Analysis Of Molecular Events Associated With Metastatic Capability Of Lung Cancer And Molecular Residual Disease Predicts Disease Recurrence

Background Surgery is the maj or treatment modality for localized stage lung cancer cases,but a significant proportion of patients still face the risk of disease recurrence after complete resection.Disease recurrence after surgery is an important issue for localized-stage lung cancer patients,especially for stage Ⅲ patients with a 5-year disease recurrence rate near 60%.Hence,to further explore the potential molecular events related to tumor metastasis and how to precisely predict the risk of disease recurrence is two major unsolved clinical problems in non-small cell lung cancer.(NSCLC).Objective 1.To explore the genomic events which may be related to the metastatic capacity of lung cancer through the spatial multi-omics techniques,including intra-tumoral heterogeneity(ITH),chromosomal instability(CIN)and transcriptomic enrichment analysis.2.To explore the feasibility of circulating tumor DNA(ctDNA)from peripheral blood as a detection source of molecular residual disease(MRD)in lung cancer patients.To assess the efficacy and potential limitations for MRD postoperative monitoring in NSCLC.Methods Part 1.Spatial multi-omics analysis of T4N0M0 NSCLC Eight NSCLC cases with tumor diameter over 7 cm but without lymph nodes or distant organ metastasis were prospectively enrolled,which were considered as a special subset of tumors with low metastatic capacity.Multi-regions of tumor tissues were collected intraoperatively(three regions per tumor,over 2cm apart).Adjacent normal lung tissues and peripheral blood samples were also obtained as controls.Whole exome sequencing and transcriptome sequencing were performed to analyze the genomic events which may be related to the low metastatic capability,including ITH,CIN,transcriptomic enriched function and immune cell infiltration.Part 2.Prospective study of postoperative MRD monitoring261 patients with stage Ⅰ-Ⅲ NSCLC who after complete resection were prospectively enrolled in this study.Preoperative peripheral blood,tumor tissue and postoperative peripheral blood(at least every 6 months)were collected for ctDNAbased MRD detection.And then systematically comprehensive analysis the predictive value of MRD monitoring on disease recurrence and postoperative adjuvant therapy.Results Part1.Spatial multi-omics analysis of T4N0M0 NSCLC1.A total of 24 tumor samples from 8 patients with pathologically confirmed T4N0M0 NSCLC were sequenced.Overall,35.2%,of the single base variants and small fragment insertion/deletion mutations and 91.1% of the somatic copy number variants(SCNA)belong to sub-clonal events,respectively,which indicated that an extremely high level of ITH was observed in these T4N0M0 NSCLCs.2.T4N0M0 tumors showed a significantly lower degree of whole genome doubling,SCNA load,loss of heterozygosity,chromosomal ploidy and genomic instability index,which indicated that this cohort of T4N0M0 NSCLC exhibited a lower degree of CIN.Part 2.Prospective study of postoperative MRD monitoring for stage Ⅰ-ⅢNSCLC1.There was a significant difference of disease-free survival between the undetectable and detectable MRD group(hazard ratio [HR]=0.02,95% CI:0.01-0.06,p<0.001).The positive predictive value of MRD for disease recurrence was up to 97.5% and the negative predictive value of MRD was up wo 90.0%.2.A total of 55 patients received postoperative adjuvant therapy.Among them,10 patients with detectable MRD,and the DFS of these patients was found to be significantly better than 13 patients with detectable MRD patients without adjuvant therapy(HR=0.37,95% CI:0.14-0.99,p=0.047).On the other hand,for patients with undetectable MRD,after propensity-score matching,there was no difference in DFS between patients received adjuvant therapy or not(HR=1.93,95% CI:0.36-10.4,p=0.382).Conclusions 1.Chromosomal instability may be related to the metastatic capability of NSCLC,including SCNA load,loss of heterozygosity,chromosomal ploidy and genomic instability index.2.Postoperative ctDNA-based MRD detection is an effective and feasible tool of disease monitoring for NSCLC patients who after complete resection.And the positive or negative predictive value is much higher than that of CEA.3.Postoperative MRD status might be used to predict the value of adjuvant therapy,especially for patients with undetectable MRD who might be spared from overtreatment.