Background: VATS lobectomy is an established option for the treatment of early-stage NSCLC. Complete lymph node dissection (CD), systematic sampling (SS) or resecting a specific number of lymph nodes (LNs) and stations are possible intra-operative LN management strategies.
Methods: All VATS lobectomies from the "Italian VATS Group" prospective database were retrospectively reviewed. The type of surgical approach (CD or SS), number of LN resected (RN), the positive/resected LN ratio (LNR) and the number and types of positive LN stations were recorded. The rates of nodal upstaging were assessed based on different LN management strategies.
Results: CD was the most frequent approach (72.3%). Nodal upstaging rates were 6.03% (N0-to-N1), 5.45% (N0-to-N2), and 0.58% (N1-to-N2). There was no difference in N1 or N2 upstaging rates between CD and SS. The number of resected nodes was correlated with both N1 (OR =1.02; CI, 1.01-1.04; P=0.03) and N2 (OR =1.02; CI, 1.01-1.05; P=0.001) upstaging. Resecting 12 nodes had the best ability to predict upstaging (6 N1 LN or 7 N2 LN). The finding of two positive LN stations best predicted N2 upstaging [area under the curve (AUC) of receiver operating characteristic (ROC) =0.98].
Conclusions: Nodal upstaging (and, indirectly, the effectiveness of intra-operative nodal management) cannot be predicted based on the surgical technique (CD or SS). A quantitative assessment of intra-operative LN management may be a more appropriate and measurable approach to justify the extension of LN resection during VATS lobectomy.
Keywords: VATS lobectomy; lymph node (LN); nodal upstaging.