Human papillomavirus and cervical neoplasia: a case-control study in Taiwan

The East Africa Consortium for human papillomavirus and cervical cancer in women living with HIV/AIDS

The East Africa Consortium was formed to study the epidemiology of human papillomavirus (HPV) infections and cervical cancer and the influence of human immunodeficiency virus (HIV) infection on HPV and cervical cancer, and to encourage collaborations between researchers in North America and East African countries. To date, studies have led to a better understanding of the influence of HIV infection on the detection and persistence of oncogenic HPV, the effects of dietary aflatoxin on the persistence of HPV, the benefits of antiretroviral therapy on HPV persistence, and the differences in HPV detections among HIV-infected and HIV-uninfected women undergoing treatment for cervical dysplasia by either cryotherapy or LEEP. It will now be determined how HPV testing fits into cervical cancer screening programs in Kenya and Uganda, how aflatoxin influences immunological control of HIV, how HPV alters certain genes involved in the growth of tumours in HIV-infected women. Although there have been challenges in performing this research, with time, this work should help to reduce the burden of cervical cancer and other cancers related to HIV infection in people living in sub-Saharan Africa, as well as optimized processes to better facilitate research as well as patient autonomy and safety. KEY MESSAGESThe East Africa Consortium was formed to study the epidemiology of human papillomavirus (HPV) infections and cervical cancer and the influence of human immunodeficiency virus (HIV) infection on HPV and cervical cancer.Collaborations have been established between researchers in North America and East African countries for these studies.Studies have led to a better understanding of the influence of HIV infection on the detection and persistence of oncogenic HPV, the effects of dietary aflatoxin on HPV detection, the benefits of antiretroviral therapy on HPV persistence, and the differences in HPV detections among HIV-infected and HIV-uninfected women undergoing treatment for cervical dysplasia by either cryotherapy or LEEP.

Factors affecting utilization of cervical cancer screening services among women attending public hospitals in Tigray region, Ethiopia, 2018; Case control study

BACKGROUND

Incidence and mortality of cervical cancer is the leading cancer among women in Ethiopia. Absence of effective detection methods and treatment strategies is a major reason for the sharply rising cervical cancer rates in developing countries.

OBJECTIVE

To determine factors affecting utilization of cervical cancer screening services among women attending public hospitals in Tigray region in 2018.

METHODS

Hospital based unmatched case control study was applied with sample size of 312 cases and 312 controls. Data was entered to Epi data version 3.1 and exported to SPSS version 20. The odds ratio with their 95% confidence interval, two-tailed P value was calculated. Variables with P value ≤ 0.05 in the bivariate analysis were included in the multivariate logistic regression model.

RESULTS

Being in the age group of 30-39 and 40-49 years were two and four times more likely to utilize cervical cancer screening than those who were 21-29 years (AOR = 2.15 95%CI:1.11, 4.17 and AOR = 3.86 95%CI:1.48, 10.06) respectively. Current occupation with governmental and private employee were four and three times more likely to utilize the screening service than those housewife respectively (AOR = 3.85 95%CI: 1.87, 7.92 and AOR = 3.17 95%CI: 1.31, 7.66). Having ever given birth and history of multiple sexual partners were more likely to utilize the screening service (AOR = 2.57 95%CI: 1.02, 6.50) and (AOR = 2.65 95%CI: 1.10, 6.40) respectively.

CONCLUSIONS

There is a need to strengthen policy and guidelines on cervical cancer screening among women particularly with regarding age group of 21-29, current occupation with housewife, single sexual partner and null parity. All stakeholders should give priority on the promotion and initiation of women to acquired good knowledge and attitude on cervical cancer screening.

Niche adaptation and viral transmission of human papillomaviruses from archaic hominins to modern humans

Recent discoveries on the origins of modern humans from multiple archaic hominin populations and the diversity of human papillomaviruses (HPVs) suggest a complex scenario of virus-host evolution. To evaluate the origin of HPV pathogenesis, we estimated the phylogeny, timing, and dispersal of HPV16 variants using a Bayesian Markov Chain Monte Carlo framework. To increase precision, we identified and characterized non-human primate papillomaviruses from New and Old World monkeys to set molecular clock models. We demonstrate specific host niche adaptation of primate papillomaviruses with subsequent coevolution with their primate hosts for at least 40 million years. Analyses of 212 HPV16 complete genomes and 3582 partial sequences estimated ancient divergence of HPV16 variants (between A and BCD lineages) from their most recent common ancestors around half a million years ago, roughly coinciding with the timing of the split between archaic Neanderthals and modern Homo sapiens, and nearly three times longer than divergence times of modern Homo sapiens. HPV16 A lineage variants were significantly underrepresented in present African populations, whereas the A sublineages were highly prevalent in European (A1-3) and Asian (A4) populations, indicative of viral sexual transmission from Neanderthals to modern non-African humans through multiple interbreeding events in the past 80 thousand years. Remarkably, the human leukocyte antigen B*07:02 and C*07:02 alleles associated with increased risk in cervix cancer represent introgressed regions from Neanderthals in present-day Eurasians. The archaic hominin-host-switch model was also supported by other HPV variants. Niche adaptation and virus-host codivergence appear to influence the pathogenesis of papillomaviruses.

Classification and evolution of human papillomavirus genome variants: Alpha-5 (HPV26, 51, 69, 82), Alpha-6 (HPV30, 53, 56, 66), Alpha-11 (HPV34, 73), Alpha-13 (HPV54) and Alpha-3 (HPV61)

HPV variants from the same type can be classified into lineages and sublineages based on the complete genome differences and the phylogenetic topologies. We examined nucleotide variations of twelve HPV types within the species Alpha-5 (HPV26, 51, 69, 82), Alpha-6 (HPV30, 53, 56, 66), Alpha-11 (HPV34, 73), Alpha-13 (HPV54) and Alpha-3 (HPV61) by analyzing 1432 partial sequences and 181 complete genomes from multiple geographic populations. The inter-lineage and inter-sublineage mean differences of HPV variants ranged between 0.9-7.3% and 0.3-0.9%, respectively. The heterogeneity and phylogenies of HPV isolates indicate an independent evolutionary history for each type. The noncoding regions were the most variable regions whereas the capsid proteins were relatively conserved. Certain variant lineages and/or sublineages were geographically-associated. These data provide the basis to further classify HPV variants and should foster future studies on the evolution of HPV genomes and the associations of HPV variants with cancer risk.

Clinical performance of multiplex high-risk e6 mrna expression in comparison with hpv dna subtypes for the identification of women at risk of cervical cancer

We compared multiplex E6 messenger ribonucleic acid (mRNA) tests using real-time quantitative reverse transcriptase polymerase chain reactions (PCR) with human papillomavirus (HPV) DNA subtypes using a MY11/GP6+ PCR-based reverse-blot assay to identify cervical intraepithelial neoplasias of grade 2 or worse (CIN2+). In total, 684 women were studied, of whom 377 (55%) were diagnosed with CIN2+ histologically. The specificity of HPV mRNA to predict histological CIN2+ was higher than that of HPV DNA (81.3% vs. 44.2%). The odds ratios (ORs) to predict histological CIN2+ in women with positive for type 16, 18, 31, and 45 E6 mRNA or by HPV DNA detection were 7.1 (95% confidence interval [CI] 3.9-13.1) and 2.5 (95%CI 1.9-3.5), respectively, compared to those with negative for E6 mRNA or HPV DNA. The OR to predict histological CIN2+ in women with a cytological grade <CIN2+ and positive for type 16, 18, 31, and 45 E6 mRNA was 9.7 (95%CI 3.2-29.2), compared to those with a cytological grade <CIN2+, and negative for E6 mRNA (OR = 1), those with a cytological grade CIN2+, and negative for mRNA (OR = 6.9, 95%CI 4.4-10.8), and those with a cytological grade CIN2+ and positive for mRNA (OR = 28.0, 95%CI 9.8-79.6). As a HPV DNA positive triage, the OR to predict histological CIN2+ in women with a cytological grade <CIN2+ and positive for mRNA was higher than those with negative for mRNA (OR:12.8 [95%CI 3.6-5.4] vs. OR:1.6 [95%CI 0.9-2.9]). In conclusion, multiplex HPV E6 mRNA detection can be used as a triage for women with cytological grade <CIN2+.

Meta-analysis on prevalence and attribution of human papillomavirus types 52 and 58 in cervical neoplasia worldwide

Objective

To estimate the prevalence and attribution of two non-vaccine-covered HPV types (HPV52 and HPV58) across the world.

