High prevalence of human papillomavirus infection and possible association with betel quid chewing and smoking in oral epidermoid carcinomas in Taiwan

Expression of Human Papillomavirus and the p16 Gene in Oral Potentially Malignant Disorders (OPMD): a Comparative Study With Oral Squamous Cell Carcinoma

BACKGROUND

The incidence of oral squamous cell carcinoma (OSCC) of the tongue is increasing in the younger population without traditional risk habits that lead researchers to find other related factors such as diet and viruses, especially human papillomavirus (HPV). It is noteworthy that many OSCCs develop from oral potentially malignant disorders (OPMDs). Correct diagnosis and timely management of OPMDs may help to prevent malignant transformation, and therefore it is worth seeing the involvement of HPV in OPMDs and oral cancers, as the preventive and curative measures in HPV-induced cancer types are different from the conventional types of OPMDs and OSCCs. Therefore, the main objective of this study was to identify a relationship between HPV and p16 in OPMDs and compare it with OSCC.

METHODS

This study was conducted on 83 cases of known OSCCs and OPMDs (oral submucous fibrosis, leukoplakia, and oral lichen planus). Assays, such as polymerized chain reaction (PCR) and reverse transcription-PCR, were carried out for HPV and p16 . The results were compared with clinical information and with the literature. The results were analyzed using SPSS 16.0 for windows.

RESULTS

P16 expression was mostly seen in males than in female patients. Out of 21 cases of keratosis with dysplasia, 19% expressed p16 . Of 26 oral lichen planus patients, 29% showed the p16 gene with immunohistochemistry. Interestingly, a high percentage of OSF cases expressed p16 (48.27%). Minimal expression was observed in OSCC (6.25%). HPV DNA was detected in 2.4% of the total sample. Both p16 and HPV were detected in a single case of OSCC. OPMDs expressed a significant amount of the p16 gene by immunohistochemistry and reverse transcription-PCR technique when compared with malignant lesions, suggesting a possible inactivation of the p16 gene. HPV and p16 are mostly negative in our OSCC sample, exhibiting low prevalence.

CONCLUSIONS

OPMDs expressed a significant amount of the p16 gene when compared with malignant lesions, suggesting a possible inactivation of the p16 gene. Although OSF expressed p16 , HPV was not detected, suggesting that over-expression could be independent of HPV. OSCC shows low HPV prevalence.

Which Factors, Smoking, Drinking Alcohol, Betel Quid Chewing, or Underlying Diseases, Are More Likely to Influence the Severity of COVID-19?

The global outbreak of the coronavirus disease 2019 (COVID-19) pandemic occurred in late 2019 and early 2020. The factors that influence disease severity should be of clinical concern. Existing findings on the effects of smoking on COVID-19 are also controversial and need to be confirmed by further research. In addition, the effects of alcohol consumption and betel quid (BQ) chewing on COVID-19 are unclear. The aim of this study was to examine the demographic characteristics of COVID-19 patients and the effects of smoking, drinking, BQ chewing, and underlying diseases on the severity of COVID-19. A retrospective study was conducted on 91 patients with confirmed cases of COVID-19 hospitalized in Yueyang, Hunan Province, China from 21 January to 8 March, 2020. Patient demographic data, and information on smoking, drinking and BQ chewing, and underlying diseases were extracted from the patient electronic medical records (EMR) and telephone interviews. The chi-square test was used to conduct a univariate analysis of the factors influencing the severity of COVID-19, and ordinal logistic regression analysis was used to identify the factors related to the severity of COVID-19. The results showed that the rates of smoking, drinking and BQ chewing were 15.4, 26.4, and 7.1%, respectively, there was no significant relationship between these lifestyle factors and the severity of COVID-19 (P > 0.05). However, underlying diseases such as diabetes [odds ratio (OR) = 7.740, 95% confidence interval (CI):1.000-60.740, P = 0.050], source of infection (OR = 0.180, 95% CI: 0.030-0.980, P = 0.049), and employment status (retired/unemployed vs. employed: OR = 29.430, 95% CI, 1.050 - 822.330, P = 0.047) were significant independent predictors of severe COVID-19 infection. These individuals should be informed of methods to increase personal protection, and doctors should prevent these individuals from developing serious diseases. It is important to pay attention to the source of infection and timely medical treatment. This study showed that the clinical classification of COVID-19 was associated with patients with diabetes, source of infection, and retired/unemployed. Therefore in the clinical practice of COVID-19 should be more concern these factors. Although no statistical significance was found in smoking, drinking alcohol, BQ chewing, and severity of COVID-19 patients, more studies have confirmed that are harmful and risk factors for underlying diseases in the population. Health authorities should formulate policies to publicize the harmful effects of smoking, drinking, and betel nut chewing and promote a healthy lifestyle.

Importance of human papillomavirus infection in squamous cell carcinomas of the tongue in Guangdong Province, China

Objective

Methods

Results

Conclusion

HPV in Head and Neck Cancer-30 Years of History

The interesting history of papillomavirus (PV) research has been reviewed before. The history of human papillomavirus (HPV) in head and neck region starts in 1901 when the contagious transmission of warty lesions into the mouth via oral sex was described, although the confirmation of their viral etiology had to wait until 1907. Ullman was the first to associate the human wart virus with laryngeal warts. Parsons and Kidd described the natural history of oral PV infections in rabbits already in 1942, but these findings were corroborated in humans only recently. Koilocytotic atypia described by Koss and Durfee in 1956 was recognized as a sign of HPV infection in cervical precancer lesions only in 1976-1977 (Meisels and Fortin; Purola and Savia). This prompted systematic surveys of head and neck lesions for the detection of koilocytosis since the late 1970s, and the authors of this communication were the first to propose the HPV involvement in a subgroup of head and neck cancers. Brandsma and Abramson demonstrated HPV16 DNA in tonsillar SCCs in 1989. Since the early 2000s, HPV research of head and neck squamous cell carcinomas (HNSCC) has made impressive progress, confirming that the specific anatomic site plays a key role in determining the susceptibility to HPV infection. The most likely cancer sites associated with HPV are the base of the tongue and palatine tonsils, followed by oral cavity, larynx, and sinonasal mucosa. There is substantial geographic variation in HPV association with HNSCC. Patients with HPV-associated HNSCC are younger, and survival is better than in the absence of HPV.

Molecular characterization of oral squamous cell carcinoma using targeted next-generation sequencing

OBJECTIVES

Many genetic factors play an important role in the development of oral squamous cell carcinoma. The aim of this study was to assess the mutational profile in oral squamous cell carcinoma using formalin-fixed, paraffin-embedded tumors from a Taiwanese population by performing targeted sequencing of 26 cancer-associated genes that are frequently mutated in solid tumors.

METHODS

Next-generation sequencing was performed in 50 formalin-fixed, paraffin-embedded tumor specimens obtained from patients with oral squamous cell carcinoma. Genetic alterations in the 26 cancer-associated genes were detected using a deep sequencing (>1000X) approach.

RESULTS

TP53, PIK3CA, MET, APC, CDH1, and FBXW7 were most frequently mutated genes. Most remarkably, TP53 mutations and PIK3CA mutations, which accounted for 68% and 18% of tumors, respectively, were more prevalent in a Taiwanese population. Other genes including MET (4%), APC (4%), CDH1 (2%), and FBXW7 (2%) were identified in our population.

CONCLUSIONS

In summary, our study shows the feasibility of performing targeted sequencing using formalin-fixed, paraffin-embedded samples. Additionally, this study also reports the mutational landscape of oral squamous cell carcinoma in the Taiwanese population. We believe that this study will shed new light on fundamental aspects in understanding the molecular pathogenesis of oral squamous cell carcinoma and may aid in the development of new targeted therapies.

Statistical analysis of human papillomavirus in a subset of upper aerodigestive tract tumors

Human papilloma virus (HPV) has been detected in some upper aerodigestive tract tumors, but the correlation between HPV and these tumors is not well understood. There is also some controversy regarding this correlation because a large variation in the prevalence of HPV in these tumors has been reported. To discuss the impact of HPV infection on upper aerodigestive tract tumors, this review estimated systematically the prevalence and risk of HPV in upper aerodigestive tract tumors from studies published between 1982 and 2012. In total, 418 articles were selected, which included 273 studies on the head and neck and 145 studies on esophageal squamous cell carcinoma. The overall prevalence of HPV in the 5,467 head and neck squamous cell carcinoma specimens was 36.3%. HPV was detected more frequently in the Americas (40%), than in Asia (38.6%), Europe (32%), or others regions (30.5%). The prevalence of HPV was significantly higher in oropharyngeal (48.5%) than in oral (32.5%), laryngeal (30.7%), and unselected head and neck squamous cell carcinoma (33.3%) (P < 0.001). The pooled prevalence of HPV in the 6,912 esophageal squamous cell carcinoma cases was 38.9% and it was significantly higher in China (44%) versus other regions (31.3%) (P < 0.05). Meta-analysis showed that head and neck and esophageal squamous cell carcinoma are associated with HPV infection (combined OR: 3.58, OR for head and neck and esophageal squamous cell carcinoma: 4.20). These findings suggest that HPV might be linked etiologically to the development of some upper aerodigestive tract tumors.

