RESUMEN
The insight into the biological nature of head and neck squamous cell carcinoma has evolved significantly in the last few years. Tobacco use and alcohol consumption are proven risk factors of head and neck squamous cell carcinoma. Cancer patients possessing such a tumor are generally elderly, mostly in fifth or sixth decade of life. In addition, significant association of head and neck squamous cell carcinoma with infection by human papillomavirus (HPV) was proven. HPV is now considered to be one of the most important risk factors, particularly for oropharyngeal carcinoma. HPV âpositive tumors of oropharynx are associated with significantly better prognosis. Experimental and clinical data indicate that HPV positive and HPV negative tumors can be considered as two different entities and it has not been clarified which factors are crucial for better prognosis of HPVâ positive tumors. The character of immune reaction, which contributes to distinct prognosis, may be one of the important factors. This review summarizes current knowledge concerning various aspects of antitumor immune responses in HPV âpositive and HPV ânegative tumors. Recent studies have shown that a broad repertoire of tumorâinfiltrating HPVâspecific T-cells is detectable in almost all patients with HPVâpositive tumors. Despite this, there is a development of tumor, which may be facilitated by abnormalities in antigen processing, T-cell dysfunction or prevalence of immunosuppressive cells. Nonetheless, the immunologic profile of HPVâpositive vs. HPVânegative head and neck squamous cell carcinoma is associated with better outcome, and HPVâ specific immune response is suggested to play an essential role in the better response to conventional therapy of HPV âpositive patients. We also discuss HPV specific antitumor immunotherapy approaches, which are now tested in clinical trials.