Methods

Meta-analysis on studies reported in English and Chinese between 1994 and 2012.

Results

The pooled prevalence and attribution rates of HPV52 and HPV58 in invasive cervical cancers were significantly higher in Eastern Asia compared to other regions (HPV52 prevalence: 5.7% vs. 1.8–3.6%, P<0.001; HPV52 attribution: 3.7% vs. 0.2–2.0%; HPV58 prevalence: 9.8% vs. 1.1–2.5%, P<0.001; HPV58 attribution: 6.4% vs. 0.7–2.2%, P<0.001). Oceania has an insufficient number of studies to ascertain the prevalence of HPV52. Within Eastern Asia, the attribution of HPV58 to invasive cervical cancer was 1.8-fold higher than that of HPV52. Similarly, HPV52 and HPV58 shared a higher prevalence and attribution among cervical intraepithelial neoplasia in Eastern Asia. In contrast to the classical high-risk type, HPV16, the prevalence and attribution of HPV52 and HPV58 decreased with increasing lesion severity. Thus, HPV52 and HPV58 behave as an “intermediate-risk” type.

Conclusion

The attribution of HPV52 and HPV58 to cervical intraepithelial neoplasia and invasive cancer in Eastern Asia were respectively 2.5–2.8 and 3.7–4.9 folds higher than elsewhere. Changes in the attributed disease fraction can serve as a surrogate marker for cross-protection or type replacement following widespread use of HPV16/18-based vaccines. This unique epidemiology should be considered when designing HPV screening assays and vaccines for Eastern Asia.

Human papillomavirus and non-small cell lung cancer

Lung cancer is the most common cause of cancer-related deaths in the world, causing more than one million deaths worldwide each year. Human papillomavirus (HPV) are small non-enveloped DNA viruses that infect squamous epithelial cells. Relevant studies have reported lung cancer-related HPV infection rates that fluctuate between 10% and 80%, depending on the various research methods and geographical factors. Various scholars gathered statistics from global research reports and found that 22.4% of the patients with lung cancer presented with an HPV infection, which suggested that HPV infection may relate to the tumorigenesis of non-small cell lung cancer. This article will review the history and discovery of HPV, the correlation between HPV and lung cancer development, and carcinogenesis caused by HPV regulatory genes, such as p53, p21, p16INK4a, and genes related to hypermethylation and genome instability in lung cancer patients with HPV infection. In addition, because studies have highlighted the difference in clinical prognosis for HPV-positive and HPV-negative patients, articles demonstrating the correlation between HPV infection and prognosis for lung cancer patients will be reviewed.

Evolution and taxonomic classification of alphapapillomavirus 7 complete genomes: HPV18, HPV39, HPV45, HPV59, HPV68 and HPV70

BACKGROUND

The species Alphapapillomavirus 7 (alpha-7) contains human papillomavirus genotypes that account for 15% of invasive cervical cancers and are disproportionately associated with adenocarcinoma of the cervix. Complete genome analyses enable identification and nomenclature of variant lineages and sublineages.

METHODS

The URR/E6 region was sequenced to screen for novel variants of HPV18, 39, 45, 59, 68, 70, 85 and 97 from 1147 cervical samples obtained from multiple geographic regions that had previously been shown to contain an alpha-7 HPV isolate. To study viral heterogeneity, the complete 8 kb genome of 128 isolates, including 109 sequenced for this analysis, were annotated and analyzed. Viral evolution was characterized by constructing phylogenic trees using maximum-likelihood and Bayesian algorithms. Global and pairwise alignments were used to calculate total and ORF/region nucleotide differences; lineages and sublineages were assigned using an alphanumeric system. The prototype genome was assigned to the A lineage or A1 sublineage.

RESULTS

The genomic diversity of alpha-7 HPV types ranged from 1.1% to 6.7% nucleotide sequence differences; the extent of genome-genome pairwise intratype heterogeneity was 1.1% for HPV39, 1.3% for HPV59, 1.5% for HPV45, 1.6% for HPV70, 2.1% for HPV18, and 6.7% for HPV68. ME180 (previously a subtype of HPV68) was designated as the representative genome for HPV68 sublineage C1. Each ORF/region differed in sequence diversity, from most variable to least variable: noncoding region 1 (NCR1) / noncoding region 2 (NCR2) > upstream regulatory region (URR) > E6 / E7 > E2 / L2 > E1 / L1.

CONCLUSIONS

These data provide estimates of the maximum viral genomic heterogeneity of alpha-7 HPV type variants. The proposed taxonomic system facilitates the comparison of variants across epidemiological and molecular studies. Sequence diversity, geographic distribution and phylogenetic topology of this clinically important group of HPVs suggest an independent evolutionary history for each type.

Prevalence of human papillomavirus in university young women

Cervical cancer is the second most prevalent female cancer worldwide. The majority of cases appear between the age of 30 and 50. Human papillomavirus (HPV) plays a central role in cervical cancer with 99.7% of HPV DNA identified in invasive cervical carcinomas. The prevalence of the HPV infection varies substantially among countries and according to age and lifestyle. HPV is a common sexually transmitted infection among males and females with a 70% higher incidence in sexually active females. This study aimed to determine the prevalence of human papillomavirus in young university women by analyzing the correlation between Papanicolaou (PAP)-stained cervical tests and HPV detection by genotyping, as well as other risk factors. A total of 200 women aged between 18 and 25 years were enrolled in this study, which took place between September 2008 and May 2009 at the Universidad de Tarapacá, Arica, Chile. Results of the PAP smears showed that 97.5% of cells had normal characteristics, although an inflammatory pattern was noted. The prevalence of generic HPV infection was 3.5% when testing for HPV DNA using the polymerase chain reaction (PCR) method. An analysis of the genotype of infected female individuals indicated that high-risk HPV types, such as HPV 16 and 31 were present in 42.84 and 14.29% of females, respectively, and low-risk types such as HPV 6, in 14.29%. Only one sample with differentiated non-HPV (14.29%) was found. A 95% correlation between PAP-stained cervical tests and the method of testing for HPV was observed. Using the PCR method, it was found that of the 195 negative PAP smears, 5 were positive for HPV and two of the samples that were positive for ASC-US were also positive. A significantly increased (P<0.05) HPV infection risk was observed in the 18-21 age group with a higher prevalence (71.40%) when compared to the 22-25 age group (28.6%). A significant (P<0.042) difference was found between smoking and HPV infection. In conclusion, a significant (P<0.05) correlation was found between PAP and PCR methods for HPV testing in young university women. A significant correlation between smoking and HPV was detected, whereas no difference was noted with other parameters.

Human papillomavirus type 58: the unique role in cervical cancers in East Asia

Background

About 15 types of human papillomavirus (HPV) are classified as high-risk based on their epidemiological link with cervical cancer. These HPV types have deferent degrees of oncogenicity and their distribution among cervical precancers and cancers varies ethnogeographically. HPV58 is rare worldwide but being found more commonly in East Asia.

Findings

A high prevalence of HPV58 among squamous cell carcinoma has been reported from China (28% in Shanghai, 10% in Hong Kong and 10% in Taiwan) and other countries in East Asia including Korea (16%) and Japan (8%). HPV58 ranks the third in Asia overall, but contributes to only 3.3% of cervical cancers globally. The reasons for a difference in disease attribution may lie on the host as well as the virus itself. HLA-DQB1*06 was found to associate with a higher risk of developing HPV58-positive cervical neoplasia in Hong Kong women, but not neoplasia caused by other HPV types. An HPV58 variant (E7 T20I, G63S) commonly detected in Hong Kong was found to confer a 6.9-fold higher risk of developing cervical cancer compared to other variants. A study involving 15 countries/cities has shown a predilection in the distribution of HPV58 variant lineages. Sublineage A1, the prototype derived from a cancer patient in Japan, was rare worldwide except in Asia.

Conclusions

HPV58 accounts for a larger share of disease burden in East Asia, which may be a result of differences in host genetics as well as the oncogenicity of circulating variants. These unique characteristics of HPV58 should be considered in the development of next generation vaccines and diagnostic assays.

