HPV types and cofactors causing cervical cancer in Peru

The contribution of Latin American research to HPV epidemiology and natural history knowledge

Our aim was to review the major contributions of studies conducted in different Latin American (LA) countries to the field of human papillomavirus (HPV) epidemiology, natural history, risk of disease, and prevention strategies, mainly in the uterine cervix. Although cytological screening is established in several countries in LA, incidence and mortality rates from cervical cancer (CC) are still extremely high. Finally, data from large cohort studies conducted in LA countries provided seminal data to propose primary and secondary prevention modalities: the HPV vaccine has been introduced in the national immunization programs of several LA countries and multiple screening experiences using HPV testing are under evaluation in the region.

Frequency and coinfection between genotypes of human papillomavirus in a population of asymptomatic women in northern Peru

Objective

Describe the prevalence of HPV genotypes via PCR and DNA sequencing in 397 women who attended to the gynecological outpatient center in the Hospital Regional Docente de Cajamarca from March to September 2017.

Results

A positive PCR result for HPV was observed in 121 cervical samples. A high-risk genotype was found in 63.6% (77/121) of patients, a probably oncogenic type in 23.1% (28/121) and a low-risk type in 7.4%. Among the high-risk genotypes, HPV-31 was the most common one present in 20% (21/77), followed by HPV-16 in 11.4% (12/77). Coinfections between two or more genotypes were observed in 12 cases.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3644-7) contains supplementary material, which is available to authorized users.

Frequency of Human papillomavirus in women attending cervical cancer screening program in Chile

Background

Human papillomavirus (HPV) is the etiological factor for cervical cancer and its precursor lesions. The characterization of HPV genotypes in preneoplastic lesions and cervical cancer could establishes the effectiveness of vaccination plan in Chilean population. The aim of this study was to determine HPV frequency in a group of women including in a cervical screening program in the public health care system in Chile.

Methods

We analyzed 985 cervical smears samples from women with different histological diagnosis, attending to public health care in Temuco-Chile between 2004 and 2012, to detect HPV genotypes, through PCR followed by reverse line blotting assay.

Results

HPV was found present in 80.8% (n = 796) of samples. Only a 5.6% of 985 samples were infected with a low-risk HPV, considering multiple infections. 10.5% (n = 8/76) of normal cervical epithelia, 83.5% (n = 208/249) and 87.6% (n = 557/636) of low and high grade squamous intraepithelial lesions, respectively, and 95.8% (n = 23/24) of squamous cervical carcinomas tested positive for HPV. HPV 16 was the most frequent genotype found (Overall 44.9%, n = 442/985; SCC: 62.5%, n = 15/24). A high variability of HPV types was also found in preneoplastic lesions, whereas there was a selection of genotypes in neoplasia. Also, there was a higher risk of infection with HPV 16 in women ≤26 years and 34–41 years old (p < 0.05), meanwhile infections with HPV 16 or HPV 18 have related with cancer development (p < 0.01).

Conclusions

These data provide further information about the frequency of HPV genotypes in women with cervical lesions in Chile, and the introduction of new targeted vaccines against a wider spectrum of HPV is suggested.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3496-x) contains supplementary material, which is available to authorized users.

Nicotine promotes cervical carcinoma cell line HeLa migration and invasion by activating PI3k/Akt/NF-κB pathway in vitro

Cigarette smoking is one of highly risk factors of cervical cancer. Recently nicotine has been reported to increase proliferation and invasion in some smoking related cancers, like non-small cell lung cancer and esophageal squamous cell cancer. However, the effects and mechanisms of nicotine stimulation on cervical cancer cells are not clear. Here, we investigated the effects and mechanisms of nicotine stimulation on HeLa cells in vitro. In our study, we found that nicotine could accelerate HeLa cells migration and invasion, activate PI3K/Akt and NF-κB pathways and increase the expression of Vimentin in vitro. Moreover, we demonstrated that the specific PI3K inhibitor LY294002 could reverse nicotine-induced cell migration and invasion, NF-κB activation and up-regulation of Vimentin. Inhibition of NF-κB by Pyrrolidine dithiocarbamate (PDTC) also antagonized nicotine-induced cell migration, invasion and up-regulation of Vimentin. Simply put, these findings suggest that nicotine promotes cervical carcinoma cell line HeLa migration and invasion by activating PI3k/Akt/NF-κB pathway in vitro.

