Predictive Factors of Occult Lymph Node Involvement in Advanced Laryngeal Squamous Cell Carcinoma.

Objective: Determine the rate of occult lymph node metastasis in advanced laryngeal squamous cell carcinoma and identify its predictive factors.

Methods: A retrospective study including 98 patients with laryngeal cancer classified as T3-T4 N0, who underwent bilateral lymph node dissection in sectors II, III and IV.

Result: The median age of our patients was 61. The main symptom was dysphonia (96%). On CT scan, the thyroid cartilage was invaded in 53.5% of cases, and the HTE space in 50% of cases. It was essentially laryngeal squamous cell carcinoma of high grade in 6.1% of cases and of low grade in 93.9% of cases. We found lymph node involvement in 33 lymph node dissections (33.6%) in 24 patients (24.4%) with extranodal extension in 4 cases. Level IIA and III were the most commonly affected, with 28.6% and 21.4% of cases respectively. We noted a vascular emboli and perineural invasion in 5 patients. The predictive factors for MGO in our present study were age over 65, invasion of the subglottic stage, involvement of the thyroid cartilage, the hyo-thyro-epiglottic space, peri-neural invasion and limits of resection.

Conclusion: The criteria for performing lymph node dissection in cases of laryngeal cancer are becoming more restricted for patients with clinically negative lymph nodes (cN0). Nevertheless, for cases of locally advanced tumors, proactive lymph node dissection is advocated, particularly when certain predictive factors for hidden lymph node metastases are present.