HPV involvement in tonsillar cancer: Prognostic significance and clinically relevant markers

Abstract

The association of high-risk human papillomaviruses (HR HPVs) with tonsillar cancer (TC) has been documented. Because patients with HPV-associated tumors show better survival rates, modification of their treatment regimen is being considered. It is therefore crucial to find markers for the identification of patients whose tumors are linked to viral infection. A cohort of 109 patients with primary TC was screened for HPV DNA presence in the tumor tissues and HPV-specific antibodies in sera. Data regarding risk factors and clinical parameters were collected. Forty-five specimens were analyzed for the expression of viral E6 and E2-region mRNA, and the p16 and p53 protein expression status was assessed by immunohistochemistry. The overall prevalence of HPV DNA in TC tissues was 65.1%. Ninety-three percent of HR HPV DNA-positive samples expressed E6*I mRNA. E2-region mRNA expression was detected in 36% of positive samples, which implies that the virus is integrated in 64% of HPV DNA/RNA-positive tumors. p16 overexpression and the presence of antibodies specific to HPV16 E6/E7 oncoproteins correlated well with HPV DNA and RNA presence. The disease-specific survival rate of patients with HPV DNApositive tumors was significantly higher than that of HPV DNA-negative patients. In addition to providing further evidence of the involvement of HPV infection in the etiopathogenesis of a proportion of TC cases, our study demonstrates that p16 immunostaining and anti-E6/E7 antibodies as surrogate markers of HPV involvement represent specific, sensitive and clinically accessible assays for the identification of TC patients who have a considerably better prognosis.Recent studies have shown that 20-25% of head and neck squamous cell cancers (HNSCCs) appear to be causally linked with high-risk human papillomavirus (HR HPV) infection.

Factors associated with lip and oral cavity cancer

“…Some studies in Oncology have assessed the predisposition of individuals to the onset of cancer [28][29][30] , which can even predispose them to the recurrence of it, with or without treatment. In the literature, cases of genetic predisposition to cancer of the head and neck areas is not well observed, but cases of genetic alteration acquired through the association of behavioral habits, such as tobacco use 29,31 , alcohol consumption 29,31 , viruses such as HPV 32,33 and even the consumption of red meat 34 . Such findings show that the prevention of this type of cancer becomes more feasible by combating and controlling factors related to habits and associated factors susceptible to intervention.…”

Biologic importance and prognostic significance of selected clinicopathological parameters in patients with oral and oropharyngeal squamous cell carcinoma, with emphasis on smoking, protein p16INK4a expression, and HPV status

“…Recently, the HPV testing in exfoliated tumor cells from oral washings has been shown to be a reliable tool for determination the HPV tumor status, with sensitivity and specificity of 0.83 and 0.88, respectively [35]. The detection of anti-E6/E7 antibodies in patients´sera seems to be an other promising method for indirect checking of HPV status of the HNSCCs [40].…”

“…The manufacturer´s protocol was modified to adapt the test for use on paraffin-embedded tissue according to Siriaunkgul et al [14]. The test involves three steps: PCR amplification of target DNA, nucleic acid hybridization, and detection of 37 HPV types, specifically 6,11,16,18,26,31,33,35,39,40,42,45 PCR was performed in a total volume of 100 µL containing 50 µL of the manufacturer´s master mix and 50 µL of GP5+/GP6+ PCR product. The amplification program consisted of 2 min at 50°C, and 9 min at 95°C, followed by 40 cycles of 30 s at 50°C, of 1 min at 55°C, and of 1min at 72°C, with a final extension at 72°C for 5 min.…”

High Level of Tregs Is a Positive Prognostic Marker in Patients with HPV-Positive Oral and Oropharyngeal Squamous Cell Carcinomas

“…We have previously shown that in HNSCC patients, HPV positivity is a strong prognostic factor for both better survival and less frequent recurrent disease [9, 36]. Another study from our group on immunological markers in HNSCC patients has shown higher Tregs counts in the peripheral blood of these patients when compared to healthy controls and increased probability of early recurrence with higher Tregs counts in the peripheral blood [29].…”

“…HR HPVs are being detected in 67% of oropharyngeal tumors and now are widely accepted as an etiological factor of 20–25% of head and neck squamous cell carcinomas [7, 8]. As has been shown by us and others, patients with HPV-positive tumors have better prognosis which is an important observation of clinical relevance [9, 10]. …”