Cervical cytological changes in HIV-infected patients attending care and treatment clinic at Muhimbili National Hospital, Dar es Salaam, Tanzania

BACKGROUND

Tanzania is among Sub-Saharan countries mostly affected by the HIV and AIDS pandemic, females being more vulnerable than males. HIV infected women appear to have a higher rate of persistent infection by high risk types of human papillomavirus (HPV) strongly associated with high-grade squamous intraepithelial lesions (HSIL) and invasive cervical carcinoma. Furthermore, although HIV infection and cervical cancer are major public health problems, the frequency and HIV/HPV association of cervical cancer and HSIL is not well documented in Tanzania, thus limiting the development of preventive and therapeutic strategies.

METHODS

A prospective unmatched, case-control study of HIV-seropositive, ≥ 18 years of age and consenting non-pregnant patients attending the care and treatment center (CTC) at Muhimbili National Hoospital (MNH) as cases was done between 2005 and 2006. HIV seronegative, non-pregnant and consenting women recruited from the Cervical Cancer Screening unit (CCSU) at ORCI were used as controls while those who did not consent to study participation and/or individuals under < 18 years were excluded. Pap smears were collected for routine cytodiagnosis and P53 immunohistochemistry (IHC). Cervical lesions were classified according to the Modified Bethesda System.

RESULTS

A total of 170 participants from the two centers were recruited including 50 HIV-seronegative controls were from the CCSU. Ages ranged from 20-66 years (mean 40.5 years) for cases and 20-69 years (mean 41.6 years) for controls. The age group 36-45 years was the most affected by HIV (39.2%, n = 47). Cervicitis, squamous intraepithelial lesions (SIL) and carcinoma constituted 28.3% (n = 34), 38.3% (n = 46) and 5.8% (n = 7) respectively among cases, and 28% (n = 14), 34% (n = 17) and 2% (n = 1) for controls, although this was not statistically significant (P-value = 0.61). IHC showed that p53 was not detectable in HPV + Pap smears and cell blocks indicating possible degradation.

CONCLUSIONS

The frequency of SIL and carcinoma appeared to be higher among HIV-infected women on HAART compared to seronegative controls and as expected increased with age. HIV seropositive patients appeared to present earlier with SIL compared to those HIV seronegative suggesting a role of HIV in altering the natural history of HPV infection and cervical lesions. The absence of p53 immunoreactivity in HPV + lesions is indicative of the ability of HPV E6 proteins to interact with the tumor suppressor gene and pave way for viral-induced oncogenesis in the studied Tanzanian women.

Persistence of type-specific human papillomavirus infection and increased long-term risk of cervical cancer

BACKGROUND

Human papillomavirus (HPV) persistence is the pivotal event in cervical carcinogenesis. We followed a large-scale community-based cohort for 16 years to investigate the role of genotype-specific HPV persistence in predicting cervical cancer including invasive and in situ carcinoma.

METHODS

At the baseline examination in 1991-1992, 11,923 participants (aged 30-65 years) consented to HPV testing and cytology; 6923 participants were reexamined in 1993-1995. For HPV testing, we used a polymerase chain reaction-based assay that detected 39 HPV types. Women who developed cervical cancer were identified from cancer and death registries. Cumulative risks for developing cervical cancer among infected and persistently infected women were calculated by the Kaplan-Meier method.

RESULTS

Of 10,123 women who were initially cytologically normal, 68 developed cervical cancer. The 16-year cumulative risks of subsequent cervical cancer for women with HPV16, HPV58 (without HPV16), or other carcinogenic HPV types (without HPV16 or HPV58) were 13.5%, 10.3%, and 4.0%, respectively, compared with 0.26% for HPV-negative women. Women with type-specific persistence of any carcinogenic HPV had greatly increased risk compared with women who were HPV-negative at both visits (hazard ratio = 75.4, 95% confidence interval = 31.8 to 178.9). The cumulative cervical cancer risks following persistent carcinogenic HPV infections increased with age: The risks were 5.5%, 14.4%, and 18.1% for women aged 30-44 years, 45-54 years, and 55 years and older, respectively. However, newly acquired infections were associated with a low risk of cervical cancer regardless of age.

CONCLUSIONS

HPV negativity was associated with a very low long-term risk of cervical cancer. Persistent detection of HPV among cytologically normal women greatly increased risk. Thus, it is useful to perform repeated HPV testing following an initial positive test.

Integration of human papillomavirus correlates with high levels of viral oncogene transcripts in cervical carcinogenesis

A prospective, cross-sectional study was conducted to investigate the correlation between the integration of high-risk human papillomavirus and disease severity of cervical lesions. 720 liquid-based cytology specimens including 422 normal cytology, 78 low-grade squamous intraepithelial lesions, 172 high-grade squamous intraepithelial lesions, and 48 women with cervical cancers were examined using HPV blot and type-specific E6 PCR. Positive HPV DNA types 16, 18, 52 and 58 were examined for viral DNA using real-time PCR. Expression of E6 transcripts was 89.5% (pure integration), 71.7% (mixed type), and 47.1% (pure episomal) (p<0.0001). Geometric mean levels ranged from 110.6 (episomal form) to 508.4 (mixed form), and 5966.2 (integration form) by real-time PCR (p<0.0001). Geometric mean levels of E6 transcript in HPV 16, 18, 52, and 58 correlated with the severity of cervical lesions and the physical integration state of the viral genome (p<0.0001). We conclude that this is the first paper to point out that integration of high-risk HPVs not only 16 and 18 but also 52 and 58 is correlated with high levels of oncogene transcripts from normal cervix, CIN to cervical cancer.

Evolution and taxonomic classification of human papillomavirus 16 (HPV16)-related variant genomes: HPV31, HPV33, HPV35, HPV52, HPV58 and HPV67

Background

Human papillomavirus 16 (HPV16) species group (alpha-9) of the Alphapapillomavirus genus contains HPV16, HPV31, HPV33, HPV35, HPV52, HPV58 and HPV67. These HPVs account for 75% of invasive cervical cancers worldwide. Viral variants of these HPVs differ in evolutionary history and pathogenicity. Moreover, a comprehensive nomenclature system for HPV variants is lacking, limiting comparisons between studies.

Methods

DNA from cervical samples previously characterized for HPV type were obtained from multiple geographic regions to screen for novel variants. The complete 8 kb genomes of 120 variants representing the major and minor lineages of the HPV16-related alpha-9 HPV types were sequenced to capture maximum viral heterogeneity. Viral evolution was characterized by constructing phylogenic trees based on complete genomes using multiple algorithms. Maximal and viral region specific divergence was calculated by global and pairwise alignments. Variant lineages were classified and named using an alphanumeric system; the prototype genome was assigned to the A lineage for all types.

Results

The range of genome-genome sequence heterogeneity varied from 0.6% for HPV35 to 2.2% for HPV52 and included 1.4% for HPV31, 1.1% for HPV33, 1.7% for HPV58 and 1.1% for HPV67. Nucleotide differences of approximately 1.0% - 10.0% and 0.5%–1.0% of the complete genomes were used to define variant lineages and sublineages, respectively. Each gene/region differs in sequence diversity, from most variable to least variable: noncoding region 1 (NCR1) /noncoding region 2 (NCR2) >upstream regulatory region (URR)> E6/E7 > E2/L2 > E1/L1.

Conclusions

These data define maximum viral genomic heterogeneity of HPV16-related alpha-9 HPV variants. The proposed nomenclature system facilitates the comparison of variants across epidemiological studies. Sequence diversity and phylogenies of this clinically important group of HPVs provides the basis for further studies of discrete viral evolution, epidemiology, pathogenesis and preventative/therapeutic interventions.

Unique variants of human papillomavirus genotypes 52 and 58 and risk of cervical neoplasia

Human papillomavirus (HPV) 52 and 58 are oncogenic HPV types prevalent in Asia. Our study aims to explore intratypic variants of HPV 52 and 58 in Taiwan. A total of 11,923 women were enrolled from seven townships in 1991-1992. HPV DNA in their cervical cells was detected and typed by EasyChip® HPV blot. Among 424 participants infected with HPV 52 and/or 58, nucleotide variations were determined in cervical cell samples of 406 participants by the polymerase chain reaction sequencing of the long control region, E6 and E7 genes. Nonprototype-like variants including lineages B and C were detected in 278 (99.3%) of 280 HPV 52 samples. The prototype and prototype-like group (lineage A) of HPV58 was found in 132 (98.5%) of 134 HPV 58 samples, with sublineage A1, A2 and A3 variant in 14.2, 27.6 and 56.7%, respectively. Among women infected with single HPV 52 type, the C variant (vs. B variant) was associated with an increased prevalence of cytologically diagnosed high-grade squamous intraepithelial lesion or worse lesions showing an age-adjusted odds ratio (95% confidence interval, CI) of 5.2 (1.0-27.6) and an increased prevalence of histologically confirmed high-grade cervical intraepithelial neoplasia or more severe lesions with an age-adjusted odds ratio (95% CI) of 7.6 (1.3-43.8). It was concluded that frequency distributions of HPV 52 and 58 variants in Taiwan were different from those in European and American populations. The association between C variant of HPV 52 and prevalence of cervical neoplasia needs further validation.

