HPV infection in relation to OSCC histological grading and TNM stage. Evaluation by traditional statistics and fuzzy logic model

Low Frequency of Human Papillomavirus in Strictly Site-Coded Oral Squamous Cell Carcinomas, Using the Latest NHI/SEER-ICD Systems: A Pilot Observational Study and Critical Review

Simple Summary

The incidence of oropharyngeal squamous cell carcinomas (OPSCCs) has increased in the last decades, and this seems to be correlated to the infectious epidemiological trend of human papillomavirus (HPV). The prevalence of HPV-positive OPSCCs is approximately 70%, with involvement mainly of the tonsillar area. On the role of HPV in oral squamous cell carcinoma (OSCC), very few studies have investigated the prevalence of HPV in strictly site-codified OSCC, excluding the base of the tongue as distinct oropharyngeal entity. As a result, an inappropriate estimation of HPV infection in OSCC has been observed. We investigated HPV status, using a combination of detection methods, in a sample of 40 subjects with OSCC coded by the latest site classifications. Moreover, we performed a critical review of the studies with the same outcomes. The main finding of our investigation was a low frequency of HPV-positive OSCC, suggesting no significant HPV role in strictly oral carcinogenesis.

Abstract

The aim of this study was to evaluate HPV status in oral squamous cell carcinoma (OSCC), as coded by the latest classifications and applying a combination of detection methods used in clinical practice. Forty-two patients with suspect OSCC were consecutively recruited. Patients underwent an incisional biopsy for histological OSCC diagnosis and HPV identification by PCR DNA and p16 IHC. All lesions were coded by the latest ICD-0-3.2 site/histology classifications, as proposed for OSCC by the National Cancer Institute Surveillance, Epidemiology and End Results Programs. Moreover, a comparative analysis review, critically evaluated by the same site-coded systems and HPV detection methods, was performed. In 40 confirmed cases of OSCC, the frequency of HPV infection was 10% (4/40). Among positive patients, two cases were PCR DNA/p16 IHC positive (high-risk HPV 51, high-risk HPV 67), two cases were PCR DNA positive/p16 IHC negative (high-risk HPV 31 + 68, high-risk HPV 66). Applying the latest site coding systems for OSCC, the frequency of HPV infection in this study and in similar, reviewed investigations was low (from 3.3% to 12.5%). These results suggested no significant HPV role in oral carcinogenesis, particularly where an updated site-coded classification of OSCCs (categorically excluding the base of the tongue) had been performed.

Periostin serves an important role in the pathogenesis of oral squamous cell carcinoma

The mechanism underlying OSCC tumorigenesis remains unclear. Periostin is considered to be a prominent oncogene in various solid tumors, although its precise role in OSCC progression remains unknown. In the present study, periostin expression was examined in surgical specimens of OSCC cases, and the results were analyzed for possible correlations with clinical characteristics. In addition, the proliferation and invasiveness of OSCC cells were evaluated following transfection with a Periostin small interfering RNA or an overexpression plasmid. The results revealed that periostin levels were significantly higher in patients with OSCC as compared with those in the controls (P<0.05). In addition, periostin levels in patients with OSCC were significantly associated with permeation classification. Furthermore, periostin expression was observed to promote the proliferation and invasiveness of OSCC cells. The present results suggest that periostin is significantly involved in the pathogenesis of OSCC.

A systematic investigation of the association between HPV and the clinicopathological parameters and prognosis of oral and oropharyngeal squamous cell carcinomas

