Analysis of human papillomavirus prevalence and TP53 polymorphism in head and neck squamous cell carcinomas

Human papillomavirus prevalence in oral and oropharyngeal squamous cell carcinoma in South America: A systematic review and meta-analysis

Some studies have addressed the prevalence of human papillomavirus (HPV) in head and neck cancer in South America; however, no studies have systematically gathered prevalence and conducted a meta-analysis. This study aims to estimate the prevalence of HPV in oral and oropharyngeal squamous cell carcinomas in South America. We performed a systematic review and metaanalysis using the following databases: PubMed, Embase, Lilacs, Medline, Scopus, and Web of Science. Data were extracted and analyzed using random-effects models to estimate the pooled prevalence of HPV. We identified 209 nonduplicated studies, of which 38 were selected. The overall prevalence of HPV was 24.31% (95% CI 16.87-32.64; I2 = 96%, p heterogeneity <0.001). HPV prevalence in oropharyngeal cancer was 17.9% (95% CI 7.6-31.4; I2 = 96%, p heterogeneity <0.001) and that in oral cavity cancer was 23.19% (95% CI 14.94-32.63; I2 = 94%, p heterogeneity <0.001). We found an overall prevalence of HPV in 24.31% of oral and oropharyngeal squamous cell carcinomas in South American patients. The prevalence of HPV was 17.9% for oropharyngeal cancer and 23.19% for oral cavity cancer.

Effect of p53 codon 72 polymorphism on the survival outcome in advanced stage cervical cancer patients in India

Background & objectives:

The Arg>Pro polymorphism in codon 72 of p53 gene is known to affect the susceptibility of cervical cancer differently in different population worldwide although information regarding its role in determining survival status and disease outcome in patients is lacking. The present study was conducted to determine the genotype frequency and prognostic role of p53 codon 72 Arg>Pro polymorphism in patients with advanced stage cervical cancer in India.

Methods:

The p53 codon 72 polymorphism was determined in tumour biopsies (n = 107) and matched blood samples (n = 19) in cervical cancer patients using polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). Effect of p53 genotype on the overall survival (OS) and recurrence-free survival (RFS) was analyzed. Individual Arg or Pro alleles were studied for their significance on survival as Pro carriers (Pro/Pro + Arg/Pro) versus Arg/Arg individuals or Arg carriers (Arg/Arg + Arg/Pro) versus Pro/Pro individuals.

Results:

The frequencies for Arg/Arg, Arg/Pro and Pro/Pro genotypes were 27.2, 49.5 and 23.3 per cent, respectively. There was no significant difference in the genotypes with respect to patients’ OS or RFS.

Interpretation & conclusions:

The findings of our study indicated that p53 codon 72 polymorphism might not be an independent marker in predicting clinical outcome in advanced stage cervical cancer patients. Further studies need to be done in larger samples to confirm these findings.

Prevalence of oral and oropharyngeal human papillomavirus infection in Brazilian population studies: a systematic review

Introduction

Human papillomavirus has been associated with head and neck squamous cell carcinoma. However, there is no conclusive evidence on the prevalence of oral or pharyngeal infection by human papillomavirus in the Brazilian population.

Objective

To determine the rate of human papillomavirus infection in the Brazilian population.

Methods

Systematic review of published articles. Medline, The Cochrane Library, Embase, Lilacs (Latin American and Caribbean Health Sciences) and Scielo electronic databases were searched. The search included published articles up to December 2014 in Portuguese, Spanish and English. A wide search strategy was employed in order to avoid publication biases and to assess studies dealing only with oral and/or oropharyngeal human papillomavirus infections in the Brazilian population.

Results

The 42 selected articles enrolled 4066 patients. It was observed that oral or oropharyngeal human papillomavirus infections were identified in 738 patients (18.2%; IC 95 17.6–18.8), varying between 0.0% and 91.9%. The prevalences of oral or oropharyngeal human papillomavirus infections were respectively 6.2%, 44.6%, 44.4%, 27.4%, 38.5% and 11.9% for healthy people, those with benign oral lesions, pre-malignant lesions, oral or oropharyngeal squamous cell carcinoma, risk groups (patients with genital human papillomavirus lesions or infected partners) and immunocompromised patients. The risk of human papillomavirus infection was estimated for each subgroup and it was evident that, when compared to the healthy population, the risk of human papillomavirus infection was approximately 1.5–9.0 times higher, especially in patients with an immunodeficiency, oral lesions and squamous cell carcinoma. The rates of the most well-known oncogenic types (human papillomavirus 16 and/or 18) also show this increased risk.

