No of samples/group p16 status HPV DNA status from FFPE material HPV DNA+ status after using material from glass slides TSCC 13 + + 13/13 TSCC 9 - - 0/9 TSCC 1 + - 0/1 BOTSCC 11 + + 9/11 BOTSCC 11 - - 0/11 BOTSCC 2 + - 0/2 Total 24 + + 22/24 Total 20 - - 0/20 Total 3 + - 0/3

Table 1: HPV status and p16 overexpression in pre-treatment biopsies and p16 stained glass slides derived from 47 patients with tonsillar squamous cell carcinoma (TSCC) and base of tongue squamous cell carcinoma (BOTSCC).