Type-specific human papillomavirus oncogene messenger RNA levels correlate with the severity of cervical neoplasia

This study aimed to evaluate whether quantitation of high-risk human papillomavirus (HR-HPV) E6 messenger RNA (mRNA) can be a potential biomarker for detecting the severity of cervical lesions. HPV genotyping was performed using a modified MY11/GP6+ PCR for HPV DNA amplification, followed by HPV genotype-specific hybridization with on a gene chip. E6 type-specific PCR was used to validate multiple infections. Quantitative real-time reverse transcriptase (QRT-PCR) and real-time PCR used to measure mRNA levels and DNA viral loads of 6 HPV oncogenic types (HPV 16, 18, 31, 33, 52 and 58) in 720 liquid-based cytology samples. The HPV DNA and RNA measurements were correlated with cervical lesions diagnosed by histopathologic examination. mRNA transcripts in the 6 types HPV DNA-positive cases was lower in normal women and <CIN 1 (23%), women with CIN 1 (54%), CIN2+ (77%) and CIN3+ (80%) (p < 0.001). Geometric mean mRNA levels ranged from 24.5 (copies per 50 ng total RNA) in normal women and <CIN 1 to 210.8 in those with CIN 1, 629.0 in CIN2+ and 699.0 in CIN3+ (p < 0.0001). Trends of increasing viral mRNA with severity of histopathologic diagnosis were significant for HPV 16, 18, 52 and 58 transcripts but not for HPV 31 and 33 transcripts. However, geometric mean DNA viral loads of HPV 16, 18, 52 and 58 DNA did not significantly increase with the severity of cervical dysplasia. Therefore, quantitative HPV E6 mRNA levels of high-risk HPV types are potentially useful biomarkers for distinguishing among HPV infections, cervical precancerous lesions and cancer.

Cost-effectiveness of human papillomavirus vaccination for prevention of cervical cancer in Taiwan

BACKGROUND

Human papillomavirus (HPV) infection has been shown to be a major risk factor for cervical cancer. Vaccines against HPV-16 and HPV-18 are highly effective in preventing type-specific HPV infections and related cervical lesions. There is, however, limited data available describing the health and economic impacts of HPV vaccination in Taiwan. The objective of this study was to assess the cost-effectiveness of prophylactic HPV vaccination for the prevention of cervical cancer in Taiwan.

METHODS

We developed a Markov model to compare the health and economic outcomes of vaccinating preadolescent girls (at the age of 12 years) for the prevention of cervical cancer with current practice, including cervical cytological screening. Data were synthesized from published papers or reports, and whenever possible, those specific to Taiwan were used. Sensitivity analyses were performed to account for important uncertainties and different vaccination scenarios.

RESULTS

Under the assumption that the HPV vaccine could provide lifelong protection, the massive vaccination among preadolescent girls in Taiwan would lead to reduction in 73.3% of the total incident cervical cancer cases and would result in a life expectancy gain of 4.9 days or 8.7 quality-adjusted life days at a cost of US$324 as compared to the current practice. The incremental cost-effectiveness ratio (ICER) was US$23,939 per life year gained or US$13,674 per quality-adjusted life year (QALY) gained given the discount rate of 3%. Sensitivity analyses showed that this ICER would remain below US$30,000 per QALY under most conditions, even when vaccine efficacy was suboptimal or when vaccine-induced immunity required booster shots every 13 years.

CONCLUSIONS

Although gains in life expectancy may be modest at the individual level, the results indicate that prophylactic HPV vaccination of preadolescent girls in Taiwan would result in substantial population benefits with a favorable cost-effectiveness ratio. Nevertheless, we should not overlook the urgency to improve the compliance rate of cervical screening, particularly for older individuals.

Age-specific prevalence of infection with human papillomavirus in females: a global review

PURPOSE

Global data on age-specific prevalence of human papillomavirus (HPV) infection overall, and for high-risk HPV types 16 and 18, are essential for the future implementation of HPV prophylactic vaccines for cervical cancer prevention.

METHODS

A systematic review of peer-reviewed publications was conducted to summarize worldwide data on genital HPV-DNA prevalence in women. Studies with clear descriptions of polymerase chain reaction or hybrid capture detection assays were included.

RESULTS

A total of 346,160 women were included in 375 studies. Of 134 studies with age-stratified HPV prevalence data (116 low sexual risk populations, 18 high sexual risk populations), over 50% were from Europe and the Middle East (38%) and North America (19%), with smaller proportions from Asia and Australia (21%), Central and South America (11%), and Africa (10%). Across all geographical regions, data on HPV prevalence were generally limited to women over 18 years of age. Consistently across studies, HPV infection prevalence decreased with increasing age from a peak prevalence in younger women (< or =25 years of age). In middle-aged women (35-50 years), maximum HPV prevalence differed across geographical regions: Africa (approximately 20%), Asia/Australia (approximately 15%), Central and South America (approximately 20%), North America (approximately 20%), Southern Europe/Middle East (approximately 15%), and Northern Europe (approximately 15%). Inconsistent trends in HPV prevalence by age were noted in older women, with a decrease or plateau of HPV prevalence in older ages in most studies, whereas others showed an increase of HPV prevalence in older ages. Similar trends of HPV 16 and/or 18 prevalence by age were noted among 12 populations with available data.

DISCUSSION

Genital HPV infection in women is predominantly acquired in adolescence, and peak prevalence in middle-aged women appears to differ across geographical regions. Worldwide variations in HPV prevalence across age appear to largely reflect differences in sexual behavior across geographical regions. Further studies of HPV prevalence in adolescents are needed for all geographic regions.

The physical state of HPV16 infection and its clinical significance in cancer precursor lesion and cervical carcinoma

PURPOSE

Integration of high-risk human papillomavirus (HR-HPVs) into the host DNA has been proposed as a risk for cervical carcinogenesis. HPV-16 is the predominant high-risk type and its integration ration varied largely in different cervical cancer (CC) samples. The aim of this study was to evaluate the correlation between physical state of HPV16 infection and extent of cervical lesion, as well as the clinical significance of virus existing state.

METHODS

A total of 252 cases of paraffin-embedded blocks derived from cancer precursor lesion and cervical carcinoma samples were detected by HC-II for HR-HPV infection. HPV16 infection was confirmed by PCR and immunohistochemistry for HPV16 E7 simultaneously. The physical state of HPV16 infection were assessed by PCR for 3 overlapping fragments in E2 gene and multiple PCR for E2 gene and E7 gene.

RESULTS

The infection ratio of HR-HPV in normal cervical tissue, cervical intraepithelial neoplasia (CIN) I, CIN II, CIN III and cervical cancer were 15.0, 32.8, 54.3, 69.7, 93.8%, respectively. HR-HPV positive samples of 62.8% were infected with HPV16. The integration ratio of HPV16 in CIN III and cervical carcinoma were 35.7 and 58.1% respectively, both of which were significantly higher than that of CIN I and normal cervical tissues. The discrepancy was statistically significant (P < 0.05). Furthermore, it was observed that persistent virus infection and progression of cervical lesion were more common in CIN I with integrated HPV16 than that with episomal HPV16.

CONCLUSION

The integration ratio of HPV16 was accompanied by an increase in the grade of cervical lesion. The integrated state of HPV16 infection was strongly associated with persistent HPV infection and progression of cervical lesions.

