Human papilloma virus (HPV) and p53 immunostaining in advanced tonsillar carcinoma--relation to radiotherapy response and survival.

BACKGROUND

Human papilloma virus (HPV), which is frequently present in tonsillar carcinoma seems to be a prognostically favourable factor for patient survival and also for low risk of relapse. Since HPV may abrogate the function of wild type p53 and hence influence radiosensitivity we attempted to analyse if HPV and p53 status in tonsillar carcinoma affected tumour response to radiotherapy (RT) and patient survival.

MATERIALS AND METHODS

Pre-treatment primary tonsillar carcinoma specimens were obtained retrospectively from 40 patients, 21 complete responders (CR) and 19 non-complete responders (non-CR) of which 38/40 were stage III and IV tumours. The paraffin-embedded biopsies were analysed for presence of HPV DNA, by general and type specific PCR, and for p53 overexpression by immunohistochemical staining with the murine Mab DO-1.

RESULTS

It was possible to analyse HPV in 34 and p53 in 39 patients. Presence of HPV DNA (HPV+) and p53 immunostaining (p53+) were not correlated with response to RT, since 8/18 CR patients and 6/16 non-CR patients were HPV+ and 11/21 CR patients and 8/18 non-CR patients were p53+. A tendency towards a survival benefit in patients with HPV+ tumours was observed and this tendency was significant for patients with stage IV HPV + tumours (p = .0431), and in particular HPV+/p53- cancers (p = .0195). A difference in survival between patients with p53+ cancer as compared to patients with p53- lesions was not demonstrated. In conclusion, although presence of HPV and p53 immunoreactivity in tonsillar carcinoma could not be related to RT response, determination of HPV and p53 status may still prove useful as predictive/prognostic markers.