This multicenter, retrospective cohort study plans to enroll patients with lung adenocarcinoma who received neoadjuvant immunotherapy prior to surgery and did not achieve pathological complete response (non-pCR) upon postoperative pathological evaluation. Using Deoxyribonucleic Acid(DNA) and Ribonucleic Acid(RNA) next-generation sequencing (NGS), the investigators aim to detect driver genetic alterations to investigate the real-world frequency of driver gene positivity in postoperative samples from patients with lung adenocarcinoma-whose EGFR and ALK status had been previously excluded via pathological complete response(pCR) or DNA-based next-generation sequencing-yet still did not attain pathological complete response(pCR) after neoadjuvant immunotherapy. Additionally, the study will characterize the driver-positive patient subgroup and compare the efficacy of postoperative adjuvant immunotherapy between driver-positive and driver-negative populations.

Inclusion Criteria:

• Aged 18 years or older, regardless of sex.
• Pathologically confirmed, resectable non-small cell lung cancer (NSCLC); having received neoadjuvant therapy containing immune checkpoint inhibitors prior to surgery; without achieving pathological complete response (non-pCR) upon postoperative pathological assessment.
• Molecular characteristics: Pre-treatment biopsy specimens tested negative for EGFR mutations and ALK fusions by DNA-based NGS or PCR methods.
• Sample requirements: Availability of 5-10 formalin-fixed, paraffin-embedded (FFPE) sections prepared from surgical tissue specimens, with ≥5% tumor cell content confirmed by H&E staining.

Exclusion Criteria:

• Failure to meet any one of the requisite eligibility criteria specified in the inclusion criteria.
• History of a concurrent or prior malignancy at other sites.
• Failure to complete the planned cycles of neoadjuvant immunotherapy due to treatment-related toxicities.
• Any other condition that, in the judgment of the investigator, renders the patient unsuitable for participation in this study.

This multicenter, retrospective cohort study plans to enroll patients with non-small cell lung cancer (NSCLC). Cases meeting the eligibility criteria between January 2022 and December 2024 will first be identified through the hospital pathology information management system. The screening process consists of two stages:

Initial Screening: Extraction of data from electronic medical records for patients aged ≥18 years, with pathologically confirmed NSCLC, and who underwent genetic testing prior to surgery.

Collection of Neoadjuvant Immunotherapy Information:

1. Received preoperative neoadjuvant immunotherapy, including regimens such as immune monotherapy, immune combination chemotherapy, or immune combination with antiangiogenic agents, with available postoperative pathological assessment results;
2. Exclusion of EGFR and ALK positivity in pre-treatment biopsy samples;
3. Availability of qualifying surgical tissue samples. Estimating a requirement of 300 cases.