Human papillomavirus and risk of oral cancer

The role of human papillomavirus in oral carcinogenesis

Human papillomavirus (HPV) infection with high-risk types 16 and 18 has widely been reported as one of the prominent mechanisms behind the development of cervical squamous cell carcinoma. Links between HPV and oral cavity cancer have been suggested as well, based on epidemiologic and molecular means, though the association is less well-established. It is likely that HPV plays a role in oral cavity carcinogenesis, though only in a small subset of cases. The difficulty in providing true causal evidence of HPV's role in oral cancer lies in our lack of understanding of the significance of mechanisms by which HPV leads to oral carcinogenesis, as well as limitations in the molecular analysis of HPV. Further studies are necessary for the contribution of HPV in oral cavity malignancy to be better demonstrated.

Gender differences in sexual biomarkers and behaviors associated with human papillomavirus-16, -18, and -33 seroprevalence

BACKGROUND

The elevated risk for incident head and neck cancer among human papillomavirus (HPV)-16-seropositive individuals has substantiated a role for HPV in the etiology of head and neck cancers. The relationship between HPV seroreactivity and prevalent oral HPV infection in men and women without cancer has yet to be investigated.

GOAL

The goal of this study was to evaluate a possible association between oral HPV infection and HPV seroreactivity after adjustment for gender, sexual behaviors, and sexually transmitted disease.

STUDY DESIGN

A cross-sectional study of factors associated with HPV-16, -18, and -33 seroreactivity was performed in a population of 586 men and women with and without HIV infection. Antibodies in sera were measured by use of a virus-like protein (VLP)-based enzyme-linked immunosorbent assay. Exfoliated cells from the tonsillar and oral mucosa were analyzed for the presence of 38 mucosal HPV types by polymerase chain reaction.

RESULTS

Women had significantly greater seroreactivity for all HPV types investigated when compared with men (odds ratio, 4.3; 95% confidence interval, 3.0-6.0). Seroprevalence was greatest in men and women aged 35 to 45 years. Tonsillar HPV infection, oral sex with men, and HIV infection were independently associated with HPV seroreactivity in men after adjustment for age and number of sexual partners. In women, HSV-2 seropositivity and a history of sexually transmitted diseases were similarly important. Oral and tonsillar HPV infection were not associated with HPV seroreactivity in women.

CONCLUSION

HPV seropositivity is associated with sexually transmitted diseases among women and possibly mucosal HPV exposures in men. Tonsillar HPV infection could impact seroprevalence, particularly in men.

Human papillomavirus in oral exfoliated cells and risk of head and neck cancer

BACKGROUND

Human papillomavirus (HPV) has been associated with the development of head and neck cancers. In this study, we investigated whether the risk factors for head and neck cancer in relation to HPV infection are different from those in the absence of HPV infection and whether HPV detected in oral exfoliated cells is an independent predictor of head and neck cancer risk.

METHODS

We conducted a case-control study in 201 head and neck cancer case patients and 333 control subjects, frequency matched for age and sex. Oral exfoliated cells and tumor tissue were evaluated for HPV using polymerase chain reaction and DNA sequencing to type HPV. Logistic regression was used to calculate odds ratios (ORs) for head and neck cancer with HPV infection and 95% confidence intervals (CIs), adjusted for age, tobacco use, and alcohol consumption.

RESULTS

Oncogenic, or high-risk (HR), HPV types were detected in oral cells from 22.9% of case patients and 10.8% of control subjects. HPV16 was the most frequently detected type (19% versus 10% of case patients and control subjects, respectively). After adjusting for age, tobacco use, and alcohol consumption, the risk of head and neck cancer was statistically significantly greater in individuals with HPV-HR types (adjusted OR = 2.6, 95% CI = 1.5 to 4.2) but not in individuals with nononcogenic HPV types (adjusted OR = 0.8, 95% CI = 0.4 to 1.7) compared with HPV-negative individuals. Compared with individuals who were HPV-negative and did not use alcohol or tobacco, there was a statistically significant synergistic effect between detection of HPV-HR and heavy alcohol consumption (OR = 18.8, 95% CI = 5.1 to 69.5) but an additive effect between detection of HPV-HR and tobacco use (OR = 5.5, 95% CI = 2.1 to 14.1). HPV-HR types detected in oral exfoliated cells were predictive of HPV-HR types in tumor tissue.

