Positive lymph node number and extranodal extension for predicting recurrence and survival in patients with salivary gland cancer.

Abstract

This study compared our proposed N classification including the addition of the number of positive lymph node (LN+) and extranodal extension (ENE) with the current and previous American Joint Committee on Cancer (AJCC) N classifications in salivary gland cancer (SGC). This study involved 172 SGC patients who underwent surgery. Cox proportional hazard regression analyses were used to identify factors associated with overall survival (OS) and disease-free survival (DFS). In multivariate analyses, LN+ number, LN ratio, and ENE were associated with OS and DFS outcomes (all P < .05). Our new N classification proposed three categories: N0 (0 LN+), N1 (1 LN+), and N2 (≥2 LN+ or ENE). The C-index of our N classification showed improvement in OS prediction (0.768) compared with the AJCC seventh (0.743) and eighth (0.756) edition N classifications. Our proposed N classification incorporating LN+ number and ENE may improve prediction of post-treatment survival and recurrence in patients with SGC.