Human papillomavirus types 16 and 18 in epithelial dysplasia of oral cavity and oropharynx: a meta-analysis, 1985-2010

Human papillomavirus (HPV) types 16 and 18 are causally related to a sub-set of oral cavity and oropharyngeal squamous cell cancers. However, a clear estimate of the prevalence of HPV-16/18 in oral cavity and oropharyngeal dysplasia (OOPD) is not available. This literature review and meta-analysis was conducted to provide a prevalence estimate for HPV-16/18 in OOPD. Twenty-two studies that reported prevalence of HPV-16 and/or 18 in 458 OOPD lesions were analyzed. Meta-analysis was used to evaluate the prevalence of HPV-16/18 and logistic regression was used for stratified analysis by age, gender, and histological grade. The overall prevalence of HPV-16/18 in OOPD lesions was 24.5% [95% confidence interval (CI), 16.4-36.7%)]. The individual prevalence for HPV-16 alone was 24.4%. The prevalence of HPV-16/18 in oral cavity lesions alone was 25.3% (95% CI, 14.2-45.2%). The odds of detection of HPV-16/18 in dysplastic lesions in males were twice that of females [odds ratio (OR), 2.44]. HPV-16/18 were 3 times more common in dysplastic lesions (OR, 3.29; 95% CI, 1.95-5.53%) and invasive cancers (OR, 3.43; 95% CI, 2.07-5.69%), when compared to normal biopsies. There was no significant difference in HPV-16/18 rates between dysplastic lesions and cancers or between mild, moderate or severe dysplastic lesions. This meta-analysis provides a quantification of the prevalence of HPV types 16/18 in OOPD lesions. These results also support the assumption that HPV-16/18 infection occurs during the early phase of the oral cavity and oropharyngeal carcinogenesis.

Human papillomaviruses in oral carcinoma and oral potentially malignant disorders: a systematic review

OBJECTIVES

Human papillomavirus (HPV) in oral carcinoma (OSCC) and potentially malignant disorders (OPMD) is controversial. The primary aim was to calculate pooled risk estimates for the association of HPV with OSCC and OPMD when compared with healthy oral mucosa as controls. We also examined the effects of sampling techniques on HPV detection rates.

METHODS

Systematic review was performed using PubMed (January 1966-September 2010) and EMBASE (January 1990-September 2010). Eligible studies included randomized controlled, cohort and cross-sectional studies. Pooled data were analysed by calculating odds ratios, using a random effects model. Risk of bias was based on characteristics of study group, appropriateness of the control group and prospective design.

RESULTS

Of the 1121 publications identified, 39 cross-sectional studies met the inclusion criteria. Collectively, 1885 cases and 2248 controls of OSCC and 956 cases and 675 controls of OPMD were available for analysis. Significant association was found between pooled HPV-DNA detection and OSCC (OR = 3.98; 95% CI: 2.62-6.02) and even for HPV16 only (OR = 3.86; 95% CI: 2.16-6.86). HPV was also associated with OPMD (OR = 3.87; 95% CI: 2.87-5.21). In a subgroup analysis of OPMD, HPV was also associated with oral leukoplakia (OR = 4.03; 95% CI: 2.34-6.92), oral lichen planus (OR = 5.12; 95% CI: 2.40-10.93), and epithelial dysplasia (OR = 5.10; 95% CI: 2.03-12.80).

CONCLUSIONS

The results suggest a potentially important causal association between HPV and OSCC and OPMD.

Prevalence of viral (HPV, EBV, HSV) infections in oral submucous fibrosis and oral cancer from India

CONCLUSION

There is a high prevalence of human papilloma viruses (HPV) in oral submucous fibrosis (OSMF) and the etiologic implication of this finding warrants further studies.

OBJECTIVE

The prevalence of oral squamous cell carcinoma (OSCC) and OSMF is high in India, and the diseases are partly attributed to high consumption of betel quid containing areca nut and tobacco. This study investigated the prevalence of HPV, herpes simplex virus (HSV), and Epstein–Barr virus (EBV) DNA in two groups of patients using betel quid with tobacco, those with OSMF (n = 12) and those with OSCC (n = 62).

METHODS

DNA was extracted from all the samples and viral genome was examined by PCR/DNA sequencing. HPV-positive samples were analyzed separately for the high-risk types HPV 16 and 18.

RESULTS

HPV DNA, HSV DNA, and EBV DNA were detected in 11 (91%), 1 (8%), and 3 (25%) of the 12 samples from patients with OSMF compared with 15 (24%), 3 (5%), and 18 (29%), respectively, from 62 patients with OSCC. HPV 16 and 18 DNA was detected in 8/12 (67%) in the OSMF group and 10/62 (16%) in the OSCC group. The difference between presence of HPV DNA in OSMF and OSCC groups was statistically significant, while the difference between HSV and EBV DNA content in OSMF and OSCC groups was insignificant.

Significant association of high-risk human papillomavirus (HPV) but not of p53 polymorphisms with oral squamous cell carcinomas in Malaysia

PURPOSE

The purpose of this study was to evaluate the role of HPV and p53 polymorphisms in oral squamous cell carcinomas (OSCC) affecting Malaysian population.

METHODS

We analysed frozen samples from 105 OSCC as well as 105 oral specimens derived from healthy individuals. PCR assays targeting two regions of the virus were used. PCR amplification for the analysis of p53 codon 72 arginine/proline alleles was carried out in a separate reaction.

RESULTS

HPV DNA was detected in 51.4% OSCC samples, while 24.8% controls were found to be HPV positive. HPV was found to be significantly associated with OSCC (P < 0.001, OR = 4.3 after adjustment for habits) when compared to controls. High-risk HPV was found to be significantly associated with OSCC cases (P < 0.05). Demographic profiles of age, gender, race and habits were not associated with HPV presence in cases and controls. However, significantly less HPV positivity was seen in poorly differentiated compared to well-differentiated OSCCs. No significant association was found between HPV positivity and p53 polymorphisms in cases and control groups. Additionally, we found no association of codon 72 polymorphism with oral cancer.

CONCLUSIONS

This study indicates that high-risk HPV infection is one of the contributing factors for OSCCs. HPV 16 was the predominant type found in Malaysian patients with OSCC. Further, we did not find any association between p53 codon 72 polymorphism and HPV infection or between the p53 polymorphism and the risk of oral cancer.

Human papillomaviruses in oral squamous cell carcinoma and pre-cancerous lesions detected by PCR-based gene-chip array

Human papillomavirus (HPV) infection is a significant risk factor for uterine cervical carcinoma. Many studies have also demonstrated the presence of HPV in oral epithelia tissue, but the role of HPV infection in oral squamous cell carcinoma (OSCC) is still controversial. The aim of this study was to determine the frequency and type of HPV in OSCC and oral pre-cancerous lesions. DNA samples were collected by cytobrushing from 51 patients with OSCC, 46 with oral pre-cancerous lesions and 90 normal controls. Nested polymerase chain reaction and gene-chip arrays were used to identify the HPV types in the samples. In pre-cancerous lesions, there was a higher frequency of HPV of any type (14/46, OR = 2.844, CI = 1.186-6.816, P = 0.0216) and of low-risk HPV types (9/46, OR = 5.529, CI = 1.597-19.14, P = 0.0096) than in control samples. The prevalence of high-risk types was significantly higher in OSCC than in control lesions (11/51 vs 8/90, OR = 2.819, CI = 1.051-7.558, P = 0.0420) but this was not the case for HPV of any type (13/51 vs 12/90, OR = 2.244, CI = 0.9266-5.337, P = 0.1066). High-risk HPV types are prevalent in OSCC and may play a role in its progression, while low-risk types are associated with oral pre-cancerous lesions.

