Chapter 9: Role of mucosal human papillomavirus in nongenital cancers

The combined influence of oral contraceptives and human papillomavirus virus on cutaneous squamous cell carcinoma

The vast majority of cutaneous squamous cell carcinoma (CSCC) will occur in those with fair complexion, tendency to burn, and high ultraviolet radiation (UVR) exposure. Organ transplant recipients also are an important population at great risk for CSCC. An association has been reported between oral contraceptive (OC) use, human papillomavirus virus (HPV) and cervical cancer, and there could be a similar association for CSCC. The cutaneous HPV β-E6 protein, a close cousin of the transformative E6 protein underlying anogenital cancers, has been shown to inhibit apoptosis in response to UVR damage and stimulate morphologic transformation in rodent fibroblast cell lines. Furthermore, OC use has been shown to enhance HPV transcription and may contribute to CSCC risk through this pathway.

Cellular expression of INK4a gene in cells of bladder cancer associated with human papilloma virus-16

Hyperexpression of p16(INK4a) protein is an early marker of cervical cancer. Hyperexpression of INK4a gene encoding this protein at the level of mRNA and p16(INK4a) was detected in tumor cells of some patients with bladder cancer associated with human papilloma virus-16. However, in contrast to cervical cancer, this phenomenon in urothelial carcinomas does not correlate with expression of human papilloma virus-16 oncogenes E6 and E7.

Low prevalence of HPV in Brazilian children with retinoblastoma

Retinoblastoma is the most frequent intra-ocular malignant tumor of the childhood, occurring in 1 of 18,000-30,000 live births. Little is known about the causes of sporadic retinoblastoma and only a few authors have investigated the etiologic role of human papillomavirus (HPV), with controversial results. Formalin-fixed, paraffin-embedded tissue blocks containing retinoblastoma were retrieved from the archives of the Department of Pathology at Hospital A C Camargo, São Paulo, Brazil. All patients were treated with enucleation (21 children had both eyes enucleated). Retinoblastoma and, when possible, normal retina of each specimen, were micro-dissected under direct light microscopic visualization by using a PixCell II Laser Capture Micro-dissection System. The DNA quality was evaluated by polymerase chain reaction (PCR) amplification of 110 base pairs fragment of the human β-globin gene using primers PCO3+/PCO4+. All globin positive specimens were analyzed by PCR for the presence of HPV DNA using consensus primers GP5+/GP6+. A total of 154 specimens were evaluated. Forty-four patients also had normal retinal specimens available for analysis of DNA HPV. The DNA HPV prevalence among all tumor specimens was 4.6% (95% CI 2.0; 8.8) (7 positive specimens/153 adequate specimens). Among normal retinal specimens, the DNA HPV prevalence was 9.1% (95% CI 2.9; 20.5) (4 positive specimens/44 specimens). There was no statistically significant difference between these rates (P = 0.318). Excluding any experimental failure, our results indicate a low prevalence of HPV DNA in retinoblastomas. We were therefore unable to conclude about the association between these oncogenic viruses and this rare pediatric neoplasm.

Assessment of human papillomavirus in lung tumor tissue

Background

Lung cancer kills more than 1 million people worldwide each year. Whereas several human papillomavirus (HPV)–associated cancers have been identified, the role of HPV in lung carcinogenesis remains controversial.

Methods

We selected 450 lung cancer patients from an Italian population–based case–control study, the Environment and Genetics in Lung Cancer Etiology. These patients were selected from those with an adequate number of unstained tissue sections and included all those who had never smoked and a random sample of the remaining patients. We used real-time polymerase chain reaction (PCR) to test specimens from these patients for HPV DNA, specifically for E6 gene sequences from HPV16 and E7 gene sequences from HPV18. We also tested a subset of 92 specimens from all never-smokers and a random selection of smokers for additional HPV types by a PCR-based test for at least 54 mucosal HPV genotypes. DNA was extracted from ethanol- or formalin-fixed paraffin-embedded tumor tissue under strict PCR clean conditions. The prevalence of HPV in tumor tissue was investigated.

Results

Specimens from 399 of 450 patients had adequate DNA for analysis. Most patients were current (220 patients or 48.9%) smokers, and 92 patients (20.4%) were women. When HPV16 and HPV18 type–specific primers were used, two specimens were positive for HPV16 at low copy number but were negative on additional type-specific HPV16 testing. Neither these specimens nor the others examined for a broad range of HPV types were positive for any HPV type.

Conclusions

When DNA contamination was avoided and state-of-the-art highly sensitive HPV DNA detection assays were used, we found no evidence that HPV was associated with lung cancer in a representative Western population. Our results provide the strongest evidence to date to rule out a role for HPV in lung carcinogenesis in Western populations.

Meta-analysis of human papillomavirus infection concordance

BACKGROUND

Estimates of human papillomavirus (HPV) concordance among sexual partners are important for various public health activities, from counseling individual patients to predicting the effect of HPV vaccination.

METHODS

We systematically searched the PubMed and EMBASE databases for studies of HPV concordance among heterosexual couples published through 2008 in English. Two coders independently abstracted data using standardized forms. We integrated concordance data using random-effects meta-analysis.

RESULTS

Thirty studies (33 study populations) that met inclusion criteria reported concordance data for 2,972 couples. Most studies were cross-sectional cohort studies conducted in Europe or Asia that used DNA hybridization to test for HPV, sometimes in conjunction with PCR. Overall, 25.5% (95% confidence interval, 17.2-36.1%) of couples were infected with 1 or more of the same HPV types. Among couples with both members HPV-positive, 63.2% (95% confidence interval, 49.1-75.3%) were infected with 1 or more of the same viral types. Positive concordance was higher for female partners of men with HPV infections than for male partners of women with HPV infections. Positive concordance was also higher for studies using PCR and for the few studies that recruited men with HPV-related disease.

