Dynamic ctDNA informs whole-course postoperative precise management of NSCLC (LUNGCA study)

BACKGROUND: Circulating tumor DNA (ctDNA) is valuable for detecting minimal residual disease (MRD). However, studies involving long-term blood sampling are required to comprehensively interpret the clinical use of ctDNA analyses. METHODS: We conducted a prospective multicenter cohort study (LUNGCA) for dynamic ctDNA monitoring in lung cancer patients receiving curative-intent surgery. ctDNA analysis was conducted on preoperative plasma samples, at postoperative 3 days and 1 month, and then every 3-6 months for up to 3 years. RESULTS: In total, 233 non-small cell lung cancer (NSCLC) patients and 2336 longitudinal plasma samples were included; the median follow-up was 51.4 months. Post-comprehensive treatment (after radical surgery + necessary adjuvant therapy) MRD status was better at predicting relapse than postoperative MRD status (positive predictive value: 100% vs 90.0%; negative predictive value: 90.3% vs 90.1%). Patients with positive pre-adjuvant ctDNA and targetable mutations in tumor tissues had improved recurrence-free survival (RFS) with corresponding adjuvant tyrosine kinase inhibitor (TKI) treatment (hazard ratio [HR] = 0.01, P = .005), but adjuvant chemotherapy failed to improve RFS (HR = 0.6, P = .491). Of patients receiving adjuvant therapies, patients with a negative- or positive-negative ctDNA change pattern had favorable and similar RFS (P = .419), whereas patients with a positive- or negative-positive pattern had worse RFS (P < .001). TKI therapy was more effective than chemotherapy in clearing ctDNA. Post-relapse ctDNA negativity was associated with favorable OS (HR = 0.4; P = .029). CONCLUSIONS: Comprehensive interpretation of dynamic ctDNA monitoring data can inform precise whole-course postsurgical management of NSCLC patients.