Oropharyngeal cancer epidemic and human papillomavirus

Role of viruses in oral squamous cell carcinoma

The etiology of oral squamous cell carcinoma (OSCC) is complex and involves many factors. The most clearly defined risk factors are smoking and alcohol, which substantially increase the risk of oral SCC. However, despite this clear association, a substantial proportion of patients develop OSCC without exposure to them, emphasizing the role of other risk factors such as genetic susceptibility and oncogenic viruses. Some viruses are strongly associated with OSCC while the association of others is less frequent and may depend on co-factors for their carcinogenic effects. Therefore, the exact role of viruses must be evaluated with care in order to improve the diagnosis and treatment of OSCC.

The distribution of human papillomavirus in tissues from patients with head and neck squamous cell carcinoma

Several types of HPVs have been shown to be associated with the development of malignant cancers in various head and neck tumors. More information on the HPV prevalence in patients with head and neck squamous cell carcinomas (SCCs) need to be obtained. In this study, formalin-fixed and paraffin-embedded tissues of 93 pathologically diagnosed head and neck SCC patients were collected from Peking University Cancer Hospital. HPV DNA sequences in tumor tissues were screened by a commercial Luminex technique for HPVs and HPV-specific PCR assays. Presence of HPV16/18 oncoprotein in tumor tissues was assessed by immunohistochemistry (IHC) with HPV16/18 E6-specific antibodies. Of the 93 patients, 16 (17.2%) cases were found to be HPV DNA-positive, including 7 HPV18-positive, 8 HPV16-positive and 1 HPV52-positive. IHC assays demonstrated that 31.2% (29/93) tested sections showed positive signals in the tumor cells. The total positive rate of HPV genome and its encoding products in the tested samples was 44.1% (41/93). Further analyses revealed that HPV infections in head and neck SCCs were significantly related with the tumor anatomic sites, showing decreasing tendency from outside (lip cancer) to inside (laryngeal cancer), but had no correlation with pathological, clinical grades and age of the patients. In all, HPV infections are commonly identified in the tumor tissues of patients with head and neck SCCs, in which HPV16 and 18 are the most prevalent HPV genotypes. Direct detection of high-risk HPV oncoprotein by IHC may be a good tool for classifying a tumor as truly HPV-associated.

Primary chemotherapy and radiation as a treatment strategy for HPV-positive oropharyngeal cancer

The incidence of human papillomavirus-positive oropharyngeal cancer (HPV/OPSCC) is rapidly increasing, which will represent a major public health burden for decades to come. Although HPV/OPSCC is generally associated with a better prognosis than HPV-negative OPSCC, the survival rate of individuals with higher-risk clinical and pathologic features remains unchanged. Emerging evidence suggests that HPV/OPSCC is pathologically and molecularly distinct from HPV-negative OPSCC. This review focuses on summarizing treatment strategies for HPV/OPSCC by reviewing the peer-reviewed literature and noting ongoing and planned clinical trials in this disease. We also discuss the potential of designing targeted therapy based on the recent genomic findings of HPV/OPSCC.

Tumor infiltrating CD8+ and Foxp3+ lymphocytes correlate to clinical outcome and human papillomavirus (HPV) status in tonsillar cancer

Background

Human papillomavirus (HPV) is a causative factor for tonsillar squamous cell carcinoma (TSCC) and patients with HPV positive (HPV⁺) TSCC have a better clinical outcome than those with HPV negative (HPV⁻) TSCC. However, since not all patients with HPV⁺TSCC respond to treatment, additional biomarkers are needed together with HPV status to better predict response to therapy and to individualize treatment. For this purpose, we examined whether the number of tumor infiltrating cytotoxic and regulatory T-cells in TSCC correlated to HPV status and to clinical outcome.

Methods

Formalin fixed paraffin embedded TSCC, previously analysed for HPV DNA, derived from 83 patients, were divided into four groups depending on the HPV status of the tumor and clinical outcome. Tumors were stained by immunohistochemistry and evaluated for the number of infiltrating cytotoxic (CD8⁺) and regulatory (Foxp3⁺) T-cells.