Human papillomavirus (HPV), the causal factor of cervical cancers, was closely linked to the etiology and prognosis of oropharyngeal squamous cell carcinoma (OPSCC), but its role in oral squamous cell carcinoma (OSCC) was unclear. In addition, few researches based on Chinese population were documented. Hence, we sought to investigate the relationship of HPV marker P16 protein to the clinicopathological parameters and survival of OPSCC and OSCC patients systematically to assess the influence of ethnic, regional difference on HPV susceptibility. Specimens from 93 OPSCC patients and 95 OSCC patients were recut, and P16 immunohistochemistry (IHC) was performed. Moreover, survival analysis was conducted to confirm the independent factors that influenced the prognosis. The P16 results were positive in 25.8% and 9.5% of patients with OPSCC and OSCC, respectively. The overall survival (OS) of HPV‐positive OPSCC patients was significantly longer than that of HPV‐negative OPSCC patients (P = 0.004). Conversely, statistical significance was not observed regarding the OS of OSCC patients (P = 0.343). Cox regression analysis indicated that T stage and P16 status were independent factors that affected the prognosis of OPSCC patients, and the smoking index influenced the prognosis of OSCC patients. Among OPSCC patients who received radiochemotherapy (RCT), HPV‐positive patients had a better survival rate than their HPV‐negative counterparts (P = 0.015). Conversely, no significant difference was observed between HPV‐positive and HPV‐negative OSCC patients who received RCT (P = 0.237). P16 is a credible surrogate by which to define HPV status. HPV expression had a favorable effect on OPSCC patients as opposed to their OSCC counterparts in this single center population‐based study.

Evidences suggesting involvement of viruses in oral squamous cell carcinoma

Oral cancer is one of the most common cancers and it constitutes a major health problem particularly in developing countries. Oral squamous cell carcinoma (OSCC) represents the most frequent of all oral neoplasms. Several risk factors have been well characterized to be associated with OSCC with substantial evidences. The etiology of OSCC is complex and involves many factors. The most clearly defined potential factors are smoking and alcohol, which substantially increase the risk of OSCC. 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 cofactors 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. Although a viral association within a subset of OSCC has been shown, the molecular and histopathological characteristics of these tumors have yet to be clearly defined.

The role of human papillomavirus in oral squamous cell carcinoma: myth and reality

INTRODUCTION

As the traditional risk factors for oral squamous cell carcinoma, especially tobacco, decline, new potential causative agents become the focus of research. Since the discovery of human papillomavirus (HPV) and its importance in carcinogenesis in cervical cancer, a lot of research has been undertaken to define its role in different types of cancer. In the present study, we evaluate the role of high-risk HPV types in initiation and progression of oral squamous cell carcinoma (OSCC) using a systematic review of the current literature.

MATERIAL AND METHODS

A literature research with the search term "HPV oral squamous cell carcinoma" was performed via PubMed. Results were screened systematically for relevance and classified into the following categories: molecular biology, genetics, clinical aspects, and prevalence. Articles were then further analyzed to assess quality.

RESULTS

The literature research led to 527 results, with an overall HPV prevalence of 30.1 % in OSCCs. The most frequently identified subtypes were HPV-16 and HPV-18 (25.4 and 18.1 %, respectively). Prognostic relevance of HPV was discussed controversially. HPV detection via polymerase chain reaction is the most established method today. Molecular changes according to carcinogenic pathways described for cervix carcinoma were not routinely found in OSCC. In general, no definite role of high-risk HPV is currently deducible from the literature.

CONCLUSIONS

High-risk subtypes 16 and 18 are present in the genome in approximately one third of OSCC. Its role as a causative agent is less clear than the role in oropharyngeal tumors. The infection might not be the cause of carcinogenesis in a significant number of patients but may become proportionally more important with the decrease of the classical risk factors of tobacco and alcohol.

Epidemiology of human papillomavirus-related head and neck cancer

Human papillomavirus (HPV) is now recognized to cause a subset of head and neck squamous cell carcinomas (HNSCC). Although excessive tobacco and alcohol use continue to be important risk factors for HNSCC, epidemiologic studies suggest that more than 25% of HNSCC are now caused by HPV. The incidence of HPV-related HNSCC is increasing, highlighting the need to understand the oral HPV infections causing these cancers. This article reviews the evidence for a causal association between HPV and HNSCC, examines the changing epidemiologic trends of HNSCC, and discusses what is currently known about oral HPV infection, natural history, and transmission.