CONCLUSION

Infection of oral exfoliated cells with HPV-HR types is a risk factor for head and neck cancer, independent of alcohol and tobacco use, and acts synergistically with alcohol consumption. HPV testing of an oral rinse may be predictive of an HPV-related head and neck cancer.

Age, sexual behavior and human papillomavirus infection in oral cavity and oropharyngeal cancers

There are few well-established patient risk factors associated with human papillomavirus (HPV) infection in cancers of the oral cavity and oropharynx. The purpose of this study was to determine if there were significant different risk factors and tumor characteristics between HPV-positive and HPV-negative cancer cases. HPV was evaluated in cancer tissue and exfoliated oral cells of 193 oral cavity/oropharynx cancer patients using PCR and direct DNA sequencing. A patient questionnaire collected information about risk factors, sexual practices and medical history. The prevalence of HPV high-risk (HR) types was 20% in cancer cases. Three types were identified: HPV-16 (87%), HPV-18 (3%) and HPV-33 (11%). Risk factors for HPV-HR included younger age (< or = 55 years vs. > 55 years; adjusted OR = 3.4; 95% CI = 1.6-7.3) and younger-age cases who had more lifetime sex partners (adjusted OR = 3.8; 95% CI = 1.4-10.1), practiced oral-genital sex (adjusted OR = 4.3; 95% CI = 1.8-10.4) or oral-anal sex (adjusted OR = 19.5; 95% CI = 3.4-113). Compared to HPV-negative cancers, HPV-HR cancers were more likely to have a positive HPV-HR exfoliated oral cytology test (adjusted OR = 7.8; 95% CI = 3.4-18.4), later stage (adjusted OR = 3.0), nodal involvement (adjusted OR = 4.1) and advanced grade (adjusted OR = 3.0). This study shows new evidence that the prevalence of oncogenic mucosal HPV is higher in younger-age oral cavity/oropharynx cancer cases whose sexual practices are typically associated with sexual transmission of the virus. HPV detection also appears to be an indicator of advanced disease characteristics that may require different clinical treatment for this subset of patients. An exfoliated oral cytology test for HPV was a significant predictor of HR types in the cancers, suggesting that an oral rinse may provide an early biomarker of infected tumors.

Human papillomavirus prevalence and types in newborns and parents: concordance and modes of transmission

BACKGROUND AND OBJECTIVES

The purpose of this investigation was to determine the risk of vertical and early contact transmission of human papillomavirus (HPV) in newborn infants based on concordance and sequence match to HPV types in parents.

STUDY DESIGN

The genitals of pregnant women and newborns and oral cavity of parents and newborns were analyzed using polymerase chain reaction and DNA sequencing. Data were collected about reproductive health and risk factors for HPV.

RESULTS

Only one mother/newborn and no father/newborn pair was concordant for an HPV type. All other infected newborns had uninfected or discordant type infected parents.

CONCLUSION

The risk of vertical transmission to the oral or genital region of newborns is rare, and transmission between parents and the hospitalized newborn does not appear to occur. Lack of parent/child concordance suggests that newborns detected with HPV in their oral cavity or genitals could have become infected by their mother at untested intervals during pregnancy or in newborns with infection in the oral cavity by other contacts after birth.