Results

A high CD8⁺ T-cell infiltration was significantly positively correlated to a good clinical outcome in both patients with HPV⁺ and HPV^- TSCC patients. Similarly, a high CD8⁺/Foxp3⁺ TIL ratio was correlated to a 3-year disease free survival. Furthermore, HPV⁺TSCC had in comparison to HPV⁻TSCC, higher numbers of infiltrating CD8⁺ and Foxp3⁺ T-cells.

Conclusions

In conclusion, a positive correlation between a high number of infiltrating CD8⁺ cells and clinical outcome indicates that CD8⁺ cells may contribute to a beneficial clinical outcome in TSCC patients, and may potentially serve as a biomarker. Likewise, the CD8⁺/Foxp3⁺cell ratio can potentially be used for the same purpose.

Prevalence of human papillomavirus and survival in oropharyngeal cancer other than tonsil or base of tongue cancer

Today, most oropharyngeal squamous cell carcinoma (OSCC) is human papillomavirus (HPV) positive and HPV alone or in combination with p16 is reported to be a favorable prognostic factor for OSCC. Patients with tumors at other OSCC sites (OOSCC) are often included in the same treatment and study protocols as patients with tonsillar- and base of tongue SCC, even though the prevalence and clinical significance of HPV infection in OOSCC is unknown. Since tonsillar and base of tongue SSC cover roughly 90% of all OSCC, there is an obvious risk that there may be a misinterpretation of the results for OOSCC. Herein, we therefore study the prevalence of HPV and p16 and their impact on survival in OOSCC. A total of 69 patients were included in the study, and 61 were included in the survival analysis. HPV and p16 were present in only 17% (12/69) and 25% (17/69) of the OOSCC cases, respectively, while the majority 69% (48/69) was both HPV and p16 negative. Neither HPV nor p16 had predictive value for clinical outcome in OOSCC in this study. In conclusion, the prevalence of HPV and/or p16 is much lower in OOSCC compared to earlier reports including all OSCC, or tonsillar- and base of tongue cancer alone and HPV and p16 had no impact on clinical outcome in OSCC in this study. Our data highlight the diversity of head neck cancer sub-sites and the importance of taking OSCC sub-sites in consideration in future clinical trials and treatment.

HPV-associated neuroendocrine carcinoma of the oropharynx: a rare new entity with potentially aggressive clinical behavior

High-grade neuroendocrine carcinoma of the head and neck is an aggressive neoplasm which rarely arises in the oropharynx. Here we report a series of 8 oropharyngeal neuroendocrine carcinomas associated with both human papillomavirus (HPV) infection and tobacco exposure. The tumor occurred predominantly in male patients (6 of 8) at a mean age of 59 years. Histologically, these cases were all classified as poorly differentiated neuroendocrine carcinoma (small cell carcinoma) with high mitotic activity [mean 53.3 mitoses per 10 HPF], necrosis, high nuclear-to-cytoplasmic ratio, and nuclear molding. One case also exhibited a moderately differentiated component, and one other case had a component of squamous cell carcinoma with basaloid features. Neuroendocrine differentiation was confirmed by immunoreactivity for synaptophysin and/or chromogranin A in all cases. P63 staining was negative, except in 1 case. Seven of the 8 cases showed strong and diffuse p16 expression, a surrogate marker for high-risk HPV infection. HPV infection was confirmed in 6 of these 7 cases by HPV in situ hybridization and/or polymerase chain reaction analysis. HPV subtypes 16, 18, and 33 were identified in 1 case each by polymerase chain reaction testing. Six of the 7 patients for whom clinical history was available presented with advanced disease (4 with regional lymph node metastases, 1 with distant metastases, and 1 with distant and locoregional metastases). Disease recurred in 5 of the 6 patients with available clinical follow-up, with 3 developing distant metastases to brain, bones, lung, pleura, adrenal glands, and pancreas. These 3 cases were all from the HPV-positive group. In summary, neuroendocrine carcinoma of the oropharynx represents a rare novel HPV-associated entity with high-grade histologic features and aggressive clinical behavior.

