[Cervical lymphnode metastasis of early or late T2 tongue carcinoma]

Between 1986 and 1997, 72 patients (47 males, 25 females) with previously untreated tongue cancer were treated at our institution (surgery: 67, interstitial radiotherapy: 3, palliative therapy: 2). These patients, especially T2 tongue cancer, were classified into two groups (early T2: < or = 3 cm, late T2: > 3 cm) according to the maximum diameter of the primary lesion, and were analyzed for treatment outcome and cervical lymphnode metastasis. (1) The cumulative 5-year survival rates were 65.9% for all cases, 95.0% for T1 cases, 77.5% (94.1% for early T2, 59.7% for late T2) for T2 cases, 24.3% for T3 cases (4-year survival rate), and 0% for T4 cases. (2) The cumulative 5-year survival rates were 90.8% for pN- patients and 21.7% for pN+ patients and the difference was statistically significant (p < 0.05%). In prognosis, pN- patients were better than pN+ patients. Since the N factor was related to the cause of death in 87.5% (7/8) of T2 tongue cancer, control of regional lymph node involvement was the most important prognostic factor. (3) The overall incidence of cervical lymph node metastasis (pN+ or secondary nodal metastasis) was 35.3% for early T2 and 750% for late T2. The control rate of secondary nodal metastasis was 75.0% for early T2 and 33.3% for late T2. Partial glossectomy only (observation for occult lymphnode metastasis) is recommended for treatment of T2N0, whereas glossectomy with selective neck dissection by the pull-through method is recommended for treatment of late T2.