Preoperative swallowing muscle mass is associated with 1-year skeletal muscle loss and subsequent survival in lung cancer.

BACKGROUND & AIMS

Cancer cachexia is associated with systemic skeletal muscle loss and poor survival; however, early muscle changes preceding systemic muscle loss remain unclear. Therefore, this study aimed to determine whether tongue-complex muscle area (TCMA) can serve as an early indicator of systemic skeletal muscle loss in patients with lung cancer.

Specifically, we examined its association with preoperative cachexia and the percentage change in erector spinae muscle cross-sectional area at 1 year after surgery (pcESMcsa). We further evaluated the prognostic significance of pcESMcsa using a 1-year landmark analysis.

METHODS

In this single-center retrospective study, among 304 patients screened who underwent lobectomy for lung cancer between 2017 and 2024, 257 eligible patients were included.

Patients were classified into the cachexia group (modified Glasgow Prognostic Score [mGPS] ≥1) and the non-cachexia group (mGPS = 0). TCMA was measured using preoperative CT images obtained within 3 months before surgery.

Patients were categorized into a low TCMA group (<4.48 cm 2/m 2, first quartile; Q1) and a non-low TCMA group (≥4.48 cm 2/m 2). Multivariable analyses were performed to evaluate the associations between cachexia and TCMA, and between TCMA and pcESMcsa.

The association between the pcESMcsa decline group (<-9.3%, Q1) and 3-year overall survival (OS) was assessed using a Cox proportional hazards model. Survival outcomes were compared using Kaplan-Meier curves and the log-rank test.

RESULTS

During the follow-up period, 51 patients (20%) died.

Multivariable logistic regression analysis showed that mGPS was independently associated with low TCMA (odds ratio [OR]: 4.40, 95% confidence interval [CI]: 2.00-9.66, p < 0.001). In addition, low TCMA was independently associated with a decline in pcESMcsa (OR: 2.94, 95% CI: 1.48-5.86, p < 0.01).

In the Cox proportional hazards model, the pcESMcsa decline group was an independent prognostic factor for 3-year OS (hazard ratio: 1.98, 95% CI: 1.08-3.64, p = 0.02). Kaplan-Meier analysis showed significantly lower 3-year overall survival in the pcESMcsa decline group than in the non-decline group (75% vs. 90%, p < 0.01).

CONCLUSIONS

Preoperative cancer cachexia was associated with reduced TCMA, which was associated with subsequent systemic skeletal muscle loss and poorer survival.

These findings suggest that TCMA may serve as an early marker of muscle deterioration preceding systemic muscle loss, potentially facilitating earlier risk stratification and informing future nutritional and rehabilitative strategies in patients with lung cancer.