# Prognostic Value of Lymph Node Density in Lingual Squamous Cell Carcinoma
## 4 Discussion  
LND has been shown to be a valid predictor of survival in the case of some solid tumors, including breast cancer, colon cancer and pancreatic cancer [12]. Some studies suggest that LND may have a greater prognostic significance than conventional pathologic staging N in OSCC [12; 14; 17] and specifically in LSCC [18]. LND can be used as a predictor of survival as well as an indicator for the use of adjuvant therapy in LSCC [18; 19]. The purpose of this study was to investigate the value of LND in the prognosis of patients diagnosed with LSCC, and to compare it with other conventional risk factors. In our study, we established the cut-off point for LND at 0.04 because it was referred to in the literature and because it included patients with pN0 and bilateral dissections. The results of the present study show a strong correlation between LND and the presence of tumor disease in the lymph nodes (\(p<0.001\)). This seems logical, as lymphatic tumor invasion is likely to increase the risk of developing cervical metastases and, subsequently, affect LND. This finding is in accordance with findings reported in other publications, including tumor locations other than LSCC [19]. The correlations observed with T stage (\(p\) 0.006) and with other pathological risk factors, such as pathological tumor staging according to AJCC (\(p<0.001\)) and perineural tumor invasion (\(p\) 0.005), can be considered a sign of increased tumor aggressiveness, and support the validity of using LND to establish the prognosis of patients with LSCC. The main objective of this work was to correlate LND with OS and DFS in LSCC. Although it was not possible for a multivariable analysis to be performed due to the limited number of patients and, although not reaching statistical significance, Kaplan-Meier curves for OS (Figure 3) and DFS (Figure 5) suggest a worse outcome for the group with LND \(\geq\) 0.04 (OS = 56.67 \(\pm\) 10.53 months; DFS = 45.22 \(\pm\) 10.59 months) with respect to the group with LND \(<\) 0.04 (OS = 76.97 \(\pm\) 5.27 months; DFS = 76.13 \(\pm\) 5.72 months), suggesting that higher LND may be associated with reduced survival. Survival rates in our patients were similar to those published in the scientific literature. [PERSON] et al. [20] studied a cohort similar to that of this work, with 130 patients with LSCC, and established a cut-off point of 0.012 for LND. In their study, the mean OS of those patients with LND \(>\) 0.012 was 38.1 months vs. 52.1 months in those with LND \(<\) 0.012. The mean DFS in the lower LND group was 53.6 months vs. 39.2 months in the higher LND group. In both cases, the association between LND and survival is significant. [PERSON] et al. [18] included 72 patients with LSCC and N+ in their cohort and set the cut-off point for LND at 0.143. They found prognostic significance of LND in terms of OS (mean 82.3 months in the high-risk LND group vs. 14.7 months in the low-risk group). [PERSON] et al. [12], in the largest study of LND in OSCC conducted to date (4000 patients stratified according to an LND of 0.07), demonstrated the prognostic reliability of LND in terms of OS and DFS. In  
Figure 8: Pathologic stage (AJCC) depending on the LND. their study they reported a 5-year OS rate of 49% in the low LND group vs. 35% in the high LND group. The 5-year DFS rate was 55% in patients with low LND vs. 38% in those with high LND. [PERSON] et al. [21] included 95 patients in their study with OSCC stratified into two risk groups based on an LND cut-off point of 0.04. In their analysis, they demonstrated that LND is a prognostic factor for overall survival (5-year OS rate of 90.5% for patients with low LND and 68.8% for patients with high LND). As for secondary objectives, this study demonstrates a significant association between LND and perineural invasion as well as pathologic staging according to AJCC. No significance was reached in the relationship between LND and pathologic margin status and DOI, although in the latter it was very close to significance. [PERSON] et al.