P16(INK4a) correlates to human papillomavirus presence, response to radiotherapy and clinical outcome in tonsillar carcinoma.

BACKGROUND: Human papillomavirus (HPV) in tonsillar carcinoma is correlated with favourable clinical outcome. Here, p16(INK4A), in situ HPV DNA hybridisation (ISH) and HPVL1 capsid detection were evaluated in tonsillar carcinoma to predict the response to radiotherapy (RT) and prognosis. MATERIALS AND METHODS: Fifty-one pre-treatment paraffin-embedded tonsillar cancer biopsies were analysed. Immunohistochemistry (IHC) was used for p16(INK4A) and HPVL1 capsid analysis and PCR and ISH for HPV detection. RESULTS: High-risk HPV DNA was detected by PCR in 49% of the tumours. P16(INK4a) staining was correlated to HPV In the high-grade p16(INK4a) staining group, 94% had a complete RT response. High p16(INK4a) staining as well as the HPV PCR-positive cases had a favourable prognosis. HPV DNA ISH and L1 IHC could not predict RT response or clinical outcome. CONCLUSION: P16(INK4a) overexpression was correlated to HPV in tonsillar carcinoma and is useful for predicting RT response and prognosis in tonsillar carcinoma patients.

Human papillomavirus is more common in base of tongue than in mobile tongue cancer and is a favorable prognostic factor in base of tongue cancer patients.

The frequency of human papilloma virus (HPV) and its influence on clinical outcome was analyzed retrospectively in pre-treatment paraffin embedded biopsies from 110 patients with tongue cancer. The presence of HPV DNA was examined in 85 mobile tongue tumors and 25 base of tongue tumors by a polymerase chain reaction (PCR) with 2 general primer pairs, GP5+/6+ and CPI/IIG. When HPV-DNA was found, HPV-type specific primers and direct sequencing were used for HPV sub-type verification. Twelve of 110 (10.9%) samples were HPV-positive; 9 for HPV-16, 1 for HPV-33, 1 for HPV-35 and 1 could not be analyzed because of shortage of DNA. HPV was significantly more common in base of tongue tumors (10/25, 40.0%) compared to tumors of the mobile tongue (2/85, 2.3%). The influence of HPV on clinical outcome in mobile tongue cancer could not be studied, due to that HPV was present in too few cases. Of the 19 patients with base of tongue cancer that were included in the survival analysis, however, 7 patients with HPV-positive base of tongue cancer had a significantly favorable 5-year survival rate compared to the 12 HPV-negative patients. In conclusion, HPV is significantly more common in base of tongue cancer than in mobile tongue cancer, and has a positive impact on disease-specific survival in patients with base of tongue cancer.

Comparative genomic hybridization analysis of tonsillar cancer reveals a different pattern of genomic imbalances in human papillomavirus-positive and -negative tumors.

Our aim was to map and compare genomic imbalances in human papillomavirus (HPV)-positive and -negative squamous cell carcinomas of the tonsil. Twenty-five primary carcinomas were analyzed by comparative genomic hybridization. Fifteen (60%) were found to be HPV-positive by PCR, and the majority were HPV-16. There were statistically significant differences in the distribution of DNA gains and losses between the HPV-positive and -negative samples. Eleven of 15 HPV-positive samples (73%) showed gain on chromosome 3q24-qter, while only 4/10 (40%) HPV-negative samples had the same gain (p = 0.049). Furthermore, 4/10 (40%) HPV-negative samples but no HPV-positive samples had gain on chromosome 7q11.2-q22 (p = 0.017). As expected, and similar to previous studies, patients with an HPV-positive tumor had a statistically significantly better disease-specific survival than patients with an HPV-negative tumor (p = 0.002). The most common changes, e.g., gain on 3q or 8q, loss on 11q or 13 and loss on chromosome 7q in HPV-negative tumors, did not have any influence on prognosis. However the number of cases in each subgroup was limited.