A comprehensive review on host genetic susceptibility to human papillomavirus infection and progression to cervical cancer

Mortality patterns of patients with tonsillar squamous cell carcinoma: a population-based study

Objective

Tonsillar squamous cell carcinoma (TSCC) and second primary malignancies (SPMs) are the most common causes of mortality in patients with primary TSCC. However, the competing data on TSCC-specific death (TSD) or SPM-related death in patients with TSCC have not been evaluated. This study aimed to analyze the mortality patterns and formulate prediction models of mortality risk caused by TSCC and SPMs.

Methods

Data on patients with a first diagnosis of TSCC were extracted as the training cohort from the 18 registries comprising the Surveillance, Epidemiology, and End Results (SEER) database. A competing risk approach of cumulation incidence function was used to estimate cumulative incidence curves. Fine and gray proportional sub-distributed hazard model analyses were performed to investigate the risk factors of TSD and SPMs. A nomogram was developed to predict the 5- and 10-year risk probabilities of death caused by TSCC and SPMs. Moreover, data from the 22 registries of the SEER database were also extracted to validate the nomograms.

Results

In the training cohort, we identified 14,530 patients with primary TSCC, with TSCC (46.84%) as the leading cause of death, followed by SPMs (26.86%) among all causes of death. In the proportion of SPMs, the lungs and bronchus (22.64%) were the most common sites for SPM-related deaths, followed by the larynx (9.99%), esophagus (8.46%), and Non-Melanoma skin (6.82%). Multivariate competing risk model showed that age, ethnicity, marital status, primary site, summary stage, radiotherapy, and surgery were independently associated with mortality caused by TSCC and SPMs. Such risk factors were selected to formulate prognostic nomograms. The nomograms showed preferable discrimination and calibration in both the training and validation cohorts.

Conclusion

Patients with primary TSCC have a high mortality risk of SPMs, and the competing risk nomogram has an ideal performance for predicting TSD and SPMs-related mortality. Routine follow-up care for TSCC survivors should be expanded to monitor SPMs.

Unraveling Immunological Dynamics: HPV Infection in Women-Insights from Pregnancy

During pregnancy, hormonal and immune adaptations are vital for supporting the genetically distinct fetus during elevated infection risks. The global prevalence of HPV necessitates its consideration during pregnancy. Despite a seemingly mild immune response, historical gestational viral infections underscore its significance. Acknowledging the established HPV infection risks during pregnancy, our review explores the unfolding immunological changes in pregnant women with HPV. Our analysis aims to uncover strategies for safely modulating the immune system, mitigating adverse pregnancy consequences, and enhancing maternal and child health. This comprehensive narrative review delves into the existing knowledge and studies on this topic.

Incorporating HPV 33 and cytology into HPV 16/18 screening may be feasible. A cross-sectional study

PURPOSE

The distribution of human papillomavirus (HPV) varies geographically, and each country is making its screening and vaccination program. This study questioned the need for colposcopy for HPV types other than HPV 16 and 18, and the need for cytology incorporated into HPV testing.

METHODS

1043 consecutive patients referred for colposcopy are included in this retrospective study. Logistic regression analysis, ANOVA, and Pearson's correlation were used for statistical analysis. The value of p < 0.05 was considered statistically significant.

RESULTS

HPV 16 was the most common HPV type referred, followed by HPV 18, 52, 51, and 31, respectively. HPV 16 tends to be positive in younger patients than other HPV types (p < 0.05). Only HPV 16 (OR: 1.41, 1.06-1.88 95% CI) and HPV 33 (OR: 2.23; 1.06-4.64 95% CI) (p < 0.05) had significant prediction for CIN 2 + lesions. In patients with only a cytological abnormality, cytological abnormality with single other high-risk (hr) HPV (without HPV 16 or 18) or double other hrHPV positivity but without HPV 16 and 18 infections, we detected 159 (19%) CIN 2 + lesions.

CONCLUSION

HPV 33 may be implemented in hrHPV screening protocols for direct colposcopy referral as well as HPV 16 and HPV 18 in specific regions. If we had opted for HPV-based screening only for HPV 16 and 18 without cytology, 19% of all CIN 2 + lesions would have been missed. HPV-based screening only with HPV 16 and 18 may not be feasible. Nonavalent vaccines should be considered for the vaccination of specific populations.