An increased lung cancer risk associated with codon 72 polymorphism in the TP53 gene and human papillomavirus infection in Mazandaran province, Iran

The TP53 gene has a polymorphism in exon 4 at codon 72 that presents the arginine or proline genotype. The association of TP53 codon 72 polymorphism with lung cancer risk has been studied by several groups, although with inconsistent results. Our previous study showed that the human papillomavirus (HPV) infection is associated with the development of lung cancer in Mazandaran, north part of Iran (cases=25.6% versus controls=9.0%, P=0.002). The frequency of TP53 codon 72 polymorphism was studied in a north part Iranian group of 92 healthy controls and 141 lung cancer patients. The allelic distribution of the three genotypes (ArgArg, ArgPro, ProPro) in healthy normal controls was 46.1, 32.6 and 21.3%, respectively, which differs from that of lung cancer patients showing genotype frequency as 42.6, 49.6 and 7.8%. A relation between the presence of the Arg allele and lung cancer risk was observed. Our study reveals that Arg allele, active smoking and HPV infection are the important risk factors in lung cancer development in the north part of Iran, Mazandaran province.

Risk of oral nonmalignant lesions associated with human papillomavirus infection, betel quid chewing, and cigarette smoking in Taiwan: an integrated molecular and epidemiologic study

CONTEXT

In contrast to previous studies about the association of oral squamous cell carcinoma with human papillomavirus (HPV) 16/18, the associations between nonmalignant oral lesions (chronic inflammation, submucous fibrosis, leukoplakia, and squamous papilloma) and HPV are much less well understood.

OBJECTIVE

We conducted this study using an in situ polymerase chain reaction in situ hybridization assay, which is one of the most sensitive methods for in situ viral detection. Other known oral cancer risk factors, including betel quid chewing and cigarette smoking, were also analyzed.

DESIGN

Oral specimens from 23 patients with submucous fibrosis, 36 patients with leukoplakia, 22 patients with squamous papilloma, and 21 patients without significant lesions were analyzed for the presence of HPV DNA. Their betel quid chewing and cigarette smoking histories were reviewed.

RESULTS

HPV-16 and HPV-18 were frequently identified in all 3 oral lesions (61.5% and 42.1%), while HPV-6 and HPV-11 were seen only in squamous papilloma (21.1% and 5.0%). HPV-18, betel quid chewing, and smoking were significantly associated with leukoplakia and squamous papilloma, while only betel quid chewing and smoking were significantly associated with submucous fibrosis. Multivariate analysis showed that the betel quid chewing habit remained an independent factor for leukoplakia and squamous papilloma.

CONCLUSIONS

Our data indicated that betel quid chewing and smoking habits are 2 important risk factors for these nonmalignant or premalignant oral lesions, while for high-risk HPV, only HPV-18--not HPV-16--is a significant risk factor for leukoplakia and squamous papilloma.

Tumor necrosis factor-alpha promoter polymorphism is associated with susceptibility to oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the leading cancers in most Asian countries. Alterations of immune function have been detected in OSCC patients. The pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is a central mediator of the immune response involved in a wide range of immuno-inflammatory and infectious diseases. Polymorphism of the TNF-alpha gene has been intensively studied as a potential determinant of susceptibility to numerous cancers.

METHODS

We genotyped 192 patients with OSCC and 146 healthy case controls by using polymerase chain reaction-double restriction fragment length polymorphism with amplification-created restriction sites to assess allelic determinants at the TNF-alpha polymorphic sites -308 and -238 in the promoter region. Genotype frequencies were evaluated with Fisher's test.

RESULTS

The -308 TNFG (tumor necrosis factor G) allele genotype was higher in patients with OSCC (91.2% vs. 82.2%; P = 0.02) and TNFG/A was lower (8.3% vs. 11.8%; P = 0.02); the -238 TNFG/A allele genotype was lower in patient with OSCC (2.1% vs. 6.9%; P = 0.02).

CONCLUSION

This is the first report that the TNF-alpha polymorphism is associated with the risk for OSCC in Taiwan.

p53 mutations and human papillomavirus infection in oral squamous cell carcinomas: correlation with overall survival

PURPOSE

The study investigated the pattern of p53 gene mutations and human papillomavirus (HPV) infection concerning their relation to overall survival in patients with oral squamous cell carcinomas of the tongue and floor of the mouth.

PATIENTS AND METHODS

The presence of HPV infection in 50 patients, and p53 gene mutations (42 patients from the same group) in the tumour specimens were analysed by polymerase chain reaction and single-stranded conformational polymorphism method. The follow-up period ranged from 12 to 48 (median 29) months.

RESULTS

p53 mutations were identified in 11/42 tumours. HPV infection was detected in 32/50 cases, mostly HPV16 (10/32), HPV18 and HPV31 (6/32). A significantly higher incidence of HPV infection was found among smokers (p<0.05) and among patients with poor oral hygiene (p<0.01). The highest incidence of p53 mutations was detected in tumours of histological grade I and nuclear grade III. Patients with p53 mutation or with HPV infection had significantly shorter overall survival when compared with those that were without p53 mutations (p<0.01) or HPV infection (p<0.05). HPV-infected patients with p53 mutation had the worst prognosis when compared with patients with HPV infection only (p<0.01) or with patients negative for both HPV and p53 (p<0.01).

CONCLUSION

The results stress once more the importance of HPV for the prognosis of survival of patients with squamous cell carcinoma of lower parts of the oral cavity. The presence of p53 mutations in HPV-infected tumours was associated with an even poorer prognosis for the patients.

Human papilloma virus in oral squamous cell carcinoma in a Mexican population

OBJECTIVE

To determine the human papilloma virus (HPV) infection in oral cancer and its association with smoking and drinking habits.

STUDY DESIGN

A cross-sectional study was performed; samples were collected from 51 patients with histological diagnosis of squamous-cell carcinoma were collected at the Instituto Nacional de Cancerología in Mexico City. HPV infection was detected by polymerase chain reaction, and the clinical characteristics of this population were analyzed.

RESULTS

Fifty samples out of 51 were positive for beta-globin; 21 (42%) cases were HPV-positive, and 14/21 were positive for HPV-16. We found more samples positive in men than in women (71% vs 29%). No differences were observed between HPV-positive and -negative patients in relation to smoking and drinking habits (81% vs 79%).

CONCLUSIONS

HPV infection was present in 42% of patients with oral squamous-cell carcinoma (OSCC); HPV-16 was the most frequent type, identified in 66.6%. Other cofactors participate in the development of OSCC, independent of HPV infection.

Lung adenocarcinoma and human papillomavirus infection

Over the past three decades, the incidence of lung adenocarcinoma has increased worldwide. Most individuals with lung adenocarcinoma (especially women) are nonsmokers. Reported risk factors for the development of lung adenocarcinoma include cigarette smoking; exposure to cooking fumes, air pollution, second-hand smoke, asbestos, and radon; nutritional status; genetic susceptibility; immunologic dysfunction; tuberculosis infection; and asthma. Human papillomavirus (HPV) infection is a known risk factor for the development of squamous cell carcinoma (SCC), but it has not been thoroughly assessed as a potential risk factor for the development of pulmonary adenocarcinoma. More than 50% of people are infected with HPV during their lifetimes, either via intrauterine or postnatal infection. Recent studies involving Taiwanese patients have demonstrated a possible association between HPV infection and the risk of developing pulmonary adenocarcinoma. HPV transmission pathways have not yet been conclusively identified. The observation of certain types of HPV in association with cervical and oral SCC raises the possibility of sexual transmission of HPV from the cervix to the oral cavity, with subsequent transmission to the larynx and then to the lung. HPV infection and metaplasia in lung tissue may increase an individual's susceptibility to the tumorigenesis of pulmonary adenocarcinoma. Further epidemiologic and pathologic investigations will be necessary to establish a causal relation.

The molecular markers for prognostic evaluation of areca-associated buccal squamous cell carcinoma

BACKGROUND

Buccal squamous cell carcinoma (BSCC) is the most frequently occurring oral cancer in Asians due to the popularity of areca use in this area. The aim of the present study was to evaluate the survival of areca-associated BSCC associated with multiple molecular markers.

METHODS

Using immunohistochemistry, we evaluated the survival of a cohort of 55 patients with BSCC being followed long term, as correlated to the expression of variable markers.

RESULTS

We found that p53, p21, Rb, cyclin D1 (CCD1), MDM2, and gamma-catenin were positive in 81, 60, 70, 31, 88, and 44% of patients, respectively. Subjects with -ve immunoreactivity for CCD1, and +ve immunoreactivity for MDM2 and gamma-catenin had significantly better survival than subjects with the opposite immunoreactive pattern. KAPLAN-meier survival curves confirmed this association.

