Human papillomavirus status in head and neck cancer

Human papillomavirus (HPV) is an emerging causative factor for squamous carcinoma of the oropharynx and perhaps other head and neck cancers. There is a great deal of uncertainty regarding the clinical significance and implications of HPV status in this patient population. As a result, there is no established protocol for informing patients of the potential link between viral infection and their cancer. This paper discusses some of the ethical issues involved with informing head and neck cancer patients of their HPV status, recognizing the dilemma posed by unresolved clinical questions and the need to respect the autonomy of patients by disclosing relevant information. Cancer 2010; 116:4221–6. © 2010 American Cancer Society.     

Risk factors and survival by HPV‐16 E6 and E7 antibody status in human papillomavirus positive head and neck cancer

High‐risk human papillomavirus types (HPV‐HR) are associated with head and neck cancer (HNC) risk and better survival. Most patients with HPV‐HR DNA‐positive tumors develop anti‐HPV E6/E7 antibodies; however, it is unclear whether those who mount an immune response have similar risk factors or clinical outcomes as those who do not. HPV‐16 DNA tumor‐positive HNC cases were evaluated for HPV‐16 E6 and E7 antibodies using a GST capture ELISA system. Among 57 HPV‐16 DNA tumor‐positive HNC cases, 67% were detected with HPV‐16 E6 and/or E7 antibodies. Male gender (76% vs. 42%, p = 0.02), younger age (63% vs. 16%, p = 0.001) but not tobacco or alcohol were associated with E6 and/or E7 seropositivity. Seropositivity was associated more often with late stage (76%), poor grade (65%), positive nodes (82%). and in the oropharynx (82%), Median disease‐specific and recurrence‐free survival were longer in E6 and/or E7 seropositive compared to E6/E7‐negative cases (2.2 years vs. 1.4 years, both outcomes), although results were not statistically significant. When examined jointly with p16 expression, E6 and/or E7‐positive/p16‐positive cases had better disease‐specific (2.1 years vs. 1.1 years, p = 0.06) and recurrence‐free (2.3 years vs. 1.1 years, p = 0.03) survival compared to E6‐/E7‐/p16‐ cases. These findings suggest there are 2 distinct HNC patient groups with HPV DNA‐positive tumors, distinguishable by E6 and/or E7 antibody status. Differences in antibody status are associated with distinct risk factors and clinical outcomes. This information can be available as a simple blood test at initial presentation, before the removal of tissue through biopsy or surgery.     

Human papillomavirus 16E6 oncogene mutation in cervical cancer

Objective: Cervical cancer (CC) is the second most common type of cancer in women worldwide, after breast cancer. High-risk human papillomaviruses (HR-HPVs) are considered to be the major causes of cervical cancer. HPV16 is the most common type of HR-HPVs and HPV16 E6 gene is one of the major oncogenes. Specific mutations are considered as dangerous factors causing CC. This study was designed to find mutations of HPV16 E6 and the relationship between the mutations and the happening of CC.Methods: The tissue DNA was extracted from 15 biopsies of CC. Part of HPV16 E6 gene (nucleotide 201-523) was amplified by polymerase chain reaction (PCR) from the CC tissue DNA. The PCR fragments were sequenced and analyzed.Results: The result of PCR showed that the positive rate of HPV16 E6 was 93.33% (14/15). After sequencing and analyzing, in the 13 out of 14 PCR fragments, 4 maintained prototype (30.77%), 8 had a same 350G mutation (61.54%), and 1 had a 249G mutation (7.69%).Conclusion: This study suggest that there is a high infection rate of HPV in cervical cancer and most of the HPV16 E6 gene has mutations. Those mutations may have an association with the development of cervical cancer.     

Role of Chemotherapy in head and neck cancer

For head and neck cancer, a recent meta-analysis of published randomized trial results showed that concurrent chemoradiotherapy, adjuvant chemotherapy and neoadjuvant chemotherapy may increase absolute survival by 12.1%, 6.5%, and 3.7%, respectively. Initial response rates to first line chemotherapy are high, but this responsiveness does not appear to translate into a survival benefit. Thus, chemotherapy can be indicated as the standard therapy for a very limited range of advanced head and neck cancers. With the aim of prolonging survival, N stage advanced nasopharyngeal cancer is a good candidate for neoadjuvant chemotherapy. Among a large number of randomized trials of neoadjuvant chemotherapy, organ function preservation studies showed the possibility of laryngeal preservation for locally resectable T2 and T3 laryngeal and hypopharyngeal cancer. Concurrent chemoradiotherapy may be indicated for advanced T stage head and neck cancers, especially those with locally unresectable lesions. For N stage advanced pharyngeal cancer patients, adjuvant chemotherapy with applied after the standard therapy has a role in the treatment. With palliative treatment in advanced and/or recurrent disease, there is less benefit from chemotherapy and indications for chemotherapy should be selected for individual patients.     