Incidence and risk factors of second primary cancer after the initial primary human papillomavirus related neoplasms

Comprehensive studies in second primary cancer (SPC) after the initial primary human papillomavirus (HPV)-related cancer still remain warranted. We aimed to analyze the incidence and risk factors of SPC after HPV-related cancer. We identified 86 790 patients diagnosed with initial primary HPV-related cancer between 1973 and 2010 in the SEER database. Standardized incidence ratio (SIR) and cumulative incidence were calculated to assess the risk of SPC after HPV-related cancer. The SIR of SPC after HPV-related cancer was 1.60 (95% confidence interval [CI], 1.55-1.65) for male and 1.25 (95% CI, 1.22-1.28) for female. SIR of second primary HPV-related cancer (7.39 [95% CI, 6.26-8.68] male and 4.35 [95% CI, 4.04-4.67] female) was significantly higher than that of HPV-unrelated cancer (1.54 [95% CI, 1.49-1.60] male and 1.16 [95% CI, 1.13-1.19] female). The 5-year cumulative incidence of SPC was 7.22% (95% CI, 6.89-7.55%) for male and 3.72% (95% CI, 3.58-3.88%) for female. Risk factors for SPC included being married and having initial primary cancer (IPC) diagnosed at earlier stage for both genders, and IPC diagnosed at older age as well as surgery performed for female. Patients diagnosed with HPV-related cancer are more likely to develop another primary cancer, compared with the age-specific reference population.

A Review of Cancer Genetics and Genomics Studies in Africa

Cancer is the second leading cause of death globally and is projected to overtake infectious disease as the leading cause of mortality in Africa within the next two decades. Cancer is a group of genomic diseases that presents with intra- and inter-population unique phenotypes, with Black populations having the burden of morbidity and mortality for most types. At large, the prevention and treatment of cancers have been propelled by the understanding of the genetic make-up of the disease of mostly non-African populations. By the same token, there is a wide knowledge gap in understanding the underlying genetic causes of, and genomic alterations associated with, cancer among black Africans. Accordingly, we performed a review of the literature to survey existing studies on cancer genetics/genomics and curated findings pertaining to publications across multiple cancer types conducted on African populations. We used PubMed MeSH terms to retrieve the relevant publications from 1990 to December 2019. The metadata of these publications were extracted using R text mining packages: RISmed and Pubmed.mineR. The data showed that only 0.329% of cancer publications globally were on Africa, and only 0.016% were on cancer genetics/genomics from Africa. Although the most prevalent cancers in Africa are cancers of the breast, cervix, uterus, and prostate, publications representing breast, colorectal, liver, and blood cancers were the most frequent in our review. The most frequently reported cancer genes were BRCA1, BRCA2, and TP53. Next, the genes reported in the reviewed publications’ abstracts were extracted and annotated into three gene ontology classes. Genes in the cellular component class were mostly associated with cell part and organelle part, while those in biological process and molecular function classes were mainly associated with cell process, biological regulation, and binding, and catalytic activity, respectively. Overall, this review highlights the paucity of research on cancer genomics on African populations, identified gaps, and discussed the need for concerted efforts to encourage more research on cancer genomics in Africa.

Protecting Tumors by Preventing Human Papilloma Virus Antigen Presentation: Insights from Emerging Bioinformatics Algorithms

Recent developments in bioinformatics technologies have led to advances in our understanding of how oncogenic viruses such as the human papilloma virus drive cancer progression and evade the host immune system. Here, we focus our review on understanding how these emerging bioinformatics technologies influence our understanding of how human papilloma virus (HPV) drives immune escape in cancers of the head and neck, and how these new informatics approaches may be generally applicable to other virally driven cancers. Indeed, these tools enable researchers to put existing data from genome wide association studies, in which high risk alleles have been identified, in the context of our current understanding of cellular processes regulating neoantigen presentation. In the future, these new bioinformatics approaches are highly likely to influence precision medicine-based decision making for the use of immunotherapies in virally driven cancers.

Human Leukocyte Antigen (HLA) Class II -DRB1 and -DQB1 Alleles and the Association with Cervical Cancer in HIV/HPV Co-Infected Women in South Africa

Background: A subset of women who are co-infected with Human Immunodeficiency Virus type 1 (HIV) and Human papillomavirus (HPV), progress rapidly to invasive cervical cancer regardless of antiretroviral therapy (ART) or immune status. We posit that HIV/HPV co-infection along with specific host HLA II -DRB1 and -DQB1 alleles play a major role in cervical cancer development.