Targeting women with free cervical cancer screening: challenges and lessons learnt from Osun state, southwest Nigeria

Introduction

The study was conducted to determine the challenges and suggest solutions to conducting free cervical cancer screening among Nigerian women.

Methods

Awareness was created among women groups and mass media in Osun State for women to undergo free cervical cancer screening programme. Consenting women had their socio-demographic characteristics, awareness and uptake of HPV vaccine documented and papanicolaou smear procedure done with adequate referral for treatment given where necessary.

Results

A total of 287 women had cervical cancer screening. Mean (SD) age was 51.6 (14.3) years. Most participants were urban based (87.1%), married (63.1%), had secondary education (39%) and were traders (79.1%). None of the women were aware of the preventive HPV vaccine or had been vaccinated against HPV. About 6% were pre-invasive while 0.7% had invasive cervical cancer. The highest proportions of respondents affected were young, married and had lower education. Challenges identified included poor attendance, low risk perception and logistic issues.

Conclusion

Most participants were urban based. There is need to decentralize cancer of cervix screening through mobile clinics and establishment of screening centres in the rural areas. Neighbour to neighbour sensitization is essential. Also, HPV vaccine should be available and affordable to all girls before sexual maturity.

Human papillomavirus genotypes distribution in cervical cancer cases in Gabon

BACKGROUND

Cervical cancer is a real public health problem in African countries. The relation between HPV and cervical cancer is well established. However, it is known that the distribution of HPV genotypes differ geographically and this may influence the effectiveness of the three available vaccines, which among other HPV genotypes targets the genotypes 16 and 18 that cause about 70 % of cervical cancers cases. The objective of this study was to identify for the first time the HPV genotypes distribution in cervical cancer specimens obtained from Gabonese women.

METHODS

A total of 105 cervical samples including 93 formalin-fixed paraffin embedded tissues collected between 2007 and 2013 and 12 fresh biopsies collected in August 2013 were investigated. The presence of HPV DNA was analyzed by nested PCR with primers MY09/11 and GP5+/6+ followed by sequencing for HPV genotyping.

RESULTS

Amplification of the housekeeping gene (β-globin) with PCO4/GH20 primers was successful for 91.4 % (96/105) of the cervical cancer samples and HPV DNA was detected in all the 96 samples. Five different HPV genotypes were identified. HPV 16 [58.3 %; 95 % IC: 48.44-68.16] was the most common genotype followed by HPV 33 [25.0 %; 95 % IC: 16.34-33.66], HPV 18 [8.4 %; 95 % IC: 2.86-13.94], HPV 70 [7.3 %; 95 % IC: 2.1-12.5] and HPV 31 [1.1 %; 95 % IC: -0.986-3.186]. HPV 16 was also the most prevalent in all histological malignant lesions. It was found in 56.6 % of squamous cervical carcinoma and 69.2 % of adenocarcinoma. Concerning the HPV positive adenocarcinoma cases, HPV 18 was identified in 7.7 % (1/13).

CONCLUSION

These findings show the predominance of HPV 16 in cervical cancer cases among Gabonese women. However, HPV33 is more prevalent than HPV18. Our study suggests that HPV vaccines may be effective at reducing the burden of cervical cancer in Gabon.