Long-term outcomes of high-risk human papillomavirus infection support a long interval of cervical cancer screening

Knowing that infection of high-risk human papillomavirus (HPV) causes virtually all cervical cancer (CC), the long-term outcomes of HPV infection, especially the absolute risk and time lapse of developing CC, are beyond the scope of ordinary follow-up study owing to ethical concerns. The present study followed the natural history and long-term outcomes of HPV infection in a cohort of women by national health insurance care and data linkage without additional disturbance. The status of cervical HPV infection was determined in 1708 healthy women, aged 20–90 (median 43), enrolled from 10 hospitals in seven cities around the island country of Taiwan. Records of consecutive Pap smear results and cancer reports of 108 cytology-negative, HPV-positive and 1202 cytology- and HPV-negative women with no prior record of CC or abnormal cervical cytology were retrospectively analysed for a duration of up to 75 months (median 61 months). The cumulative incidences of high-grade squamous intraepithelial lesion (HSIL) and in situ/invasive cancer in HPV-positive women were 5.6 and 3.7%, respectively, and those in HPV-negative women were 0.3 and 0%. After adjusting for other risk factors, HPV-positive subjects had 24.9 (95% CI: 7.0–108.3; P<0.0001) folds of risk of developing HSIL or above cervical neoplasia as compared to HPV-negative subjects, whereas risk for low-grade intraepithelial lesion and atypical squamous cytology was not increased. The study showed that women with a prevalent infection of high-risk HPV had a 4% cumulative risk for CC in 6 years, whereas those tested negative had little risk. The result supports an HPV test-orientated CC screening programme with intervals of at least 5 years.

Seroprevalence of human papillomaviruses and Chlamydia trachomatis and cervical cancer risk: nested case-control study

A nested case-control study of invasive and in situ cervical cancer was performed within a community-based cohort of 13,595 Taiwanese women assembled in 1991, with a follow-up period of 9 years. Baseline serum or plasma samples were analysed for antibodies against human papillomavirus (HPV) types 6, 16 and 18 and Chlamydia trachomatis. In total, 114 cases (42 incident cases identified during follow-up and 72 prevalent cases identified at baseline) and 519 matched controls were included in the study. HPV-16 seropositivity was strongly associated with cervical cancer (OR=6.33; 95% CI 3.45-11.62). Overall, C. trachomatis was not associated with cervical cancer, but was associated with cervical cancer in analyses restricted to incident cases of cancer (OR=2.94; 95% CI 1.17-7.42) or to cases in which serum samples were analysed (OR=3.13; 95% CI 1.16-8.47). An antagonistic interaction between HPV-6 and -16 was found in a multiplicative model. These results suggest that different HPV types might interfere in cervical carcinogenesis and that C. trachomatis is associated with cervical cancer in prospective studies, and support the notion that HPV-16 seropositivity is strongly associated with cervical cancer.

The distribution and differential risks of human papillomavirus genotypes in cervical preinvasive lesions: A Taiwan Cooperative Oncologic Group Study

To clarify the distribution and relative risk of different human papillomavirus (HPV) genotypes in cervical preinvasive lesions, 1246 women with abnormal Papanicolaou smear including atypical squamous cell of unknown significance (ASCUS), atypical glandular cell of unknown significance (AGUS), low-grade squamous intraepithelial lesion (LSIL), and high-grade squamous intraepithelial lesion (HSIL) were enrolled in a multicenter, cross-sectional study. Colposcopy and HPV tests with hybrid capture 2 and polymerase chain reaction-reverse line blot were performed. The prevalences of HPV in ASCUS/AGUS-negative histology, ASCUS/AGUS, LSIL, HSIL, and invasive cancer were 33.8%, 38.3%, 74.9%, 84.3% and 100%, respectively, with an overall positive rate of 68.8%. The most common HPV types were HPV 16 (18.5%), 52 (16.5%), 58 (13.2%), 33, 51, 53, 18, 39, 59, 66, MM8, and 31. In comparing the relative risk of HPV infection in different disease status, LSIL and HSIL/carcinoma had a 4.64 (95% CI: 2.98-7.24) and 10.53 (95% CI: 6.69-16.58) folds of risk of high-risk HPV infection than the negative group. The same was true in mixed HPV infection, but not in low-risk type infection. Looking into each high-risk HPV type, the relative infection risks for LSIL and HSIL/carcinoma, in comparison with the negative group, were 1.67 (0.63-4.43) and 8.67 (3.46-21.70), 2017 (1.01-4.68) and 3.04 (1.42-6.47), and 1.40 (0.52-3.77) and 5.22 (2.07-13.19) for HPV type 16, 52 and 58, respectively. The study confirmed the high prevalence and risky nature of HPV 52 and 58 in Taiwanese population and conveyed the need to include these HPV types in vaccine development.

Human papillomaviral load changes in low-grade squamous intraepithelial lesions of the uterine cervix

To better predict risk of progression of low-grade squamous intraepithelial lesions (LSILs) of the uterine cervix in women with human papillomavirus (HPV) infections, 294 baseline cervical specimens from women with LSILs were evaluated. Specimens were tested for HPV DNA using hybrid capture 2 (HC2) and PCR-reverse line blotting. 65 LSILs with HPV DNA types 16, 18, 52, or 58 were examined for physical status, E2/E6 ratio and viral load at two time points, along with patient age. Women with LSILs whose viral loads increased between baseline and 6 month follow-up had a 45% risk of developing HSIL (OR=7.6, 95% CI=1.9–29.4, P<0.01), as evaluated by real-time PCR and a 44% risk (OR=6.1, 95% CI=1.6–22.7, P<0.01), as evaluated by HC2. The two viral load measures correlated well (Person's coefficient, r=0.687, P<0.001). Such evaluations of viral load changes (increased or not increased) through repeat HPV DNA testing could predict progression of disease in LSIL cases of HPV types 16, 18, 52, and 58, which correlates to clinical implications.

Differential viral loads of human papillomavirus 16 and 58 infections in the spectrum of cervical carcinogenesis

Human papillomavirus (HPV) load was reported to be related to the severity of cervical neoplasia but with controversy. The viral load-disease severity relationship was showed in HPV 16, but no study was made in HPV 58, the second most prevalent HPV in cervical cancer in East Asia. We studied cervical HPV loads in HPV 16- and HPV 58-infected cases of normal, low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL), and invasive cervical cancer (CC) by using quantitative polymerase chain reaction (Q-PCR) with type-specific primers in defined cell number. With the exception of HPV 16 infection in normal, viral loads varied greatly in each disease regardless of genotypes. The load of HPV 16 differed significantly among disease severities, with a dramatic increase from normal (1.14 +/- 2.25 copies/cell) to LSIL, HSIL, and CC (1599 +/- 2301, 7489 +/- 24,087 and 1878 +/- 2979 copies/cell, respectively) (P < 0.01). No significant difference was noted among different HPV 58 infections, with loads in normal, LSIL, HSIL, and CC of 503 +/- 641, 7951 +/- 27,557, 353 +/- 744, and 1139 +/- 2895 copies/cell, respectively. In comparison with HPV 16, HPV 58 subclinical infection confers a significant higher load (P < 0.01). Different HPV types behave differentially in the spectrum of cervical carcinogenesis. Unlike HPV 16, the infection load of HPV 58 does not correlate to the clinical severity. The wide variation of HPV loads among different HPV types and among squamous intraepithelial lesions and CC makes the viral load test unrealistic in differentiating different severities of cervical neoplasia.

Integrated human papillomavirus types 52 and 58 are infrequently found in cervical cancer, and high viral loads predict risk of cervical cancer

OBJECTIVE

The aim of this prospective study was to analyze whether integration or high viral loads of human papillomavirus (HPV) is essential for malignant transformation of HPV types 52 and 58 as well as types 16 and 18.

METHODS

Cervical swabs from 178 consecutive patients, including 81 with invasive cervical cancers and 97 with cervical intraepithelial neoplasias (CIN) II-III, were collected and examined to determine the physical status and viral load of HPV types 16, 18, 52 and 58 DNA using genechip and real-time PCR (polymerase chain reaction) analysis.

RESULTS

In cervical cancer patients, the integrated form of HPV 52 and 58 DNA was found in 25.0% and 12.5% of swabs, respectively; while HPV16 and 18 DNA was found in 82.6% and 100% of swabs, respectively (P < 0.01, for pair-wise comparison of types 16, 18 versus types 52, 58). The viral loads reflected by the amount of E6 for HPV 16, 18, or 52 were significantly increased in invasive cervical cancer compared to CINII-III (P = 0.022 for type 16, P = 0.003 for type18, and P = 0.001 for type 52, respectively). Area under the receiver operating characteristic (ROC) curve for cervical cancer versus CIN II-III was 73.8%, 92.9%, and 88.5% for HPV 16, 18, and 52, respectively, indicating that real-time PCR had good diagnostic value in differentiating cervical cancer from CIN II-III.

CONCLUSIONS

Infrequent integration of HPV 52 and 58 DNA in cervical cancer suggests that it is not prerequisite for progression to cervical cancer. High viral loads (E6) of HPV 16, 18, and 52 DNA may be predictive of the transition of CIN II-III to cervical cancer. Our results indicate that both viral DNA physical status and viral loads of HPV are important factors in the carcinogenesis of different HPV types.

