The impact of lymph node density as a predictive factor for survival and recurrence of tongue squamous cell carcinoma

The oral tongue is considered the most frequently involved site in cases of oral squamous cell carcinoma (OSCC). Lymph node (LN) density, defined as the number of positive LNs divided by the total number of resected LNs, is considered an important prognostic factor in OSCC; however the cut-off point remains uncertain. A retrospective study was performed involving 104 patients who underwent a glossectomy procedure for oral tongue squamous cell carcinoma (OTSCC) between the years 2008 and 2018. LN density and other related prognostic factors, including pathological N-stage (pN), extranodal extension (ENE), perineural invasion (PNI), and depth of invasion (DOI), were investigated in relation to survival and recurrence rates. pN + stage, the presence of ENE, the presence of PNI, and increased DOI were found to be associated with increased LN density values, as well as lower patient survival and higher recurrence rates. The statistical analysis identified a cut-off point for LN density of 2.5%. In advanced stage disease, LN density values above 2.5% had a significant impact on the survival rate (P = 0.005), as well as the recurrence rate (P = 0.038). In conclusion, in addition to other previously known prognostic factors, LN density may serve as a strong prognostic factor for survival and recurrence in patients with advanced- and early-stage OTSCC.