The association of nodal upstaging with surgical approach and its impact on long-term survival after resection of non-small-cell lung cancer

OBJECTIVES: Proponents of open thoracotomy (OPEN) and robot-assisted thoracic surgery (RATS) claim its oncological superiority over video-assisted thoracic surgery (VATS) in terms of the accuracy of lymph node staging. METHODS: The National Cancer Database was queried for patients with non-small-cell lung cancer (NSCLC) undergoing lobectomy without neoadjuvant therapy from 2010 to 2014. Nodal upstaging rates were compared using a surgical approach. Overall survival adjusted for confounding variables was examined using the Cox proportional hazards model. RESULTS: A total of 64 676 patients fulfilled the selection criteria. The number of patients who underwent lobectomy by RATS, VATS and OPEN approaches was 5470 (8.5%), 17 545 (27.1%) and 41 661 (64.4%), respectively. The mean number of lymph nodes examined for each of these approaches was 10.9, 11.3 and 10 (P<0.01) and upstaging rates were 11.2%, 11.7% and 12.6% (P<0.01), respectively. For patients with clinical stage I disease (N=46 826; RATS=4338, VATS=13 416 and OPEN=29 072), the mean lymph nodes examined were 10.6, 10.8 and 9.4 (P<0.01), and upstaging rates were 10.8%, 11.1% and 12.1% (P<0.01), respectively. A multivariable analysis suggested an association with improved survival with RATS and VATS compared with OPEN surgery [hazard ratio (HR)=0.89 and 0.89, respectively; P<0.01] for patients with all stages. In stage I disease, VATS but not RATS was associated with increased overall survival compared with the OPEN approach (HR=0.81; P<0.01). CONCLUSIONS: RATS lobectomy is not superior to VATS lobectomy with respect to lymph node yield or upstaging of NSCLC. Increased nodal upstaging by the OPEN approach does not confer a survival advantage in any stage of NSCLC and may be associated with decreased overall survival.