CONCLUSION

The data indicate that expression of CCD1, MDM2, and gamma-catenin might serve as potential prognostic markers for BSCC in areca-using patients.

Human papillomavirus infections and oral tumors

In the past 20 years, there has been an increasing interest in human papillomaviruses (HPV) because of their potential role in the pathogenesis of malignant tumors. In 1983, we published the first evidence that HPV might be involved in oral squamous cell carcinomas. The identification of morphological similarities between oral and cervical mucosa lead us to this original proposal. In a recent meta-analysis, HPV was indeed confirmed as an independent risk factor for oral carcinoma. To date, totally more than 100 types of HPV have been identified. As in anogenital cancers, HPV type 16 is the most prevalent type in oral carcinomas. The benign oral lesions, associated with HPV infection, include squamous cell papilloma, condyloma acuminatum, verrucca vulgaris and focal epithelial hyperplasia (FEH). Papillomas and condylomas are mostly caused by HPV type 6 or 11, while oral verrucas are associated with the skin types 2 or 4. A family history of FEH has been suggested. The FEH lesions are caused by HPV types 13 and 32, only detected in oral epithelium. In immunocompromised patients, benign HPV-induced lesions are characterized by atypical morphology and the simultaneous detection of multiple HPV types. Oral benign HPV lesions are mostly asymptomatic, and may persist or regress spontaneously.

Risk of oral cancer associated with human papillomavirus infection, betel quid chewing, and cigarette smoking in Taiwan--an integrated molecular and epidemiological study of 58 cases

BACKGROUND

The association between oral squamous cell carcinoma (OSCC) and human papillomavirus (HPV) 6, 11, 16 and 18 is uncertain. Past reports varied in the methodology and results. We conducted this study using in situ PCR in situ hybridization (ISH) assay which was considered as the most sensitive method for detection of viral DNA. We undertook an epidemiologic survey about the history of betel quid chewing and cigarette smoking, since these habits are common in Taiwan.

METHODS

In situ PCR ISH was performed on the tumor specimens from 29 patients with OSCC and the oral mucosal specimens from 29 patients without OSCC. Their betel quid chewing and cigarette smoking histories were also reviewed.

RESULTS

HPV16, HPV18, betel quid chewing and cigarette smoking were statistically significant risk factors in univariate analysis. HPV6 and 11 were not. Multivariate analysis showed that HPV16 infection (adjusted Odds ratio = 11.20) and betel quid chewing (adjusted Odds ratio = 17.06) remained to be independent factors for OSCC.

CONCLUSIONS

Our results showed that HPV16 and betel quid chewing were two major risk factors for OSCC in Taiwan, indicating that they act through different mechanisms in the pathogenesis of OSCC.

The increase in the frequency of MICA gene A6 allele in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) was reported to be associated with immune function. The MICA (MHC class I chain-related gene A) is expressed by keratinocytes and other epithelial cells, and its encoded protein interacts with gamma/delta T cells localized in submucosa. The MICA also influences the heat shock protein function. We speculated that the alterations of MICA might influence the pathogenesis of OSCC through the aberration in presenting tumor antigens or heat shock protein. MICA gene has a triplet repeat (GCT) polymorphism in the transmembrane domain, resulting in five distinctive allelic patterns.

METHODS

We analysed this MICA polymorphism in 67 OSCC patients and 351 randomly selected unrelated controls. By using the ABI Prism 377-18 DNA sequencer (Applied Biosystems, Foster City, CA, USA) to analyse the sample DNA PCR products. The number of micro-satellite repeats was estimated with Genescan 672 software (Applied Biosystems) with a standard size marker of GS-350 TAMRA (N,N,N,N-tetramethyl-6-carbohydroxyl rhodamine; Applied Biosystems).

RESULTS

The phenotype frequency of allele A6 of MICA in subjects with OSCC was significantly higher than that in controls (RR = 3.46, 95% CI = 1.73-6.94, P = 0.0002), as was the frequency of allele (RR = 2.64, 95% CI = 1.39-5.02, P = 0.002).

CONCLUSION

The results suggest that allele A6 in MICA might confer the risk of OSCC.

The effect of betel nut extract on cell growth and prostaglandin endoperoxide synthase in human epidermoid carcinoma cells

The objective of this study was to find out whether prostaglandin endoperoxide synthase (PHS) involves the action of betel nut extract (BNE) on the growth of oral cancers. Therefore, growth and PHS activity were examined in two human oral carcinoma cell lines (OEC-M1 and KB) and one normal fibroblast cell line (NF) in the presence of increasing BNE concentration. BNE at concentrations above 50 microg/ml significantly inhibited the cell growth of OEC-M1 after 72 h in culture, of KB and NF after 48 h in culture. The IC50 of BNE in OEC-M1, KB and NF at 24 h in culture was about 406, 37.5 and 140 microg/ml respectively. PHS activity in OEC-M1 was significantly increased by low BNE concentrations (50 microg/ml, 114%; 100 microg/ml, 33%; 150 microg/ml, 30%) but significantly reduced at higher BNE concentrations (300 microg/ml, 33%; 500 microg/ml, 61%). The PHS activity in KB was significantly inhibited by BNE and this effect was intensified as concentrations increased (50 microg/ml, 31%; 100 microg/ml, 24%; 150 microg/ml, 43%; 300 microg/ml, 60%; 500 microg/ml, 92%). Similar to that in OEC-M1, the PHS activity in NF was significantly increased at low BNE concentrations (50 microg/ml, 139%; 100 microg/ml, 87%;150 microg/ml, 77%) but reduced at higher concentrations (300 microg/ml, 55%; 500 microg/ml, 72%). The PHS activity in all cell lines was almost completely blocked by indomethacin (5 x 10(-6) M). We conclude that these findings suggest that PHS may be an important biochemical mediator of the effect of BNE on the growth of two human oral carcinoma cell lines.

Prognostic role of p21WAF1 expression in areca quid chewing and smoking-associated oral squamous cell carcinoma in Taiwan

BACKGROUND

Alterations in p21WAF1 protein expression have been observed in a wide variety of human cancers by immunohistochemistry, and both decreased and increased levels of p21WAF1 protein expression have been shown to correlate with poor prognosis.

METHOD

To examine the relation between p21WAF1 protein expression and prognosis in oral squamous cell carcinomas (SCCs), we performed an immunohistochemical study with antip21WAF1 antibody on 43 oral SCCs. Immunostaining results were then correlated with p53 protein levels, clinicopathological parameters of the tumors and overall patient survival.

RESULTS

Of the 43 patients, 31 (72%) had tumors with positive p21WAF1 nuclear staining and 27 (63%) had tumors with p53 nuclear staining. There was no significant correlation between p21WAF1 and p53 protein expressions and both mutant p53-containing oral SCCs overexpressed p21WAF1 protein. In addition, no significant correlation was found between the p21WAF1 expression and the patients' age, sex, oral habit, cancer location, or primary tumor TNM status at the time of initial presentation. The Kaplan-Meier analysis showed a significant correlation between p21WAF1 protein overexpression and poor patient overall survival (P = 0.049). When p53 and p21WAF1 were evaluated together, the 5-year overall survival was lowest in p53(+)-p21WAF1(+) patients and highest in p53(-)-p21WAF1(-) patients (P = 0.057).

CONCLUSION

Combined evaluation of p21WAF1 and p53 expressions may be useful in estimating the prognosis of patients with oral SCCs in Taiwan.

Human papillomavirus as a risk factor for oral squamous cell carcinoma: a meta-analysis, 1982-1997

OBJECTIVE

Human papillomavirus (HPV) infection is a significant risk factor for uterine cervical carcinoma. However, the role of HPV infection in oral squamous cell carcinoma (OSCC) is less well defined. To determine the significance of the relationship of this virus in the progressive development of oral cancer, we estimated the risk of HPV detection in normal oral mucosa, precancerous oral tissue, and oral carcinoma using meta-analysis.

STUDY DESIGN

Case reports and clinical series published in English-language journals were retrieved by searching MEDLINE (January 1980-August 1998). Review articles were also examined to identify additional studies. Studies that used biochemical, immunologic, microscopic, or molecular analyses to detect HPV in tissue or cells derived from normal oral mucosa (n = 25), benign leukoplakia (n = 21), intraepithelial neoplasia (ie, dysplasia and carcinoma in situ; n = 27), and oral cancer (n = 94) were included in the meta-analysis. Information on sample size, age, sex, method of tissue preservation (ie, fresh, frozen, paraffin-embedded), assay, primer amplification region (early, late), high-risk versus low-risk genotype, and use of tobacco or alcohol was abstracted by one author (C.S.M.).