Biopsy vs. brushing: comparison of two sampling methods for the detection of HPV-DNA in squamous cell carcinoma of the oral cavity

BACKGROUND

HR HPV infection was proposed as aetiological factor of oral squamous cell carcinomas (OSCC). HPV frequency in OSCC is highly variable, due to the discrepancy in oral sampling procedures, HPV testing methods and inclusion criteria regarding tumour site (strictly oral cavity vs. nearby structures). Our aim was to compare HPV DNA frequency and type-specific distribution in paired cytological and histological samples of SCC strictly located in oral cavity. The correlation between HPV detection rate by each method of sampling and demographical, behavioural and clinical-pathological variables was also examined.

PATIENTS AND METHODS

HPV DNA was detected in brushed cells and formalin-fixed paraffin-embedded biopsies obtained from 83 consecutive unselected immunocompetent adults with OSCC. HPV DNA detection was performed in all samples by nPCR followed by direct DNA sequencing and the assay INNO-LiPA HPV Genotyping. Univariate and multivariate statistics were used, including Cohen κ index to evaluate agreement between two methods and association between HPV infection and demographical, behavioural and clinical-pathological variables for each method of sampling (p<0.05 statistically significant).

RESULTS

HPV DNA was detected in 15.7% (13/83) of brushings and 12.1% (10/83) of biopsies (p>0.05). High risk HPV 51, 16 and 39 were genotypes more frequently detected, especially among biopsies; no concordance between two methods was found (Cohen κ index=0.04, p=0.34).

CONCLUSION

A fraction of OSCC could be linked to HR HPV infection in the Mediterranean area. Although without a statistical significance, biopsy specimen demonstrated more accurate for HR HPV detection than brushing in OSCC.

TP53 gene expression in HPV-positive oral tongue SCC and its correlation with nodal metastasis

In this study, we investigated the prevalence of human papilloma virus (HPV) infection and TP53 expression in patients with squamous cell carcinoma (SCC) of the tongue and, subsequently, its significance in cervical lymph node metastases and tumor differentiation. Sections of formalin-fixed, paraffin-embedded tissue blocks from 94 histologically confirmed tongue SCC cases were investigated in this study. Immunohistochemistry was used to study TP53 expression, and polymerase chain reaction (PCR) was performed for the detection of high risk HPV types (16 and 18). The frequency of HPV-16 and HPV-18 infection was 10.6% and 16%, respectively. Overexpression of TP53 was observed in 70.2% of patients. Young patients (aged below 45 years) comprised 20% of all patients. There was no significant association between TP53, HPV-16, or HPV 18 presence and higher stages of the tumor, tumor differentiation, or presence of nodal metastasis. Although an association between head and neck SCC and HPV infection is being recognized and reported, our data implicate that HPV infection or TP53 expression does not play a significant role in oral tongue SCC pathogenesis, differentiation, or metastasis, as seen in our patients.

Hypoxia inducible factor-1 alpha expression is increased in infected positive HPV16 DNA oral squamous cell carcinoma and positively associated with HPV16 E7 oncoprotein

Background

There is increasing evidence for the role of High Risk (HR) Human PapillomaVirus (HPV) in the pathogenesis of Oral Squamous Cell Carcinoma (OSCC). The E6 and E7 oncogenes from HR HPVs are responsible for the deregulation of p53 and pRB proteins involved in cell cycle and apoptotic pathways. In cell lines experiments, the HPV E7 protein seems to be able to enhance Hypoxia Inducible Factor-1 alpha (HIF-1α) activity, normally involved in the response to hypoxia and able to enhance angiogenesis.

Results

We studied tumor specimens from 62 OSCC; a higher prevalence of tumors in TNM stage II and also in pT2 class between OSCC infected positive HPV16 DNA than non-infected ones was observed. HIF-1α positivity was detected throughout the analysed fields, not associated with areas of necrosis and also observed in cells immediately adjacent to blood vessels. A significant increase in mean values of the HIF-1α labeling indexes was observed for pT1-T2, as well for stage I-II, in the infected positive HPV16 DNA tumors than non-infected ones. HIF-1α and HPV16 E7 labeling indexes showed a significantly positive correlation which suggested a positive association between HPV16 E7 and HIF-1α expression.