Identification of human papillomaviruses in tumors of the oral cavity in an Indian community

Oral cancers and other squamous cell cancers of the head and neck are common cancers in India, primarily due to tobacco chewing/smoking and alcohol consumption. Recent reports indicate involvement of human papillomavirus (HPV), HPV 16, in a subset of squamous cell carcinoma of head and neck (SCCHN) cases. To investigate the types of HPVs present in 83 oral cancers and 19 other head and neck tumors, degenerate primers directed to consensus regions in the HPV L1 open reading frame (ORF) were employed to amplify genomic DNA from tumor and when available, the adjacent normal mucosa. PCR-amplified products were cloned and sequenced. Similar studies were done on exfoliated buccal cells of 102 individuals visiting a dental hospital for dental complaints. HPV was detected in 32 out of 102 patients (31%), in either the tumor or the adjacent normal mucosa, while 5% (5/102) of the comparative group were found to be HPV-positive. Sequence analysis revealed a number of cutaneous HPVs, predominantly HPV types of the genus Beta-Papillomavirus, in the oral cavity. Multiple HPV infections were also commonly observed in patients (14/102; 14%). HPV 16 and 18 were each detected in 6 patients (6/102; 6%). Neither high-risk HPVs nor multiple infections were observed in the mouthwash samples of the comparative group. We report that the oral cavity harbors a variety of different HPVs. These viruses, in conjunction with the carcinogens present in tobacco could contribute to carcinogenesis.

Prevalence of human papillomavirus type 16 DNA in squamous cell carcinoma of the palatine tonsil, and not the oral cavity, in young patients: a distinct clinicopathologic and molecular disease entity

Squamous cell carcinoma of the head and neck commonly affects patients in their sixth decade and older, particularly those with a prolonged history of alcohol and tobacco abuse. Less frequently, carcinomas occur in young individuals even in the absence of known risk factors. The purpose of this study is to investigate a possible relationship between these tumors and human papilloma virus (HPV). Thirty-three cases of squamous cell carcinoma of the head and neck in young patients under the age of 40 years were studied: 15 oral, 11 tonsillar, and 7 laryngeal. HPV DNA was detected by polymerase chain reaction in 10 tonsillar and 2 laryngeal carcinomas and in none of the oral tumors. Of the 12 HPV-positive tumors, 11 were HPV16 and 1 was HPV31. HPV-positive tumors had a distinct nonkeratinizing basal cell morphology, they stained diffusely and strongly with p16 antibodies, had higher Ki-67 and lower p53 staining scores as compared with the conventional keratinizing HPV negative carcinomas. It is concluded that in young patients high-risk HPV, particularly HPV16, is strongly associated with tonsillar squamous cell carcinoma and some cases of laryngeal, but not oral, tumors. The HPV-positive carcinomas have a distinct histopathologic and immunophenotypic features.

Chapter 7: Human papillomavirus and cancer of the upper aerodigestive tract

We discuss current evidence of the role of human papillomavirus (HPV) in some cancers of the upper aerodigestive tract, including the oral cavity, the pharynx, and the larynx. Cancers of the oral cavity and the pharynx are associated mainly with tobacco and alcohol exposure, but there is evidence from case series, from case-control studies, and from cohort studies that HPV plays a role in a fraction of these cancers, particularly cancer in the oropharynx and tonsil. The HPV type most commonly associated with cancers in these locations is HPV 16. Laboratory evidence indicates that the virus is integrated and that HPV oncogenes are transcriptionally active in these tumors. Many aspects of the association remain to be investigated, including the epidemiology and natural history of HPV infection in the mouth, the role of cofactors, and the potential use of HPV testing and vaccines in the prevention of these tumors. An analogous role for the virus at other anatomic sites in the upper aerodigestive tract such as the larynx is less clear. The relationship between HPV infection and laryngeal cancer is of particular interest, given that recurrent respiratory papillomatosis is clearly caused by benign proliferative growths induced by HPV 6 or 11 infection of the laryngeal epithelium. Although HPV genomic DNA has been detected in a proportion of laryngeal cancers and despite the many efforts made during the last 15 years, there is not yet compelling evidence that HPV plays a substantial role in laryngeal cancer.