Human papilloma virus in head and neck squamous cell cancer

BACKGROUND

Epidemiologic and molecular evidences have established a strong link between high risk types of Human Papilloma Virus and a subgroup of Head and Neck Squamous Cell Carcinomas (HNSCC). We evaluated the frequency of HPV positivity in HNSCC and its relationship to demographic and some risk factor variables in an open case- control study.

METHODS

Fourteen recently diagnosed patients with squamous cell cancer of oropharynx, hypopharynx and larynx aged 18-50 years were examined from 2008-2010 in Tabriz, Iran. HPV DNA was extracted from paraffin-embedded blocks of each patient's sample for PCR evaluation. Saliva samples of 94 control cancer-free subjects were collected for DNA analysis. Multivariable logistic regression method was used to calculate odds ratio for case-control comparisons.

RESULTS

High risk HPV was detected in 6(42.8%) patients, and 6(5.3%) control subjects which was statistically significant (p<0.0001). HPV-18 was the most frequent type both in the cases and controls. HPV-16 DNA was detected in two patients of the case group, but it was not detected in any of the controls. The relation between demographic and risk factor variables was not statistically significant.

CONCLUSION

HPV infection has a significant impact on HNSCC. Despite HPV-16 stronger impact, HPV-18 is more likely to cause malignant degeneration in such cancers amongst some communities. It is vital to introduce and conduct immunization schedules in health care systems to protect communities to some extent.

Human papillomavirus-related small cell carcinoma of the oropharynx

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSqCC) represents an important subgroup of head and neck cancer that is characterized by a distinct risk factor profile, a relatively consistent microscopic appearance, and a favorable prognosis. A growing experience with HPV testing of OPSqCCs has uncovered variants that deviate from prototypic HPV-related cancer with respect to morphology but not clinical behavior. In effect, HPV positivity confers a favorable prognosis independent of morphologic subtype. We report 5 cases of HPV-related oropharyngeal carcinomas with well-developed features of small cell carcinoma (SCC) to define the prognostic impact of HPV positivity in a tumor type universally regarded as highly aggressive. Four of the SCCs arose in association with a conventional HPV-related OPSqCC. All 5 SCCs were HPV positive by in situ hybridization. By immunohistochemistry, all 5 cases were p16 positive, synaptophysin positive, and cytokeratin 5/6 negative. Four of the patients were men. The mean age was 61 years (range, 49 to 67 y). The SCCs were associated with metastatic spread to distant sites (60%) and poor survival outcomes: 3 patients (60%) died as a result of their disease (mean survival time, 10 mo; range, 6 to 15 mo). HPV testing has disclosed a previously unrecognized variant of HPV-related oropharyngeal carcinoma that is microscopically characterized by the small cell phenotype. Recognition of this component, even in association with conventional HPV-related OPSqCC, is important as it may indicate an aggressive phenotype that supersedes HPV positivity as a prognostic indicator.

Performance of a New HPV Cervi-Collect Collection and Transportation Kit

Background. Liquid-based Pap (L-Pap) media are used for Pap and human papillomavirus (HPV) testing. Objectives. To compare RealTime High Risk (HR) HPV testing of a new collection kit (Cervi-Collect) and PreservCyt L-Pap specimens. To determine ease of use and safety of Cervi-Collect. Methods. L-Pap samples (n = 203) were tested with HC2 and RealTime HR HPV and Cervi-Collect with RealTime HR HPV. Discordant samples were genotyped. Results. L-Pap and Cervi-Collect specimens tested by RealTime HR HPV showed 93.1% agreement (Kappa 0.86). RealTime HR HPV and HC2 on L-Pap had 90.3% agreement (Kappa 0.80). RealTime HR HPV on Cervi-Collect and HC2 on L-Pap showed 88.2% agreement (Kappa 0.76). Sixteen of 21 samples which were HC2 negative and RealTime HR HPV positive on L-Pap or Cervi-Collect contained HR HPV genotypes. Eleven healthcare collectors were in strong agreement on a usability and safety questionnaire. Conclusion. Cervi-Collect samples were easy to collect and showed strong agreement with L-Pap samples tested with RealTime HR HPV or HC2.

