RESUMO
Purpose: To identify the incidence, preoperative risk factors, and prognosis associated with pathologically positive lymph node (pN+) in patients undergoing a sub-lobar resection (SLR). Methods: This is a retrospective study using the National Cancer Database (NCDB) from 2004 to 2014 analyzing SLR excluding those with any preoperative chemotherapy and/or radiation, follow-up <3 months, stage IV disease, or >1 tumor nodule. Multivariable modeling (MVA) was used to determine factors associated with overall survival (OS). Propensity score matching (PSM) was used to determine preoperative risk factors for pN+ in patients having at least one node examined to assess radiation's effect on OS in those patients with pN+ and to determine whether SLR was associated with inferior OS as compared to lobectomy for each nodal stage. Results: A total of 40,202 patients underwent SLR, but only 58.3% had one lymph node examined. Then, 2,615 individuals had pN+ which decreased progressively from 15.1% in 2004 to 8.9% in 2014 (N1, from 6.3 to 3.0%, and N2, from 8.4 to 5.9%). A lower risk of pN+ was noted for squamous cell carcinomas, bronchioloalveolar adenocarcinoma (BAC), adenocarcinomas, and right upper lobe locations. In the pN+ group, OS was worse without chemotherapy or radiation. Radiation was associated with a strong trend for OS in the entire pN+ group (p = 0.0647) which was largely due to the effects on those having N2 disease (p = 0.009) or R1 resections (p = 0.03), but not N1 involvement (p = 0.87). PSM noted that SLR was associated with an inferior OS as compared to lobectomy by nodal stage in the overall patient population and even for those with tumors <2 cm. Conclusion: pN+ incidence in SLRs has decreased over time. SLR was associated with inferior OS as compared to lobectomy by nodal stage. Radiation appears to improve the OS in patients undergoing SLR with pN+, especially in those with N2 nodal involvement and/or positive margins.
RESUMO
BACKGROUND: The aim of the present study was to compare the prognostic outcomes of patients with stage IA right middle lobe non-small cell lung cancers (RML NSCLCs) that underwent either lobectomy (LR) or sub-lobar resection (SLR) after 1:1 propensity score matching (PSM). METHODS: Patients with stage IA RML NSCLC were identified from the Surveillance, Epidemiology and End Results (SEER) database from 2005 to 2015. Cox regression analysis was carried out to compare lung cancer specific survival (LCSS) following LR or SLR before and after PSM. Subgroup analysis of LCSS stratified by tumor size (≤1, 1-2, and 2-3 cm) was also performed. RESULTS: A total of 1,104 patients met the inclusion criteria. One hundred ninety-eight (17.9%) patients underwent SLR, and 906 (82.1%) underwent LR. There were significant differences between patients of LR and SLR groups with regard to the tumor size and the number of examined lymph nodes. After PSM, 147 matched pairs (n=294) were selected. Multivariable cox regression analysis revealed no difference in the LCSS of patients that underwent either LR or SLR before [hazard ratio (HR): 0.881, 95% CI: 0.547-1.422, P=0.605] and after PSM (HR: 0.778, 95% CI: 0.409-1.480, P=0.444). Subgroup analysis revealed no significant difference in LCSS between patients of LR and SLR groups with regard to the tumor size (all P>0.05). CONCLUSIONS: Similar to lymphadenectomy, the prognostic outcomes in patients with stage IA RML NSCLC were comparable between LR and SLR.