Squamous cell carcinoma of the head and neck in nonsmokers and nondrinkers: an analysis of clinicopathologic characteristics and treatment outcomes

BACKGROUND

The objective of this study was to describe the clinicopathologic manifestations of disease and outcomes of treatment among individuals without a history of smoking tobacco or consuming alcohol who develop head and neck cancer.

METHODS

Of 1648 invasive head and neck cancer cases treated between 1970 and 2001 at Roswell Park Cancer Institute, 40 patients were identified as never having smoked tobacco or consumed alcohol during their lifetime. These cases were reviewed to gather data on multiple clinicopathologic variables.

RESULTS

Mean age at presentation of nonsmoker/nondrinker head and neck cancer patients was 60 years (range, 27 to 90 years), and 78% (n = 31) of the patients were women. The distributions of tumor sites were 75.0% oral cavity (n = 30), 20.0% oropharynx (n = 8), and 5.0% larynx (n = 2). Sixteen patients (40%) experienced a recurrence of disease during the follow-up period, and 10 patients (25.0%) developed a second primary tumor a median of 6 years after their initial diagnosis.

CONCLUSIONS

The nonsmoker/nondrinker head and neck cancer patient tends to be elderly and female, have oral cavity primary tumors, and be predisposed to second primary tumor development.

Human papillomavirus infection as a prognostic factor in carcinomas of the oral cavity and oropharynx

Although studies have established human papillomaviruses (HPVs) as a risk factor for oral and oropharyngeal cancer, it is not clear whether viral infection affects survival in head and neck malignancies. This investigation examined the relationship between HPV and survival in carcinomas of the oral cavity and oropharynx. Formalin-fixed, paraffin-embedded tumor specimens from 139 newly diagnosed cases were tested for HPVs by PCR and DNA sequencing. Patient and tumor characteristics were obtained from questionnaires, pathology reports and cancer registries. Odds ratios (ORs) and relative risks (RRs) were based on logistic and Cox regression models, respectively. HPVs were detected in 21% of the tumors; 83% were HPV-16. Greater risk of HPV infection was associated with males (OR = 2.9, 95% CI = 1.0-8.6), a history of oral-genital sex (OR = 4.2, 95% CI = 1.5-11.7), and oropharyngeal tumors (OR = 10.4, 95% CI = 3.5-31.2). As tobacco usage increased, the odds of HPV detection decreased (OR = 0.97/pack-year, 95% CI = 0.96-0.99). HPV infected patients had better overall survival (RR = 0.3, 95% CI = 0.1-0.8) than those with HPV-negative tumors. There was an interaction between gender and HPV for overall (p = 0.05) and disease-specific (p = 0.03) survival that suggested that HPV infected males had better prognosis than HPV-negative males, but this was not the case among females. HPV status was identified as an independent prognostic factor in oral and oropharyngeal cancers. This result appeared to be gender-specific, suggesting the need for further study of the interaction between HPV and gender on survival.

Expression of p16 protein identifies a distinct entity of tonsillar carcinomas associated with human papillomavirus

Recent analyses of head and neck squamous cell carcinomas revealed frequent infections by oncogenic human papillomavirus (HPV) type 16 in tonsillar carcinomas. Concerning involvement of risk factors, clinical course of the disease, and prognosis there are strong indications arguing that the HPV-positive tonsillar carcinomas may represent a separate tumor entity. Looking for a surrogate marker, which in further epidemiological studies could replace the laborious and expensive HPV detection and typing we analyzed p16 protein expression in 34 tonsillar carcinoma for correlation to HPV status and load of viral DNA. p16 has been shown to be of diagnostic value for clinical evaluation of cervical dysplasia. We found 53% of the tested tonsillar carcinomas to be HPV-positive. Fifty-six percent of all tumors tested were immunohistochemically positive for the p16 protein. In 16 of 18 of the HPV-positive carcinomas diffuse p16 expression was observed. In contrast, only one of the HPV-negative carcinomas showed focal p16 staining (P < 0.001). As determined by laser-assisted microdissection and quantitative real-time polymerase chain reaction, p16 expression correlated with the presence of HPV-DNA in the individual tumor specimens. Clinical outcome analysis revealed significant correlation of p16 expression with increased disease-free survival (P = 0.02). These data indicate that p16 is a technically simple immunohistological marker, applicable for routine pathological histology, and its prognostic value for survival is fully equivalent to HPV-DNA detection.