Associations of high-risk HPV types and viral load with cervical cancer in China

BACKGROUND

Cervical cancer is the second most common cancer in women worldwide. Infection with some genotypes of human papillomavirus is the most important risk factor associated with cervical cancer.

OBJECTIVE

The aim of this study was to determine the prevalence and genotypes of HPV in China, and to evaluate the correlation between viral load of high risk HPV and cervical cancer and its precursors.

STUDY DESIGN

A cross-sectional study was carried out, wherein cervical samples were collected from 541 patients with cervical cancer, 262 with CIN, 139 with cervicitis and 68 age-matched healthy controls. Hybrid Capture 2 was employed to detect HPV DNA. Specimens from HPV DNA positive cervical cancer were tested for HPV types by using type specific PCR and general primer PCR with sequence-based typing (GP PCR-SBT).

RESULTS

Overall high risk HPV prevalence was 68.8% in CIN1, 80.3% in CIN2, 90.2% in CIN3, 90.9% in cervical cancer in situ, 89.9% in invasive cervical cancer and 25% in healthy controls from China. The most common HPV DNA type found in patients with cervical cancer was HPV16 (79.6%), followed by HPV58 (5.92%), HPV33 (3.29%), HPV18 (1.97%), HPV6 (1.97%), HPV31 (1.31%), HPV39 (1.31%), HPV68 (1.31%) and other HPV types (3.3%). It was found that there was a significantly increased risk of increasing CIN stage with high viral load. Frequency of low viral load found in the controls was 13.2% and 22.9% of CIN1, obtaining an OR of 4.2 (1.5-12.0). Associations (OR) among low viral load and CIN2/3, CIS, and CC were 6.7 (2.9-15.6), 9.4 (2.7-32.3) and 8.3 (3.7-18.4), respectively. While high viral loads were found in 5.9% of controls, 27.1% of CIN1, 42.1% of CIN2/3 and 48.5% of CIS, demonstrating increasing odds ratios with severity of disease (OR for CIS=68.0, 95% CI=17.8-259.7).

CONCLUSIONS

HPV16 was the most common genotype in central China. The developing cervical cancer precursors were associated with elevated high-risk HPV viral load.

Association between quantitative high-risk human papillomavirus DNA load and cervical intraepithelial neoplasm risk

Human papillomavirus (HPV) infection is a high-risk factor for cervical intraepithelial neoplasm (CIN) but the association between the quantitative HPV DNA load and the severity of CIN remains controversial. We conducted a community study to investigate the correlation between the two. Potential study subjects were selected through Pap smear screening in Kaohsiung County, Taiwan. Ninety-one subjects with either their first case of inflammation or > or =CIN1 by biopsy confirmation were assigned to a case group; 175 normal subjects with negative findings by Pap smears or biopsies were assigned to a control group. Cervical HPV load was detected with Hybrid Capture II assay for high-risk HPV infection, with nested PCR for high- and low-risk HPV infection, and with type-specific PCR for HPV type 16 (HPV-16). Individuals with positive high-risk HPV infection had an increased risk of developing CIN. Compared with HPV-negative subjects, the odds ratios were 32.2 [95% confidence interval (95% CI), 10.4-99.5] for subjects with CIN1, 37.2 (95% CI, 7.4-187.6) for subjects with CIN2, and 68.3 (95% CI, 14.1-328.5) for subjects with > or =CIN3 after adjusting for other confounding factors. The similar trend was also found among the HPV-16-negative individuals. In addition, high-risk HPV DNA load levels were highly correlated with the different grades of CINs in the overall population (Spearman's correlation coefficient r = 0.67, P < 0.0001, n = 266) and the HPV-16-negative population (Spearman's correlation coefficient r = 0.58, P < 0.0001, n = 234). We concluded that high-risk HPV infection, irrespective of HPV-16 infection, was highly and positively associated with the development of CIN.

HLA-B alleles, high-risk HPV infection and risk for cervical neoplasia in southern Chinese women

A population-based study was conducted on 256 southern Chinese with cervical intraepithelial neoplasia grade III (CIN III) or invasive cervical cancer (ICC) and on 258 controls to examine the associations between HLA-B alleles, infection with high-risk human papillomaviruses (HPVs) and the development of cervical neoplasia. HLA-B15 was found to be protective for CIN III/ICC overall (p(corrected) = 0.003), and for HPV52-positive CIN III/ICC (p(corrected) = 0.003). A marginal protective effect of B15 was observed for HPV16-positive CIN III/ICC, but no significant associations were revealed for HPV18- or HPV58-positive cases. None of the HLA-B alleles were found to confer an increased risk for cervical neoplasia. HLA-B15 is common among Asian for whom HPV52, a worldwide uncommon HPV type, also exists in a relatively high prevalence. It would also be worthwhile to assess the association between HLA-B15, HPV52 and cervical cancer in other Asian populations.

Risk stratification of patients with advanced squamous cell carcinoma of cervix treated by radiotherapy alone

PURPOSE

To identify prognostic factors for local and distant relapse and perform risk stratification for patients with advanced cervical cancer treated with radiotherapy (RT) alone.

METHODS AND MATERIALS

A total of 1031 patients with Stage IB-IVA squamous cell carcinoma of the cervix treated with full-course RT but without any chemotherapy were included for analysis. Of these, 311 patients with nonbulky Stage IB-IIA disease were designated the reference group and the other 720 patients were the study group. The associations of stage, squamous cell carcinoma antigen (SCC-ag) level, hemoglobin level, age, cell differentiation, and pelvic lymph node status with treatment failure were evaluated. The independent prognostic factors were identified by multivariate analysis. The study group was further stratified into subgroups using combinations of these risk factors.

RESULTS

In the study group, independent risk factors for local relapse were advanced stage and age <45 years. The 5-year local relapse-free survival rate was 86% for patients > or =45 years with bulky Stage IB-IIA or IIB disease, and was even greater, up to 90% if the SCC-ag level was <2. In contrast, it was 65% for patients with Stage IIIB who were <45 years old. The independent risk factors for distant failure were advanced stage, SCC-ag level >2, and positive pelvic lymph nodes. The 5-year distant relapse-free survival rate was 83% for patients with bulky Stage IB-IIA and IIB disease, SCC-ag level <2, and negative lymph nodes and 43% for patients with Stage III, SCC-ag level >2, and positive lymph nodes.

CONCLUSION

The risk of treatment failure in advanced-stage cervical cancer patients treated by RT alone can be more precisely predicted by risk stratification. A certain subgroup of patients had better control than the others. The benefit of treating these relatively low-risk patients with additional treatment such as concurrent chemotherapy should be further evaluated in prospective studies or meta-analyses.

Detection of high-risk human papillomavirus E6 and E7 oncogene transcripts in cervical scrapes by nested RT-polymerase chain reaction

The oncogenic potential of the high-risk human papillomavirus (HPV) genotypes (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68) depends on the expression of the two viral oncogenes E6 and E7. Thus, the detection of HPV E6/E7 oncogene transcripts could serve as a factor in the evaluation of a risk of development of cervical intraepithelial neoplasia (CIN) and its progression to cervical cancer. A nested RT-PCR assay for the detection of E6/E7 oncogene transcripts of all known high-risk HPV genotypes was established. In the study described, 779 high-risk HPV-DNA-positive cervical scrapes exhibiting all grades of CIN, including non-dysplastic cervical mucosa (CIN 0), were examined. Spliced E6/E7 oncogene transcripts of all the high-risk HPVs were detected in numerous samples, with an overall detection rate of 47%. In 227 cases with agreement between the cytologic and histologic findings, the prevalence increased with lesion severity: CIN 0, 18%; CIN I, 58%; CIN II, 77%; CIN III, 84%. Multiple transcriptionally active high-risk HPVs were detected in 12% (33/279) of patients with multiple high-risk HPV infections. This work sets the stage for a prospective follow-up study currently being undertaken to evaluate the prognostic relevance of the detection of high-risk HPV E6/E7 oncogene transcripts for the persistence of a high risk HPV infection, and the possible evolution and further development of a CIN. Future applications of the assay described may include the monitoring of women in studies investigating antiviral treatment or vaccination.