CONCLUSIONS

Sexual partners of HPV-infected individuals had high rates of HPV infection, suggesting a need for increased attention to this group.

IMPACT

Our refined estimates of HPV concordance can inform clinical encounters and public health planning. Future HPV concordance studies should use more rigorous research designs, characterize their participants in greater detail, and study more meaningful populations.

Joint disease mapping of cervical and male oropharyngeal cancer incidence in blacks and whites in South Carolina

Human papillomavirus (HPV) infection is an established causal agent for cervical cancer and a subset of oropharyngeal cancers. It is hypothesized that orogenital transmission results in oral cavity infection. In this paper we explore the geographical association between cervical and male oropharyngeal cancer incidence in blacks and whites in South Carolina using Bayesian joint disease mapping models fit to publicly available data. Our results suggest weak evidence for county-level association between the diseases, and different patterns of joint disease behavior for blacks and whites.

No role for human papillomavirus in esophageal squamous cell carcinoma in China

Certain regions of China have high rates of esophageal squamous cell carcinoma (ESCC). Previous studies of human papillomavirus (HPV), a proposed causal factor, have produced highly variable results. We attempted to evaluate HPV and ESCC more definitively using extreme care to prevent DNA contamination. We collected tissue and serum in China from 272 histopathologically-confirmed ESCC cases with rigorous attention to good molecular biology technique. We tested for HPV DNA in fresh-frozen tumor tissue using PCR with PGMY L1 consensus primers and HPV16 and 18 type-specific E6 and E7 primers, and in formalin-fixed paraffin-embedded tumor tissue using SPF(10) L1 primers. In HPV-positive cases, we evaluated p16(INK4a) overexpression and HPV E6/E7 seropositivity as evidence of carcinogenic HPV activity. beta-globin, and thus DNA, was adequate in 98.2% of the frozen tumor tissues (267/272). Of these, 99.6% (95% confidence interval (CI) = 97.9-100.0%) were negative for HPV DNA by PGMY, and 100% (95% CI = 98.6-100%) were negative by HPV16/18 E6/E7 PCR. In the corresponding formalin-fixed paraffin-embedded tumor specimens, 99.3% (95% CI = 97.3-99.9%) were HPV negative by SPF(10). By PGMY, 1 case tested weakly positive for HPV89, a noncancer causing HPV type. By SPF(10), 2 cases tested weakly positive: 1 for HPV16 and 1 for HPV31. No HPV DNA-positive case had evidence of HPV oncogene activity as measured by p16(INK4a) overexpression or E6/E7 seropositivity. This study provides the most definitive evidence to date that HPV is not involved in ESCC carcinogenesis in China. HPV DNA contamination cannot be ruled out as an explanation for high HPV prevalence in ESCC tissue studies with less stringent tissue procurement and processing protocols.

Beyond cervical cancer: burden of other HPV-related cancers among men and women

Human papillomavirus (HPV) infection is a necessary cause of cervical cancer, and is etiologically associated with a subset of cancers of the anus, oropharynx, penis, vagina, and vulva. Current data indicate that HPV infection is potentially associated with 90%-93% of anal cancers, 12%-63% of oropharyngeal cancers, 36%-40% of penile cancers, 40%-64% of vaginal cancers, and 40%-51% of vulvar cancers. HPV infection accounts for up to 492,800 cervical cancers and 97,215 cases of noncervical HPV-related cancers worldwide during 2002, including up to 50,780 cancers among men (13,485 anal cancers, 26,775 oropharyngeal cancers, and 10,520 penile cancers) and up to 46,435 cancers among women (14,787 anal cancers, 6,048 oropharyngeal cancers, and 25,600 vaginal/vulvar cancers). In the United States annually (1998-2003), up to 10,846 cervical cancers, 4,753 noncervical cancers among men, and 4,128 noncervical cancers among women are potentially attributable to HPV infection. Incidence rates for cervical cancer have declined significantly during the past 30 years in the United States, consistent with the success of Pap smear screening. However, incidence rates for anal, oropharyngeal, and vulvar cancers have increased substantially in recent years. The high proportion of cervical and noncervical cancers caused by HPV types 16 and 18, that is, 70%-76% for cervical cancers and 63%-95% for noncervical cancers, underscores the potential for prevention of a majority of cervical as well as noncervical HPV-related cancers through prophylactic HPV vaccination.

Human papilloma virus and female lung adenocarcinoma

Lung cancer is the leading cause of cancer among women worldwide, and adenocarcinoma is the most common histological subtype among non-smoking women. Previous studies showed that human papillomavirus (HPV) infection may relate to the tumorigenesis of pulmonary adenocarcinoma. Women with anogenital malignancy have a higher risk of lung cancer, which raises the possibility of HPV transmission from the cervix to the lung. Two postulated pathways are discussed in this work. First, HPV may infect the female cervix and then move to the lung by blood circulation. The second transmission route is the HPV infection of oral cavity resulting from dangerous sexual contacts, and subsequently transmitted to the lung. This chapter also reviews the techniques for detecting the existence, subtypes, and viral load of HPV. Future studies are needed to demonstrate the causal inference between HPV infection and the risk of female lung adenocarcinoma.

Increased expression of cellular retinol-binding protein 1 in laryngeal squamous cell carcinoma

PURPOSE

To investigate the genomic alterations in larynx carcinomas (LaCa) tissues and its prognostics values in predicting survival.

METHODS

To analyse the aberrations in the genome of LaCa patients, we used array comparative genomic hybridization in 19 human laryngeal tumour samples. DNA samples were also subjected to detect human papillomavirus (HPV) sequences by polymerase chain reaction (PCR). Copy number gain was confirmed by real-time PCR. The cellular retinol-binding protein 1 (CRBP-1) gene expression was also confirmed by immunohistochemistry assay on LaCa tissues. To identify prognostic feature, CRBP-1 gene gain was correlated to patient survival.