Genetic susceptibility--molecular epidemiology of head and neck cancer

In parts of the developing world (South Central Asia in particular), squamous cell carcinoma of the head and neck (SCCHN) is one of the most common malignancies encountered. Although tobacco and alcohol are clearly defined as etiologic factors in these malignancies, clinical observations have suggested that inherited genetic factors put some individuals at increased risk for SCCHN. Emerging data (both phenotypic and genotypic) support this concept of genetic susceptibility to SCCHN and point to differences in DNA repair ability, carcinogen metabolism, and cell cycle control as the systems important to the risk of tobacco-induced malignancies. The ability to identify such high-risk individuals will have major influences on the practice of cancer prevention in the future.

Oral squamous cell carcinoma; from an hypothesis about a virus, to concern about possible sexual transmission

Nearly two decades ago, we produced the first evidence for the presence of viral nucleic acids in oral squamous cell carcinoma (OSCC) tissues, hypothesising that there may be a viral involvement in at least some OSCC. Subsequently, human papillomaviruses (HPV) in particular have been implicated in OSCC. Antibody responses to HPV are seen and HPV-DNA detected in tumors by us and many others, the virus being mainly HPV-16, the genotype associated with ano-genital cancer. HPV are seen by in situ hybridisation only in tumour and premalignant tissue but not in surrounding normal mucosa suggesting HPV has a causal relationship. HPV may also be integrated in the host genome, further suggesting a causal role. Studies of patients with OSCC have suggested possible sexual transmission of HPV. Recent studies have indicated that HPV may be aetiologically important particularly in some types of oropharyngeal cancer, at least in tonsillar carcinogenesis, and may represent an alternative pathway in carcinogenesis to the established factors of tobacco and alcohol. We have come a very long way in the two decades since our first suggestion of a viral aetiopathogenesis was greeted with incredulity, and data from on-going studies by the International Agency for Research on Cancer, Johns Hopkins Oncology Center and others are eagerly awaited.

Prevalence, distribution, and viral load of human papillomavirus 16 DNA in tonsillar carcinomas

BACKGROUND

Oncogenic human papillomaviruses (HPV) DNA have repeatedly been observed in many head and neck carcinomas (HNSCCs), and HPV infections are currently considered a possible factor in the etiology of these tumors. However, the reported prevalences of HPV-DNA in HNSCC are variable. In the current study the authors used highly sensitive polymerase chain reactions (PCRs) to analyze the occurrence of viral sequences in 98 carefully stratified HNSCCs. The authors determined the load and localization of HPV DNA in a subset of tonsillar carcinomas and their metastases.

METHODS

Nested PCR and an HPV16 specific single step PCR were used to screen 98 HNSCCs for HPV DNA for genital- and Epidermodysplasia verruciformis (EV)-associated HPVs. Typing was performed by direct sequencing and/or sequencing of cloned amplimers. In two patients HPV16 subtypes in tonsillar carcinomas and their metastases were compared by amplification and sequencing of the long control region of the virus. In a subset of HPV16 positive tonsillar carcinomas and their metastases, localization and viral load were determined using laser assisted microdissection and real time fluorescent PCR, respectively.