Influence of beliefs about cervical cancer etiology on Pap smear use among Latina immigrants

OBJECTIVE

To assess Latina immigrants' beliefs about the role of sexual activities in cervical cancer etiology and the impact of the beliefs on Papanicolaou (Pap) smear use. Previous research has found that Latinas, particularly immigrants, believe that cervical cancer is related to 'unwise' sexual activities; however, their beliefs about the nature of the relationship are unclear.

DESIGN

We conducted semi-structured face-to-face interviews with a non-probability purposive sample of 20 Mexican immigrant women who resided in Orange County, California regarding their beliefs about risk factors for cervical cancer and Pap smear use. We used qualitative content analysis to identify major themes. Three investigators independently reviewed transcripts of the audio-taped interviews to identify themes and came to a consensus about them.

RESULTS

The women had a mean age of 39 years and had resided in the USA for an average of 16.3 years. We identified several themes. The majority of respondents had limited knowledge about cervical cancer and no knowledge about human papillomavirus (HPV); believed that infections caused by physical trauma, certain sexual activities, and poor hygiene caused cervical cancer; believed that they only needed a Pap smear if they developed symptoms of a pelvic infection; and felt that women who engaged in 'unwise' sexual behaviors, in particular, should receive regular Pap smear exams.

CONCLUSION

The results suggest that culturally related beliefs about the etiology of cervical cancer play a role in the decision to obtain Pap smears for Latina immigrants. The findings may help to explain why researchers have found Latino ethnicity to be an independent predictor of Pap smear use. They also suggest that programs designed to improve cervical cancer screening, particularly among Latina immigrants, should stress the nature of HPV transmission, its role in the etiology of cervical cancer, and the importance of Pap smear screening in the absence of symptoms.

Estrogen receptor, progesterone receptor, and bcl-2 are markers with prognostic significance in CIN III

There are no known biological markers or technologies to predict the natural history of an individual CIN III. The probability of progression is considered greater with the persistence of high-risk human papillomavirus (HPV) infection and age. p53 polymorphism has been associated with cervical carcinogenesis. Hormone-induced cervical cancer is mediated by estrogen receptor (ER) and progesterone receptor (PR). In cervical cancer, increased bcl-2 and Bax immunoreactivity is generally associated with a better prognosis. The purpose of this study was to evaluate the value of HPV 16 and HPV 18 typing and p53 codon polymorphism genotyping by polymerase chain reaction and ER, PR, bcl-2, and Bax expression by immunohistochemistry in predicting the CIN III clinical behavior of CIN III lesions. We studied the expression of these prognostic factors in the CIN III adjacent to squamous cell microinvasive carcinomas of the cervix (MIC) from 29 patients with FIGO stage IA1 cervical cancer and in 25 patients with CIN III and no documented focus of invasion. In the MIC group, only the CIN III was considered at least 2 mm away from the microinvasive complex. The ER, PR, bcl-2, and Bax immunoreactivity was scored as positive (>10% staining cells) and negative (<10% staining cells). No significant difference was observed between MIC and CIN III group concerning HPV infection and p53 polymorphism. The ER, PR, bcl-2, and Bax immunohistochemical expression was stronger and more frequent in the CIN III group. After multivariable analysis, coexpression of ER, PR, and bcl-2 was the only independent factor in defining low risk of progression for CIN III. Our study suggests that coexpression of ER, PR, and bcl-2 may be a useful tool in identifying the CIN III lesions with low risk of progression to cervical cancer.

Comparative analysis of characteristics of women with cervical cancer in high- versus low-incidence regions

OBJECTIVE

To identify particular characteristics that might help explain the markedly higher rate of invasive cervical cancer in southern China as compared with Australia.

METHODS

One hundred eighty-five women with cervical cancer were recruited between 1999 and 2001: 106 from Guangzhou and Changsha (southern China), and 79 from Sydney (southeast Australia). Demographic and risk factor information was obtained by questionnaire; clinicopathologic data were extracted from hospital records. The human papillomavirus (HPV) status of cancer biopsies was ascertained by consensus PCR assays, direct sequencing and/or Amplicor trade mark hybridisation.

RESULTS

The mean age of the Chinese was significantly lower than the Australians (44 versus 53 years), although mean age at first sexual intercourse was similar. Australian women were more likely to smoke, to report multiple sexual partners and to have a history of sexually transmitted diseases (but not of genital warts). However, they were better educated, were more frequent users of barrier contraception and were far more likely to report regular Pap smears before diagnosis. The HPV positivity rate of Chinese cancers (83%) was less than Australian tumours (90%); but HPV 16 and 18 were the most common genotypes in both populations (59% and 77%), and predominated in cancers from younger women. HPV types 58 or 59 were amplified from 12 (14%) of the Chinese but from only one Australian cancer.

CONCLUSIONS

Cervical cancer is not only more common in China but also develops at a younger age than in Australia. While significant differences in some risk factors were observed, the much lower participation in cervical screening in southern China is likely to be of greatest consequence.

Cervical cancer among Hmong women in California, 1988 to 2000

BACKGROUND

The Hmong immigrated to the United States from Laos after the Vietnam conflict ended. Hmong encounter numerous readjustment issues, including health care. Traditional Hmong health beliefs and practices encompass more spiritual than biological etiologies. Hmong usually seek the first course of treatment from traditional healers, as they had in Laos. This practice delays early diagnosis and treatment of disease because biomedicine is used only as a last resort. This study examined cervical cancer incidence, mortality, and other tumor characteristics in the Hmong female population of California between 1988 and 2000.

METHODS

Data from the California Cancer Registry were used to calculate annual average incidence, mortality, and age-specific rates for Hmong women diagnosed with cervical cancer. The population at risk was estimated with linear interpolation using data from the 1990 and 2000 censuses.

RESULTS

Hmong women experienced incidence and mortality rates three and four times higher than Asian/Pacific Islander and non-Hispanic white women, respectively. Fifty-one percent of Hmong women chose no treatment, compared to 5.8% for Asian/Pacific Islander women and 4.8% for non-Hispanic white women. Hmong women aged >/= 40 years carried an unequal burden of cervical cancer. They were more likely to be diagnosed with cervical cancer at later stages and poorer histologic grades, and had a lower survival rate than younger Hmong females.

CONCLUSIONS

Cervical cancer is clearly a public health issue that threatens the health and well-being of Hmong women. Culturally sensitive screening and prevention programs need to be developed to target older Hmong women using bilingual and bicultural Hmong women health educators using verbal communication.

Restriction fragment length polymorphism of L1 amplicon using Rsa 1 detects five different human papillomavirus types and their co-infections among women attending a gynaecological outpatient department

Detection of human papillomavirus (HPV) types 6, 11, 16, 18, and 33 including co-infections among females attending gynaecological outpatient department and cancer clinics, was done by restriction fragment length polymorphism (using Rsa-1), of approximately 450bp amplicon, obtained by the amplification of the L1 region of HPV genome with consensus primers MY09/11 [Cancer Cells 7 (1989) 209]. The results were further tested with HPV type specific primers [J. Med. Virol. 29 (1989) 20]. The technique was found to be low-cost and less time consuming. The advantage of Rsa 1 over other enzymes was that it detects the five most prevalent HPV types commonly associated with warts, cervical dysplasia, and cancer.

Correlation between histological criteria and human papillomavirus presence based on PCR assay in cervical biopsies

The aim was to correlate histological findings in cervix lesions to human papillomavirus (HPV), as detected by polymerase chain reaction (PCR). One hundred and seven women with atypical Pap smear were submitted to colposcopic examination, and suspicious images were biopsied. The PCR assay was performed with the primers MY09/11 and GP05/06+ and, as control, the beta-globin gene was amplified. The morphological findings were correlated to HPV positivity: parakeratosis, acanthosis, koilocytotic atypia (KA), binucleation, dyskeratosis, and number of mitoses. From 107 patients, 61 biopsies were taken: 11 chronic cervicitis (CC), 36 cervical intraepithelial neoplasia (CIN) (13 CIN I; 10 CIN II; 13 CIN III), and 14 suggestive for HPV (SHPV). DNA extraction was not possible in eight cases. HPV was found in 35% CC, 77% CIN, and 64% SHPV. The analysis did not indicate any morphological criteria strongly related to HPV. The findings with highest sensitivity for HPV were KA (88.89%) and binucleation (75%), but with low specificity of 29.41 and 52.94%, respectively. The higher predictive positive values (PV+) for HPV were also KA (72.73%) and binucleation (77.14%). Considering KA, dyskeratosis and binucleation together, PV+ was 72.41%.

