ObjectiveTo investigate the effect of different lymph node dissection methods on the prognosis of patients with stage ⅠA spread through air space (STAS)-positive lung adenocarcinoma≤ 2 cm. MethodsClinical data of 3148 patients with lung adenocarcinoma who underwent surgery at the Department of Thoracic Surgery, the First Affiliated Hospital of University of Science and Technology of China from 2016 to 2018 were retrospectively analyzed. Patients with stage ⅠA STAS-positive lung adenocarcinoma≤ 2 cm were included and divided into two groups based on lymph node dissection methods: systematic lymph node dissection group and limited lymph node dissection group. Compare the clinical and pathological data of two groups of patients and use Cox proportional hazards regression model for multivariate survival analysis. ResultsA total of 209 STAS-positive patients were enrolled in the study, including 98 males and 111 females, aged 28-83 (60.42±10.15) years. Univariate analysis showed that the mode of lymph node dissection, past history, micropapillary histological subtype, and papillary histological subtype were risk factors for patient prognosis. Multifactorial analysis showed that lymph node dissection method, past history, and solid-type histological subtype were risk factors for patient prognosis. Meanwhile, among STAS-positive patients, systematic lymph node dissection had a better prognosis than limited lymph node dissection patients. ConclusionSTAS plays an important role in patient prognosis as an independent risk factor for prognosis of stage ⅠA ≤2 cm lung adenocarcinoma. When STAS is positive, the choice of systematic lymph node dissection may be more favourable to patients' long-term prognosis.