Conclusions

In our specimens HIF-1α immunoreactivity hints for an O₂-independent regulatory mechanism in infected positive HPV16 DNA tumors, especially for pT1-T2 and stage I-II tumors, suggesting a very early involvement in the development of HPV-induced OSCC. HIF-1α and HPV16 E7 labeling indexes suggest also a positive association between the two proteins in infected positive HPV16 DNA OSCC.

Podoplanin expression predicts prognosis in patients with oral squamous cell carcinoma treated with neoadjuvant radiochemotherapy

Despite new therapeutic approaches patients with advanced oral squamous cell carcinoma still have a dismal prognosis. The main factor contributing to this problem is locoregional failure due to a lack of response to treatment. Several trials have proven the effect of neoadjuvant radiochemotherapy followed by radical surgery in comparison to primary surgery followed by adjuvant radiochemotherapy. No reliable parameters have been identified so far to predict response to radiochemotherapy. The aim of our study was to assess whether podoplanin expression in pretreatment biopsies could serve as a biomarker to predict the host response to neoadjuvant radiochemotherapy. In this retrospective study, podoplanin expression was examined in a set of 63 patients with oral squamous cell carcinoma by immunohistochemistry. We analyzed associations between the level of podoplanin expression and various clinicopathologic parameters, including response to radiochemotherapy, clinical and histological N-status. Furthermore we evaluated the effects of these parameters on overall survival and on locoregional control in univariate and multivariate analysis. The χ(2)-test revealed that high expression of podoplanin in pretreatment biopsy material was associated with non-regression of the tumor (p=0.013) and poor overall survival (p<0.001). Five-year survival rates of 92.9% for patients with weak expression and 15.0% for high expression were revealed. Podoplanin expression was also significantly associated with ypN status (p=0.004) and ypUICC status (p<0.001). We concluded that podoplanin might serve as a factor to predict treatment response in oral squamous cell carcinoma treated with neoadjuvant platin-based radiochemotherapy as well as a prognostic factor for overall survival and locoregional control.

Human papillomavirus as a risk factor in oral carcinogenesis: a study using in situ hybridization with signal amplification

INTRODUCTION

It is still controversial whether human papillomavirus (HPV) can be considered a risk factor in oral carcinogenesis. The aim of this study was to detect HPV DNA in 50 cases diagnosed as oral leukoplakias, with different degrees of epithelial dysplasia, and as oral squamous cell carcinomas, using in situ hybridization with signal amplification (CSA-ISH).

METHODS

HPV DNA was assessed in paraffin sections using CSA-ISH with a wide-spectrum biotinylated DNA probe. In HPV-positive cases, genotyping with specific probes to HPV types 6/11, 16/18 and 31/33 was performed.

RESULTS

The overall prevalence of HPV infection was 24%, markedly higher than that found in the control group. Results showed a discrete proportional relationship in the indices found in leukoplakia with no dysplasia, leukoplakia with dysplasia, and squamous cell carcinoma, but this was not statistically significant. When separating the group of leukoplakia by degrees of dysplasia, this relation of proportion was not observed. In genotyping, HPV types 16/18 were the most prevalent, and types 6/11 were only found in groups of mild or no dysplasia.

CONCLUSION

The results suggest that HPV is not likely to play a role in the progression of malignant transformation in oral lesions. Nevertheless, the increased prevalence of HPV infection compared to normal oral mucosa and the fact that high-risk HPV types were the most frequently identified do not allow the exclusion of HPV as a risk factor in oral carcinogenesis.

Recent advances in Oral Oncology

This paper reviews the main papers related to oral squamous cell carcinoma published in 2006 in oral oncology - an international interdisciplinary journal which publishes high quality original research, clinical trials and review articles, and all other scientific articles relating to the aetiopathogenesis, epidemiology, prevention, clinical features, diagnosis, treatment and management of patients with neoplasms in the head and neck, and orofacial disease in patients with malignant disease.