[Survival Analysis of Stage I Non-small Cell Lung Cancer Patients Treated with 
Da Vinci Robot-assisted Thoracic Surgery].

BACKGROUND:Da Vinci robotic surgery system is widely used in department of thoracic surgery. The aim of this study is to investigate the treatment outcome of stage I non-small cell lung cancer (NSCLC) via da Vinci Surgical System. METHODS:Clinical date of 347 stage I NSCLC patients, who underwent lobectomy and systematic node dissection from Jan. 2012 to Dec. 2017, were reviewed. 134 patients underwent robot-assisted thoracic surgery (RATS) and 213 patients underwent video-assisted thoracic surgery (VATS). To compare perioperative outcome (blood lose, postoperative drainage, drainage time, postoperative hospital stay, number of the LN dissection) and analyze overall survival (OS), disease free survival (DFS) of the two groups and prognostic factors. RESULTS:The RATS group got less blood lose [(49±39 mL for RATS vs (202±239) mL for VATS, P<0.05] and postoperative drainage [Day 1: (248±123) mL for RATS vs (350±213) mL for VATS; Day 2: (288±189) mL for RATS vs (338±189) mL for VATS, P<0.05]. There were no significant difference for drainage time (10±5 for RATS vs 11±8 for VATS, P<0.05) and postoperative hospital stay (13±6 for RATS vs 14±9 for VATS, P<0.05) between the two groups. The RATS group harvested a more number of mean stations (5±2 for RATS vs 4±2 for VATS) and amounts (18±9 for RATS vs 11±8 for VATS) of the lymph nodes, P<0.05. There was no statistically significant difference of OS between RATS and VATS group [1-year OS: 97.3% vs 96%; 3-year OS: 89.8% vs 83.1%; 5-year OS: 87.5 % vs 70.3%; overall survival time (mean): 61 months vs 59 months, P>0.05]; corresponding there had a statistically significant difference of DFS between the two groups [1-year DFS: 93.7% vs 91.3%; 3-year DFS: 87.7% vs 68.4%; 5-year DFS: 87.7% vs 52.5%; disease free survival time (mean): 61 months vs 50 months, P<0.05]. The univariate analysis found that the amounts of the lymph nodes dissection was the prognostic factor for OS and tumor diameter, surgical approach, stations and amounts of the lymph nodes dissection were respectively the prognostic factors for DFS. However, multivariate analysis found that there was not independently factors for OS, but the tumor diameter and surgical approach were independently associated with DFS. CONCLUSIONS:There was no significant difference about OS between the two groups, but the RATS got better DFS. RATS got more number of the LN dissection and less blood lose.