RESULTS

Data from 94 reports that analyzed 4680 samples were included in the meta-analysis. Analyses made by means of a random-effects model with and without adjustments for assay sensitivity showed increased probability of HPV detection in tissue with precancerous and cancerous features compared with normal mucosa. The likelihood of detecting HPV in normal oral mucosa (10.0%; 95% confidence interval [CI], 6.1%-14.6%) was significantly less than of detecting benign leukoplakia (22.2%; 95% CI, 15.7%-29.9%), intraepithelial neoplasia (26.2%; 95% CI, 19.6%-33.6%), verrucous carcinoma (29.5%; 95% CI, 23%-36.8%), and OSCC (46.5%; 95% CI, 37.6%-55.5%). Adjustment of findings for differences in assay sensitivity indicated that these estimates may be conservative. Overall, HPV was between 2 and 3 times more likely to be detected in precancerous oral mucosa and 4.7 times more likely to be detected in oral carcinoma than in normal mucosa. The pooled odds ratio for the subset of studies directly comparing the prevalence of HPV in normal mucosa and OSCC was 5.37, confirming the trend observed in the overall sample. The probability of detecting high-risk HPVs in OSCCs was 2.8 times greater than that of low-risk HPVs.

CONCLUSION

This meta-analysis indicates that HPV is detected with increased frequency in oral dysplastic and carcinomatous epithelium in comparison with normal oral mucosa. The findings provide further quantitative evidence that oral infection with HPV, particularly with high-risk genotypes, is a significant independent risk factor for OSCC.

Recent striking changes in histological differentiation and rate of human papillomavirus infection in squamous cell carcinoma of the lung in Okinawa, a subtropical island in southern Japan

AIMS

The incidence of lung cancer in Okinawa has been the highest in Japan since 1975, and squamous cell carcinoma (SCC), especially the well differentiated form, is the most prevalent form in Okinawa, although well differentiated SCC is relatively rare in mainland Japan. Furthermore, a high proportion of SCC of the lung in Okinawa was positive for human papillomavirus (HPV). In this study, we report recent striking changes in histological features and in the incidence of HPV infection.

METHODS

In Okinawa between 1986 and 1998, 1109 surgically resected lung tumours were examined histopathologically. In addition, human papillomavirus infection was detected by the polymerase chain reaction and Southern blot analysis in SCC cases reported in 1993 and 1995-8. Non-isotopic in situ hybridisation of HPV DNA was also carried out.

RESULTS

Up until 1994 SCC, especially the well differentiated form, was the most prevalent type of tumour. However, since 1995 the number of such cases has diminished steadily, accompanied by a slight rise in the incidence of adenocarcinoma. Although most present and past patients are heavy smokers, the incidence of SCC, especially the well differentiated form, continues to decrease steadily. Furthermore, in 1993, HPV was detected in 79% of all cases, and was particularly prevalent in the well differentiated form, but the rate fell to 68% in 1995, 35% in 1996, 23% in 1997, and 24% in 1998. The age distribution of patients, the male to female ratio, and the number of tumours overexpressing p53 protein did not change significantly over the study period, and thus did not correlate with changes in the differentiation of SCC.

CONCLUSIONS

The decreasing incidence of viral infection correlates strongly with the falling numbers of SCC cases, especially well differentiated cases. These findings suggest that HPV might be involved in the development of SCC of the lung, affecting the histological differentiation of SCC in particular, at least in Okinawa, a subtropical island in southern Japan.

Prognostic implication of human papillomavirus infection in squamous cell carcinoma of the lung

On the subtropical island of Okinawa, squamous cell carcinoma (SCC), particularly the well-differentiated form, is the most frequent type of lung cancer, while this form is relatively rare on the Japanese mainland and in other countries. Furthermore, in Okinawa, in 1993, 80% of SCC cases of the lung were found to be infected with human papillomavirus (HPV). We studied the prognosis of SCC of the lung with HPV infection (n = 25) and compared it with non-HPV-infected SCC (n = 16). Using the Kaplan-Meier method (Wilcoxon analysis), the prognosis of HPV-infected cases was found to be better than that of the non-infected cases. In the virus-infected cases, apoptosis and infiltration of a large number of Langerhans cells were demonstrated. In addition to these findings, the virus-infected tumors were demonstrated to be histologically well-differentiated, perhaps contributing to the favorable prognosis. However, among the virus-infected cases, the type 16 virus-infected cases showed a poorer prognosis, compared to those infected with other HPV types. p53 gene mutation was also examined, and was considered to be an unfavorable prognostic factor, as reported elsewhere. However, in Okinawa, HPV-positive cases with p53 mutations showed a slightly better prognosis than did non-viral infected cases with p53 mutations. The TNM staging system was also useful for categorizing the virus-infected cases. The prognosis of stage III (A and B) cases was poor. All of our present cases received surgical treatment. Chemotherapy and radiation therapy were not performed. Such treatment, however, might be effective, because virus-infected uterine cervical carcinomas have been routinely treated with chemotherapy and radiation. Furthermore, if the immunological basis of increased Langerhans cell infiltration in HPV-infected cases is elucidated, a clinical trial with immunotherapy may be favorable for the clinical outcome.

"High risk" HPV types are frequently detected in potentially malignant and malignant oral lesions, but not in normal oral mucosa

Studies on the involvement of the human papillomavirus (HPV) in initiation and progression of oral neoplasia have generated conflicting results. The observed discrepancy is attributable mainly to the varying sensitivity of the applied methodologies and to epidemiologic factors of the examined patient groups. To evaluate the role of HPV in oral carcinogenesis, we analyzed 53 potentially neoplastic and neoplastic oral lesions consisting of 29 cases of hyperplasia, 5 cases of dysplasia, and 19 cases of squamous cell carcinomas, as well as 16 oral specimens derived from healthy individuals. A highly sensitive nested polymerase chain reaction (PCR) assay was used, along with type-specific PCR, restriction fragment length polymorphism analysis, dot blotting, and nonisotopic in situ hybridization. Nested PCR revealed the presence of HPV DNA in 48 of the 53 (91%) pathologic samples analyzed, whereas none (0%) of the normal specimens was found to be infected. Positivity for HPV was independent of histology and the smoking habits of the analyzed group of patients. At least one "high risk" type, such as HPV 16, 18, and 33, was detected by type-specific PCR in 47 (98%) infected specimens, whereas only 1 (2%) squamous cell carcinoma was solely infected by a "low risk" type (HPV 6). HPV 16 was the prevailing viral type, being present in 71% of infected cases. Single HPV 16 and HPV 18 infections were confirmed by restriction fragment length polymorphism. HPV 58 was detected by dot blotting in three hyperplastic lesions. HPV positivity and genotyping were further confirmed, and the physical status of this virus was evaluated by nonisotopic in situ hybridization. Diffuse and punctate signals, indicative of the episomal and integrative pattern of HPV infection, were observed for low- and high-risk types, respectively. Our findings are suggestive of an early involvement of high-risk HPV types in oral carcinogenesis.

Human papillomavirus in head and neck squamous cell carcinoma: are some head and neck cancers a sexually transmitted disease?

There is abundant epidemiologic and virologic evidence that high-risk human papillomaviruses (HPVs) are tumorigenic in human epithelia, particularly in the cervix, where HPV infection is necessary for cancer development. HPV DNA has been detected in a proportion of head and neck squamous cell carcinomas (HNSCCs) in numerous case series. The mere presence of the virus in tumor specimens, by itself, does not imply a causal relationship. However, recent studies support an etiologic role for HPVs in a subset of HNSCC, particularly poorly differentiated tumors arising from Waldeyer's tonsillar ring. Epidemiologic studies have shown that exposure to HPV increases the risk of HNSCC, and HPV infection may interact with alcohol and tobacco exposure in tumor promotion. Molecular studies indicate that transcriptionally active virus is confined to tumor cells. It will be important to clarify further the role that HPV has in HNSCC development, because HPV-based therapeutic vaccines which are currently being developed for cervical cancer may also be of benefit in the management of HNSCC.

