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;