Surgical selection and regional lymph node dissection for stage I second primary lung cancer patients following surgery for stage I first primary lung cancer

Introduction: Studies investigating surgery for second primary non-small cell lung cancer (SP) patients are rare. The aim of this study was to explore the effects of surgical methods and regional lymph node (LN) dissection on lung cancer-specific mortality (LCSM) in stage I SP patients following surgery for stage I first primary non-small cell lung cancer (FP). Methods: Data on patients diagnosed with stage I SP after surgery for stage I FP were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Cumulative incidence function (CIF) curves, a competing risk model and propensity score matching (PSM) were adopted to compare the LCSM among different subgroups (including surgery and regional LN dissection). Results: A total of 238 stage I SP patients were extracted from the SEER database. Overall, the 5-year LCSM rate was 29.8% (CI: 23.1%-36.5%) for the whole cohort. Both before and after PSM, lobectomy had a similar LCSM incidence as sublobectomy, and >= 4 regional LN dissections had a significantly lower LCSM incidence than 1 similar to 3 regional LN dissections.In addition, patients who underwent 1 similar to 3 regional LN dissections had a comparable incidence of LCSM to those without LN dissections. Discussion: Stage I SP patients tended to gain more survival benefits when surgeons dissect >= 4 regional LNs. Allowing for the comparable LCSM incidence of sublobectomy to lobectomy, sublobectomy may be a reasonable choice for thoracic surgeons when performing surgery for these patients.