CONCLUSION

Although indicative, none of the studied morphological criteria was always related to PCR virus detection, denoting some limitations for histological diagnosis.

Characterization of human papillomavirus infection, P53 and Ki-67 expression in cervix cancer of Mozambican women

In this study, we aimed at evaluating the distribution of HPV types and the expression of P53 and Ki-67 in cervix carcinomas of Mozambican women. Fourty-seven invasive carcinomas, 10 CIN III, and 10 normal cervix were studied. P53 and Ki-67 expression was examined immunohistochemically. HPV infection and HPV types were detected by PCR (GP5+/bio-GP6+) and enzyme-immunoassay, respectively. Expression of P53 and Ki-67 and detection of HPV were as follows: normal cervix--0%, 10%, and 0%, respectively; CIN III--10%, 0%, and 100%, respectively; invasive carcinomas--50%, 55.5%, and 70%, respectively. HPV 16 was identified in 54% of invasive carcinomas, HPV 31, 33, 35, and 45 in 23%, "unidentified" HPV in 19%, and HPV 18 in 4% of invasive carcinomas. No significant associations were observed between P53 expression, Ki-67 expression, and HPV infection. In conclusion, we observed a high frequency of HPV infection in CIN III lesions and invasive carcinomas from Mozambican women, with HPV 16 representing the most frequent viral type. HPV status was not related to P53 and Ki-67 expression. Both P53 and Ki-67 are associated with invasive cervix carcinomas, mainly of the squamous keratinizing histotype.

Chapter 1: Human papillomavirus and cervical cancer--burden and assessment of causality

Cervical cancer remains the second most common cancer in women worldwide and the most frequent in developing countries. Pre-neoplasic cervical lesions represent an additional burden in countries where screening is widespread. The human papillomavirus (HPV) prevalence and type distribution in normal smears and in cancer specimens are being described and show relatively small international variation. State-of-the-art detection techniques have unequivocally shown that HPV-DNA can be detected in 95% to 100% of adequate specimens of cervical cancer, supporting the claim that HPV is the necessary cause. The odds ratios for cervical cancer related to a cross sectional detection of HPV-DNA range from 50 to several hundred in all studies. The risk for any of 15 high-risk types is not statistically different from the risk reported for HPV16. The estimates of the attributable fraction range from 90% to 98%. Additional work should be done in providing information on incidence of cervical cancer and on HPV infection in areas where the disease is common. Theoretical work including modeling of the incidence could be of potential use in the evaluation of the existing and novel preventive strategies. Research is currently being conducted on the mechanisms of HPV carcinogenesis. These include the determinants of the systemic and cellular immune response to the viral infection, the interaction between the host and the virus and the relevance of the different strains and variants of the HPV viral types. Technology developments in this area suitable for epidemiological studies are needed.

Decreased expression of human papillomavirus E2 protein and transforming growth factor-beta1 in human cervical neoplasia as an early marker in carcinogenesis

BACKGROUND AND OBJECTIVES

Human papillomavirus (HPV) is thought to be one of the possible causative factors in cervical carcinogenesis, and cervical carcinoma cells are refractory to tumor transforming growth factor (TGF)-beta1. The purpose of this study is to investigate the possible cause-effect association between HPV and TGF-beta1 during cervical tumorigenesis.

METHODS

We assessed the expression of HPV capsid proteins, HPV-16 E7, HPV-16 E2 (C and N terminals), TGF-beta1, and their receptors TGF-beta RI and RII by immunohistochemistry in 48 paraffin-embedded blocks of tumor tissue derived from patients of cervical neoplasia.

RESULTS

Expression of TGF-beta1 decreased as tumor cells progressed from cervical intraepithelial neoplasia (CIN)1, CIN2, CIN3, to microinvasive carcinoma (P < 0.05). Levels of TGF-betaRI and TGFbeta-RII stayed the same in all cases. HPV was found in 89.6% of the studied sections, and cervical lesions without HPV infection expressed significantly less TGF-beta1 (P < 0.05). By comparing the expression pattern of TGF-beta1 and HPV in the neoplastic cells with that of normal cervical epithelium in each section, we found loss of HPV-16 E2 higher in CIN3 (15/24) than in CIN1 or CIN2 (3/7), and there is a significant trend that loss of HPV-16 E2 expression correlated with a >50% loss of TGF-beta1 at the lesion site (P < 0.05).

CONCLUSIONS

Our result showed co-suppression of HPV and TGF-beta1 expression during progression of cervical squamous cell cancer. Using antibody against HPV-16 E2 may be an auxiliary tool for the investigation of cervical tumor progression.

Meta-analysis of social inequality and the risk of cervical cancer

Previous studies of the relationship between socio-economic status and cervical cancer have been mainly based on record linkage of routine data, such as cancer registry incidence rates and regional measures of social class based on census data. These routine data are liable to substantial misclassification with respect to socio-economic status. Previous reports are also primarily from developed countries, whereas the major burden of cervical cancer is in developing countries. We have therefore pooled the data from previously reported case-control studies of cervical cancer or dysplasia, which contain individual-level information on socio-economic characteristics to investigate the relationship between cervical cancer, social class, stage of disease, geographical region, age and histological type. Based on 57 studies, we found an increased risk of approximately 100% between high and low social class categories for the development of invasive cervical cancer, and an increased risk of approximately 60% for dysplasia, including carcinoma in situ. Although the difference was observed in all countries, it was stronger in low/middle income countries and in North America than in Europe. No clear differences were observed between squamous cell carcinoma and adenocarcinoma, or between younger and older women. These results indicate that both cervical infection with human papillomavirus, which is linked to both female and male sexual behaviour, and access to adequate cervical cancer screening programmes are likely to be important in explaining the large cervical cancer incidence rates observed in different socio-economic groups, and that the importance of these factors may vary between different geographical regions.

Prevalence of specific types of human papillomavirus and cervical squamous intraepithelial lesions in consecutive, previously unscreened, West-African women over 35 years of age

Previous studies among women worldwide have demonstrated that infection with specific types of human papillomaviruses (HPV) is central to the pathogenesis of cervical neoplasia. There is little data, however, concerning the prevalence of specific HPV types and the association of each type with cervical neoplasia among women in sub-Saharan Africa, who remain at very high risk of cervical cancer. We studied 2,065 consecutive patients aged 35 years or older, presenting to community health clinics in Dakar and Pikine, West Africa, who had not been screened previously for cytologic abnormalities or HPV. Cytologic diagnosis and HPV detection were accomplished using a ThinPrep Pap and a polymerase chain reaction-based reverse-line strip assay, respectively. Odds ratios (OR) and associated 95% confidence intervals (CI) were estimated using polynomial logistic regression. Cytologic abnormalities were found in 426 women (20%), including 254 (12%) with atypical squamous cells of undetermined significance, 86 (4%) with low-grade squamous intraepithelial lesions, 66 (3%) with high-grade squamous intraepithelial lesions (HSIL) and 20 (1%) with invasive cancer. HPV infection was detected in 18%. Among women with negative cytologic findings, the prevalence of high risk but not low risk HPV types increased with age. HPV16 (2.4%) and HPV58 (1.6%) were the most frequently detected HPV types in this population, as well as being the most strongly associated with risk of HSIL/cancer (HPV16: OR = 88, 95% CI = 39-200; HPV58: OR = 51, 95% CI = 16-161). These data suggest that in addition to HPV16, HPV58 should be considered in the strategic planning of vaccination against cervical cancer in this geographic region.

Cost-effectiveness of a potential vaccine for human papillomavirus

Human papillomavirus (HPV) infection, usually a sexually transmitted disease, is a risk factor for cervical cancer. Given the substantial disease and death associated with HPV and cervical cancer, development of a prophylactic HPV vaccine is a public health priority. We evaluated the cost-effectiveness of vaccinating adolescent girls for high-risk HPV infections relative to current practice. A vaccine with a 75% probability of immunity against high-risk HPV infection resulted in a life-expectancy gain of 2.8 days or 4.0 quality-adjusted life days at a cost of $246 relative to current practice (incremental cost effectiveness of $22,755/quality-adjusted life year [QALY]). If all 12-year-old girls currently living in the United States were vaccinated, >1,300 deaths from cervical cancer would be averted during their lifetimes. Vaccination of girls against high-risk HPV is relatively cost effective even when vaccine efficacy is low. If the vaccine efficacy rate is 35%, the cost effectiveness increases to $52,398/QALY. Although gains in life expectancy may be modest at the individual level, population benefits are substantial.