Methodology: We conducted a hospital-based genetic susceptibility case-control study in Cape Town, South Africa. We recruited 256 women of the same race, from which a total of 624 HLA-DRB1 and -DQB1 class II genotypes were studied. We characterized HLA II candidate genes using PCR based, Luminex intermediate resolution genotyping and confirmed significant associated genotypes at four-digit resolution by high resolution gel typing. We analyzed 160 alleles from cancer, 64 alleles from pre-cancer and 400 alleles from healthy control women. Whole blood was used for HIV antibody test and HLA II typing. Cervical tumor tissue biopsies were used for HPV genotyping. Tests were statistically significant if p<0.05.

Results: Women who were co-infected with HIV/HPV had advanced cervical disease compared to women who were HIV negative. HLA class II -DQB1*03:01 and -DQB1*06:02 alleles were associated with cervical cancer in HIV/HPV co-infected women (p=0.001 and p<0.0001, respectively) while HLA class II -DRB1*13:01 and -DQB1*03:19 were rare or absent in women with cervical disease when compared to the control population (p=0.012 and 0.011, respectively).

Conclusion: We describe associations between HLA class II genotypes with cervical cancer, or likely protection from cervical cancer disease in HIV/HPV co-infected South African women. Identifying mechanisms that give rise to this likely protective HLA association will provide insight into development of immune-based prevention measures.

Risk of CIN2+ following a diagnosis of genital warts: a nationwide cohort study

OBJECTIVES

Individuals with genital warts may be particularly susceptible to human papillomavirus since they have failed to clear the virus. Consequently, women with genital warts could be at increased risk of cervical dysplasia. In this cohort study we aimed to compare the incidence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) in women with a diagnosis of genital warts with that of the general female population without genital warts.

METHODS

Using the Danish nationwide population-based health data registers, we identified women between 15 and 45 years and followed them for diagnoses of CIN2+ from 1995 to 2006. Genital wart diagnoses were recorded from birth, and Cox regression with attained age as underlying scale was used to estimate age-dependent HRs for the risk of CIN2+ with genital warts as a time-varying exposure.

RESULTS

Among 918 609 women without genital warts and 32 218 women with genital warts, 30 209 and 1533 women, respectively, had a subsequent diagnosis of CIN2+. A significantly higher risk of CIN2+ was found among women with genital warts relative to those without (HR, 2.43; 95% CI 2.30 to 2.56). Treatment-resistant genital warts posed a significantly higher risk of CIN2+ than did transient genital warts (HR, 1.20; 95% CI 1.01 to 1.43). The risks remained elevated more than 4 years after the genital wart diagnosis.

CONCLUSION

Clinicians should ensure that women with genital warts are screened for cervical cancer after the genital wart diagnosis and that they continue to be screened on time.

Mucosal and Cutaneous Human Papillomavirus Infections and Cancer Biology

Papillomaviridae is a family of small non-enveloped icosahedral viruses with double-stranded circular DNA. More than 200 different human papillomaviruses (HPVs) have been listed so far. Based on epidemiological data, a subgroup of alphapapillomaviruses (alpha HPVs) was referred to as high-risk (HR) HPV types. HR HPVs are the etiological agents of anogenital cancer and a subset of head and neck cancers. The cutaneous HPV types, mainly from beta and gamma genera, are widely present on the surface of the skin in the general population. However, there is growing evidence of an etiological role of betapapillomaviruses (beta HPVs) in non-melanoma skin cancer (NMSC), together with ultraviolet (UV) radiation. Studies performed on mucosal HR HPV types, such as 16 and 18, showed that both oncoproteins E6 and E7 play a key role in cervical cancer by altering pathways involved in the host immune response to establish a persistent infection and by promoting cellular transformation. Continuous expression of E6 and E7 of mucosal HR HPV types is essential to initiate and to maintain the cellular transformation process, whereas expression of E6 and E7 of cutaneous HPV types is not required for the maintenance of the skin cancer phenotype. Beta HPV types appear to play a role in the initiation of skin carcinogenesis, by exacerbating the accumulation of UV radiation-induced DNA breaks and somatic mutations (the hit-and-run mechanism), and they would therefore act as facilitators rather than direct actors in NMSC. In this review, the natural history of HPV infection and the transforming properties of various HPV genera will be described, with a particular focus on describing the state of knowledge about the role of cutaneous HPV types in NMSC.

