Analysis of lymph node metastasis based on consolidation tumor ratio and maximum standardized uptake value in clinical stage IA non-small cell lung cancer.

Abstract

Background: Sublobar resection has been established as an acceptable treatment for early-stage non-small cell lung cancer (NSCLC). As a result, preoperative prediction of lymph node (LN) metastasis is becoming an important factor in determining surgical strategy. This study aimed to investigate the predictive accuracy of the consolidation tumor ratio (CTR) and the maximum standardized uptake value (maxSUV) of the primary tumor for LN metastasis in patients with clinical stage IA NSCLC.

Methods: We performed a retrospective analysis using data from 1,338 patients with clinical stage IA NSCLC who underwent surgery between 2011 and 2019. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to identify the optimal maxSUV and CTR for predicting LN metastasis. Multivariate logistic regression analysis was performed to identify independent predictors of LN metastasis. Survival analyses were performed using Cox proportional hazards models to identify prognostic factors for death and recurrence.

Results: Among the 896 patients who underwent lobectomy with systematic LN dissection, 9.8% (88 patients) were found to have LN metastasis. The ROC curve for CTR revealed an AUC of 0.689 [95% confidence interval (CI): 0.646-0.732, P<0.001], while the ROC curve for maxSUV yielded an AUC of 0.748 (95% CI: 0.705-0.791, P<0.001) for predicting LN metastasis. In pure solid mass (CTR =1) with maxSUV exceeding 5.0, LN metastasis was observed in 13.8% of tumor 0-2 cm and 25.7% of tumor 2.1-3 cm. Multivariate analysis identified CTR >0.5 (HR =1.741, 95% CI: 1.122-2.701, P=0.01) and maxSUV >5.0 (HR =2.004, 95% CI: 1.421-2.825, P<0.001) as independent prognostic factors for disease-free survival.

Conclusions: In clinical stage IA NSCLC, LN metastasis can be predicted using CTR and maxSUV of the primary mass. It is crucial not to underestimate the rate of LN metastasis when determining the surgical extent.