Conclusions

Globally, the Brazilian healthy population has a very low oral human papillomavirus infection rate. Other groups, such as at-risk patients or their partners, immunocompromised patients, people with oral lesions and patients with oral cavity or oropharyngeal squamous cell carcinoma have a high risk of human papillomavirus infection.

Molecular characteristics of endometrial cancer coexisting with peritoneal malignant mesothelioma in Li-Fraumeni-like syndrome

Background

Endometrial cancer that occurs concurrently with peritoneal malignant mesothelioma (PMM) is difficult to diagnose preoperatively.

Case presentation

A postmenopausal woman had endometrial cancer extending to the cervix, vagina and pelvic lymph nodes, and PMM in bilateral ovaries, cul-de-sac, and multiple peritoneal sites. Adjuvant therapies included chemotherapy and radiotherapy. Targeted, massively parallel DNA sequencing and molecular inversion probe microarray analysis revealed a germline TP53 mutation compatible with Li-Fraumeni-like syndrome, somatic mutations of PIK3CA in the endometrial cancer, and a somatic mutation of GNA11 and JAK3 in the PMM. Large-scale genomic amplifications and some deletions were found in the endometrial cancer. The patient has been stable for 24 months after therapy. One of her four children was also found to carry the germline TP53 mutation.

Conclusions

Molecular characterization of the coexistent tumors not only helps us make the definite diagnosis, but also provides information to select targeted therapies if needed in the future. Identification of germline TP53 mutation further urged us to monitor future development of malignancies in this patient and encourage cancer screening in her family.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1010-x) contains supplementary material, which is available to authorized users.

Association between p53 Arg72Pro polymorphism and the risk of human papillomavirus-related head and neck squamous cell carcinoma: a meta-analysis

This study aimed to investigate the association between p53 Arg72Pro polymorphism and the risk of human papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) by conducting meta-analysis. The PubMed database was searched for relevant studies until May 30, 2013. Relevant studies were selected and data were extracted by two independent authors. Overall, subgroup, and sensitivity analyses were then conducted using the Comprehensive Meta- Analysis v2.2 software. Wild-genotype ArgArg was considered as reference [odds ratio (OR) = 1.00]. Nine studies involving 1071 HNSCC cases were obtained. Meta-analysis results indicated no association between p53 Arg72Pro polymorphism and the risk of HPV-related HNSCC: for Pro/Pro vs. Arg/Arg, OR = 1.17, 95% confidence interval (CI) = 0.70-1.98; for Arg/Pro vs. Arg/ Arg, OR = 1.25, 95% CI = 0.97-1.72; and for (Pro/Pro + Arg/Pro) vs. Arg/Arg, OR = 1.28, 95% CI = 0.95-1.70. These meta-analysis results were supported by subgroup and sensitivity analysis results. In conclusions, p53 Arg72Pro polymorphism is a potential marker of HP infection-related HNSCC rather than a susceptibility gene polymorphism.

Genetic modifiers of cancer risk in Lynch syndrome: a review

The report by Aldred Scott Warthin in 1913 of a cancer family history and expanded on by Henry T. Lynch demonstrated one of the most enduring traits observed in patients with Lynch syndrome. The recognition of a variety of malignancies occurring at differing ages within a single family suggested the role of genetic variance on disease expression in an autosomal dominantly inherited genetic condition. With the identification of the genetic basis of Lynch syndrome and the subsequent collection of families and their medical records it has become possible to identify subtle genetic effects that influence the age at which disease onset occurs in this cancer predisposition. Knowledge about genetic modifiers influencing disease expression has the potential to be used to personalise prophylactic screening measures to maximise the benefits for family members and their carers.