Role of taxoids in head and neck cancer

Docetaxel and paclitaxel represent a new class of cytotoxic agents having both a specific chemical structure and mechanism of action. They act to promote tubulin polymerization and the formation of stable microtubules. The microtubules produced in the presence of taxoids are resistant to disassembly by physiologic stimuli, and cells exposed to these agents exhibit an accumulation of disorganized microtubule arrays. This affects the normal mitotic process and eventually results in cell death. Both drugs are active as single agents in patients with head and neck cancer with response rates ranging from 20% to 40%. They may be combined with other cytotoxic agents, radiotherapy, or both. A review is given of the presently available data.     

Human papillomavirus seropositivity and risks of head and neck cancer

We examined antibody response to VLP HPV-16, HPV-16 E6 and E7 antibodies as potential seromarkers of HPV-related head and neck cancer (HNC). The study included 204 HNC cases and 326 controls evaluated for HPV presence in sera using ELISAs for anti-HPV VLP antibodies and HPV-16 E6 and/or E7 antibodies, and in tumor tissue using PCR and DNA sequencing. Anti-HPV-16 VLP was detected in 33.8% of cases and 22.4% of controls, anti-E6 in 20.6% of cases and 0.9% of controls and anti-E7 in 18.6% of cases and 0.6% of controls. HPV-16 DNA was detected in 26.1% of tumors. The adjusted risk of HNC was elevated among those seropositive for HPV-16 VLP (odds ratio (OR) = 1.7, 1.1-2.5), E6 (OR = 32.8, 9.7-110.8) or E7 (OR = 37.5, 8.7-161.2). Compared to HPV DNA-negative/seronegative cases, tumor HPV-16 cases had increased risk of detection with anti-VLP antibodies (OR = 6.8, 3.1-14.9). The odds were more pronounced among cases seropositive for E6 (OR = 69.0, 19.3-247) or E7 (OR = 50.1, 14.7-171). Antibodies against E6 or E7 were associated with risk of cancer in the oral cavity (OR = 5.1, 1.2-22.4) and oropharynx (OR = 72.8, 16.0-330), and with disease characteristics: stage, grade and nodal status. Anti-E6 and/or E7 antibodies were found in 74% of tumor HPV-16 positive cases but in only 5% of tumor HPV-negative cases (K =0.7, 0.6-0.8) suggesting good correlation between the serologic marker and HPV tumor status. Antibodies to HPV-16 E6 and/or E7 represent a more specific biomarker than anti-HPV-16 VLP of an HPV-related HNC. Because of the survival advantage of HPV-related HNC, HPV-16 E6/E7 detection may be useful in therapy targeted for HPV-related tumors.     

Geographic heterogeneity in the prevalence of human papillomavirus in head and neck cancer

Human papillomavirus (HPV) causes oropharyngeal squamous cell carcinoma (OPSCC), although strongly divergent results have been reported regarding the prevalence of HPV16 in different countries, whether this represents important differences in etiology remains unclear. Applying rigorous protocols for sample processing, we centrally evaluated 1,420 head and neck tumors (533 oropharynx, 395 oral cavity and 482 larynx) from studies conducted in the US, Europe and Brazil for mucosal HPV DNA and p16^INK4a expression to evaluate regional heterogeneity in the proportion of HPV16‐associated OPSCC and other head and neck cancer, and to assess covariates associated with the risk of HPV16‐positive OPSCC. While majority of OPSCC in the US (60%) were HPV16‐positive, this proportion was 31% in Europe and only 4% in Brazil (p < 0.01). Similar differences were observed for other head and neck tumors, ranging from 7% in the US and 5% in Europe, to 0% in South America. The odds of HPV16‐positive OPSCC declined with increasing pack years of smoking (OR: 0.75; 95% CI: 0.64–0.87) and drink years of alcohol use (OR: 0.64; 95% CI: 0.54–0.76). These results suggest that while the contribution of HPV16 is substantial for the oropharynx, it remains limited for oral cavity and laryngeal cancers.     