Absence of toll-like receptor 9 Pro99Leu polymorphism in cervical cancer

Background: Toll-like receptor 9 (TLR9) plays a key role in the elimination of viral pathogens by recognising their CpG DNA. Polymorphisms in the TLR9 gene may influence their recognition and subsequent elimination. Therefore, the present study was designed to elucidate the role of a rare unexplored TLR9 gene polymorphism C296T/ Pro99Leu (rs5743844) in cervical cancer susceptibility among Indian women. Methods: The genotyping of TLR9 Pro99Leu polymorphism in 110 cervical cancer patients and 141 healthy controls was performed by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Results: The genotype frequency detected in both cervical cancer and control populations was 1.0 (CC), 0.0 (CT) and 0.0 (TT); while the allele frequency was found to be 1.0 (C) and 0.0 (T). Conclusions: The present study demonstrates no involvement of TLR9 C296T/ Pro99Leu polymorphism in cervical cancer susceptibility and supports minor allele frequency (MAF) (0.0002) status of the same as no nucleotide variation was detected in any of the study subjects.

Absence of toll-like receptor 9 Pro99Leu polymorphism in cervical cancer

Background: Toll-like receptor 9 (TLR9) plays a key role in the elimination of viral pathogens by recognising their CpG DNA. Polymorphisms in the TLR9 gene may influence their recognition and subsequent elimination. Therefore, the present study was designed to elucidate the role of a rare unexplored TLR9 gene polymorphism C296T/ Pro99Leu (rs5743844) in cervical cancer susceptibility among Indian women. Methods: The genotyping of TLR9 Pro99Leu polymorphism in 110 cervical cancer patients and 141 healthy controls was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: The genotype frequency detected in both cervical cancer and control populations was 1.0 (CC), 0.0 (CT) and 0.0 (TT); while the allele frequency was found to be 1.0 (C) and 0.0 (T). Conclusions: The present study results demonstrate no involvement of TLR9 C296T/ Pro99Leu polymorphism in cervical cancer susceptibility and supports worldwide minor allele frequency (MAF) (0.0002) status of the same as no nucleotide variation was detected in any of the study participants.

Role of high-risk human papillomavirus in the etiology of oral and oropharyngeal cancers in Thailand: A case-control study

Background:

Among developing countries, Thailand shows no increase in the incidence of human papillomavirus–driven oropharyngeal cancer. The causal role of human papillomavirus infection in this pathology has not been researched thoroughly.

Methods:

A hospital-based, case–control study was performed which included 104 patients with newly diagnosed oral and oropharyngeal squamous cell carcinomas and 104 individuals without cancer. The Cervista high-risk human papillomavirus and 16/18 assays were used to detect human papillomavirus. Odds ratios were used to assess the association between high-risk genotypes of human papillomavirus and the cancers.

Results:

High-risk human papillomavirus was detected in 4 of 52 (7.7%) oral cancer cases, 6 of 52 (11.5%) oropharyngeal cancer cases, and 1 of 104 (0.96%) control subjects. Of 104 cancer patients in the study, 83 were smokers. High-risk human papillomavirus was significantly associated with oropharyngeal cancer (odds ratio = 13.44, 95% confidence interval = 1.6–114.8) but was nonsignificantly associated with oral cancer (odds ratio = 8.58, 95% confidence interval = 0.9–78.9). However, after adjustment for smoking, high-risk human papillomavirus was determined to be nonsignificantly associated with oropharyngeal cancer (adjusted odds ratio = 5.83, 95% confidence interval = 0.8–43.5).

Conclusion:

Although low human papillomavirus prevalence was observed, the rate of high-risk human papillomavirus infection in the cancer group was still higher than that in the control group. Smoking may have an influence on the etiology of human papillomavirus–related cancers. However, the study is underpowered to clarify the role of human papillomavirus as the independent risk factor for oral and oropharyngeal cancers in the Thai population.

Genetic polymorphisms of glutathione S transferase and cervical intraepithelial neoplasia

Aim: The present study aim to analyze the relationship between GST M/T genotypes of glutathione S-transferases and cervical intraepithelial neoplasia.

Materials and Methods: A prospective case-control study has been designed including 69 cases with different degrees of cervical dysplasia and 107 controls. All patients had been examined colposcopically. For every patient both cervical and blood specimen have been obtained. The peripheral blood was used for GST M/T genotyping. The statistical analysis was performed using OR and chi-square at a level of significance inferior to 0.05.

Results: No statistically significant differences had been found between cases and controls for GST T-/M- geno-type (T-/M-, χ2=0.03, p= 0.8610) and T+/M+ χ2=0.65, p = 0.4197. Patients with in situ carcinoma had significant GST genotype association for T-/M+ genotype (OR=4.66, CI 95% [0.6528,24.9725], χ2=4.6, p=0.0314) and for T+/M- genotype (OR=0.12, CI 95% [0.0027,0.9465], χ2=0.05, p=0.0219).