RESULTS

Altogether 25 HNSCCs (26%) were found to be HPV positive. Stratified according to the tumor localization, the frequency of HPV positive lesions was 18% in the oral cavity, 45% for oropharynx, 25% for hypopharynx, 8% for nasopharynx, and 7% for larynx. The highest HPV DNA prevalence (58%) was found in tonsillar carcinomas. The high risk HPV type 16 was found in 84% of positive HNSCCs, in 14% of which EV-associated HPVs were detected. Human papillomavirus sequences were detected in 64% of biopsies with normal mucosa from 11 patients with positive carcinomas. As a control group, 14 tumor free tonsils were analyzed. In none of these specimens were HPV sequences detected. Viral long transcriptional control region sequences in homologous metastases were identical with those in primary tumors and the load values in both locations were roughly comparable. Viral loads differed substantially in different areas of one tumor. Statistical evaluation of data related to clinicopathologic parameters showed a significant linkage of HPV with tonsillar carcinomas compared to other locations. Furthermore, a significant correlation of HPV status of tonsillar carcinomas with tumor grading and alcohol consumption was found.

CONCLUSIONS

Our study shows a preferential association of HPV-DNA with tonsillar carcinomas. The data support the view of HPV negative and positive tonsillar carcinomas being different tumor entities and conventional cancer risk factors being of less importance in HPV-infected individuals. The HPV genome is located in the cancer cells, whereas the infection of normal mucosa is a rare event. Data on quantification of HPV16 in tonsillar tumors and their metastases showed mean viral loads comparable to other HPV associated malignancies.

Human papillomavirus infection and survival in oral squamous cell cancer: a population-based study

OBJECTIVE

To determine whether human papillomavirus (HPV) type 16 affects survival in oral squamous cell carcinoma.

STUDY DESIGN

Two hundred fifty-four patients diagnosed with primary oral cancer were studied for survival in relation to tumor HPV type 16 status. Kaplan-Meier analysis and Cox proportional hazard models were used to assess survival and estimate hazard ratios adjusted for potential confounders.

RESULTS

HPV type 16 DNA was detected in 15.1% of tumors. HPV 16 positive patients had significantly reduced all-cause mortality (hazard ratio [HR] estimates = 0.34, 95% CI = 0.14, 0.83) and disease-specific mortality (HR = 0.17, 95% CI = 0.04, 0.76) compared with HPV 16 negative patients after adjustment for age, stage, treatment, smoking, alcohol, education, and comorbid disease.

CONCLUSIONS

The presence of HPV type 16 DNA is independently associated with a favorable prognosis in patients with oral squamous cell carcinoma.

CLINICAL SIGNIFICANCE

Although HPV genotyping is currently not widely available, it may provide important prognostic information.

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.

Human papillomavirus infection as a risk factor for squamous-cell carcinoma of the head and neck

BACKGROUND

Oncogenic human papillomaviruses (HPVs), especially HPV type 16 (HPV-16), cause anogenital epithelial cancers and are suspected of causing epithelial cancers of the head and neck.

METHODS

To examine the relation between head and neck cancers and HPVs, we performed a nested case-control study within a joint Nordic cohort in which serum samples were collected from almost 900,000 subjects. Samples collected at enrollment from 292 persons in whom squamous-cell carcinoma of the head and neck developed, on average, 9.4 years after enrollment and from 1568 matched controls were analyzed for antibodies against HPV-16, HPV-18, HPV-33, and HPV-73 and for cotinine levels as a marker of smoking habits. Polymerase-chain-reaction (PCR) analyses for HPV DNA were performed in tumor tissue from 160 of the study patients with cancer.

RESULTS

After adjustment for cotinine levels, the odds ratio for squamous-cell carcinoma of the head and neck in subjects who were seropositive for HPV-16 was 2.2 (95 percent confidence interval, 1.4 to 3.4). No increased risk was observed for other HPV types. Fifty percent of oropharyngeal and 14 percent of tongue cancers contained HPV-16 DNA, according to PCR analysis.

CONCLUSIONS

HPV-16 infection may be a risk factor for squamous-cell carcinoma of the head and neck.

