The prognostic value of lymph node ratio in survival of head-and-neck squamous cell carcinoma.

Background: Head-and-neck squamous cell carcinoma (HNSCC) is the sixth most prevalent type of cancers in the world. Due to its relatively high rate of recurrence, the prognosis of patients is poor and the survival rate is low; therefore, identifying the prognostic factors is considered necessary for better treatment.

Materials and Methods: This historical cohort study was conducted on 201 patients diagnosed with aerodigestive SCC who underwent surgery and lymph node dissection. We determined the prognostic value of lymph node ratio (LNR) on overall survival (OS), disease-free survival (DFS), and locoregional failure-free survival (LFFS). We noticed an association between LNR and survival by Kaplan-Meier analysis. Hazard ratio (HR) of LNR was determined by Cox's regression model.

Results: Two hundred and one patients entered this study after their medical histories were evaluated. The mean of lymph node count and LNR was 14.30 (±9.50) and 0.12 (±0.23), respectively. Eighty patients (39.80%) experienced recurrence of SCC. Five-year OS, DFS, and LFFS were 32%, 21%, and 64%, respectively. The median of OS was 40.70 months and 30.11 months in patients with LNR of ≤0.06 and >0.06, respectively ( P < 0.01). The LNR >0.06 was found to be a significant prognostic factor for lower OS of patients with HNSCC (HR = 2.11 [1.10, 4.40]; P = 0.04). DFS was not significantly different among patients with LNR ≤0.06 and patients with LNR >0.06 ( P = 0.9). However, LFFS was slightly different among two groups (HR = 2.04 [0.90-4.80]; P < 0.1).

Conclusion: We recommend more intensive adjuvant therapies such as chemotherapy with radiotherapy and short interval follow-up for patients with LNR >0.06. Further investigations with larger sample sizes are recommended.