Purpose: The aim of this study was to investigate prognostic factors in advanced-stage oral tongue cancer treated with postoperative adjuvant therapy and to identify indications for adjuvant concomitant chemoradiotherapy (CCRT).
Methods and materials: We retrospectively reviewed the records of 201 patients with advanced squamous cell carcinoma of the oral tongue managed between January 1995 and November 2002. All had undergone wide excision and neck dissection plus adjuvant radiotherapy or CCRT. Based on postoperative staging, 123 (61.2%) patients had Stage IV and 78 (38.8%) had Stage III disease. All patients were followed for at least 18 months after completion of radiotherapy or until death. The median follow-up was 40.4 months for surviving patients. The median dose of radiotherapy was 64.8 Gy (range, 58.8-72.8 Gy). Cisplatin-based regimens were used for chemotherapy.
Results: The 3-year overall survival (OS) and recurrence-free survival (RFS) rates were 48% and 50.8%, respectively. Stage, multiple nodal metastases, differentiation, and extracapsular spread (ECS) significantly affected disease-specific survival on univariate analysis. On multivariate analysis, multiple nodal metastases, differentiation, ECS, and CCRT were independent prognostic factors. If ECS was present, only CCRT significantly improved survival (3-year RFS with ECS and with CCRT = 48.2% vs. without CCRT = 15%, p = 0.038). In the presence of other poor prognostic factors, results of the two treatment strategies did not significantly differ.
Conclusions: Based on this study, ECS appears to be an absolute indication for adjuvant CCRT. CCRT can not be shown to be statistically better than radiotherapy alone in this retrospective series when ECS is not present.