (GBM).
Results
A total of 2110 patients (median (IQR) age 59.00 (52.00, 66.00) years, 1125 (53.32%) males, median follow-up of 64.73 months) were evaluated. Kaplan-Meier survival analysis showed that the RFS rate, DMFS rate, lung metastasis-free survival (MFS) rate, liver MFS rate, brain MFS rate, bone MFS rate, and adrenal MFS rate of patients in the high PMI group were higher than those in the low PMI group, all with P < 0.001. In the multivariable analysis, low PMI is still associated with shorter RFS ( hazard ratio [HR] = 1.34, 95% confidence interval [CI]: (1.10, 1.62), P = 0.004), DMFS (HR = 1.35, 95% CI: (1.11, 1.65), P = 0.003), lung MFS (HR = 1.47, 95% CI (1.19, 1.81), P < 0.001) and bone MFS (HR = 1.38, 95% CI: (1.11, 1.73), P = 0.004). These associations were consistent in subgroup analysis of different gender, age, tumor stage, histologic type, and surgical approach group.
Conclusions
As an independent predictor of RFS and DMFS in patients with early-stage NSCLC, preoperative CT-based PMI may contribute to further refining the risk stratification of NSCLC.