OBJECTIVETo analyze the clinical characteristics, prognosis and molecular biological changes of tonsillar squamous cell carcinoma (TSCC).

METHODSRetrospective analysis of 61 TSCC cases treated from January 1999 to December 2012. Demographic data and clinical charts, including histologic grade of tumor, treatment and outcome of the patients, were reviewed.Human papillomavirus (HPV)-DNA were detected using SPF10-DNA enzyme immunoassay and LiPA genotyping method. Expressions of p16 and p53 proteins were examinated by immunohistochemistry. Survival rate was calculated with SPSS 19.0 software using the Kaplan-Meier method.

RESULTSThere were 55 males and 6 females, with a median age of 57 years. Of the 61 TSCC, 21 were with well differentiation, 19 with moderate differentiation and 21 with poor differentiation, including 7 patients at stage II, 10 at stage III and 44 at stage IV. HPV-positive rate of TSCC was 29.5% (18/61) and high-risk HPV-16 subtype accounted for 72.2% (13/18). The percentage of famel patients in HPV-positive TSCC was higher than HPV-negative TSCC (22.2% vs 4.7%).HPV-positive TSCC was more common in non-smoking patients (50.0% vs 79.1%, χ(2) = 5, 155, P = 0.023) and non-drinking patients (27.8% vs 51.2%, χ(2) = 4.346, P = 0.037). HPV-positive TSCC mostly presented with high expression of p16 protein (88.9% vs 16.3%, χ(2) = 28.481, P = 0.000), and low expression of p53 protein (72.7% vs 46.5%, χ(2) = 5.028, P = 0.025). The prognosis of patients with HPV-associated TSCC was significantly better than non-HPV-associated TSCC, and The 3-year and 5-year overall survival rates of patients with HPV-positive TSCC were higher than those of patients with HPV-negative TSCC (87.7% vs 49.5% and 78.9% vs 33.0%, respectively).

CONCLUSIONHPV-associated TSCC had unique clinicopathological and molecular biological features, showing better prognosis compared to HPV-negative TSCC.