Conclusion: The combination of GST genotypes can be included in a predictive score for patients with cervical carcinoma.

The Prevalence of High-Risk HPV Types and Factors Determining Infection in Female Colombian Adolescents

This study reports six HR-HPV types’ infection prevalence discriminated by species and multiple infection in unvaccinated Colombian female adolescents, as well as some factors modulating the risk of infection. HPV DNA for six high-risk viral types was identified in cervical samples taken from 2,134 12–19 year-old females using conventional generic and type-specific PCR. Binomial logistical regression analysis was used for modelling HR-HPV infection and multiple infection risk. The interaction between variables in a stepwise model was also included in such analysis. Viral DNA was detected in 48.97% of the females; 28.52% of them had multiple infections, HPV-16 being the most frequently occurring type (37.44%). Cytological abnormality prevalence was 15.61%. Being over 16 years-old (1.66: 1.01–2.71 95%CI), white ethnicity (4.40: 1.16–16.73 95%CI), having had 3 or more sexual partners (1.77: 1.11–2.81 95%CI) and prior sexually-transmitted infections (STI) (1.65: 1.17–2.32 95%CI) were associated with a greater risk of HPV infection. Having given birth was related to a higher risk of infection by A7 species and antecedent of abortion to less risk of coinfection. Where the females in this study came from also influenced the risk of infection by A7 species as female adolescents from the Andean region had a lower risk of infection (0.42: 0.18–0.99 95%CI). The presence of factors related to risky sexual behaviour in the study population indicated that public health services should pay special attention to female adolescents to modify the risk of infection by high-risk HPV types and decrease their impact on this age group.

The protective role of the -1306C>T functional polymorphism in matrix metalloproteinase-2 gene is associated with cervical cancer: implication of human papillomavirus infection

Cervical cancer is the major reproductive health problem among women caused by persistent infection of high-risk human papillomavirus (HR-HPV). Metalloproteinase-2 (MMP-2) is an endopeptidase highly expressed in cervical cancer; however, the genetic link between aberrant expression of MMP-2 and cervical carcinogenesis is not known. The genotypic distribution, expression pattern of MMP-2 and HPV infection, was analyzed in a total of 300 fresh surgically resected cervical tissue biopsies. The MMP-2 C1306T (rs243865) promoter polymorphism dominant model (CC v/s CT + CT + TT) revealed that the CC genotype had a 4.33-fold significant increased risk for development of cervical cancer (OR = 4.33; 95 % CI = 2.36-4.02, p = 0.0001) compared to those with variant genotypes (-1306 CT + TT). The C allele was associated with 3-fold significant increased risk (OR = 2.95; 95 % CI = 1.90-4.60, p = 0.0002) compared to T allele. Interestingly, a significant correlation was found between high expression of MMP-2 protein and CC genotype in cancer patients (p = 0.001) compared to normal controls (p = 0.012). Further analysis showed that the risk of cancer was extremely pronounced in HPV positive patients (OR = 9.33; 95 % CI = 2.88-30.20, p = 0.0001) compared to HPV negative ones, implicating the possible interaction between -1306CC genotype and HPV infection in increasing the cancer risk (p = 0.0001). The leads from the present study suggest the protective role of gene variant -1306C>T at the promoter region of the MMP-2 against HPV-mediated cervical cancer. These findings substantiate the functional role of MMP-2 C1306T polymorphism in a significant downregulation of MMP-2 protein in women with variant genotype (CT/TT) compared to the normal wild CC genotype.

Inferring interaction type in gene regulatory networks using co-expression data

Background

Knowledge of interaction types in biological networks is important for understanding the functional organization of the cell. Currently information-based approaches are widely used for inferring gene regulatory interactions from genomics data, such as gene expression profiles; however, these approaches do not provide evidence about the regulation type (positive or negative sign) of the interaction.

Results

This paper describes a novel algorithm, “Signing of Regulatory Networks” (SIREN), which can infer the regulatory type of interactions in a known gene regulatory network (GRN) given corresponding genome-wide gene expression data. To assess our new approach, we applied it to three different benchmark gene regulatory networks, including Escherichia coli, prostate cancer, and an in silico constructed network. Our new method has approximately 68, 70, and 100 percent accuracy, respectively, for these networks. To showcase the utility of SIREN algorithm, we used it to predict previously unknown regulation types for 454 interactions related to the prostate cancer GRN.