Human papillomavirus in the oral cavities of children and adolescents

OBJECTIVE

The purpose of this pilot study was to determine the frequency of human papillomavirus (HPV) in the oral cavities of children and adolescents and to identify potential risk factors for HPV infection.

STUDY DESIGN

Sociodemographic information was obtained on 268 healthy infants, children, and adolescents who were < or = 20 years old. Oral squamous cells were collected from swabs with young children and from oral saline solution rinses with older children and adolescents. Extracted DNA was evaluated for HPV by polymerase chain reaction, dot blot hybridization, and DNA sequencing. Factors associated with the presence of HPV were tested by using chi(2), Fisher's exact test, and logistic regression tests.

RESULTS

HPV was detected in 6.0% of the participants. HPV frequency among young children (<7 years old) was 8.7% (11/127), and among adolescents (13-20 years old) it was 5.2% (5/97). HPV was not detected in children aged 7 to 12 years old (0/44). Fifty-four percent (6/11) of HPV-positive children were 1 year of age or less; 3 of the HPV-positive children (<7 years old) were delivered by cesarean section. No statistically significant association was found between the detection of HPV in the oral cavity and method of delivery or gender; parent's race, education, HPV-related conditions, smoking history, or number of sex partners; or adolescent's smoking history or history of sexual activity.

CONCLUSIONS

This study suggests that HPV is present in the oral cavity primarily in children 2 years old and younger and in adolescents 13 years and older. Cesarean delivery was not protective against oral HPV infection; in fact, half of the HPV-positive infants were born by cesarean delivery.

Genetic alterations in head and neck cancer: interactions among environmental carcinogens, cell cycle control, and host DNA repair

Head and neck squamous cell carcinomas (HNSCC) arise as a consequence of cumulative genetic changes brought about by continued exposure to carcinogens associated with tobacco and alcohol use, influenced by viral agents such as human papillomaviruses, in a background of acquired or heritable genetic susceptibility. The presence of widespread genomic instability in HNSCC, such as cytogenetic aberrations, allelic imbalance/loss of heterozygosity, and microsatellite instability, suggests that there is an imperfection in the host DNA repair machinery. Genomic instability with progressive accumulation of detrimental genetic alterations appears to be dependent upon a circuitous interaction between the environmental genotoxic insults and the host DNA repair machinery, the functional integrity of which is governed by the proper cell cycle control and host DNA repair capacity. Thus, it can be hypothesized that continued exposure to environmental carcinogens (ie, longstanding history of smoking and drinking), loss of proper cell cycle control (eg, inactivation of p53 or p16 tumor suppressor genes or amplification of the proto-oncongene cyclin D1), and impaired DNA repair capacity (both inherited and acquired) are prerequisites in head and neck carcinogenesis.

Human papillomavirus and risk of laryngeal cancer

We determined the relationship between human papillomavirus (HPV) infection and the HPV types detected in 44 patients with squamous cell carcinoma, 10 laryngeal leukoplakia patients, and 12 patients evaluated for benign laryngeal conditions (controls). The sources of HPV DNA were from brushings from the upper respiratory tract and lesion (benign or malignant), oral rinses, and biopsies of patient lesions. Polymerase chain reaction (PCR) and DNA sequencing were used to identify and type HPV. We detected HPV in 25.0% (11/44) of patients with laryngeal cancer, in 30.0% (3/10) of patients with laryngeal leukoplakia, and in 16.7% (2/12) of noncancer controls. Patients with cancer were not more likely to be identified with oncogenic HPV types ( 18.2%) than either the leukoplakia group (20%) or the control group (16.7%). An increased risk of disease was associated with current tobacco use and former alcohol drinking in cancer patients versus controls and in leukoplakia patients versus controls (all p < .05). After we controlled for tobacco and alcohol effects on the risk of disease, exposure to oncogenic HPV types was associated with an increased risk of laryngeal cancer (odds ratio = 3.0) and of laryngeal leukoplakia (odds ratio = 6.0) compared to controls, although the results were not statistically significant. This study suggests that although HPV infection and HPV oncogenic types are not found at a higher frequency in laryngeal cancer or laryngeal leukoplakia as compared to controls, infection is associated with an increased risk of disease after controlling for the effects of alcohol and tobacco use.

