Is immunohistochemical evaluation of p16 in oropharyngeal cancer enough to predict the HPV positivity?

Overexpression of p16 is accepted as a surrogate diagnostic marker for detecting HPV infection in oropharyngeal cancer. However, one should remember about existence of the small subgroups of p16 positive but HPV negative tumors, with relatively worse prognosis. Immunostaining for p16, however useful on everyday basis, should be complemented with other techniques in terms of reliable identification of the HPV infection.