RESULTS

The most common gains were detected for CRBP-1 and EGFR genes, while DNA lost in RAF-1 gene. Immunohistochemistry assay was revealed strong expression of CRBP1 protein in those cases with CRBP-1 gene gain. The CRBP-1 gene gain and its expression correlated significantly with survival (P = 0.003). Cox regression analysis indicated that CRBP-1 expression level was a factor of survival (P = 0.008). HPV sequences were detected in 42% of the samples, and did not show any relationship with specific gene alterations.

CONCLUSION

Our data shows that CRBP-1 gene gain can be determined by immunohistochemistry on routinely processed tissue specimens, and could support as a potential novel marker for long-term survival in laryngeal squamous cell carcinoma.

Human papillomavirus and p16 expression in inverted papillomas of the urinary bladder

Human Papillomaviruses (HPVs) have been found in association with benign and malignant growth of epithelia. The cell cycle inhibitor p16(Ink4a) has been shown to be overexpressed in HPV-positive cervical pre-malignant and malignant lesions, probably as a result of pRB targeting by the viral E7 protein. Inverted papillomas of the urinary bladder are epithelial tumors considered to be of benign nature. In this report we analyze the expression of p16(Ink4a) and the presence of HPV sequences in inverted papillomas and in non-tumoral bladder controls. Our results show no association of HPV infection and inverted papillomas. Further, no correlation between p16 overexpression and HPV positivity was found. We conclude that HPV does not play an indispensable role in the development of urinary bladder inverted papillomas and that overexpression of p16(Ink4a) does not correlate with HPV infection in these tumors.

Risk of human papillomavirus-associated cancers among persons with AIDS

BACKGROUND

Although risk of human papillomavirus (HPV)-associated cancers of the anus, cervix, oropharynx, penis, vagina, and vulva is increased among persons with AIDS, the etiologic role of immunosuppression is unclear and incidence trends for these cancers over time, particularly after the introduction of highly active antiretroviral therapy in 1996, are not well described.

METHODS

Data on 499 230 individuals diagnosed with AIDS from January 1, 1980, through December 31, 2004, were linked with cancer registries in 15 US regions. Risk of in situ and invasive HPV-associated cancers, compared with that in the general population, was measured by use of standardized incidence ratios (SIRs) and 95% confidence intervals (CIs). We evaluated the relationship of immunosuppression with incidence during the period of 4-60 months after AIDS onset by use of CD4 T-cell counts measured at AIDS onset. Incidence during the 4-60 months after AIDS onset was compared across three periods (1980-1989, 1990-1995, and 1996-2004). All statistical tests were two-sided.

RESULTS

Among persons with AIDS, we observed statistically significantly elevated risk of all HPV-associated in situ (SIRs ranged from 8.9, 95% CI = 8.0 to 9.9, for cervical cancer to 68.6, 95% CI = 59.7 to 78.4, for anal cancer among men) and invasive (SIRs ranged from 1.6, 95% CI = 1.2 to 2.1, for oropharyngeal cancer to 34.6, 95% CI = 30.8 to 38.8, for anal cancer among men) cancers. During 1996-2004, low CD4 T-cell count was associated with statistically significantly increased risk of invasive anal cancer among men (relative risk [RR] per decline of 100 CD4 T cells per cubic millimeter = 1.34, 95% CI = 1.08 to 1.66, P = .006) and non-statistically significantly increased risk of in situ vagina or vulva cancer (RR = 1.52, 95% CI = 0.99 to 2.35, P = .055) and of invasive cervical cancer (RR = 1.32, 95% CI = 0.96 to 1.80, P = .077). Among men, incidence (per 100 000 person-years) of in situ and invasive anal cancer was statistically significantly higher during 1996-2004 than during 1990-1995 (61% increase for in situ cancers, 18.3 cases vs 29.5 cases, respectively; RR = 1.71, 95% CI = 1.24 to 2.35, P < .001; and 104% increase for invasive cancers, 20.7 cases vs 42.3 cases, respectively; RR = 2.03, 95% CI = 1.54 to 2.68, P < .001). Incidence of other cancers was stable over time.

CONCLUSIONS

Risk of HPV-associated cancers was elevated among persons with AIDS and increased with increasing immunosuppression. The increasing incidence for anal cancer during 1996-2004 indicates that prolonged survival may be associated with increased risk of certain HPV-associated cancers.

Human papilloma virus and esophageal carcinoma in a Latin-American region

AIM: To investigate the presence of high-risk human papilloma virus (HPV) in esophageal squamous cell carcinomas (ESCCs) in a non-selected Mexican population.

METHODS: Cases with a pathological diagnosis of squamous cell carcinoma of the esophagus were obtained from Department of Pathology files, at the National Cancer Institute in Mexico City during the period between 2000 and 2008. Slides from each case were reviewed and cases with sufficient neoplastic tissue were selected for molecular analysis. DNA was extracted from paraffin-embedded tissue samples for polymerase chain reaction analysis to detect HPV DNA sequences. Demographic and clinical data of each patient were retrieved from corresponding clinical records.

RESULTS: HPV was detected in 15 (25%) of ESCCs. HPV-16 was the most frequently observed genotype, followed by HPV-18; HPV-59 was also detected in one case. Unfortunately, HPV genotype could not be established in three cases due to lack of material for direct sequencing, although universal primers detected the presence of HPV generic sequences. No low-risk HPV genotypes were found nor was HPV-16/18 co-infection. HPV presence in ESCC was not significantly associated with gender, age, alcohol consumption, smoking, anatomic location, or histologic grade. All patients belonged to low and very low socioeconomic strata, and were diagnosed at advanced disease stage. Male patients were most commonly affected and the male:female ratio in HPV-positive ESCC increased two-fold in comparison with HPV-negative cases (6.5:1 vs 3.1:1).

