This study aims to evaluate the real-world effectiveness and safety of third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs)-such as osimertinib, aumolertinib, and furmonertinib-as adjuvant therapy for patients with early-stage non-small cell lung cancer (NSCLC) in China.

Approximately 500 eligible patients are planned to be enrolled. All participants must have been diagnosed with Stage IA NSCLC (according to the 8th edition of the AJCC staging system) following surgical resection, harboring EGFR-sensitive mutations, and presenting with high-risk recurrence factors (e.g., poor differentiation, lymphovascular invasion, and spread through air spaces).

This is a non-interventional, real-world study that does not alter physicians' original prescribing habits or clinical management strategies. Patients will receive standard treatment with third-generation EGFR-TKIs according to routine clinical practice (typically for a duration of three years). The research team will periodically collect follow-up data, with a primary focus on postoperative disease-free survival (DFS) and drug safety profiles.

Through this investigation, we seek to determine whether this specific population of high-risk early-stage patients can derive clinical benefit from postoperative targeted therapy. The findings are expected to provide evidence to support the development of future clinical guidelines.

Inclusion Criteria:

1. Age ≥ 18 years old
2. Patients with IA-stage (8th edition of AJCC staging) non-small cell lung cancer (NSCLC) confirmed by histopathology and with high-risk factors
3. EGFR mutation positive
4. No previous systemic anti-tumor treatment
5. Expected or already received surgical treatment
6. Intended to receive or already received third-generation EGFR-TKI adjuvant therapy after surgery.

Exclusion Criteria:

1. Small cell lung cancer
2. With other malignant tumors that require treatment
3. Pregnant or lactating women
4. Those who the researchers consider not suitable to participate in this clinical trial.

This is a prospective, non-interventional, real-world study. The study population consists of 500 Chinese patients with stage IA NSCLC with high-risk factors and EGFR mutations. All participants have undergone or are planned to undergo surgical resection and are receiving or planned to receive third-generation EGFR-TKI adjuvant therapy according to the standard of care and the approved registration study protocol. Treatment duration is planned for up to 3 years until disease recurrence/progression, intolerable toxicity, withdrawal of consent, or completion of the 3-year treatment period. The study aims to collect data for final analysis without interfering with the patients' routine clinical treatment decisions.

This is a single-center retrospective observational study. Due to practical limitations in data management infrastructure and the lack of specific funding allocated for data sharing activities, the research team does not plan to share individual participant data.