Surgical resection versus radiotherapy for clinical stage IA lung cancer ≤1 cm in size: A population-based study.

With the increasing incidence of stage IA lung cancer ≤1 cm in size, the optimal primary treatment remains to be controversial, and thus, we compared the survival of these patients treated with radiotherapy, wedge resection, segmentectomy, or lobectomy in a large population.We identified patients with stage IA lung cancer ≤1 cm in size between 2004 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. We compared the overall survival (OS) via Kaplan-Meier analysis and conducted Cox regression analysis via propensity score matching (PSM) method to identify the relative hazard ratio (HR) and difference of OS among these treatments in the subgroup stratified by four variables (age, total number of tumors, pathological grade, and histology).A total of 5435 patients were included with a median age of 68 years (range, 6-94 years), of which 2131 (39.2%) were male, and 3510 (64.6%) were adenocarcinoma. The 5-year OS rate was 67.1%, 34.5%, 61.6%, 72.1%, and 75.0% for the entire study population, radiotherapy, wedge resection, segmentectomy, and lobectomy, respectively. In PSM analysis, wedge resection and segmentectomy were all superior to radiotherapy (P < 0.001), and segmentectomy was superior to wedge resection (P = 0.043), while segmentectomy was comparable with lobectomy (P = 0.058). In patients with multiple tumors, radiotherapy brought similar survival to surgery (wedge resection versus radiotherapy, P = 0.323; segmentectomy versus radiotherapy, P = 0.170; lobectomy versus radiotherapy, P = 0.796).Among stage IA lung cancer with ≤1 cm, segmentectomy and lobectomy were identified as the potential effective treatments, with segmentectomy more preferred, while radiotherapy would be recommended in those with multiple tumors, which requires further verification.