CONCLUSION: High prevalence of high-risk HPV in ESCC in Mexico does not support the hypothesis that HPV-associated ESCC is more common in areas with higher ESCC incidence rates.

Evaluating the impact of human papillomavirus vaccines

While two prophylactic HPV vaccines have been proven notably efficacious in clinical trials, the effectiveness of these vaccines at the population level remains to be evaluated. To lay the foundation for understanding the strengths and limitations of different endpoints for future effectiveness research, we present a comprehensive review of HPV-related clinical outcomes, including: (i) HPV type-specific positivity and persistence, (ii) Pap diagnoses (ASC-US, LSIL, and HSIL), (iii) histologic cervical cancer precursor lesions (i.e., CIN1, CIN2, and CIN3), (iv) invasive cervical cancer (ICC), (v) anogenital warts, (vi) recurrent respiratory papillomatosis (RRP), and (vii) other HPV-associated cancers (vulvar, vaginal, anal, penile, and oropharyngeal). While research on the vaccines' effects on these HPV clinical outcomes in the general population is presently limited, numerous large trials will soon be completed, making a priori discussion of these potential outcomes especially urgent. Furthermore, population level systems to track HPV-associated clinical outcomes may need to be developed for HPV vaccine effectiveness evaluation.

Environmental causes of esophageal cancer

This article reviews the environmental risk factors and predisposing conditions for the two main histologic types of esophageal cancer. Tobacco smoking, excessive alcohol consumption, drinking maté, low intake of fresh fruits and vegetables, achalasia, and low socioeconomic status increase the risk of esophageal squamous cell carcinoma. Results of investigations on other potential risk factors, including opium consumption, intake of hot drinks, eating pickled vegetables, poor oral health, and exposure to human papillomavirus, polycyclic aromatic hydrocarbons, N-nitroso compounds, acetaldehyde, and fumonisins are discussed. Gastroesophageal reflux, obesity, tobacco smoking, hiatal hernia, achalasia, and, probably, absence of H pylori in the stomach increase the risk of esophageal adenocarcinoma. Results of studies investigating other factors are also discussed.

Most basal-like breast carcinomas demonstrate the same Rb-/p16+ immunophenotype as the HPV-related poorly differentiated squamous cell carcinomas which they resemble morphologically

Basal-like carcinomas (BLCs) of the breast share discriminatory morphologic features with poorly differentiated high-risk human papilloma virus (HPV)-related squamous cell carcinomas of the oropharynx, penis, and vulva. Because HPV E7 protein inactivates the retinoblastoma (Rb) protein, diffuse p16 expression is a surrogate marker for these high-risk HPV-related carcinomas. HPV E6 protein also inactivates p53, further compromising the G1-S cell cycle checkpoint. The Rb/p16/p53 immunohistochemical profile of BLC of the breast has not been well characterized. Tissue microarrays containing 71 invasive ductal carcinomas (IDCs) of the breast were immunolabeled for p16, Rb, p53, and Ki-67. The cases included 4 distinct groups of IDCs having surrogate immunohistochemical profiles corresponding to categories defined by gene expression profiling (17 luminal A, 7 luminal B, 14 HER-2+, and 21 BLC), along with 12 unclassifiable triple negative carcinomas (UTNCs). Twenty-five of the 71 IDC were Rb negative/p16 diffuse positive (Rb-/p16+). These included 15 of 21 BLC and 9 of 12 UTNC, but only 1 of 14 HER-2 positive cases and none of the 17 luminal A or 7 luminal B cases (P<0.01, BLC or UTNC vs. others). Six of the Rb-/p16+ IDC also had a significant ductal carcinoma in situ component. The ductal carcinoma in situ in 4 of these 6 cases showed the same Rb-/p16+ phenotype as the associated IDC. BLC and UTNC had the highest Ki-67 indices of the 5 groups, even when matched for grade. The Rb-/p16+ phenotype and the Rb-/p16+/p53 overexpressing phenotype correlated with increased proliferation within the BLC group. In conclusion, BLC and UTNC, but not HER-2, luminal A, or luminal B carcinomas, frequently demonstrate an Rb-/p16+ phenotype, similar to the HPV-related squamous cell carcinomas that BLC resemble morphologically. This subset may represent a more homogenous group than BLC as defined currently.

Second cancers after squamous cell carcinoma and adenocarcinoma of the cervix

PURPOSE

Although cervical squamous cell carcinoma (SCC) and adenocarcinoma (AC) are both caused by human papillomavirus (HPV) infection, they differ in cofactors such as cigarette smoking. We assessed whether these cofactor differences translate into differences in second cancer risk.

PATIENTS AND METHODS

We assessed second cancer risk among 85,109 cervical SCC and 10,280 AC survivors reported to population-based cancer registries in Denmark, Finland, Norway, Sweden, and the United States. Risks compared to the general population were assessed using standardized incidence ratios (SIR).

RESULTS

Overall cancer risk was significantly increased among both cervical SCC survivors (n = 10,559 second cancers; SIR, 1.31; 95% CI, 1.29 to 1.34) and AC survivors (n = 920 second cancers; SIR, 1.29; 95% CI, 1.22 to 1.38). Risks of HPV-related and radiation-related cancers were increased to a similar extent among cervical SCC and AC survivors. Although significantly increased in both groups when compared with the general population, risk of smoking-related cancers was significantly higher among cervical SCC than AC survivors (P = .015; SIR for cervical SCC = 2.07 v AC = 1.78). This difference was limited to lung cancer (SIR for cervical SCC = 2.69 v AC = 2.18; P = .026). The increased lung cancer risk among cervical AC survivors was observed for both lung SCC and lung AC. SIRs for second cancers of the colon, soft tissue, melanoma, and non-Hodgkin's lymphoma were significantly higher among cervical AC than SCC survivors.

