Case Report: Long-term TCR repertoire dynamics in a disease-free survival stage IIIB-N3 lung adenocarcinoma patient treated with anti-PD-1 followed by surgery.

Immune checkpoint blockade (ICB) therapy has dramatically improved the survival outcomes of patients with locally advanced unresectable and metastatic non-small cell lung cancer (NSCLC). In particular, accumulated clinical trials and systematic reviews have further verified that induction ICB regimen following surgery confers superior benefits for IIIB-N3 NSCLC. Herein, we present a clinical case of a patient diagnosed with bulky contralateral mediastinal N3 (cT1bN3M0) left upper lung adenocarcinoma and devoid of actionable driver gene alterations. The patient achieved pathological complete response following anti-PD-1 treatment and subsequently underwent left upper lobectomy, followed by anti-PD-1 therapy for three consecutive years. To date, the patient has maintained a recurrence-free survival status for more than 5 years. Notably, we dynamically monitored the T-cell receptor (TCR) repertoire throughout the entire treatment course. Further analysis of TCR profiles revealed distinct dynamic patterns of certain specific T-cell clonotypes during treatment. These clonal alterations may help interpret sustained immune responses and warrant further exploration as candidate indicators for therapeutic outcome.