Human papillomavirus and survival of patients per histological subsite of tonsillar squamous cell carcinoma

Current data advocate that oropharyngeal squamous cell carcinoma (OPSCC) should be divided into subsites when evaluating the presence of human papillomavirus (HPV) and prognosis. More specifically, tonsillar squamous cell carcinoma (TSCC) and base of tongue squamous cell carcinoma (BOTSCC) have much higher HPV prevalence compared to other OPSCC. Moreover, patients with HPV positive (HPV+) TSCC and BOTSCC have a better prognosis as compared to patients with HPV negative (HPV-) corresponding tumors, while the prognostic role of HPV in other OPSCC is unclear. Furthermore, in a recent report from Denmark, TSCC was further subclassified into specified TSCC (STSCC) and nonspecified TSCC (NSTSCC), with HPV significantly more prevalent in STSCC. In this study, the histopathological influence of HPV prevalence and survival in TSCC was analyzed in a TSCC cohort with known HPV status, of patients diagnosed 1970-2002 in Stockholm. In total, 139 TSCC biopsies with both tumor and adjacent normal tissue were separated into STSCC and NSTSCC. HPV was significantly more commonly found in STSCC than in NSTSCC. Patients with HPV+ STSCC had a better disease-specific and overall survival as compared to patients with HPV+ NSTSCC, but no survival differences were observed in patients with HPV- STSCC and NSTCC. These findings confirm previous reports and suggest that TSCC subsite may also be of relevance for clinical outcome and should be further followed up in future studies.