Analysis of treatment results for base of tongue cancer

Objective. The study reported the results of treatment for base of tongue cancer with five different treatment modalities with long-term follow-up. Study Design: This was a retrospective study of 262 patients with base of tongue cancer treated in the Departments of Otolaryngology-Head and Neck Surgery and Radiation Therapy at Washington University School of Medicine (St. Louis, MO) from July 1955 to January 1998. Methods. The study population included previously untreated patients with biopsy-proven squamous cell carcinoma of the base of tongue who were treated with curative intent by one of five modalities and were all eligible for 5-year follow-up. The treatment modalities included local resection alone, composite resection alone, radiation therapy alone, local resection with radiation therapy, and composite resection with radiation therapy. Multiple diagnostic, treatment, and follow-up parameters were studied using standard statistical analysis to determine statistical significance. Results. The overall 5-year disease-specific survival (DSS) was 49.6% with death due to tumor in 50.4%. The 5-year cumulative disease-specific survival probability (CDSS) was 0.526 (Kaplan-Meier) with a mean of 7.8 years and a median of 5.6 years. Patients with early disease had significantly improved DSS compared with patients with more advanced disease (stages I and II; TN stages T1N0, T2N0, and T2N1; and T stages T1 and T2.). Patients with NO had better DSS than patients with positive lymph nodes (P =.010). The DSS for all stages by treatment modality included local resection (70.0%, composite resection (47.6%), radiation therapy (40.4%, local resection and radiation therapy (50.0%), and composite resection with radiation therapy (51.5%). Overall and within the stages there was no significant difference in either DSS or CDSS by treatment modality. Local-regional recurrence occurred in 26% of patients, and overall salvage was 10.5%. Patients with clear resection margins did better than patients with close or involved margins (DSS and CDSS). Patients treated with radiation therapy alone had improved capacity to swallow (P =.001), speak (P =.01), and work (P =.001) compared with patients treated with the other modalities. Conclusions. Cancer of the base of tongue is a lethal disease, and its treatment results in significant disability. No treatment produced a significantly improved survival advantage. Focus on improving local-regional control might improve overall survival. All treatment modalities were associated with major treatment-related complications. Radiation alone produced significantly improved post-treatment function and quality of life compared with the other modalities. Because of the recurrence rates at the primary and neck sites and the high rates of development of distant metastasis and second primary cancers, patients should be monitored for a minimum of at least 4 years.