Infrequent p53 mutations in patients with areca quid chewing-associated oral squamous cell carcinomas in Taiwan

Mutations in the conserved regions (exons 5-9) of the p53 gene were investigated in 37 untreated human primary oral squamous cell carcinomas (SCCs) using polymerase chain reaction-single strand conformation polymorphism and DNA sequencing analyses. P53 mutations were detected in 2 of 37 (5.4%) oral SCC cases. One tumor sample (case 23) showed a mis-sense point mutation at codon 177, changing CCC to CTC, which resulted in a substitution of proline to leucine in the p53 protein. The other tumor (case 33) had a point mutation at codon 266, changing GGA to AGA and causing a substitution of glycine to arginine in the p53 protein. These two patients with p53 mutations did not have an areca quid chewing habit. These results suggest that mutations in the p53 gene may not play a role in the pathogenesis of human oral SCCs in Taiwan. Recently, we have shown that positive p53 staining was observed in 47 of 81 (58%) cases of oral SCC. The discrepancies between positive p53 protein staining and the low prevalence of p53 mutation in oral SCCs indicate that other mechanism(s) are involved in p53 overexpression.

Oral cancer risk in relation to sexual history and evidence of human papillomavirus infection

BACKGROUND

Experimental models and analyses of human tumors suggest that oncogenic, sexually transmittable human papillomaviruses (HPVs) are etiologic factors in the development of oral squamous cell carcinoma (SCC). We conducted a population-based, case-control study to determine whether the risk of this cancer is related to HPV infection and sexual history factors.

METHODS

Case subjects (n = 284) were 18-65-year-old residents of three counties in western Washington State who were newly diagnosed with oral SCC from 1990 through 1995. Control subjects (n = 477) similar in age and sex were selected from the general population. Serum samples were tested for HPV type 16 capsid antibodies. Exfoliated oral tissue collected from case and control subjects and tumor tissue from case subjects were tested for HPV DNA. Odds ratios (ORs) were calculated after adjusting for age, sex, cigarette smoking, and alcohol consumption.

RESULTS

Among males only, oral SCC risk increased with self-reported decreasing age at first intercourse, increasing number of sex partners, and a history of genital warts. Approximately 26% of the tumors in case subjects contained HPV DNA; 16.5% of the tumors contained HPV type 16 DNA. The prevalence of oncogenic HPV types in exfoliated oral tissue was similar in case and control subjects. The ORs for HPV type 16 capsid seropositivity were 2.3 (95% confidence interval [CI] = 1.6-3.3) for all oral SCCs and 6.8 (95% CI = 3.0-15.2) for oral SCCs containing HPV type 16 DNA. The joint association of cigarette smoking and HPV type 16 capsid seropositivity with oral SCC (OR = 8.5; 95% CI = 5.1-14.4) was stronger than predicted from the sum of individual associations with current smoking (OR = 3.2; 95% CI = 2.0-5.2) and seropositivity (OR = 1.7; 95% CI = 1.1-2.6).

CONCLUSIONS

HPV type 16 infection may contribute to the development of a small proportion of oral SCCs in this population, most likely in combination with cigarette smoking.

Human papillomavirus DNA in adenosquamous carcinoma of the lung

AIM

To investigate the presence of human papillomavirus (HPV) DNA in adenosquamous carcinoma of the lung--which is relatively common in Okinawa but not in mainland Japan--and examine its histological features.

METHODS

Of 207 cases where primary lung cancers were surgically removed between January 1995 and June 1997 in Okinawa, 23 were adenosquamous carcinoma. HPV was detected by non-isotopic in situ hybridisation (NISH) and polymerase chain reaction (PCR) amplification with primers specific for E6 and E7 regions of the HPV genome. PCR products were analysed by Southern blotting. Immunohistochemical determination of high molecular weight cytokeratin (HMC) and involucrin was also carried out.

RESULTS

18 cases were positive for HPV DNA by PCR and NISH. HPV types 6, 11, 16, and 18 were found. Seven cases were dual positive for different types of HPV. Using NISH, HPV was also found in the squamous cell components and in neighbouring enlarged adenocarcinoma cells. The HMC and involucrin were demonstrated immunohistochemically in the same areas.

CONCLUSIONS

HPV DNA was found in a high proportion (78.3%) of adenosquamous carcinomas in Okinawa, a region where HPV has previously been shown to be prevalent in squamous cell carcinoma of the lung. The adenocarcinoma cells adjacent to the squamous cell carcinoma component were enlarged and positive for HPV, HMC, and involucrin. This is thought to indicate the transition from adenocarcinoma to squamous cell carcinoma.

Detection of HPV-16 genome in human oral cancers and potentially malignant lesions from India

The presence of high risk human papilloma virus (HPV) 16 and 18 was examined in 100 oral cancer patients of Indian descent, 80 patients with potentially malignant oral lesions and corresponding clinically normal mucosa from 48 of these patients. Additionally, presence of HPV-33, -6 and -11 was also studied in 86 oral cancers, 50 potentially malignant oral lesions and 30 corresponding normal oral mucosa. All the patients with oral cancer and oral lesions, were long term tobacco-chewers, and a majority of the patients were in Advanced Stages III and IV. The DNA samples were amplified by polymerase chain reaction (PCR) using HPV L1 consensus primers. Typing of HPV was performed by Southern hybridization analysis of the PCR products using HPV-16, -18, -33, -6 and -11 type specific oligonucleotide probes. HPV-16 was detected in 15 out of 100 (15%) oral tumours, 27 out of 80 (34%) potentially malignant lesions and 15 out of 48 (31%) of the corresponding normal mucosa in the patients with oral lesions. HPV-18 was not detected in any of the oral cancers, oral lesions and normal mucosa. HPV-33 and the low-risk HPV-6 and -11 were also not detected in the oral cancers, oral lesions and corresponding normal mucosa. A significantly higher prevalence of HPV-16 was observed in oral lesions (27 out of 80, 34%) as compared to oral cancers (15 out of 100, 15%). The observed difference of 19% (95% confidence interval [CI]: 6%, 31%), between these two proportions was statistically significant at the 5% level of significance. Our data indicates that HPV-16 may play a direct role in a certain proportion of oral cancers; whereas in a subpopulation of oral cancers HPV-16 infection may be vital in the early events associated with development of potentially malignant oral lesions, and the presence of the virus not essential in the progression of the oral lesion to frank malignancy.

p53 alterations in betel quid- and tobacco-associated oral squamous cell carcinomas from Taiwan

Alterations of p53 have been explored in Taiwanese oral squamous cell carcinomas (OSCCs) consisting of a betel quid (BQ)/tobacco-related subgroup of 36 subjects and a tobacco-related subgroup of 13 subjects. Mutations in conserved exons were found in 12 tumors. Seven mutations were clustered in a hot-spot region mapped to a region between codons 273-282 in exon 8. The incidence of p53 mutation in BQ/tobacco tumors was 22% (8/36). The frequency of p53 allelic loss (21%, 3/14) in BQ/tobacco tumors approximates to the incidence of mutation. This is the first study demonstrating allelic deletion of p53 in such malignancies. Twenty-four of 43 samples showed positive p53 immunostaining. All tumors harboring mis-sense mutations of p53 in conserved exons exhibited nuclear protein accumulation. The incidence of mutation in conserved exons in BQ/tobacco-associated Asian OSCCs (15%) is significantly different from worldwide OSCCs (46%) related primarily to tobacco consumption (P=0.00001).

Human papillomavirus and risk of oral cancer

Although human papillomavirus (HPV), a sexually transmitted virus, is established as a necessary cause for more than 95% of cervical carcinomas, the association with oral squamous cell carcinoma is less well delineated. The purpose of this study was to determine the frequency and types of HPV in squamous cells of a group of patients with newly diagnosed oral or pharyngeal cancer (n = 93) compared with an age- and gender-frequency-matched control group of patients with no history of oral cancer (n = 205). HPV was evaluated from a mouth rinse collection of cells in the oral cavity and tested by 32P-labeled HPV generic probes and DNA sequencing for HPV types. HPV was identified in 15% of the oral cancer cases but in fewer than 5% of the controls (P < .05). The risk of cancer associated with HPV infection was independent of tobacco and alcohol use (adjusted odds ratio [OR] = 3.70; 95% confidence interval [CI]: 1.47-9.32; P < .05). HPV types included similar and other types not identified previously in the genital tract. There was no statistically significant increased risk of cancer among former tobacco users (former vs. never users: adjusted OR = 0.67, 95% CI: 0.31-1.44, P < .05), but the risk was significantly increased for current users (current vs. never: adjusted OR = 2.63; 95% CI: 1.22-5.71; P < .05). Likewise, former alcohol users were not at increased risk of disease (former vs. never: adjusted OR = 1.78; 95% CI: 0.87-3.67), whereas current alcohol users were (current vs. never: adjusted OR = 2.57; 95% CI: 1.22-5.42; P < .05). HPV-related genital lesions (14.3% vs. 10.6%), oral-genital sexual behavior (42.4% vs. 45.2%), and number (11 or more) of sexual partners (23% v. 17%) were not significantly different between cases and controls. These data suggest that in addition to tobacco and alcohol, HPV plays a role in the development of oral cancer.

