Purpose/Objectives: To evaluate the outcomes of patients with tonsillar cancer treated at G.V. Sonny Montgomery VA Medical Center between 2006 and 2014 and to compare survival and patterns of failure between human papillomavirus (HPV)-positive tonsillar cancer and HPV-negative tonsillar cancer.
Methods: There were 70 patients with biopsy proven squamous cell carcinoma of the tonsil in the retrospective review. Sixty-one of 70 patients had stage III/IV disease. Forty-seven of 70 patients had their HPV status evaluated. There were 22 HPV-positive and 25 HPV-negative patients. The majority of patients were treated with concurrent chemoradiotherapy, consisting of either weekly cisplatin 45 mg/m2 or weekly cetuximab 400 mg/m2 loading dose and 250 mg/m2 once a week for 7 weeks. Radiation therapy was given using intensity modulated radiation therapy to 70 Gy at 2 Gy per fraction over 7 weeks. The median radiation dose was 70 Gy. We evaluated the outcomes, including loco-regional failure, distant metastases, and survival. Rates were estimated by Kaplan-Meier method, and comparisons between HPV groups were evaluated using the Fisher exact test for categorical variables and Kruskal-Wallis test. Intermediate risk was defined as having ≥ 10 pack-years smoking history in the HPV-positive group (11 patients) and < 10 pack-years in the HPV-negative group (5 patients).
Results: Follow-up ranged from 14 to 88 months (median 22 mo). Overall survival (OS) for the entire group was 68% at 3 years with a disease-free survival (DFS) rate of 56%. At 3 years, the OS and DFS were 73% and 59% in the HPV-positive group and 50% and 50%, respectively, in the HPV-negative group. In the HPV-positive group, the failure rate was 2/11(16%) in the low-risk group and 8/11 (72%) in the intermediate-risk group. Six of 11 (55%) of the failures in the HPV-positive intermediate-risk group were local. Failure in the HPV-negative group was 3/5 (60%) in the intermediate-risk group and 12/20 (60%) in the high-risk group.
Conclusions: The results for the entire tonsillar group were comparable with that found in published literature. Patients with HPV-positive tumors had improved OS compared with HPV-negative tonsillar cancer, although not statistically significant due to small numbers.
