Evaluation Of Sublobar Resection In Early Invasive Adenocarcinoma Of The Lung

Background: The incidence and mortality of lung cancer is the highest among all malignancies.Adenocarcinoma is the most common type of the lung cancer.Surgery is the first choice for treatment of early primary lung adenocarcinoma.Sublobar resection has been increasingly used in patients with lung adenocarcinomas.For patients with lung AIS(Adenocarcinoma in Situ)or MIA(Minimally Invasive Adenocarcinoma),sublobar resection could be considered as a routine choice.However,it is unknown whether sublobar resection is equivalent to lobectomy for patients with early invasive lung adenocarcinomas > 0cm to 2cm.Material and Methods: The SEER database(Surveillance,Epidemiology and End Results database)and HIS(Hospital Information System)of Northern Jiangsu People’s Hospital were used to identify patients who underwent sublobar resection or lobectomy.PSM(Propensity Score-Matching)was used to adjust potential confounding.The Kaplan–Meier method was used to assess OS(Overall Survival)and LCSS(Lung Cancer-Specific Survival).Results: We identified 7654 patients who met our inclusion criteria from SEER database.Overall,1822 patients underwent sublobar resection and 5832 underwent lobectomy.PSM allowed good matches of 636 sublobar resection and lobectomy pairs,217 segmentectomy and lobectomy pairs and 507 wedge resection and lobectomy pairs in terms of clinical and consequently pathological factors.Analyses of study cohort demographics after PSM showed that sublobar resection was inferior to lobectomy in terms of five-year OS(HR,1.93(1.53-2.44),P<0.001)and five-year LCSS(HR,1.76(1.31-2.36),P<0.001).And segmentectomy had a worse prognosis to lobectomy reference to the five-year LCSS(HR,2.07(1.21-3.54),P=0.008).Also,wedge resection did have a significant inferior five-year LCSS advantage compared with lobectomy(HR,1.75(1.26-2.43),P<0.001).Subgroup analyses showed that sublobar resection was just equivalent to lobectomy in terms of fiveyear LCSS(HR,1.66(0.93-2.97),P=0.09)instead of five-year OS(HR,1.67(1.06-2.63),P=0.036)among patients with 0</= 1cm,whereas lower five-year OS(HR,2.01(1.57-2.58),P<0.001)and five-year LCSS(HR,1.83(1.34-2.50),P<0.001)emerged for tumor size > 1cm to 2cm after sublobar resection compared with lobectomy.Addition,Analyses stratified by diagnosed time showed that sublobar resection was similar to lobectomy in terms of five-year OS(HR,1.57(0.97-2.54),P=0.06)and five-year LCSS(HR,1.49(0.76-2.90),P=0.24)among patients diagnosed from 2008-2014 after PSM.However,sublobar resection was not equivalent to lobectomy with five-year OS(HR,1.91(1.40-2.60),P<0.001)and five-year LCSS(HR,2.01(1.33-3.01),P<0.001)for the patients diagnosed from 1998-2007 after PSM.We obtained 154 patients from Northern Jiangsu People’s Hospital,of whom 31 patients underwent segmentectomy and 123 underwent lobectomy.And segmentectomy was equivalent to lobectomy in terms of 3-year OS(HR,1.29(0.13-12.81),P=0.81).PSM allowed good matches of 28 segmentectomy and lobectomy pairs.And segmentectomy was similar to lobectomy in terms of OS(HR,2.50(0.12-52.50),P=0.38).Conclusion: Although long-term survival time indicates that lobectomy for the patients with primary lung invasive adenocarcinomas > 0cm to 2cm still has certain advantages over sublobar resection,sublobar resection,especially segmentectomy,may be considered as an alternative surgical procedure for low-risk patients based on perfect imaging performance and proficient surgical technique.