Conclusions

SIREN is an efficient algorithm with low computational complexity; hence, it is applicable to large biological networks. It can serve as a complementary approach for a wide range of network reconstruction methods that do not provide information about the interaction type.

Electronic supplementary material

The online version of this article (doi:10.1186/s13015-015-0054-4) contains supplementary material, which is available to authorized users.

Human leukocyte antigen (HLA)-G and cervical cancer immunoediting: a candidate molecule for therapeutic intervention and prognostic biomarker?

While persistent infection with oncogenic types of human Papillomavirus (HPV) is required for cervical epithelial cell transformation and cervical carcinogenesis, HPV infection alone is not sufficient to induce tumorigenesis. Only a minor fraction of HPV infections produce high-grade lesions and cervical cancer, suggesting complex host-virus interactions. Based on its pronounced immunoinhibitory properties, human leukocyte antigen (HLA)-G has been proposed as a possible prognostic biomarker and therapeutic target relevant in a wide variety of cancers and viral infections, but to date remains underexplored in cervical cancer. Given the possible influence of HLA-G on the clinical course of HPV infection, cervical lesions and cancer progression, a better understanding of HLA-G involvement in cervical carcinogenesis might contribute to two aspects of fundamental importance: 1. Characterization of a novel diagnostic/prognostic biomarker to identify cervical cancer and to monitor disease stage, critical for patient screening; 2. Identification of HLA-G-driven immune mechanisms involved in lesion development and cancer progression, leading to the development of strategies for modulating HLA-G expression for treatment purposes. Thus, this systematic review explores the potential involvement of HLA-G protein expression and polymorphisms in cervical carcinogenesis.

Disparities in cervical cancer mortality rates as determined by the longitudinal hyperbolastic mixed-effects type II model

Background

The main purpose of this study was to model and analyze the dynamics of cervical cancer mortality rates for African American (Black) and White women residing in 13 states located in the eastern half of the United States of America from 1975 through 2010.

Methods

The cervical cancer mortality rates of the Surveillance, Epidemiology, and End Results (SEER) were used to model and analyze the dynamics of cervical cancer mortality. A longitudinal hyperbolastic mixed-effects type II model was used to model the cervical cancer mortality data and SAS PROC NLMIXED and Mathematica were utilized to perform the computations.

Results

Despite decreasing trends in cervical cancer mortality rates for both races, racial disparities in mortality rates still exist. In all 13 states, Black women had higher mortality rates at all times. The degree of disparities and pace of decline in mortality rates over time differed among these states. Determining the paces of decline over 36 years showed that Tennessee had the most rapid decline in cervical cancer mortality for Black women, and Mississippi had the most rapid decline for White Women. In contrast, slow declines in cervical cancer mortality were noted for Black women in Florida and for White women in Maryland.

Conclusions

In all 13 states, cervical cancer mortality rates for both racial groups have fallen. Disparities in the pace of decline in mortality rates in these states may be due to differences in the rates of screening for cervical cancers. Of note, the gap in cervical cancer mortality rates between Black women and White women is narrowing.

Disparity in the persistence of high-risk human papillomavirus genotypes between African American and European American women of college age

BACKGROUND

Cervical cancer incidence and mortality rates are higher in African Americans than in European Americans (white, non-Hispanic of European ancestry). The reasons for this disparity are not known.

METHODS

We recruited a population-based longitudinal cohort of 326 European American and 113 African American female college freshmen in Columbia, South Carolina, to compare clearance of high-risk human papillomavirus (HR-HPV) infection between ethnicities. HPV testing and typing from samples obtained for Papanicolaou testing occurred every 6 months.

RESULTS

African American participants had an increased risk of testing positive for HR-HPV, compared with European American participants, but the frequency of incident HPV infection was the same in African American and European American women. Thus, exposure to HPV could not explain the higher rate of HPV positivity among African American women. The time required for 50% of participants to clear HR-HPV infection was 601 days for African American women (n = 63) and 316 days for European American women (n = 178; odds ratio [OR], 1.61; 95% confidence interval [CI], 1.08-2.53). African American women were more likely than European American women to have an abnormal result of a Papanicolaou test (OR, 1.58; 95% CI, 1.05-2.39).

CONCLUSIONS

We propose that the longer time to clearance of HR-HPV among African American women leads to increased rates of abnormal results of Papanicolaou tests and contributes to the increased rates of cervical cancer observed in African American women.