CONCLUSION

The second cancer profiles among cervical SCC and AC survivors mirror the similarities and differences in cofactors for these two histologies. Because smoking is not a cofactor for cervical AC, the increased lung cancer risk suggests a role for additional factors.

HPV prophylactic vaccines and the potential prevention of noncervical cancers in both men and women

Human papillomavirus (HPV) is a necessary cause of cervical cancer. In addition, on the basis of the fulfillment of a combination of viral as well as epidemiological criteria, it is currently accepted that a proportion of anal, oropharyngeal, vulvar, and vaginal cancers among women and anal, oropharyngeal, and penile cancers among men are etiologically related to HPV. At these noncervical sites with etiologic heterogeneity, HPV-associated cancers represent a distinct clinicopathological entity, which is generally characterized by a younger age at onset, basaloid or warty histopathology, association with sexual behavior, and better prognosis, when compared with their HPV-negative counterparts. Currently available estimates indicate that the number of HPV-associated noncervical cancers diagnosed annually in the US roughly approximates the number of cervical cancers, with an equal number of noncervical cancers among men and women. Furthermore, whereas the incidence of cervical cancers has been decreasing over time, the incidence of anal and oropharyngeal cancers, for which there are no effective or widely used screening programs, has been increasing in the US. The efficacy of HPV vaccines in preventing infection at sites other than the cervix, vagina, and vulva should, therefore, be assessed (eg, oral and anal). Given that a substantial proportion of cervical cancers (approximately 70%) and an even greater proportion of HPV-associated noncervical cancers (approximately 86% to 95%) are caused by HPV16 and 18 (HPV types that are targeted by the currently available vaccines), current HPV vaccines may hold great promise (provided equivalent efficacy at all relevant anatomic sites) in reducing the burden of HPV-associated noncervical cancers, in addition to cervical cancers.

Structural differences among cost-effectiveness models of human papillomavirus vaccines

In this article we compare previously published cost-effectiveness studies of human papillomavirus (HPV) vaccines along a defined subset of key model structural assumptions relating to HPV infection and disease, cervical cancer screening and HPV vaccination. For each structural aspect examined, we summarize assumptions from each study, provide a critical review and discuss the impact upon results. Considerable variation was observed across HPV vaccine cost-effectiveness models in a number of influential assumptions. Holding constant factors for which current data are lacking, the combined impact of assumptions made for the remaining parameters examined would appear to tend toward underestimation of the cost-effectiveness of HPV vaccination within existing studies. However, uncertainty concerning parameters, such as the duration of vaccine protection and acquired immunity following HPV infection, and the relationship between age and HPV virulence, complicates precise estimation of the cost-effectiveness of HPV vaccination and rigorous evaluation of the validity of existing modeling results.

Human papillomavirus infection in Barrett's oesophagus in the UK: an infrequent event

BACKGROUND

Human papillomavirus (HPV) infection has been reported in squamous cell carcinomas of the oesophagus and has been recently described in Barrett's oesophagus, a premalignant condition which may give rise to oesophageal adenocarcinoma.

OBJECTIVES

To investigate HPV infection in Barrett's oesophagus in a UK population.

STUDY DESIGN

DNA was extracted from 73 Barrett's oesophagus biopsies and examined for the presence of DNA for 14 high risk (HR) and 6 low risk (LR) HPV types.

RESULTS

HPV DNA was present in only 1 of 73 samples; genotyping indicated this was a high risk type 51 infection.

CONCLUSIONS

HPV infection appears unlikely to be a significant factor in the aetiology of Barrett's oesophagus in the UK.

The role of infectious agents in the etiology of ocular adnexal neoplasia

Given the fact that infectious agents contribute to around 18% of human cancers worldwide, it would seem prudent to explore their role in neoplasms of the ocular adnexa: primary malignancies of the conjunctiva, lacrimal glands, eyelids, and orbit. By elucidating the mechanisms by which infectious agents contribute to oncogenesis, the management, treatment, and prevention of these neoplasms may one day parallel what is already in place for cancers such as cervical cancer, hepatocellular carcinoma, gastric mucosa-associated lymphoid tissue lymphoma and gastric adenocarcinoma. Antibiotic treatment and vaccines against infectious agents may herald a future with a curtailed role for traditional therapies of surgery, radiation, and chemotherapy. Unlike other malignancies for which large epidemiological studies are available, analyzing ocular adnexal neoplasms is challenging as they are relatively rare. Additionally, putative infectious agents seemingly display an immense geographic variation that has led to much debate regarding the relative importance of one organism versus another. This review discusses the pathogenetic role of several microorganisms in different ocular adnexal malignancies, including human papilloma virus in conjunctival papilloma and squamous cell carcinoma, human immunodeficiency virus in conjunctival squamous carcinoma, Kaposi sarcoma-associated herpes virus or human herpes simplex virus-8 (KSHV/HHV-8) in conjunctival Kaposi sarcoma, Helicobacter pylori (H. pylori,), Chlamydia, and hepatitis C virus in ocular adnexal mucosa-associated lymphoid tissue lymphomas. Unlike cervical cancer where a single infectious agent, human papilloma virus, is found in greater than 99% of lesions, multiple organisms may play a role in the etiology of certain ocular adnexal neoplasms by acting through similar mechanisms of oncogenesis, including chronic antigenic stimulation and the action of infectious oncogenes. However, similar to other human malignancies, ultimately the role of infectious agents in ocular adnexal neoplasms is most likely as a cofactor to genetic and environmental risk factors.