Human papillomavirus and head and neck cancer

An increasing subset of patients with head and neck squamous cell carcinoma (HNSCCA) is positive for high-risk human papillomavirus (HR-HPV). Patients tend to be younger, have a minimal or absent tobacco and ethanol abuse history, increased number of lifetime sexual partners (particularly oral-genital sex), and squamous cell carcinomas (SCCAs) arising in the oropharynx. The most common HR-HPV associated with HNSCCA is HPV-16. HR-HPV positivity is associated with decreased expression of the p53 and Rb genes, overexpression of p16, decreased expression of EGFR, and a different genetic expression pattern compared with patients with HR-HPV-negative SCCAs, leading to the conclusion that this is a distinct clinical entity. Patients who have HR-HPV-positive HNSCCAs have an improved prognosis, particularly those with oropharyngeal SCCAs, leading some to speculate that the intensity of treatment might be decreased. At present, whether this can be done safely remains unclear.

Tumour suppressor gene TP53 mutations in atypical vascular lesions of breast skin following radiotherapy

AIMS

Atypical vascular lesions (AVL) occurring at the site of radiotherapy represent an uncommon but well-documented complication in the setting of breast-conserving therapy for breast carcinoma. Although the biological behaviour of AVL has been regarded as benign, it has been suggested that AVL may represent a precursor of angiosarcoma. A better understanding of the biology of AVL is essential in order to assess appropriate patient management. The aim of the present study was to investigate alterations of tumour suppressor gene TP53 in a series of radiation-induced AVL and angiosarcomas (AS).

METHODS AND RESULTS

Direct sequencing analysis of the TP53 gene showed the presence of at least one variation in 10 of 12 (83.3%) AVL and in seven of eight (87.5%) AS. The most common alteration in both categories was the P72R polymorphism in exon 4. One angiosarcoma sample carried a pathogenetically relevant disruptive mutation c.592delG, a frameshift deletion in exon 6, causing a premature stop codon.

CONCLUSIONS

The presence of TP53 alterations suggests that its mutational inactivation may be implicated in the pathogenesis of radiation-associated vascular proliferations. The common mutational pathway suggested by our data supports the hypothesis that AVL and AS are biologically related entities, most probably representing the extremes of a morphological continuum.

A novel functional DEC1 promoter polymorphism -249T>C reduces risk of squamous cell carcinoma of the head and neck

Human DEC1 (deleted in esophageal cancer 1) gene is located on chromosome 9q, a region frequently deleted in various types of human cancers, including squamous cell carcinoma of the head and neck (SCCHN). However, only one epidemiological study has evaluated the association between DEC1 polymorphisms and cancer risk. In this hospital-based case-control study, four potentially functional single-nucleotide polymorphisms -1628 G>A (rs1591420), -606 T>C [rs4978620, in complete linkage disequilibrium with -249T>C (rs2012775) and -122 G>A(rs2012566)], c.179 C>T p.Ala60Val (rs2269700) and 3' untranslated region-rs3750505 as well as the TP53 tumor suppressor gene codon 72 (Arg72Pro, rs1042522) polymorphism were genotyped in 1111 non-Hispanic Whites SCCHN patients and 1130 age-and sex-matched cancer-free controls. After adjustment for age, sex and smoking and drinking status, the variant -606CC (i.e. -249CC) homozygotes had a significantly reduced SCCHN risk (adjusted odds ratio = 0.71, 95% confidence interval = 0.52-0.99) compared with the -606TT homozygotes. Stratification analyses showed that a reduced risk associated with the -606CC genotype was more pronounced in subgroups of non-smokers, non-drinkers, younger subjects (defined as ≤57 years), carriers of the TP53 Arg/Arg (rs1042522) genotype, patients with oropharyngeal cancer or late-stage SCCHN. Further in silico analysis revealed that the -249 T-to-C change led to a gain of a transcription factor-binding site. Additional functional analysis showed that the -249T-to-C change significantly enhanced transcriptional activity of the DEC1 promoter and the DNA-protein-binding activity. We conclude that the DEC1 promoter -249 T>C (rs2012775) polymorphism is functional, modulating susceptibility to SCCHN among non-Hispanic Whites.

Study on TP53 codon 72 polymorphisms with oral carcinoma susceptibility

BACKGROUND AND AIMS

Previous published data have implicated TP53 codon 72 polymorphisms as risk factors for various cancers. Growing bodies of studies have been conducted on the association of TP53 codon 72 polymorphisms with susceptibility to oral carcinoma and have yielded inconclusive results. The aim of the present study was to derive a more precise estimation of this relationship.

