{Reference Type}: Journal Article
{Title}: Feasibility of nodal classification for non-small cell lung cancer by merging current N categories with the number of involved lymph node stations.
{Author}: Chen W;Zhang C;Wang G;Yu Z;Liu H;
{Journal}: Thorac Cancer
{Volume}: 10
{Issue}: 7
{Year}: 07 2019
{Factor}: 3.223
{DOI}: 10.1111/1759-7714.13094
{Abstract}: The aim of this study was to assess the prognoses of patients with non-small cell lung cancer (NSCLC) according to the current nodal (N) categories of the tumor, node and metastasis (TNM) classification and the number of involved lymph node stations.<BR>Five hundred and seventy patients with NSCLC underwent surgery from 1 January 2005 to 31 December 2009 and were analysed retrospectively. Postoperative overall survival was analysed according to two nodal classifications: the current N0, N1, N2 and N3 categories and those based on the number of involved nodal stations: N0, N1a (single N1), N1b (multiple N1), N2a1 (single N2 without N1), N2a2 (single N2 with N1), N2b1 (multiple N2 without N1) and N2b2 (multiple N2 with N1).<BR>Five-year survival rates were 76.1%, 53.4% and 26.3% for N0, N1 and N2, respectively (P < 0.001). When survival was analysed by the number of involved nodal stations, the groups with significant differences were maintained; otherwise, they were merged, and new codes were assigned as follows for exploratory analyses: NA (N0), NB (N1a), NC (N1b, N2a (i.e., N2a1 and N2a2) and N2b1) and ND (N2b2). Five-year survival rates were 76.1%, 60.0%, 39.1%, and 11.4% for NA, NB, NC and ND, respectively, and there were significant differences among them. This N classification was an independent prognostic factor in multivariate analyses.<BR>Pending prospective and international validation, it is practical to merge the current N categories with the number of involved lymph node stations when evaluating the postoperative prognosis of NSCLC patients.