A Study to Evaluate Effectiveness of Sublobar Dissection in Patients With Non-small Cell Lung Cancer

Inclusion Criteria: * Patients \>= 18 years old; * Patients who received sublobar dissection from 2014 to 2017 (segment dissection/wedge dissection/segment and wedge dissections); * Patients who received selective or systematic lymphadenectomy; * Pathologically diagnosed patients with non-small cell lung cancer; * Pathological staging: I, II Exclusion Criteria: * Patients who received cancer treatments before surgeries (adjuvant therapies including chemotherapies, radiotherapies, target therapies); * Patients who received late-phase or intolerant palliative lobectomy or compromise sublobar dissection;