METHODS

We conducted a search in the relevant databases without a language limitation, covering all papers published until May 2009. The associated literature was acquired through deliberate searching and selected based on the established inclusion criteria for publications.

RESULTS

Nine studies including 1990 cases and 2074 controls were selected. Data were extracted and further analyzed using systematic meta-analyses. Results showed that no significant differences of oral cancer risk were found between individuals carrying homozygote Arg/Arg genotype and those carrying Pro/Pro genotype (OR: 0.96, 95% CI: 0.78-1.19). Likewise, no evidence indicated that individuals with Arg/Arg genotype have a significant risk of oral cancer compared with those with a combined Pro genotype (Arg/Pro+Pro/Pro) (OR: 0.98, 95% CI: 0.85-1.12). Similarly, individuals with a combined Arg genotype (Arg/Pro+Arg/Arg) do not have a marked increased or decreased susceptibility to oral cancer relative to those with homozygote Pro/Pro genotype (OR: 1.00, 95% CI: 0.83-1.21). Moreover, when stratifying for race, results were similar among Asians or Caucasians. In addition, TP53 codon 72 polymorphisms may not associate with oral cancer risks in smokers and HPV infection status.

CONCLUSIONS

No evidence suggests that TP53 codon 72 polymorphisms may be a risk factor for oral carcinoma.

Polymorphisms of COX-2 -765G>C and p53 codon 72 and risks of oral squamous cell carcinoma in a Taiwan population

The association between polymorphisms of COX-2 -765G>C and p53 codon 72, and oral squamous cell carcinoma (OSCC) remains unclear. We investigated the associations between COX-2 and p53 polymorphisms, oral precancerous lesions (OPL), and OSCC. Demographic data and substance use (smoking, drinking, and betel quid chewing) data were collected from 297 patients with OSCC, 70 with oral leukoplakia (OL), 39 with oral submucosal fibrosis (OSF), and 280 healthy controls. COX-2 and p53 polymorphisms were determined by PCR-RFLP methods. A significantly higher proportion of OSCC and OPL patients were male, and frequent habitual users of the three substances. No association was found between p53 and COX-2 polymorphisms, ethnicity, and gender. Polymorphisms of p53 were not associated with OSCC development and malignant potential of OPL, OSF, and OL. The frequency of COX-2 -765G/G genotype was significantly higher in healthy controls (chi(2)=93.83, p<0.0001). After adjusting for possible confounding factors, COX-2 -765C allele vs. -765G/G genotype (OR=0.22, 95%CI=0.12-0.39) was a protective factor against OSCC development, but was a risk factor for malignant potential of OSF (OR=3.20, 95%CI=1.32-8.94) and OL (OR=6.73, 95%CI=2.84-19.87). We suggest that COX-2 -765G>C polymorphisms play a different role in OSCC development than in malignant potential of OSF and OL. However, p53 codon 72 polymorphisms show no such correlation.

Exploring the relation between human papilloma virus and larynx cancer

Human papilloma virus (HPV) has a role in benign and malignant pathology of the larynx. In this review we present the biological and epidemiological aspects related to these issues.

p53 codon 72 polymorphisms in human papillomavirus-negative and human papillomavirus-positive squamous cell carcinomas of the oropharynx

BACKGROUND

Tobacco smoking, alcohol abuse, and high-risk human papillomavirus (HPV) are risk factors in the etiology of oropharyngeal squamous cell carcinomas (SCCs). The TP53 polymorphism, in which an arginine (R) is changed to proline (P) at codon 72, is functionally significant and could therefore be a predisposing genetic defect.

METHODS

The aim of the study was to investigate the role of codon 72 polymorphism by means of double gradient-denaturing gel electrophoresis in 77 oropharyngeal SCC patients including 33 TP53 mutated and 16 HPV-16-positive cases. The controls consisted of 141 consecutive healthy blood donors.

