Occult cervical metastasis of squamous cell carcinoma of tongue among CN0 patients and its treatment

Objective: To explore the treatment of clinically negative neck (CN0) patients with squamous cell carcinoma of the tongue. Methods: 165 CN0 patients with squamous cell carcinoma of the tongue from 1985 to 2002 were investigated retrospectively. Parts of the patients staged at T1, T2 and T3 underwent resection of primary lesion followed by neck observation, and other patients staged above T2 or at T1 but without follow-up were treated with elective neck dissection (END). All patients were followed up for more than 3 y or until their death. Results: Lymphatic metastasis was identified histologically after operation in 33 of 120 patients treated with END, and 9 of 45 patients treated with resection of primary lesion alone. The overall rate of occult lymphatic metastasis was 25.45%, which increased with the elevating of clinical T stage. The overall rate of neck uncontrolled death was 20.00% for observation group and 5.00% for END group, and significant difference was found between them (P<0.05). For T1 patients in the two groups, the rate of neck uncontrolled death was 7.71% and 4.00% respectively, and no significance was found between them (P>0.05). When stage T2 and T3 were considered as middle stage together, significant difference (P<0.05) could be obtained between observation (70.00%) and END group (0%). Conclusion: The occult metastasis rate of squamous cell carcinoma of tongue increases with the elevating of clinical stage, and elective neck dissection could be considered for N0 patients staged over T2 to improve neck control and survival rate; and regional resection alone of primary lesion could be considered for T1N0 patients to improve quality of life if closely followed up is conducted.