Prognostic significance of lymph node yield and lymph node ratio in oral squamous cell carcinoma after cervical
Huichao Liu1, Hong Wang1, Fei Gao1
1Jinan Key Medical and Health Laboratory of Oral Diseases and Tissue Regeneration, Jinan Key Laboratory of Oral Diseases and Tissue Regeneration, Shandong Provincial Key Medical and Health Laboratory of Oral Diseases and Tissue Regeneration, Shandong Provincial Key Medical and Health Discipline of Oral Medicine, Jinan Stomatological Hospital, Jinan, Shandong, China.
Objective:
Cervical lymph node status is a major prognostic determinant in oral squamous cell carcinoma (OSCC). In this study, the prognostic significance of lymph node yield (LNY) and lymph node ratio (LNR) in patients with OSCC undergoing cervical lymphadenectomy was evaluated.
Materials And Methods:
Total of 151 patients with previously untreated primary OSCC who underwent surgical treatment between 2006 and 2015 were retrospectively reviewed. LNY was defined as the total number of lymph nodes retrieved during surgery, and LNR was calculated as the number of positive lymph nodes divided by the total number of retrieved lymph nodes. Overall survival (OS) and disease-free survival (DFS) were analyzed using the Kaplan-Meier method and Cox proportional hazards models.
Results:
A total of 3087 lymph nodes were retrieved, with a median LNY of 19 (range 5-78). In the overall cohort, an LNY cutoff of 18 was significantly associated with improved OS. Multivariate analysis identified LNY as an independent prognostic factor for OS, DFS, and local recurrence. Among pN0 patients, an LNY value of ≥15 was associated with improved OS. Among pN + patients, an LNY value of ≥25 indicated better OS, and LNR of <0.06 was associated with improved OS in univariate analysis. In exploratory subgroup analysis, postoperative radiotherapy was associated with improved OS in pN + patients with LNR of <0.136.
Conclusion:
LNY and LNR were significantly associated with survival outcomes in OSCC after cervical lymphadenectomy. Higher LNY was consistently associated with improved survival, whereas the prognostic value of LNR was less consistent across analyses.