Human papillomavirus detected in female breast carcinomas in Japan

To investigate the aetiological role of human papillomavirus (HPV) in breast cancer, we examined the presence, genotype, viral load, and physical status of HPV in 124 Japanese female patients with breast carcinoma. Human papillomavirus presence was examined by PCR using SPF10 primers, and primer sets targeting the E6 region of HPV-16, -18, and -33. The INNO-LiPA HPV genotyping kit was used to determine genotype. Human papillomavirus DNA was detected in 26 (21%) breast carcinomas. The most frequently detected HPV genotype was HPV-16 (92%), followed by HPV-6 (46%), HPV-18 (12%), and HPV-33 (4%). In 11 normal epithelium specimens adjacent to 11 HPV-16-positive carcinomas, 7 were HPV-16-positive. However, none of the normal breast tissue specimens adjacent to HPV-negative breast carcinomas were HPV-positive. The real-time PCR analysis suggested the presence of integrated form of viral DNA in all HPV-16-positive samples, and estimated viral load was low with a geometric mean of 5.4 copies per 10(4) cells. In conclusion, although HPV DNA was detected in 26 (21%) breast carcinomas and, in all HPV-16-positive cases, the HPV genome was considered integrated into the host genome, their low viral loads suggest it is unlikely that integrated HPV is aetiologically involved in the development of Japanese breast carcinomas that we examined.

The role of viral and bacterial pathogens in gastrointestinal cancer

The association of Helicobacter pylori (H. pylori) with gastric cancer is thus far the best understood model to comprehend the causal relationship between a microbial pathogen and cancer in the human gastrointestinal tract. Besides H. pylori, a variety of other pathogens are now being recognized as potential carcinogens in different settings of human cancer. In this context, viral causes of human cancers are central to the issue since these account for 10-20% of cancers worldwide. In the case of H. pylori and gastric cancer, as well as the human papillomavirus and anal cancer, the causal relationship between the infectious agent and the related cancer in the gastrointestinal tract has been clearly confirmed by epidemiological and experimental studies. Similarly, Epstein-Barr virus and the oncogenic JC virus are being suggested as possible causative agents for cancers in the upper and lower gastrointestinal tract. This review discusses various viral and microbial pathogens and their oncogenic properties in the evolution of gastrointestinal carcinogenesis and summarizes the available experimental data make a convincing agreement favoring the associations between infectious agents and specific human cancers.

Update on molecular diagnostic tests in head and neck cancer

Head and neck cancers (HNCs) include several cancers originating in the upper airways that represent a variety of histologies. The most common type of HNC is squamous cell carcinoma (SCC), which is linked to tobacco and alcohol use and to human papilloma virus (HPV). At present, there are no standard molecular tests that are routinely used in clinics. This overview will discuss the current knowledge on molecular markers with the potential to be developed as diagnostic tests for cancer risk assessment, early detection, clinical response prediction to specific therapies, and prognosis. These markers are usually based on recent findings in tumor biology and genetic defects in HNC, and provide information both independently and in combination with currently available clinical parameters. In practice, many potential markers are difficult to measure due to assay variability, lack of standards for the interpretation of assay results, and incomplete knowledge of the effects on disease biology and response to treatment. However, there is great enthusiasm for the general concept of using molecular knowledge for the clinical management of HNC. Although it will be a great challenge to develop robust and reliable molecular diagnostic tests, the development of promising assays fueled by advances in science and technology will continue and will ultimately reach the goal of improving the care of HNC patients.

The biomarkers of human papillomavirus infection in tonsillar squamous cell carcinoma-molecular basis and predicting favorable outcome

Presence of human papillomavirus (HPV) in variable proportions in tonsillar squamous cell carcinoma tissues has been demonstrated by several worldwide studies. Some reports emphasized the significance of HPV in predicting a better prognosis, as well as ethnic differences between Chinese and Caucasians. In order to understand the biological role of HPV and find out clinically accessible methods to determine its prognostic significance in primary tonsillar squamous cell carcinoma, we collected 92 patients with primary tonsillar squamous cell carcinoma diagnosed or treated in National Taiwan University Hospital, for whom archival tumor tissue were available. Immunohistochemical stains of p16(INK4A), high-risk HPV in situ hybridization, and nested polymerase chain reaction (PCR)-based genechips were performed to detect HPV infection and determine its genotype. Clinical data were compared with HPV infection detected by the different methods mentioned above. Real-time PCR was also performed on the HPV16-positive [HPV16(+)] lesions to understand viral integration status. The positive rates of nested PCR-based genechips, overexpression of p16(INK4A), and high-risk HPV in situ hybridization were 75% (69/92), 53% (49/92), and 44% (40/92), respectively. Both overexpression of P16(INK4A) and high-risk HPV in situ hybridization positivity were associated with favorable prognoses (P=0.004 and 0.001, respectively) and also independent prognostic factors in multivariate analyses (P=0.01 and 0.01, respectively). The positivity of nested PCR-based genechips was not statistically significant. From our data, primary tonsillar squamous cell carcinoma with positive immunohistochemical stains of p16(INK4A) and/or high-risk HPV in situ hybridization is associated with a better outcome, and both methods may serve as clinically accessible markers.

Human papillomavirus and vaccination in cervical cancer

Cervical cancer is not only the most frequently reported cancer among women, but also the most common female genital tract neoplasm in Taiwan. Early detection is effective, because the development, maintenance and progression of precursor lesions (cervical intraepithelial neoplasia [CIN]) evolve slowly into invasive cancer, typically over a period of more than 10 years. It is now recognized that human papillomavirus (HPV) infection is a necessary cause for over 99% of cervical cancer cases. Advances in the understanding of the causative role of HPV in the etiology of high-grade cervical lesions (CIN 2/3) and cervical cancer have led to the development, evaluation and recommendation of HPV-based technologies for cervical cancer prevention and control. The prevention of HPV infection before the onset of CIN is now possible with recently available prophylactic HPV vaccines, e.g. the quadrivalent Gardasil (Merck & Co., NJ, USA) and bivalent Cervarix (GlaxoSmithKline, London, UK). This review article provides an up-to-date summary of recent studies and available information concerning HPV and vaccination in cervical cancer.