RESULTS

The cases and controls showed significantly different genotype distribution (P = .0005): the frequencies of the RR, RP, and PP genotypes among the cases were, respectively, 81.8%, 10.4%, and 7.8%, as opposed to 59.6%, 33.3%, and 7.1% among the controls, in agreement with the Hardy-Weinberg equilibrium (P = .35). The PP genotype was significantly overrepresented among females (22.2% vs 3.4%; P = .0243) and in HPV-16-positive cases (25.0% vs 3.3%; P = .0152). No segregation was found between either of the codon 72 genotypes and age or TP53 mutations.

CONCLUSIONS

The significantly lower frequency of the RP genotype in the patients as a whole suggests that it has a protective effect on oropharyngeal SCCs. Moreover, the PP genotype may be a risk factor for the development of oropharyngeal SCC by females and the development of HPV-16-related SCC, although the findings need to be validated in a larger number of tumors.

Association between the TP53 codon72 polymorphism and oral cancer risk and prognosis

The TP53 codon72 polymorphism has recently been extensively studied to determine the risk factor for carcinogenesis. However, there are few reports about the relationship between the TP53 codon72 polymorphism and oral cancer risk or post treatment prognosis. We evaluated the genotypic distribution of the TP53 codon72 polymorphism in 100 oral cancer cases and 271 non-cancer controls. There were no significant differences in the frequencies of the three genotypes (Arg/Arg, Arg/Pro, Pro/Pro) of the TP53 codon72 polymorphism between oral cancer cases and controls. However, stratifying by smoking status, we found that the adjusted odds ratio for non-smokers with the Pro/Pro genotype was significantly increased (adjusted OR=2.70, 95% confidence interval=1.07-6.82). We also found that the cases with the Pro/Pro genotype tended to have a shorter post-treatment survival compared with those with the Arg/Pro genotype (p=0.06). Our results suggest the Pro/Pro genotype of the TP53 codon72 polymorphism increases oral cancer risk in non-smokers and worsens their prognosis.

The prevalence of human papillomavirus in the oropharynx in healthy individuals in a Brazilian population

Oncogenic human papillomavirus (HPV), a causative agent of uterine cervical cancer, has also been detected in head and neck squamous cell cancers, especially in squamous cell carcinomas of the tonsils. However, the true HPV prevalence in normal and neoplasic oropharyngeal mucosa remains uncertain. To determine the prevalence of HPV DNA in normal oropharyngeal mucosa of cancer-free individuals, a study was carried out on 50 Brazilian subjects. PCR was performed to identify HPV DNA in samples from four sites in the oropharynx (tonsils, soft palate, base of the tongue, and back wall of the pharynx). For amplification of the HPV DNA, MY09/11 consensus primers were used, and specific genotypes were identified by dot-blot hybridization or cloning and sequencing. HPV DNA was present in 14.0% of the individuals, and the identified genotypes were 16, 18, 52, and 61. All these types are considered high-risk (HR) HPV. The tonsils and the soft palate were the sites with the highest HPV prevalence. This study shows the prevalence of HR HPV in the oropharynx of normal individuals. However, the prevalence of HPV is still unclear, and if HPV infection in a healthy it is not known individual predisposes to HPV-associated disease such as oropharyngeal cancer. Thus, it is important to assess the prevalence of HPV in cancer-free individuals, in order to compare it with the HPV prevalence in oropharyngeal carcinomas and to attempt to determine the true role of HPV in the development of head and neck squamous cell cancers.

Age of diagnosis of colorectal cancer in HNPCC patients is more complex than that predicted by R72P polymorphism in TP53

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominantly inherited cancer syndrome associated with germline mutations in DNA mismatch repair (MMR) genes. Recently a polymorphism at codon 72 (R72P) in the tumour suppressor gene TP53 has been implicated in the age of disease onset in HNPCC. In this report we have studied a large cohort of HNPCC patients to assess the impact of this polymorphism on disease expression and age of diagnosis of colorectal cancer (CRC). DNA samples from 218 HNPCC mutation positive patients from Australia and Poland were genotyped for the arginine to proline change at codon 72 in the TP53 gene. The association between the polymorphism and disease characteristics (mutation status, disease expression and age of diagnosis of CRC) was tested using Pearson's Chi-square and Kaplan-Meier survival analysis. Our study of Australian and Polish HNPCC patients does not provide evidence for an association between the Arg/Pro (GC) genotype of the R72P polymorphism and age of diagnosis of CRC. The R72P polymorphism was examined in HNPCC patients and found to be not associated with disease development in either the Australian or Polish populations. When gene mutation status (hMLH1 or hMSH2) was included in the analysis some evidence of an affect was observed. The genotyping revealed in the Australian population that the R72P polymorphism was under-represented in the hMSH2 group whereas it was over-represented in the Polish hMSH2 group. A similar trend was observed for hMLH1 in both groups but was not significant. Age of diagnosis of CRC in HNPCC patients is therefore more complex than that predicted by the R72P TP53 polymorphism alone, suggesting an inter-relationship with other genetic and/or environmental factors.

