Purpose: We assessed whether perioperative circulating tumor DNA (ctDNA) could be a biomarker for early detection of molecular residual disease (MRD) and prediction of postoperative relapse in resected non–small cell lung cancer (NSCLC). Experimental Design: Based on our prospective, multicenter cohort on dynamic monitoring of ctDNA in lung cancer surgery patients (LUNGCA), we enrolled 950 plasma samples obtained at three perioperative time points (before surgery, 3 days and 1 month after surgery) of 330 stage I–III NSCLC patients (LUNGCA-1), as a part of the LUNGCA cohort. Using a customized 769-gene panel, somatic mutations in tumor tissues and plasma samples were identified with next-generation sequencing and utilized for ctDNA-based MRD analysis. Results: Preoperative ctDNA positivity was associated with lower recurrence-free survival (RFS; HR = 4.2; P < 0.001). The presence of MRD (ctDNA positivity at postoperative 3 days and/or 1 month) was a strong predictor for disease relapse (HR = 11.1; P < 0.001). ctDNA-based MRD had a higher relative contribution to RFS prediction than all clinicopathologic variables such as the TNM stage. Furthermore, MRD-positive patients who received adjuvant therapies had improved RFS over those not receiving adjuvant therapy (HR = 0.3; P = 0.008), whereas MRD-negative patients receiving adjuvant therapies had lower RFS than their counterparts without adjuvant therapy (HR = 3.1; P < 0.001). After adjusting for clinicopathologic variables, whether receiving adjuvant therapies remained an independent factor for RFS in the MRD-positive population (P = 0.002) but not in the MRD-negative population (P = 0.283). Conclusions: Perioperative ctDNA analysis is effective in early detection of MRD and relapse risk stratification of NSCLC, and hence could benefit NSCLC patient management.

Tumor-associated macrophages (TAMs) are important components of cancer microenvironment. In the present study, we searched PubMed, Embase, Cochrane library and Web of Science to perform a meta-analysis of 20 studies including a total of 2,572 non-small cell lung cancer (NSCLC) patients, in order to determine the association between TAMs and NSCLC prognosis. The combined hazard ratio (HR) of 9 studies showed that the density of total CD68+ TAMs in the tumor islet and stroma was not associated with overall survival (OS) of the patients. However, the pooled HR of 4 studies showed that high density of CD68+ TAMs in the tumor islet predicted better OS, while the pooled HR of 6 studies showed that high density of CD68+ TAMs in the tumor stroma was associated with poor OS. A high islet/stroma ratio of CD68+ TAMs was associated with better OS. A high density of M1 TAMs in the tumor islet was associated with better OS, while a high density of M2 TAMs in the tumor stroma predicted poor OS. These findings suggest that, although the density of total CD68+ TAMs is not associated with OS, the localization and M1/M2 polarization of TAMs are potential prognostic predictors of NSCLC.

IMPORTANCEIt is important to develop a surgical technique to reduce dissemination of tumor cells into the blood during surgery.OBJECTIVE To compare the outcomes of different sequences of vessel ligation during surgery on the dissemination of tumor cells and survival in patients with non-small cell lung cancer. DESIGN, SETTING, AND PARTICIPANTSThis multicenter, randomized clinical trial was conducted from December 2016 to March 2018 with patients with non-small cell lung cancer who received thoracoscopic lobectomy in West China Hospital, Daping Hospital, and Sichuan Cancer Hospital. To further compare survival outcomes of the 2 procedures, we reviewed the Western China Lung Cancer database (2005-2017) using the same inclusion criteria.INTERVENTIONS Vein-first procedure vs artery-first procedure. MAIN OUTCOMES AND MEASURESChanges in folate receptor-positive circulating tumor cells (FR + CTCs) after surgery and 5-year overall, disease-free, and lung cancer-specific survival.RESULTS A total of 86 individuals were randomized; 22 patients (25.6%) were younger and 64 (74.4%) older than 60 years. Of these, 78 patients were analyzed. After surgery, an incremental change in FR + CTCs was observed in 26 of 40 patients (65.0%) in the artery-first group and 12 of 38 (31.6%) in the vein-first group (P = .003) (median change, 0.73 [interquartile range (IQR), −0.86 to 1.58] FU per 3 mL vs −0.50 [IQR, −2.53 to 0.79] FU per 3 mL; P = .006). Multivariate analysis confirmed that the artery-first procedure was a risk factor for FR + CTC increase during surgery (hazard ratio [HR], 4.03 [95% CI,]; P = .005). The propensity-matched analysis included 420 patients (210 with vein-first procedures and 210 with artery-first procedures). The vein-first group had significantly better outcomes than the artery-first group for 5-year overall survival (73.6% [95% CI, 64.4%-82.8%] vs 57.6% [95% CI, 48.4%-66.8%]; P = .002), disease-free survival (63.6% [95% CI, 55.4%-73.8%] vs 48.4% [95% CI, 40.0%-56.8%]; P = .001), and lung cancer-specific survival (76.4% [95% CI, 67.6%-85.2%] vs 59.9% [95% CI, 50.5%-69.3%]; P = .002). Multivariate analyses revealed that the artery-first procedure was a prognostic factor of poorer 5-year overall survival (HR, 1.65 [95% CI, 1.07-2.56]; P = .03), disease-free survival (HR, 1.43 [95% CI, 1.01-2.04]; P = .05) and lung cancer-specific survival (HR = 1.65 [95% CI, 1.04-2.61]; P = .03). CONCLUSIONS AND RELEVANCELigating effluent veins first during surgery may reduce tumor cell dissemination and improve survival outcomes in patients with non-small cell lung cancer.TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT03436329