This is a clinical trial from Eastern Cooperative Thoracic Oncology Project (ECTOP), numbered as ECTOP-1019. The goal of this clinical trial is to confirm the therapeutic effect of sublobar resection for AIS/MIA diagnosed by intraoperative frozen section.

Inclusion Criteria:

1. Patients who sign the informed consent form and are willing to complete the study according to the plan;
2. Aged from 18 to 80 years old;
3. ECOG equals 0 or 1;
4. Not receiving lung cancer surgery before;
5. Resectable peripheral cT1N0M0 tumors;
6. Single lung nodules with ground-glass dominant or pure ground-glass on CT, or multiple lung nodules with the major lesion being the aforementioned nodules;
7. Adenocarcinoma in Situ/Minimally Invasive Adenocarcinoma Diagnosed by Intraoperative Frozen Section
8. Not receiving chemotherapy or radiotherapy before.

Exclusion Criteria:

1. Not cT1N0M0;
2. Cannot be completely resected by sublobar resection;
3. Invasive lung adenocarcinoma or not lung adenocarcinoma diagnosed cytologically or pathologically;
4. Receiving lung cancer surgery before;
5. Receiving radiotherapy or chemotherapy.