Introduction: The presence of cervical lymph node metastases is an unfavorable prognostic factor in head and neck squamous cell carcinoma (HNSCC) and a potential cause of treatment failure. Occult lymph node metastasis occurs in approximately 15-20% of HNSCC patients with a clinically negative neck (cN0), greatly impacting on their prognosis. The present study aimed to investigate the role of pre-treatment peripheral blood markers in predicting clinically occult cervical lymph node metastasis. Methods: This multicenter, retrospective study was performed in a cohort of 472 patients diagnosed with cN0 HNSCC who underwent up-front surgery. Baseline neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic inflammatory marker (SIM), and systemic immune-inflammation index (SII) were calculated from available blood parameters. Results: Oro-hypopharyngeal and oral cancers, locally advanced stage, moderately (G2), and poorly (G3) differentiated grade were associated with an increased risk of pathological lymph node involvement. NLR, LMR, PLR, SIM, and SII were significantly associated at multivariable analysis. NLR >2.12 was the most reliable at predicting occult lymph node metastasis (OR = 5.22; 95% CI: 2.14-12.75). We describe a predictive score integrating cancer site, local stage, and NLR which is effective at predicting positive lymph node pathological status. Conclusions: The present study provides evidence that pre-treatment peripheral blood markers, in particular NLR, represent reliable predictors of clinically occult cervical lymph node metastasis in cN0 HNSCC. Therefore, the present study provides a novel useful predictive score for directing the elective management of the neck in patients with cN0 HNSCC.
