[Metastatic rule and management of occult lymphatic metastasis in supraglottic cancer with clinically negative neck].

OBJECTIVE: To investigate the metastatic rule and management methods of occult lymphatic metastasis in patients with supraglottic cancer. METHOD: The results of 139 cN0 patients with supraglottic cancer treated by neck dissection (ND) were reviewed retrospectively. Each lymph node was studied pathologically in order to define the level of the lymph node metastasis. RESULT: Of the 139 patients with supraglottic cancer and cN0 neck, 113 cases received ipsilateral ND and 26 cases with bilateral ND. Thirty-six (25.9%) of 139 patients were found to have occult lymphatic metastasis on pathological examination, 6 patients without metastasis in dissected side at pathologic examination showed metastasis in the contralateral undissected neck later. Therefore the total occult metastasis rate was 30.2% (42 of 139). The unilateral and bilateral neck occult metastases were determined in 37 cases (26.6%) and 5 cases (3.6%) respectively. A total of 3594 lymph nodes were harvested in 165 specimens, with 83 positive nodes. The distributions of the 83 positive nodes were as follows: level I 1.2% (1 node), level II 78.3% (65 nodes), level III 19.3% (16 nodes), level IV 1.2% (1 node), level V (0 node). The 3-year regional recurrence rate was 5.0% (7/139). The 5-year survival rate was 76.3% (106/139). Patients with positive neck metastasis had higher regional recurrence rates (P < 0.05). CONCLUSION: Occult metastasis rate of supraglottic cancer is as high as 30.2%, the selective lateral neck dissection of level II, III is recommended.