ABSTRACT
<p><b>OBJECTIVE</b>To investigate the clinical characteristics of second primary tumor of tongue after nasopharyngeal carcinoma (NPC) radiotherapy and the prognostic factors of patients.</p><p><b>METHODS</b>Fifty-three cases with second primary tumor of tongue after NPC radiotherapy, presenting to Cancer Centre, Sun Yat-sen University from Jan. 1st 1975 to Dec. 31st 2000 were analyzed retrospectively with regard to mortality and survival rate (Kaplan-Meier method); A multivariate analysis was performed in these patients with Cox proportional hazard model.</p><p><b>RESULTS</b>Forty of 53 patients died. Among them,37 died of second primary tumor of tongue, 2 of recurrence of NPC, 1 of perioperative period. The overall 5-year and 10-year survival rate of 51 patients receiving therapy were 41.64% and 35.69% respectively. The subsites of tumor were: tip 0, margin 26 (49.06%), ventral lateral 8 (15.09%) and dorsal aspect 19 (35.85%). Eighteen cases had recurrence of second primary tumor of tongue (33.96%) ; Six (11.32%) cases had clinical lymph node metastasis from second primary tumor of tongue and 3 (5.66%) had pathological lymph node metastasis; The univariate analysis showed the major prognostic factors influencing survival of these patients were tumor size, clinical TNM stage at presentation; Using multivariate analysis, risk factors that independently influence survival were clinical and pathological stage and the interval between two tumors.</p><p><b>CONCLUSIONS</b>The clinical and pathological stage and the interval between two tumors are the prognostic factors for second primary tumor of tongue after NPC radiotherapy.</p>