Clinical and scientific impact of human papillomavirus on head and neck cancer

Head and neck cancer (HNC) arises from the skull base to the clavicles and is the fifth most common cancer in the world by incidence. Historically, in the developed world HNC was associated with tobacco use and alcohol consumption, and the combination of the two produced a synergistic increase in risk. However, beginning in 1983, investigators have found a significant and growing proportion of HNC patients with human papillomavirus-positive (HPV) tumors who neither drank nor used tobacco. Since that time, there has been increased interest in the molecular biology of HPV-positive HNC. Multiple studies now show that HPV has shifted the epidemiological landscape and prognosis of head and neck squamous cell carcinoma (HNSCC). These studies provide strong evidence for improved survival outcomes in patients with HPV-positive HNSCC compared to those with HPV-negative HNSCC. In many reports, HPV status is the strongest predictor of locoregional control, disease specific survival and overall survival. In response to these findings, there has been significant interest in the best management of HPV-positive disease. Discussions within major cooperative groups consider new trials designed to maintain the current strong survival outcomes while reducing the long-term treatment-related toxicities. This review will highlight the epidemiological, clinical and molecular discoveries surrounding HPV-related HNSCC over the recent decades and we conclude by suggesting how these findings may guide future treatment approaches.     

Association between p53 and human papillomavirus in head and neck cancer survival

BACKGROUND: High-risk human papillomavirus (HPV-HR) is a significant risk factor for head and neck cancer (HNC), abrogating normal p53 function. In addition, HPV and p53 have been associated with prognosis of these tumors but the findings have been inconsistent. We examined p53 expression and HPV-HR individually and jointly for differences in predicting HNC survival. METHODS: HNC patients (n = 294) were evaluated for p53 by immunohistochemical staining. HPV was detected by PCR/dot blot hybridization and sequencing. RESULTS: HNC tumors showed 48% with p53 overexpression and 27% with HPV-HR. Multivariate analyses showed that p53 positivity was significantly associated with higher risk of disease-specific [hazard ratio (HR); 2.0; 95% confidence interval (95% CI), 1.1-3.7] and recurrence-free mortality (HR, 2.8; 95% CI, 1.4-5.3). HPV- cases had significantly worse disease-specific survival (HR, 2.8; 95% CI, 1.3-6.3) compared with HPV-HR cases. When analyzed jointly, with p53(-)/HPV-HR tumors as the reference group, p53(+)/HPV(-) patients had the worst disease-specific (HR, 5.3; 58% versus 15%, P = 0.006) and recurrence-free survival rates (HR, 9.5; 17% versus 89%, P = 0.001), in contrast to the p53(-)/HPV(-) and p53(+)/HPV-HR groups, which had less elevated and different risks for disease-specific survival (HR, 2.5 and 1.7, respectively) and recurrence-free survival (HR, 4.2 and 7.2, respectively). CONCLUSION: Joint assessment of p53/HPV status provides different HRs for each clinical outcome in the four biomarker groups that are distinct from the individual biomarkers. These findings suggest that joint assessment of p53/HPV provides a better indicator of prognosis and potentially different types of treatments.     

Human papillomavirus in head and neck cancer: Molecular biology and clinicopathological correlations

Human papillomaviruses are known to cause cancers of the cervix and other anogenital tract sites. Epidemiologic and molecular pathology studies have also suggested that HPV infection may be associated with cancers of the head and neck. Modes of transmission of HPV infection in the head and neck region have not been fully resolved; however, perinatal transmission and an association between sexual behavior and risk for HPV-positive cancers have been presented.Among the HPV types infecting the mucosa, high-risk, intermediate-risk and low-risk genotypes are defined, depending on their presence in carcinoma or precursor lesions. The phylogenic groups of HPVs also showed a definite correlation with the morphology of head and neck tumors. The groups A6, A7, and A9 include viruses that are frequently demonstrated in basaloid and verrucosus squamous cell carcinomas known to associate with HPV infection. Integration of HPV DNA into the host cell genome occurs early in cancer development and is an important event in malignant transformation.There is a trend for patients with HPV-positive tumors to be nondrinkers or light drinkers, the majority of these patients are females, and the median age is lower than in the case of HPV-negative tumors, but this latter difference was not always statistically significant. In the Kaplan-Meier survival model, the HPV-positive verrucous and basaloid squamous cell carcinomas showed better survival rates than the HPV-negative typical squamous cell carcinomas. An increased radiocurability of HPV-positive head and neck squamous cell carcinoma (HNSCC) has also been demonstrated.     