Current topics in the epidemiology of oral cavity and oropharyngeal cancers

Oral cancer incidence rates rose dramatically during the twentieth century in the United States and Europe, especially among individuals under the age of 60 years. Although influenced by age, sex, and country of origin, incidence trends were most strongly affected by elevated risk among individuals born after approximately 1915. This cohort effect was indicative of strong behavioral influences on oral cancer risk. In this article, associations between oral cancer risk and established behavioral risk factors including alcohol and tobacco use are reviewed. Additionally, possible associations between oral cancer risk and oral hygiene, diet, nutritional status, and sexual behavior as well as the influence of genetic factors on oral cancer risk are considered. Special emphasis is placed on evaluating possible risk differences in individuals above and below the age of 45 and in users and nonusers of alcohol and tobacco.

Second cancers among 104,760 survivors of cervical cancer: evaluation of long-term risk

BACKGROUND

Given the extended survival of patients diagnosed with cervical cancer, the large number of these women treated with radiotherapy, and the presence in this population of established cancer risk factors such as human papillomavirus (HPV) infection and cigarette smoking, it is important to clarify long-term trends in second cancer risk.

METHODS

Using data from 104,760 one-year survivors of cervical cancer reported to 13 population-based cancer registries in Denmark, Finland, Norway, Sweden, and the United States, we calculated standardized incidence ratios (SIRs) for second cancers overall and cancers at particular sites among women with cervical cancer, including cervical cancer patients who were treated or not treated with radiation, over more than 40 years of follow-up. Cox regression models were used to assess the time-varying association of radiotherapy with risk of second cancers and to assess the interaction of radiation treatment with age at diagnosis. All statistical tests were two-sided.

RESULTS

Among 104,760 one-year survivors of cervical cancer, the risk of all second cancers taken together was increased to a statistically significant extent (n = 12,496; SIR = 1.30; 95% confidence interval [CI] = 1.28 to 1.33). Compared with the general population, in both radiotherapy (N = 52,613) and no-radiotherapy groups (N = 27,382), risks for HPV-related cancers (of the pharynx, genital sites, and rectum/anus) and smoking-related cancers (of the pharynx, trachea/bronchus/lung, pancreas, and urinary bladder) were elevated to a statistically significant extent. Cervical cancer patients treated with radiotherapy, but not those who did not receive radiotherapy, were at increased risk for all second cancers and cancers at heavily irradiated sites (colon, rectum/anus, urinary bladder, ovary, and genital sites) beyond 40 years of follow-up compared with women in the general population. The association of radiotherapy with second cancer risk was modified by age at cervical cancer diagnosis for rectum/anus, genital sites, and urinary bladder, with higher hazard ratios for second cancer at younger ages of cervical cancer. After adjustment for competing mortality, the 40-year cumulative risk of any second cancer was higher among women diagnosed with cervical cancer before age 50 (22.2%; 95% CI = 21.5% to 22.8%) than among women diagnosed after age 50 (16.4%; 95% CI = 16.1% to 16.9%).

CONCLUSION

Cervical cancer patients treated with radiotherapy are at increased risk of second cancers at sites in close proximity to the cervix beyond 40 years of follow-up.

Human papillomavirus and cervical cancer

Cervical cancer is the second most common cancer in women worldwide, and knowledge regarding its cause and pathogenesis is expanding rapidly. Persistent infection with one of about 15 genotypes of carcinogenic human papillomavirus (HPV) causes almost all cases. There are four major steps in cervical cancer development: infection of metaplastic epithelium at the cervical transformation zone, viral persistence, progression of persistently infected epithelium to cervical precancer, and invasion through the basement membrane of the epithelium. Infection is extremely common in young women in their first decade of sexual activity. Persistent infections and precancer are established, typically within 5-10 years, from less than 10% of new infections. Invasive cancer arises over many years, even decades, in a minority of women with precancer, with a peak or plateau in risk at about 35-55 years of age. Each genotype of HPV acts as an independent infection, with differing carcinogenic risks linked to evolutionary species. Our understanding has led to improved prevention and clinical management strategies, including improved screening tests and vaccines. The new HPV-oriented model of cervical carcinogenesis should gradually replace older morphological models based only on cytology and histology. If applied wisely, HPV-related technology can minimise the incidence of cervical cancer, and the morbidity and mortality it causes, even in low-resource settings.

Hypothetic association between human papillomavirus infection and breast carcinoma

High-risk human Papillomaviruses (HPVs) has been proved to be the major cause of cervical cancer. It has been considered that HPV may also cause squamous cell carcinomas of the other sites such as anus, vulva and esophagus. Furthermore, a number of studies have detected HPV DNA in breast carcinoma tissues. This raises the question that whether HPV plays a carcinogenic role in breast carcinomas. On the other hand, human Papillomaviruses do not seem to be able infect normal mammary cells in vitro, nor have HPV infections in human breast glands been observed among patients with AIDS. At present, there is no explanation for these "conflicting observations". In this paper, we propose the hypothesis that mammary epithelial cells that partly lose control in proliferation are more susceptible for persistent HPV infection. The potential role of HPV infection in the carcinogenic steps of breast cancer should be further tested. One possible cost-effective way for further investigation is to conduct a case-control study comparing the prevalence of previous HPV exposure to the breast, such as history of cervical HPV infections and HPV infections in nipples between cases and controls.

Impact of the human papilloma vaccine on cervical cancer

During the last decade, research progress on cervical cancer has elucidated the role of human papilloma virus (HPV) in the pathogenesis of cervical cancer. Clinical trials on the viral-like particle HPV vaccines have good safety profiles and promising efficacy in preventing genital warts, cervical neoplasia, and cervical cancer. The implementation of the HPV vaccine is a tremendous milestone in our effort toward preventing cervical cancers. However, screening programs will continue to serve as a critical component in prevention due to the limitations of the current vaccines. The greatest impact in cervical cancer incidence worldwide requires improved health care access to underserved areas. Advances are needed to develop single-dose, heat-stable, needle-free, and affordable formulations of the HPV vaccine to overcome the socioeconomic barriers associated with this disease.