p53 polymorphism, human papillomavirus infection in the oral cavity, and oral cancer

OBJECTIVES

Human papillomavirus (HPV) infection has emerged as a risk factor in oral carcinogenesis. An arginine-coding polymorphism of the tumor suppressor protein p53 at codon 72 is more readily degraded by the HPV oncoprotein E6. Our objective was to evaluate the association between p53 polymorphism at codon 72 and HPV infection in the oral cavity, as well as its association with oral cancer.

STUDY DESIGN

Oral squamous cells from 202 patients with oral cancer and 333 age-sex frequency matched controls were evaluated by polymerase chain reaction for the presence and type of HPV and for alleles of codon 72 in p53. Fisher exact test and chi(2) tests were used to evaluate the data.

RESULTS

The p53 codon 72 polymorphism is not associated with HPV infection, whether comparing HPV-negative controls with HPV-positive controls or comparing HPV-negative cases with HPV-positive cases. Additionally, we found no association with the codon 72 polymorphism and oral cancer, whether comparing HPV-negative controls with HPV-negative cases or comparing HPV-positive controls with HPV-positive cases.

CONCLUSIONS

There is no association between p53 codon 72 polymorphism and HPV infection or between the p53 polymorphism and the risk of oral cancer.

Cancer of the tongue in patients less than forty

INTRODUCTION

It is the opinion of many surgeons that the biologic potential of cancer that develops in young people is different compared with older patients. Prior reports on small series of patients addressing this issue have inadequate statistical power to resolve the question.

METHODS

By use of the techniques of meta-analysis, patients less than 40 years old who had undergone treatment of squamous cell carcinoma (SCC) of the oral tongue were examined. Twenty-eight patients who were encountered in the Department of Otolaryngology, University of Pittsburgh School of Medicine, and 94 patients were identified in the literature for a total of 122 patients <40 years old. A control group of 150 patients, aged 40 years and older treated for SCC of the oral tongue between 1982 and 1994 was identified.

RESULTS

Three-year disease-free survival in the group of patients aged less than 40 was 53.3% compared with 3-year disease free survivorship of 55.0% in the older cohort of patients.

CONCLUSION

These data strongly suggest that the outcomes of treatment for SCC of the oral tongue in young patients are similar compared with patients older than 40 with similar extent of disease.

Oral infections and other manifestations of HIV disease

Oral lesions are important in the clinical spectrum of HIV/AIDS, arousing suspicion of acute seroconversion illness (aphthous ulceration and candidiasis), suggesting HIV infection in the undiagnosed individual (candidiasis, hairy leukoplakia, Kaposi's sarcoma, necrotizing ulcerative gingivitis), indicating clinical disease progression and predicting development of AIDS (candidiasis, hairy leukoplakia), and marking immune suppression in HIV-infected individuals (candidiasis, hairy leukoplakia, necrotizing periodontal disease, Kaposi's sarcoma, long-standing herpes infection, major aphthous ulcers). In addition, oral lesions are included in staging systems for HIV disease progression and as entry criteria or endpoints in clinical trials of antiretroviral drugs. Recognition and management of these oral conditions is important for the health and quality of life of the individual with HIV/AIDS. In keeping with this, the U.S. Department of Health Services Clinical Practice Guideline for Evaluation and Management of Early HIV Infection includes recommendations that an oral examination, emphasizing oral mucosal surfaces, be conducted by the primary care provider at each visit, a dental examination by a dentist should be done at least two times a year, and patients should be informed of the importance of oral care and educated about common HIV-related oral lesions and associated symptoms.

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.