Correlation between HPV types associated with oral squamous cell carcinoma and cervicovaginal cytology: An in situ hybridization study

Epidemiologic and clinical evidence suggests a possible relationship between the human papillomavirus types found in oral squamous cell carcinoma and cervicovaginal cancer. To try to address this question, we analyzed by in situ hybridization 50 paraffin-embedded biopsies of oral squamous cell carcinomas and their corresponding Papanicolaou smears using nonradioactive DNA probes for human papillomavirus type 6/11 and 16/18. This analysis revealed that 70% (35 of 50) of oral squamous cell carcinomas and 56% (28 of 50) of Papanicolaou smears were positive for one or both of these human papillomavirus DNA probes. In 23 of the 28 patients who were positive for human papillomavirus sequences in the cervicovaginal tract, we found the same human papillomavirus type in the oral cavity. Five of the positive in situ hybridization Papanicolaou smears were associated with negative in situ hybridization oral squamous cell carcinomas. Our data suggest that after a primary infection by human papillomavirus, other mucosal sites may eventually become infected. Local environmental factors may contribute to the pathogenesis of lesions such as oral squamous cell carcinoma.

Human papillomavirus and head and neck cancer: epidemiology and molecular biology

BACKGROUND

Human papillomaviruses (HPV) are known to cause cancers of the cervix and other anogenital tract sites. Molecular biology has provided some evidence as to the specific mechanisms involved in the HPV-related carcinogenesis. Epidemiologic and molecular biology studies have also suggested that HPV infection may be associated with cancers of the head and neck.

METHODS

This review summarizes the biology of HPV and its potential etiologic role in head and neck cancer. Published reports were used to determine the prevalence of HPV in benign, precancerous, and neoplastic lesions of the oral cavity, pharynx, and larynx. The prevalence was also examined by head and neck site, HPV type, and method of HPV detection. In addition, the occurrence of HPV in normal head and neck tissue, epidemiologic factors related to HPV infection, and clinical implications are discussed.

RESULTS

Overall, the frequency of HPV in benign and precancerous lesions ranged from 18.5% to 35.9%, depending upon the detection methodology. Based upon the most sensitive method of detection, polymerase chain reaction (PCR), the overall prevalence of HPV in head and neck tumors was 34.5% (416 of 1205 tumors). The majority of HPV-positive tumors contained the "high risk" HPV types 16 (40.0%) and 18 (11.9%). Among head and neck sites, HPV was most often detected in tumors of the oral cavity (59%), followed by the pharynx (43%), and larynx (33%). The frequency of HPV positivity in oral samples from healthy individuals ranged from 1% to 60%. A limited number of descriptive and analytic epidemiologic studies have indicated that age (<60 years) and sex (male) were associated with the presence of HPV in the tumor, whereas tobacco and alcohol use were not. The relationship between HPV and survival is unclear, with few comprehensive studies currently available.

CONCLUSIONS

The prevalence of HPV, particularly the high-risk types, suggests a potential etiologic role for the virus in head and neck cancer. Molecular biology has provided important data on the interaction of the HPV oncoproteins with genes important in cell cycle control. Nonetheless, more basic research is needed to describe the physical state of the virus in a variety of cell types and the interaction with other genes. In addition, epidemiologic research is required to further understand the association between HPV and demographic and other risk factors as well as possible routes of transmission. Finally, much work is warranted to provide a definitive assessment of the prognostic significance of HPV in head and neck cancer.

The high risk human papillomaviruses and oral cancer: evidence for and against a causal relationship

Oncogenic human papillomaviruses (HPVs) have been detected in oral squamous cell carcinoma (SCC). HPV16 is the most frequently detected HPV type in oral SCC and is present in up to 22% of cases, either alone or in combination with other HPV types. HPV18 is present in up to 14% of cases. HPV16 and HPV18 are present together in approximately 6% of cases. However, HPV16 and 18 are also detected in normal oral mucosae (10% and 11% of subjects, respectively). These data suggest that high risk HPV infection may be a co-factor in oral carcinogenesis and that latent HPV infection of the oral mucosa is common. A role for HPV infection in oral carcinogenesis is supported by the ability of high risk HPVs to immortalize oral keratinocytes in vitro. Immortalization may involve (i) deactivation of pre-formed tumor-suppressor proteins by viral oncoproteins, (ii) blocking of tumor-suppressor gene transcription as a result of HPV oncogene insertion or (iii) stimulation of cellular oncogene transcription by the upstream insertion of HPV-derived transcription activating sequences. Hence, infection of oral keratinocytes with high risk HPV may be involved in the pathogenesis of some oral SCCs although the evidence implicating HPV in oral carcinogenesis is, at present, mainly circumstantial.

Human papillomavirus (HPV) in head and neck cancer. An association of HPV 16 with squamous cell carcinoma of Waldeyer's tonsillar ring

BACKGROUND

Certain strains of human papillomavirus (HPV) have been shown to be etiologically related to the development of uterine cervical and other genital cancers, but their role in the development of malignancies at other sites is less well established. Previous studies have shown HPV DNA in tumors of the head and neck, but its prevalence has varied depending on the detection methods and the types of tumor and/or tissue examined. This study was undertaken to estimate the frequency of HPV DNA in squamous cell carcinoma (SCC) at different sites of the esophagus, head and neck and to compare the clinical behavior of HPV positive and negative tumors.

METHODS

DNA was extracted from frozen tissue of 167 SCCs of the esophagus, head and neck. The DNA was screened for HPV sequences by polymerase chain reaction with two sets of consensus primers, one to a conserved region in the L1 gene (MY09/ MY11) and the other to a conserved region in the E1 open reading frame (IU/IWDO). The products were run on agarose gels, detected by ethidium bromide staining, and then the gels were subjected to Southern blot analysis and hybridized with probes specific to HPV 6, 16, and 18. All tumors found to be HPV positive with the consensus primers were amplified with type specific primers, and in selected cases the presence of HPV DNA was confirmed by restriction enzyme digestion of the tumor DNA with conventional Southern blot analysis.

RESULTS

Overall, HPV sequences were found in 25 of 167 tumors (15%), but HPV was detected most frequently in tumors in Waldeyer's tonsillar ring. In that area, 9 of 15 (60%) were HPV positive. No HPV DNA was detected in 11 esophageal SCCs, 7 tumors of the pharynx/hypopharynx, or 6 pyriform sinus carcinomas. HPV DNA was detected in the following tumor sites: 1 of 28 (3.6%) in the larynx, 1 of 10 (10%) in the oral cavity, 5 of 39 (12.8%) in the tongue, 2 of 15 (13.5%) in the floor of the mouth, 3 of 21 (14.3%) supraglottic, and 1 of 7 (14.3%) in the lip. A high incidence of HPV DNA was also found in metastatic tumors located in cervical lymph nodes for which no primary site was clinically identified (3 of 8, 37.5%). With respect to age, gender, and tobacco and alcohol consumption, analysis of clinical data obtained by retrospective review showed no difference between patients with HPV DNA in their tumors and those in which no HPV was detected. However, HPV positive patients had larger tumors (P = 0.09) and a higher incidence of lymph node metastasis (P = 0.003). In spite of the higher stage of disease at presentation in HPV positive patients, there was no significant difference in 3-year survival rates between HPV positive patients and HPV negative patients (43.1% vs. 48.8%, respectively). Median follow-up was 27 months.

CONCLUSIONS

In the head and neck, HPV-associated SCC had site specificity with the viral DNA frequently found in tumors in Waldeyer's tonsillar ring. Patients with HPV positive tumors presented with a higher stage of disease than patients with HPV negative tumors, but there was no significant difference in the 3-year survival rates between these two groups of patients.

Risk factors for oral human papillomavirus in adults infected and not infected with human immunodeficiency virus

BACKGROUND AND OBJECTIVES

To investigate in a cross-sectional study the determinants of oral human papillomavirus infection in 287 individuals who are sexually active.

GOAL

To assess prevalence as well as risk factors for oral human papillomavirus infection.

STUDY DESIGN

One hundred seventy-eight human immunodeficiency virus-seropositive (158 men and 20 women) and 109 human immunodeficiency virus-negative (73 men and 36 women) individuals were recruited consecutively from sexually transmitted disease-human immunodeficiency virus clinics and gastrointestinal endoscopy clinics. Oral brushings were tested with the L1 consensus polymerase chain reaction assay for human papillomavirus detection.

