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Lymph node upstaging for non-small cell lung cancer after uniportal video-assisted thoracoscopy.

Background
Radical lymph node dissection (LND) plays a major role in the treatment of non-small cell lung cancer (NSCLC). This study presents the analysis of the results after uniportal video-assisted thoracoscopy (VATS) lymphadenectomy during anatomical lung resections for NSCLC, focusing on pathological nodal upstaging. Any possible risk factor affecting nodal upstaging was also investigated.


Methods
The prospectively collected clinical data of 136 patients undergone uniportal VATS anatomical lung resections, from June 2012 to September 2017, were reviewed. In particular, all details inherent the clinical and pathological node stage and any possible risk factor affecting nodal upstaging were analyzed.


Results
The patient population consisted of 90 males and 46 females; their mean age was 67.42±10.64 years. The mean number of lymph nodes retrieved during uniportal VATS lymphadenectomy was 20.14±10.73 (7.27±5.90 and 12.60±7.96 in N1 and N2 stations, respectively). The incidence of nodal upstaging was 13.3% (18 cases). In particular there was a N0-1 upstaging in 10 cases (7.4%), a N1-2 upstaging in 3 (2.2%) and a N0-2 in 4 (3%). The ROC analysis showed that the resection of 18 lymph nodes was the best predictor of a general upstaging with an AUC-ROC of 0.595, while the resection of 7 hilar lymph nodes was the best predictor of N1 upstaging (AUC-ROC: 0.554) and 11 mediastinal nodes was the best predictor of N2 upstaging (AUC-ROC: 0.671). The number of positive lymph nodes of stations 5-6 (OR: 2.035, 95% CI: 1.082-3.826, P=0.027) and stations 2-3-4 (OR: 6.198, 95% CI: 1.580-24.321, P=0.009) were confirmed to be the only independent risk factors for N2 upstaging by multivariate analysis.


Conclusions
According to our experience, uniportal VATS allows a safe and effective radical lymphadenectomy, with a satisfactory pathological nodal upstaging, comparable to other minimally invasive techniques.