Impact of imaging features on selecting limited lymph node resection for cT1N0M0 lung cancer

Controversy still exists in the medical community regarding the performance of limited mediastinal lymphadenectomy (LML) in early-stage lung cancer. The objective of this study was to identify predictors of mediastinal lymph node (mLN) status and analyze its role in guiding surgical strategy.

A retrospective cohort study was conducted on 2,834 surgical patients with peripheral cT1N0M0 non-small cell lung cancer between 2016 and 2018. Logistic regression was employed to identify predictors of N2 metastasis. Prognosis was compared between groups and independent prognostic factors were identified using Kaplan-Meier and multivariate Cox analysis.

There were 2,126 patients with systematic mLN dissection and 708 with LML. The multivariate analysis showed that N2 metastasis were associated with tumor size and consolidation tumor ratio (CTR). Patients in group A, with CTR >0.5 and tumor size ≤1 cm or CTR ≤0.5, had a significantly lower rate of N2 metastasis compared to those in group B, with CTR >0.5 and tumor size >1 cm (14.2% vs. 0.2%, P<0.001). Additionally, LML demonstrated comparable recurrence-free survival (RFS) and overall survival (OS) in group A, but a worse prognosis in group B compared to systematic lymph node dissection (SND). Furthermore, multivariate Cox regression analysis indicated that SND (vs. LML) was a favorable prognostic predictor for patients in group B [RFS: hazard ratio (HR) =0.71, P=0.005; OS: HR =0.66, P=0.01]. But univariate analysis in group A showed no significant difference in prognosis between SND and LML (RFS: P=0.24; OS: P=0.10).

The combination of CTR and tumor size can predict mLN metastasis and procedure-specific outcome (SND vs. LML). This information may assist surgeons in identifying suitable candidates for LML.