Application of the hybrid capture 2 assay to squamous cell carcinomas of the head and neck: a convenient liquid-phase approach for the reliable determination of human papillomavirus status

BACKGROUND

A growing proportion of head and neck squamous cell carcinoma (HNSCC) is caused by the human papillomavirus (HPV). In light of the unique natural history and prognosis of HPV-related HNSCCs, routine HPV testing is being incorporated into diagnostic protocols. Accordingly, there is an escalating demand for an optimal detection strategy that is sensitive and specific, transferrable to the diagnostic laboratory, standardized across laboratories, cost-effective, and amenable to broad application across specimen types including cytologic preparations.

METHODS

Cytologic preparations (fine-needle aspirates [FNAs] and brushes) were obtained from surgically resected HNSCCs and evaluated for the presence of high-risk HPV using the Hybrid Capture 2 assay. HPV analysis was also performed on the corresponding tissue sections using HPV in situ hybridization and p16 immunohistochemistry. In cases in which the immunohistochemical and in situ hybridization results were discordant, HPV status was determined by real-time polymerase chain reaction detection of E7 expression. HPV status in the tissues and corresponding cytologic samples was compared.

RESULTS

Based on benchmark HPV testing of the tissue sections, 14 HNSCCs were classified as HPV positive and 10 as HPV negative. All corresponding cytologic preparations were correctly classified using the Hybrid Capture 2 assay.

CONCLUSIONS

The Hybrid Capture 2 strategy, already widely used for the detection of high-risk HPV in cervical brushes, is readily transferrable to HNSCCs. Consistent accuracy in cytologic preparation suggests its potential application in FNAs from patients who present with lymph node metastases, and may eliminate the need to obtain tissue solely for the purpose of HPV testing.

The predicted impact of HPV vaccination on male infections and male HPV-related cancers in Australia

Australia implemented a National HPV Vaccination Program in 2007, with routine vaccination of 12-13 year old females and catch-up in females aged 13-26 years to 2009. The aim of this study was to estimate the impact of the current female-only national vaccination program on males, and then to estimate the incremental benefits to males from being included in the program. We used preliminary data to estimate vaccination coverage in females. We then fitted a dynamic model of sexual behaviour and HPV transmission in Australia to local data on female pre-vaccination age-specific HPV prevalence, predicted the corresponding pre-vaccination prevalence in males due to heterosexual transmission, and modelled the short and long term impact of female-only versus female-and-male vaccination programs. The estimated 3-dose female coverage rates were 78% (range 70-80%) for ongoing coverage in 12-13 year old girls; and from 74% (range 70-80%) in 14 year olds, to 25% (range 15-35%) for women aged 26 years old in 2007. The median estimate for age-standardised pre-vaccination HPV 16 prevalence in females and males aged 15-59 years was 3.2% (95% range: 2.4-4.1%) and 3.1% (95% range: 2.2-4.2%), respectively. The current program in females is predicted to result in a 68% reduction in male HPV 16 infections by 2050, leading to an estimated long term reduction of 14% in rates of cancers of the head, neck and anogenital area. The estimated proportion of the maximum possible vaccine-conferred benefit to males from a female-and-male program which will be achieved by female-only vaccination is 73% (range in probabilistic sensitivity analysis: 53-78%). In conclusion, up to three-quarters of the maximum possible vaccination-conferred benefit to males due to reduced heterosexual transmission will be achieved by the existing female-only program.