Incidence of cancers in people with HIV/AIDS compared with immunosuppressed transplant recipients: a meta-analysis

BACKGROUND

Only a few types of cancer are recognised as being directly related to immune deficiency in people with HIV/AIDS. Large population-based studies in transplant recipients have shown that a wider range of cancers could be associated with immune deficiency. Our aim was to compare cancer incidence in population-based cohort studies of people with HIV/AIDS and people immunosuppressed after solid organ transplantation.

METHODS

Two investigators independently identified eligible studies through searches of PubMed and reference lists. Random-effects meta-analyses of log standardised incidence ratios (SIRs) were calculated by type of cancer for both immune deficient populations.

FINDINGS

Seven studies of people with HIV/AIDS (n=444,172) and five of transplant recipients (n=31 977) were included. For 20 of the 28 types of cancer examined, there was a significantly increased incidence in both populations. Most of these were cancers with a known infectious cause, including all three types of AIDS-defining cancer, all HPV-related cancers, as well as Hodgkin's lymphoma (HIV/AIDS meta-analysis SIR 11.03, 95% CI 8.43-14.4; transplant 3.89, 2.42-6.26), liver cancer (HIV/AIDS 5.22, 3.32-8.20; transplant 2.13, 1.16-3.91), and stomach cancer (HIV/AIDS 1.90, 1.53-2.36; transplant 2.04, 1.49-2.79). Most common epithelial cancers did not occur at increased rates.

INTERPRETATION

The similarity of the pattern of increased risk of cancer in the two populations suggests that it is immune deficiency, rather than other risk factors for cancer, that is responsible for the increased risk. Infection-related cancer will probably become an increasingly important complication of long-term HIV infection.

Population-based study of human papillomavirus infection and cervical neoplasia in Athens, Greece

The aim of our study is to describe the prevalence of the different HPV types in women with pre-neoplastic lesions of the cervix in Greece. Cervical scrapes from 841 women were obtained for both cytological evaluation and analysis for the presence of HPV DNA. PCR was performed on specimens from these 841 women. The Pap test results were normal or showed benign cellular changes in 45.8% of the women, atypical squamous cells of undetermined significance (ASCUS) in 23.2%, low-grade squamous intra-epithelial lesion (LSIL) in 27.9% and high-grade squamous intra-epithelial lesion (HSIL) in 3.1%. HPV DNA was demonstrated in 23.6% of cytologically normal women. We detected HPV in 60% of the total samples. Of these, HPV-16 was the most common HPV DNA detected. Interestingly, HPV-58 was inversely correlated with positive cytological findings. A clear pattern of decreasing prevalence of HPV with age was also observed. Our results indicate that HPV infections, especially those with HPV-16, represent a significant public health concern in Greece.

Case-control study of human papillomavirus and oropharyngeal cancer

BACKGROUND

Substantial molecular evidence suggests a role for human papillomavirus (HPV) in the pathogenesis of oropharyngeal squamous-cell carcinoma, but epidemiologic data have been inconsistent.

METHODS

We performed a hospital-based, case-control study of 100 patients with newly diagnosed oropharyngeal cancer and 200 control patients without cancer to evaluate associations between HPV infection and oropharyngeal cancer. Multivariate logistic-regression models were used for case-control comparisons.

RESULTS

A high lifetime number of vaginal-sex partners (26 or more) was associated with oropharyngeal cancer (odds ratio, 3.1; 95% confidence interval [CI], 1.5 to 6.5), as was a high lifetime number of oral-sex partners (6 or more) (odds ratio, 3.4; 95% CI, 1.3 to 8.8). The degree of association increased with the number of vaginal-sex and oral-sex partners (P values for trend, 0.002 and 0.009, respectively). Oropharyngeal cancer was significantly associated with oral HPV type 16 (HPV-16) infection (odds ratio, 14.6; 95% CI, 6.3 to 36.6), oral infection with any of 37 types of HPV (odds ratio, 12.3; 95% CI, 5.4 to 26.4), and seropositivity for the HPV-16 L1 capsid protein (odds ratio, 32.2; 95% CI, 14.6 to 71.3). HPV-16 DNA was detected in 72% (95% CI, 62 to 81) of 100 paraffin-embedded tumor specimens, and 64% of patients with cancer were seropositive for the HPV-16 oncoprotein E6, E7, or both. HPV-16 L1 seropositivity was highly associated with oropharyngeal cancer among subjects with a history of heavy tobacco and alcohol use (odds ratio, 19.4; 95% CI, 3.3 to 113.9) and among those without such a history (odds ratio, 33.6; 95% CI, 13.3 to 84.8). The association was similarly increased among subjects with oral HPV-16 infection, regardless of their tobacco and alcohol use. By contrast, tobacco and alcohol use increased the association with oropharyngeal cancer primarily among subjects without exposure to HPV-16.

CONCLUSIONS

Oral HPV infection is strongly associated with oropharyngeal cancer among subjects with or without the established risk factors of tobacco and alcohol use.

Colonic squamous cell carcinoma in ulcerative colitis: Report of a case and review of the literature

Squamous cell carcinoma (SCC) is a rare neoplasm in the colorectum. A case of SCC rising from an area of squamous metaplasia in the rectum is presented in a patient with long-standing ulcerative colitis and perianal warts. This is the first report in the literature describing the evolution of squamous metaplasia in the colonic mucosa into invasive carcinoma over time. Related literature on colorectal SCC and squamous metaplasia, and their relationships with inflammatory bowel disease and human papilloma virus, is reviewed.