1244P - Association of tumor-draining lymph node metastatic patterns and neoadjuvant immunochemotherapy effectiveness in resectable non-small cell lung cancer

Background

Tumor-draining lymph node (TDLN) metastasis may impair anti-tumor immune function and disrupt the neoadjuvant immunochemotherapy (nICT) efficacy. The objective of this study was to examine the relationship between LN metastatic patterns and nICT efficacy in resectable non-small cell lung cancer (NSCLC).

Methods

NSCLC patients clinically staged as T1-4N0-2M0 and received nICT followed by surgery were collected from 3 institutions. According to the extent of TDLN (e.g. station 2R/4R for right upper lobe, 7 for right middle lobe, 4L/5/6 for left upper lobe and 7/8/9 for lower lobe tumors), patients were divided into 3 groups: uninvolved mediastinal LN (uiMLN/cN0-1) group, TDLN metastasis (mTDLN) group and non-draining LN metastasis (mNDLN) group. The outcomes were complete pathological response (pCR), major pathological response (MPR) and LN clearance (LN-CR) rates. Multivariable logistic regression was used to evaluate the associations between LN metastatic patterns and pathological response.

Results

A total of 209 patients were included (uiMLN group: 102; mTDLN group: 67; mNDLN group: 40). Compared with uiMLN group, mediastinal LN metastasis (mMLN/cN2) group had lower pCR rate in squamous cell carcinoma subgroup (31.03% vs 51.32%, P=0.019, odds ratio [OR]=0.427). In mMLN patients, mNDLN group had lower pathological response (PR) rates in contrast to mTDLN group (pCR: 7.5% vs 47.76%, P<0.001, OR=0.089; MPR: 22.5% vs 74.63%, P<0.001, OR=0.099; LN-CR: 40% vs 85.07%, P<0.001, OR=0.117). Patients with multiple-station TDLN metastasis showed higher PR rates than those with multiple-station NDLN metastasis (pCR: 47.83% vs 7.5%, OR=11.306, P<0.001; MPR: 65.22% vs 22.5%, OR=6.458, P<0.001; LN-CR: 82.61% vs 40%, OR=7.125, P=0.01). The PR rates had no statistical difference between multiple and single station TDLN metastasis groups.

Conclusions

Mediastinal LN metastasis significantly disrupted the nICT effectiveness. In mMLN patients, those with TDLN and NDLN metastasis were supposed to have poor pathological response. N-stage classification based on LN metastatic patterns showed promising potential for nICT effectiveness prediction in NSCLC.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

National Health Commission of the People's Republic of China.

Disclosure

All authors have declared no conflicts of interest.