RESULTS

Human papillomavirus DNA was detected in 32 (11.2%) of 287 individuals. Associated with oral human papillomavirus infection on univariate analyses were human immunodeficiency virus infection (odds ratio, 6.9; 95% confidence interval, 2.0-23.2), homosexuality (odds ratio, 3.7; 95% confidence interval, 1.5-9.4), unprotected oral sex (odds ratio, 5.5; 95% confidence interval, 1.6-18.4), syphilis (odds ratio, 2.5; 95% confidence interval, 1.1-6.3), gonorrhea (odds ratio, 4.2; 95% confidence interval, 1.9-9.1), Chlamydia trachomatis (odds ratio, 4.4; 95% confidence interval, 1.8-10.6), and genital herpes (odds ratio, 2.9; 95% confidence interval, 1.3-6.5). Human immunodeficiency virus infection and C. trachomatis were independently predictive of human papillomavirus infection in multivariate stepwise logistic regression.

Human papillomavirus DNA in squamous cell carcinoma of the lung

AIM

To compare the incidence of squamous cell carcinoma (SCC) of the lung in Okinawa with that in Niigata on the mainland.

METHODS

All patients presenting with SCC of the lung in Okinawa and Niigata in 1993 were included in the study. Diagnoses were confirmed by conventional histological examination of paraffin wax sections. Human papillomavirus (HPV) was detected by non-isotopic in situ hybridisation (NISH) and polymerase chain reaction (PCR) amplification with primers specific for the E6 and E7 regions of the HPV genome. PCR products were analysed by Southern and dot blotting.

RESULTS

The incidence of well differentiated SCC of the lung was high in patients from Okinawa compared with moderately and poorly differentiated types, and compared with the incidence of SCC in patients from Niigata. This is despite similar patterns of age, sex (predominatly male), and smoking habit. More patients from Okinawa, however, were positive for HPV DNA by PCR (79%) and NISH (53%). Many patients haboured HPV types 6, 16, and 18. Only 30% of patients from Niigata were positive for HPV DNA by PCR and 20% by NISH. These patients all harboured one HPV type only.

CONCLUSION

Surprisingly large numbers of patients from Okinawa were positive for HPV DNA. The detection of HPV DNA was strongly associated with well differentiated SCC. This was particularly true for HPV types 6 and 16. There was no correlation between either smoking and detection of HPV DNA, or smoking and histological differentiation.

Human papillomavirus expression in oral mucosa, premalignant conditions, and squamous cell carcinoma: a retrospective review of the literature

OBJECTIVES

The literature of human papillomavirus detection in normal oral mucosa and oral lesions associated with the dysplastic progression of epithelium was reviewed to help define the role of this virus in the development of oral squamous cell carcinoma.

STUDY DESIGN

All available data from published studies were analyzed by chi-square test for association between the human papillomavirus and age, gender, race, DNA type, location, lesional dysplastic progression, method of detection, tissue preservation, and use of tobacco and alcohol.

RESULTS

Human papillomavirus was identified with increasing frequency in normal oral mucosa (13.5%), benign leukoplakia (14.8%), intraepithelial neoplasia (18.5%), squamous carcinoma (26.2%), and verrucous carcinoma (27%). It was detected in oral squamous cell carcinoma significantly (p < 0.005) more often (37.1%; 122 of 329) in studies that used a high sensitivity assay (polymerase chain reaction) than studies that used moderate sensitivity assays (25.2%; 84 of 334) (e.g., Southern blot hybridization) and low sensitivity assays (16.9%; 61 of 362) (e.g., immunohistochemistry, in situ hybridization). Human papillomavirus DNA was detected significantly more often (p < 0.001) in frozen oral squamous cell carcinoma (51.6%; 115 of 223) than paraffin-embedded tissue (21.7%; 136 of 628). High-risk human papillomaviruses (2, 16, 18) were detected in 81.4% of OSCCs that contained the virus compared with low-risk human papillomavirus genotypes (6, 11) in 17.9% of oral squamous cell carcinoma that contained the human papillomavirus (p < 0.001). In studies that analyzed the use of chemical cofactors, the use of tobacco and alcohol (87.3%) was associated more often with oral squamous cell carcinoma than the presence of human papillomavirus (51.3%), however, the difference was not significant.

CONCLUSION

High-risk human papillomavirus genotypes have a significant association with oral squamous cell carcinoma. However, the presence of this virus in a high proportion of oral normal mucosa makes the virus alone a poor prognosticator of progression to malignancy.

Decreasing p53 overexpression in sequential, recurrent, oral squamous cell carcinomas

Expression of abnormal p53 protein is a widely recognised marker of malignancy including oral squamous cell carcinoma. This is a longitudinal study of p53 expression in fixed, paraffin-embedded tissue from 3 patients with multiple, recurrent, squamous cell carcinomas of floor of mouth (n = 4, 4, 3). All carcinomas demonstrated increased expression of p53 compared to normal tissues. However, there was reduction in expression from primaries to subsequent recurrent tumours in all 3 patients. The significance of reduction of expression of p53 in sequential recurrences is unclear, but as each of these patients has now survived for at least 5 years this may be a phenomenon indicating a favourable prognosis. As this study relates to only 3 patients, a larger study is needed to confirm this initial observation.

A possible role for human papillomaviruses in head and neck cancer

Human papillomaviruses (HPVs) cause benign tumors in the respiratory tract. Mounting evidence suggests that they also play a role in the etiology of a subset of head and neck cancers. Carcinomas in patients with a history of recurrent respiratory papillomatosis clearly are caused by persisting HPV interacting with one of more carcinogenic agents. Verrucous carcinomas of the oral cavity, tonsillar and tongue carcinomas are strongly linked with HPVs, based on molecular epidemiologic data. Tonsillar cancer have been shown to express HPV RNA, presumed necessary to induce and maintain a carcinoma, supporting a viral etiology. This paper reviews the molecular and cellular basis for considering HPVs as causative agents of cancer, and reviews the literature that considers the possible role of HPVs in head and neck cancer.

Overexpression of p53 protein in squamous cell carcinoma of buccal mucosa and tongue in Taiwan: an immunohistochemical and clinicopathological study

Sixty squamous cell carcinomas of tongue and buccal mucosa were examined for expression of p53 protein by using an immunohistochemical technique improved by an antigen retrieval method. Twenty-seven (45%) tumors demonstrated strongly positive staining. Thirteen of p53-positive tumors (48%) also exhibited overexpression of p53 in immediately adjoining hyperplastic or pre-malignant epithelium. All 22 metastatic lymph nodes and 18 local recurrent lesions (except two) had an identical p53 immunophenotype to their corresponding primary sites. Mitotic indices were significantly higher in p53-positive tumors (P < 0.01); however, no association of PCNA scores with p53 expression was found (P > 0.1). There was no correlation between p53 overexpression and tumor grade, size and staging, vascular invasion, lymph node metastasis, and early local recurrence. Overexpression of p53 was found to be relatively higher, although not statistically significant, in nonsmokers than in heavy smokers (66.7% vs. 42.9%), and in nonbetel-quid chewers than in heavy chewers (62.5% vs. 34.2%). These data are consistent with the hypothesis that inactivation of p53 protein may occur in the early phases of oral tumorigenesis. It may not be a useful prognostic marker but could possibly be used for risk assessment and surveillance of local recurrence.

Human papillomaviruses in 91 oral cancers from Indian betel quid chewers--high prevalence and multiplicity of infections

India has one of the world's highest incidences of oral cancer. The habit of chewing betel quid is widespread and is suspected to play a role in the etiology of this disease. Studies in many other countries have also pointed to a role for human papilloma-viruses (HPVs) in the etiology of some oral cancers. In this study we analyzed biopsies from 91 Indian oral cancer patients, most of whom were betel quid chewers, by PCR amplification and direct DNA sequencing. HPV DNA was detected in 74% of these lesions, of which 41% had multiple HPV infections. Among the lesions from different oral sites, lesions of the tongue had the highest rate (9 of 11) of HPV infection. These HPV prevalences are among the highest ever reported in oral cancers. As to individual HPV types, prevalences of HPV-6, HPV-11, HPV-16 and HPV-18 were 13%, 20%, 42% and 47%, respectively. No additional known or novel HPV types were detected. To understand the unexpectedly high prevalences of the "low-risk" types HPV-6 and HPV-11, we compared the subtypes and variants that were found in oral cancers against those from benign genital warts from the same patient population but found no differences. The high prevalence of HPV in the oral cancers of these Indian patients suggests that viral infection is an important etiological component, with betel quid probably causing additional mutagenic steps in the carcinogenic process.