Radiotherapy alone or combined with chemotherapy for base of tongue squamous cell carcinoma.

OBJECTIVES/HYPOTHESIS: To evaluate the long-term disease control, survival, and complications after definitive radiotherapy (RT) alone or combined with adjuvant chemotherapy with or without planned neck dissection for base of tongue squamous cell carcinoma (SCC).

STUDY

DESIGN

We retrospectively reviewed the medical records of 467 patients treated at the University of Florida with definitive RT alone or combined with adjuvant chemotherapy between 1964 and 2011 for base of tongue SCC.

METHODS

Median follow-up was 5.6 years. Median total dose to the primary site was 74.4 Gy. Eighty-seven patients (19%) were treated with once-daily fractionation, and 380 (81%) received altered fractionation schedules. Intensity-modulated RT was used in 128 patients (27%). Chemotherapy was administered to 173 (37%) patients. Planned neck dissection after RT was performed in 226 patients (48%). Data regarding p16 pathway activation were available for 25 patients.

RESULTS

At 5 years, the local, local-regional, and regional control rates were 85.5%, 80.0%, and 90.0%, respectively. The 5-year overall, cause-specific, and distant metastasis-free survival rates were 59.1%, 71.5%, and 84.1%, respectively. Sixty-four patients (14%) developed one or more severe late complications. Fifty patients (11%) required late gastrostomy tube placement.

CONCLUSIONS

This study supports the continued use of RT alone or combined with adjuvant chemotherapy for patients with base of tongue SCC, as this treatment yields high rates of cause-specific survival and disease control, with a relatively low rate of late complications.

LEVEL OF EVIDENCE: 4. Laryngoscope, 127:1589-1594, 2017.