Correlation analysis of MRD positivity after non-small cell lung cancer surgery.

Abstract

e20590 Background: To explore the relationship between postoperative molecular residual disease (MRD) status in patients with non-small cell lung cancer (NSCLC) and clinicopathological features, gene mutations, the tumour immune microenvironment and treatment effects. Methods: The clinical data of 90 patients with stage I-IIIA NSCLC who underwent radical resection of lung cancer from January 2021 to March 2022 in our hospital were retrospectively collected, and demographic data, clinicopathological characteristics, genetic test results, MRD status, and treatment effects were analysed. Results: Sex, age, smoking status, pathological type, and gene mutations were not associated with postoperative MRD status. T (tumour diameter > 3 cm) and N (lymph node metastasis) were statistically correlated with MRD positivity ( p values of 0.004 and 0.003, respectively). The higher the proportion of micropapillary and solid pathological subtypes of lung adenocarcinoma, the higher was the MRD-positivity rate after surgery ( p = 0.005). MRD positivity was correlated with vascular invasion ( p = 0.0002). For the expression of programmed cell death ligand 1 (PD-L1), tumour positive score (TPS) ≥ 1% and combined positive score (CPS) ≥ 5 were correlated with postoperative MRD status ( p value distribution was 0.0391 and 0.0153). For ctDNA clearance, among postoperative MRD-positive patients, postoperative adjuvant targeted therapy was superior to chemotherapy for patients without gene mutations. Conclusions: Postoperative ctDNA-MRD status in NSCLC patients is associated with primary tumour size, lymph node metastasis, lung adenocarcinoma pathological subtype, vascular invasion, TPS and CPS for PD-L1 expression; for postoperative MRD-positive patients, clearance of ctDNA by adjuvant EGFR-TKI target treatment is superior to chemotherapy.