Clinical relevance of oncogene expression in head and neck tumours

A study was undertaken to determine whether the variation in the increased expression of three oncogenes (Ha-ras, Ki-ras and myc) could be correlated with various clinicopathological parameters of squamous cell carcinoma (SCC) of the head and neck region. No correlation was found with sex, age, site of primary tumour, level of differentiation of the tumour, previous X-ray treatment, or fate. The one exception was myc expression with TNM staging of SCC. A significant increase was found for myc expression in TNM Stage III and IV as compared to the combined stages of I and II. Elevated expression of Ha-ras, Ki-ras and myc oncogenes was found in pleomorphic salivary adenoma (PSA), but at a lower level than SCC. It is proposed that in a percentage of cases the elevated expression of these oncogenes in PSA corresponds to a relatively early event in the multistep process of carcinogenesis.     

Combined P16 and human papillomavirus testing predicts head and neck cancer survival

While its prognostic significance remains unclear, p16^INK4a protein expression is increasingly being used as a surrogate marker for oncogenic human papillomavirus (HPV) infection in head and neck squamous cell carcinomas (HNSCC). To evaluate the prognostic utility of p16 expression in HNSCC, we prospectively collected 163 primary tumor specimens from histologically confirmed HNSCC patients who were followed for up to 9.4 years. Formalin fixed tumor specimens were tested for p16 protein expression by immunohistochemistry (IHC). HPV type‐16 DNA and RNA was detected by MY09/11‐PCR and E6/E7 RT‐PCR on matched frozen tissue, respectively. P16 protein expression was detected more often in oropharyngeal tumors (53%) as compared with laryngeal (24%), hypopharyngeal (8%) or oral cavity tumors (4%; p < 0.0001). With respect to prognosis, p16‐positive oropharyngeal tumors exhibited significantly better overall survival than p16‐negative tumors (log‐rank test p = 0.04), whereas no survival benefit was observed for nonoropharyngeal tumors. However, when both p16 and HPV DNA test results were considered, concordantly positive nonoropharyngeal tumors had significantly better disease‐specific survival than concordantly negative nonoropharyngeal tumors after controlling for sex, nodal stage, tumor size, tumor subsite, primary tumor site number, smoking and drinking [adjusted hazard ratio (HR) = 0.04, 0.01–0.54]. Compared with concordantly negative nonoropharyngeal HNSCC, p16(+)/HPV16(?) nonoropharyngeal HNSCC (n = 13, 7%) demonstrated no significant improvement in disease‐specific survival when HPV16 was detected by RNA (adjusted HR = 0.83, 0.22–3.17). Our findings show that p16 IHC alone has potential as a prognostic test for oropharyngeal cancer survival, but combined p16/HPV testing is necessary to identify HPV‐associated nonoropharyngeal HNSCC with better prognosis.     

Human papillomavirus therapeutic vaccines in head and neck tumors

Head and neck cancer represents one of the most challenging diseases as the mortality remains high despite advances in early diagnosis and treatment. Human papillomavirus has been implicated in a third of head and neck squamous cell carcinomas and human papillomavirus type 16 is strongly associated with carcinomas arising from the oropharynx, the tonsil being the preferred infected site. Novel therapeutic approaches including immunotherapy are currently under investigation. Immune vaccines developed against human papillomavirus in the genital area are already available and could simultaneously protect other anatomical localizations; however, prophylactic vaccines are expected to be effective in reducing the incidence of tumors after many years and, therefore, there is an urgent need to improve therapeutic interventions, such as immunotherapy. To date, human papillomavirus therapeutic vaccines are either at the preclinical level or at early phase human trials for genital pathologies. Nevertheless, accumulating evidence from animal and clinical studies suggests that the enhancement of specific and innate immune responses is effective in clearance of the human papillomavirus infection, promoting a cautious optimism regarding the achievement of an efficacious immunotherapy. This article reviews what has been achieved and what remains to be done in the field for the development of future viral vaccines in head and neck tumors.