This study was a multicenter, real-world observational study aimed at characterizing the genomic landscape of recurrence in patients with EGFR-sensitizing mutation-positive early-stage (clinical stage IB-IIIA) non-small cell lung cancer who received adjuvant osimertinib after surgery.

This is a multicenter, real-world, retrospective observational study designed to investigate the genomic landscape of recurrence in patients with early-stage (clinical stage IB-IIIA) non-small cell lung cancer harboring EGFR-sensitizing mutations who received adjuvant osimertinib. A total of 60 patients with resectable EGFR-sensitizing mutation-positive NSCLC (exon 19 deletion or exon 21 L858R) are expected to be included and classified into two cohorts. Cohort 1 consists of 30 patients with recurrence more than 6 months after completing 3 years of adjuvant osimertinib, and Cohort 2 consists of 30 patients with recurrence during adjuvant osimertinib treatment. Genomic profiling data of recurrence, obtained from next-generation sequencing of tissue and/or blood samples, are collected and analyzed.

The primary endpoint is to evaluate the genomic landscape of recurrence during or after adjuvant osimertinib treatment in patients with resectable NSCLC harboring EGFR-sensitizing mutations. The secondary endpoints are to explore the genomic profiles of recurrence in subgroups with different recurrence patterns (local recurrence versus distant metastasis) during or after adjuvant osimertinib treatment, and to describe the treatment patterns used in real-world clinical practice after disease progression. The exploratory endpoints are to investigate changes in the genomic profile between baseline and recurrence and to explore the mechanisms underlying tumor progression.

Inclusion Criteria:

1. Informed consent signed;
2. Age ≥ 18 years;
3. Histologically confirmed diagnosis of non-squamous non-small cell lung cancer;
4. Patients with stage IB-IIIA (TNM 8#) NSCLC undergo confirmed radical R0 resection;
5. Confirmed EGFR sensitive-mutations (exon 19 deletions, 21 L858R point mutations) prior to adjuvant osimertinib therapy;
6. Recurrence after/on Osimertinib treatment according to RECIST 1.1;
7. NGS gene test report (tumor or blood sample) at the time of recurrence;
8. Receiving or not receiving neoadjuvant treatment before surgery.

Exclusion Criteria:

1. Patients with stage I-III NSCLC whose surgical resection cannot be confirmed;
2. Received adjuvant therapy other than that specified in the ADAURA study;
3. No NGS test report at recurrence;
4. History of other malignant tumors within 2 years;
5. Patients assessed by the investigator as unfit for enrollment, such as neurological disorders or metabolic disorders, physical examination or laboratory examination suspected that the patient has a possible disease, or has treatment-related complications High risk etc.

This multicenter, retrospective, real-world study includes patients with resected stage IB-IIIA NSCLC harboring EGFR-sensitizing mutations (exon 19 deletion or exon 21 L858R) who received adjuvant osimertinib. A total of 60 patients are enrolled and classified into two cohorts based on recurrence timing: Cohort 1 comprises 30 patients with recurrence more than 6 months after completing 3 years of adjuvant osimertinib; Cohort 2 comprises 30 patients with recurrence during adjuvant osimertinib treatment. Genomic profiling data of recurrence, obtained from next-generation sequencing of tissue and/or blood samples, are collected and analyzed. All data are extracted from electronic medical records.