Despite surgery provides the best chance for the cure of early-stage lung cancer patients, 20%-40% of stage I non-small cell lung cancer (NSCLC) patients still suffer from disease relapse after R0 resection. One of the important strategies to improve survival is adjuvant therapy.~The adjuvant chemotherapies are reported to improve outcomes of patients with stage II and III lung cancer. However, for stage IA patients, adjuvant chemotherapy is not recommended, while its application in stage IB patients is still controversial. The adjuvant targeted therapy has shown promising effectiveness which can lead to better RFS of EGFR mutation-positive stage IB-IIIA NSCLC patients than chemotherapy in according to several phase III studies. According to the ADAURA study, stage IB NSCLC patients can benefit from the third-generation EGFR-TKI. However, no available study has evaluated the effectiveness of adjuvant targeted therapy in the overall cohort of stage I patients.~Molecular residual disease or minimal residual disease (MRD) refers to residual tumor cells or relative biomarkers that persist in the body after treatment and is below the conventional detection limit. Several studies have confirmed that positive MRD was associated with a poor prognosis. The use of circulating tumor DNA (ctDNA) to reflect MRD at the molecular level can overcome the shortcomings of conventional tests or radiological tests in the detection of recurrence. ctDNA has been proven to detect MRD effectively in stage I-III lung cancer patients and identifying MRD after surgery could facilitate the selection of patients for customized adjuvant therapies.~Thus, the investigators innovatively propose this study to assess the effectiveness of adjuvant targeted therapy (furmonertinib, one third-generation EGFR-TKI) in stage I lung adenocarcinoma patients and explore the role of ctDNA as an MRD monitoring marker in guiding personalized adjuvant therapies.
The purpose of this study is to determine the feasibility and effectiveness of ctDNA-MRD based adjuvant furmonertinib therapy in EGFR mutation-positive stage I lung adenocarcinoma patients after complete surgical resection.