Perspectives on the molecular epidemiology of aerodigestive tract cancers

Improving laboratory techniques and the greater availability of genetic data have led to a flurry of publications from molecular epidemiologic studies on aerodigestive tract cancers. Inconsistent results have been observed in studies of sequence variants, due to limitations such as small sample size, possible detection of false positives, moderate prior probabilities that each SNP confers a substantial increase in cancer risk, and publication bias. Meta- and pooled-analyses were shown to be effective in elucidating modest increases in aerodigestive tract cancer risk attributable to sequence variants. Phenotypic assays developed to quantify an individual's DNA repair capacity have been applied to epidemiological studies on aerodigestive tract cancers. Epigenetic events have also been studied in tumor progression and as susceptibility factors for aerodigestive tract cancers, in smaller scale studies. It is imperative that limitations of previous studies are addressed for future research in the molecular epidemiology of aerodigestive tract cancers. Some recommendations for future research are to: (i) incorporate multiple markers of different types (ex. genotype and phenotype data), (ii) enhance statistical power by conducting studies with larger sample size, and developing consortia to coordinate research efforts, (iii) improve marker selection via a hybrid strategy of incorporating data on evolutionary biology and physico-chemical properties of amino acids, with haplotype/tag SNP data, (iv) employ novel statistical methods such as hierarchical modeling with Bayesian adjustments, false positive reporting probability and modeling of complex pathways. Consortia have been initiated for head and neck cancer (International Head and Neck Cancer Epidemiology Consortium (INHANCE)) and lung cancer (International Lung Cancer Consortium (ILCCO)) with the aim to share comparable data, to focus on rare subgroups such as nonsmokers and to coordinate laboratory analyses. Such collaborative efforts and integration across disciplines will be essential in contributing to the elucidation of genetic susceptibility to aerodigestive tract cancers.

Risk assessment of p53 genotypes and haplotypes in tobacco-associated leukoplakia and oral cancer patients from eastern Idia

The role of 3 p53 polymorphisms (16 bp duplication at intron 3, codon 72 Arg/Pro and intron 6 NciI RFLP at np 13494) as potential markers for indicating cancer risk remains inconclusive. In our case-control study consisting of 197 leukoplakia and 310 oral squamous cell carcinoma (SCC) patients and 348 controls, genotype frequencies at these 3 p53 loci were determined by PCR-RFLP method and analyzed by multiple logistic regression to determine the risks of the diseases. The 2/2 genotype at codon 72 of p53 was at risk for developing leukoplakia (OR = 1.6, 95% CI 1.1-2.3), whereas the combination of 1/2 and 2/2 genotypes at intron 3 and 1/1 and 1/2 genotypes at intron 6 conferred a protective effect against leukoplakia and oral SCC development, respectively (OR = 0.5, 95% CI 0.4-0.8 and OR = 0.6, 95% CI 0.5-0.9, respectively). When subjects were stratified according to specific tobacco habit, the risk/protection estimates improved significantly in some cases. Specifically, the exclusive smokers with p53 codon 72 2/2 genotype showed a higher risk of developing leukoplakia (OR = 2.7, 95% CI 1.2-6.3). Furthermore, a particular p53 haplotype 1-2-2 was at risk for both tobacco-associated leukoplakia and oral SCC (OR = 1.5, 95% CI 1.1-1.9 and OR = 1.3, 95% CI 1.1-1.7, respectively). Our results show that both specific p53 genotype and haplotype can indicate risk of tobacco-associated leukoplakia, but risk of development of tobacco-associated oral SCC can be predicted by specific p53 haplotype only.