MTHFR/p53 Polymorphisms as Genetic Factors for Cervical Intraepithelial Neoplasia and Cervical Cancer in HPV-infected Mexican Women

We performed a case-control association study to evaluate the association between common polymorphisms in MTHFR (C677T and A1298C) and the Arg72Pro polymorphism in the p53 gene and the risk for cervical intraepithelial neoplasia (CIN) or invasive cervical cancer (ICC) in Mexican HPV-infected women. We included 131 women with diagnosis of CIN grade I-II and 78 with CIN III or ICC; as controls we also included 274 women with normal Pap smear and negative HPV test. Genotyping for MTHFR and p53 polymorphisms was performed by PCR-RFPLs. HPV was tested by Hybrid Capture II. Odds ratios and 95% confidence intervals were estimated. Genotype frequencies for the 3 studied polymorphisms were distributed according to the Hardy-Weinberg equilibrium. The A1298C-MTHFR polymorphism showed significant differences for the heterozygous AC genotype and the C allele, whereas the AA genotype and A allele resulted to be genetic risk factors for CIN or ICC (p<0.03). The Arg72Pro-p53 polymorphism showed for the genotypes Arg/Pro and Pro/Pro, and for the Pro allele, a significant association only to the risk for CIN (p<0.03). The MTHFR/p53 interaction showed that the genotype combinations AA/ArgArg and AA/ArgPro were associated, respectively, to the risk of ICC and CIN (p<0.05). This study suggests that the A1298C-MTHFR polymorphism contributes to the genetic risk for both CIN and ICC, whereas the Arg72Pro-p53 polymorphism only contributes to the risk for CIN. The MTHFR/p53 genetic combinations AA/ArgArg and AA/ArgPro are associated genetic risk factors for ICC and CIN in Mexican HPV-infected women.

Characterization of cytomegalovirus and epstein-barr virus infection in cervical lesions in Portugal

Infection by high-risk types of human papillomavirus (HPV) is considered necessary but not sufficient for the development of cervical cancer. Previous studies suggested that cytomegalovirus (CMV) and Epstein-barr virus (EBV) could be co-factors of HPV-associated carcinogenesis. The aim of this study was to characterize the prevalence of CMV and EBV and evaluate its association with the development cervical lesions in Portugal. The prevalence of CMV and EBV infections was determined by real-time PCR in 89 cervical samples from women with different histological lesions, who attended the Portuguese Institute of Oncology of Porto. This study revealed an overall prevalence of 4.5% for CMV and 10.1% for EBV. Age-stratified analysis revealed that CMV infection was present in individuals <30 and >60 years old, while EBV infection was present in all age groups. CMV was detected in 9.5% of low-grade lesions and in 22.2% of in situ/invasive carcinomas, while EBV infection was found in all different types of lesions. In addition, data revealed that CMV infection was associated with an increased risk of in situ/invasive carcinoma development (OR=1.28; P=0.035). The study reveals a low prevalence for both viruses; nevertheless, these results are important for knowledge on the shedding of EBV and CMV in cervical samples.

The association between human leukocyte antigen (HLA)-G polymorphisms and human papillomavirus (HPV) infection in Inuit women of northern Quebec

BACKGROUND

The human leukocyte antigen (HLA)-G molecules act as negative regulators of the immune response. We analyzed the associations between HLA G polymorphisms and human papillomavirus (HPV) infection and squamous intraepithelial lesions (SIL) in Inuit women from Nunavik, northern Quebec.

METHODS

Cervical specimens from a cohort study of 548 Inuit women were tested for HPV DNA. HPV genotypes were classified according to tissue-tropism groupings of alpha-papillomavirus species: alpha group 1 includes low risk (LR) cervical species, group 2 includes high risk (HR) cervical species, and group 3 includes LR vaginal species. HLA-G alleles were typed using direct DNA sequencing.

RESULTS

HLA-G(∗)01:01:01 was associated with an increased risk of period prevalent alpha groups 1 (OR = 2.23, 95% CI:1.08-4.59) and 3 (OR = 1.70, 95% CI:1.09-2.65). The homozygous HLA-G(∗)01:04:01 genotype was associated with a decreased risk of alpha group 3 infection period prevalence (OR = 1.69 95% CI = 1.07-2.67). No HLA-G alleles were significantly associated with HPV persistence. HLA-G(∗)01:01:02, G(∗)01:04:01 and G(∗)01:06 were associated with high grade (HG)SIL, but the association did not reach statistical significance.

CONCLUSIONS

These results suggest that HLA-G polymorphisms play a role in the natural history of HPV infection, likely at the stage of host immune recognition. HLA-G polymorphisms interacted differently with the three alpha papillomavirus groups.

The frequency of HLA alleles in a population of Inuit women of northern Quebec

Background

Human leukocyte antigen (HLA) alleles code for proteins that are involved in the recognition of foreign antigens and activation of the immune system. The frequency of HLA alleles varies across different populations.

Objective

To describe the frequency of HLA alleles in a population of Inuit women of Nunavik, Quebec, Canada.

Design

A cohort of women was recruited from 4 different communities between January 2002 and December 2007. HLA-B*07, HLA-DQB1*03, DQB1*06:02, DRB1*13 and DRB1*15:01 alleles were typed by PCR sequence-specific primers (PCR-SSP) and HLA-E and G alleles were type by DNA-sequencing procedures.

Results

We obtained data on 524 participants. The most frequent HLA alleles in this population were HLA-E*01:03, HLA-G*01:04:01 and HLA-DQB1*03, and they were found in 89, 75 and 94% of the population, respectively.

Conclusions

The distribution of HLA alleles in Nunavik, Quebec is unique when compared to other populations in Canada or around the world.

Racial differences in the incidence and clearance of human papilloma virus (HPV): the HPV in men (HIM) study

BACKGROUND

This analysis assessed the acquisition (incidence) and persistence (clearance) of human papilloma virus (HPV) infection by self-reported race among men in The HPV in Men (HIM) Study, a multinational prospective study of the natural history of genital HPV infections.

METHODS

Self-reported race was categorized as White, Black, Asian/Pacific Islander (PI), or multiple and mixed race. Genital samples were combined for HPV DNA testing and categorized by any, oncogenic, and non-oncogenic HPV infections.

RESULTS

Asian/PI race had significantly the lowest incidence of any, oncogenic, and non-oncogenic HPV infection (P < 0.001). In multivariable analyses, Asian/PI race was associated with a lower probability of acquiring any [HR = 0.63; 95% confidence interval (CI), 0.42-0.95] and non-oncogenic HPV infection (HR = 0.61; 95% CI, 0.40-0.93) when compared to Whites. No significant associations were evident for Asian/PI race for clearance. Multiple and mixed race was significantly associated with lower probability of acquiring non-oncogenic HPV infection (HR = 0.83; 95% CI, 0.69-0.99) and borderline significant associations were observed for any HPV (HR = 0.91) and oncogenic infections (HR = 0.92). Multiple and mixed race was associated with a lower probability of clearing any (HR = 0.92; 95% CI, 0.84-1.00) and oncogenic HPV infections (HR = 0.85; 95% CI, 0.75-0.95).

CONCLUSION

Asian/PI race had the lowest incidence of HPV and exhibited a lower probability of acquiring new HPV infections. Multiple and mixed race had the second lowest incidence of infection and was associated with a lower probability of acquiring and clearing an HPV infection.

IMPACT

Race-specific differences in HPV infection could be due to behavior, innate genetic differences, or circulating intratypic HPV variants.

The association of the immune response genes to human papillomavirus-related cervical disease in a Brazilian population

The genetic variability of the host contributes to the risk of human papillomavirus (HPV)-related cervical disease. Immune response genes to HPV must be investigated to define patients with the highest risk of developing malignant disease. The aim of this study was to investigate the association of polymorphic immune response genes, namely KIR, HLA class I and II, and single-nucleotide polymorphisms (SNPs) of cytokines with HPV-related cervical disease. We selected 79 non-related, admixed Brazilian women from the state of Paraná, southern region of Brazil, who were infected with high carcinogenic risk HPV and present cervical intraepithelial neoplasia grade 3 (CIN3), and 150 HPV-negative women from the same region matched for ethnicity. KIR genes were genotyped using an in-house PCR-SSP. HLA alleles were typed using a reverse sequence-specific oligonucleotide technique. SNPs of TNF −308G>A, IL6 −174G>C, IFNG +874T>A, TGFB1 +869T>C +915G>C, and IL10 −592C>A −819C>T −1082G>A were evaluated using PCR-SSP. The KIR genes were not associated with HPV, although some pairs of i(inhibitory)KIR-ligands occurred more frequently in patients, supporting a role for NK in detrimental chronic inflammatory and carcinogenesis. Some HLA haplotypes were associated with HPV. The associations of INFG and IL10 SNPs potentially reflect impaired or invalid responses in advanced lesions.