Control of cervical cancer in Peru: Current barriers and challenges for the future

Cervical cancer is the leading malignant neoplasm in Peruvian women. This malignancy is a public health problem and several efforts were previously performed to develop cancer control plans. Geographical, cultural, structural, infrastructural and procedural barriers can limit the implementation of such strategies. Several previous studies have characterized human papilloma virus (HPV) epidemiology, where prevalence of high-risk HPV in adult females is ~12% and the prevalence in cervical cancer is 90–95%. The predominant barriers for the control of cervical cancer are lack of specialists in remote villages, education/cultural issues, loss of patients in follow-up, lack of access to HPV testing and lack of compliance for HPV vaccination. A good strategy for the prevention and early detection of high-risk HPV, pre-malignant neoplasms and cervical cancer, identified by interventional studies, is the self-sampling test, which assists with overcoming the cultural and geographic barriers. The current cancer control plan, termed ‘Plan Esperanza’, is performed with massive training of health professionals and social sensitization campaigns leading to filling the gaps regarding education and, in addition, it provides cancer care coverage for poorer individuals. In our experience at Oncosalud-AUNA, with a cohort of ~750,000 affiliates using a pre-paid system with annual screenings for cervical cancer for women, offered free-of-charge, a lower incidence of this malignancy (5.8/100,000) is now observed compared with the national incidence (32.7/100,000). As in other countries, the HPV vaccination can be a cost-utility strategy to reduce the high burdens of cervical cancer in Peru, a rapid and cheap HPV molecular sub-typification is rapidly required.

Herpes simplex virus type 2 and the risk of cervical cancer: a meta-analysis of observational studies

OBJECTIVES

To assess whether herpes simplex virus type 2 (HSV-2) infection has an effect on the risk of cervical cancer.

METHODS

A systematic literature search of PubMed, Embase, Web of Science, and Scopus from their inception through July 2013 was conducted and reference lists of retrieved articles were reviewed. Information on the characteristics of the included studies, risk estimates, and control for possible confounding factors was extracted independently by two investigators. A random effects model was used to calculate the pooled risk estimates.

MAIN RESULTS

Sixteen articles with 20 studies (14 case control and 6 longitudinal) involving 3,337 patients with cervical cancer were included. Compared with individuals who did not experience HSV-2 infection, the pooled ORs of cervical cancer for individuals with HSV-2 infection were 1.37 (95 % CI 1.12-1.69) for traditional case-control studies and 1.04 (95 % CI 0.82-1.31) for prospective or retrospective nested case-control studies.

CONCLUSIONS

Given that a longitudinal study gives a higher level of evidence than a traditional case-control study, the existing observational epidemiological evidence do not support a harmful effect of HSV-2 infection on cervical cancer.

Detection of human papillomavirus in chronic cervicitis, cervical adenocarcinoma, intraepithelial neoplasia and squamus cell carcinoma

BACKGROUND

Cervical cancer is the second most common cancer in women worldwide. Recent studies show that human papillomavirus (HPV) DNA is present in all cervical carcinomas and in some cervicitis cases, with some geographical variation in viral subtypes. Therefore determination of the presence of HPV in the general population of each region can help reveal the role of these viruses in tumors.

OBJECTIVES

This study aimed to estimate the frequency of infection with HPV in cervicitis, cervical adenocarcinoma, intraepithelial neoplasia and squamus cell carcinoma samples from the Isfahan Province, Iran.

PATIENTS AND METHODS

One hundred and twenty two formalin fixed paraffin embedded tissue samples of crevicitis cases and different cervix tumors including cervical intraepithelial neoplasia (CIN) (I, II, III), squamus cell carcinoma (SCC) and adenocarcinoma were collected from histopathological files of Al-Zahra Hospital in Isfahan. Data about histopathological changes were collected by reexamination of the hematoxylin and eosin stained sections. DNA was extracted and subjected to Nested PCR using consensus primers, MY09/MY11 and GP5+/GP6+, designed for amplification of a conserved region of the genome coding for L1 protein.

RESULTS

In total 74.5% of the tested samples were positive for HPV. Amongst the tested tumors 8 out of 20 (40%) of CIN (I, II, III), 5 out of 21 (23.8%) of adenocarcinoma cases and 78 out of 79 chronic cervicitis cases were positive for HPV.

CONCLUSIONS

The rate of different carcinomas and also the rate of HPV infection in each case were lower than other reports from different countries. This could be correlated with the social behavior of women in the area, where they mostly have only one partner throughout their life, and also the rate of smoking behavior of women in the studied population. On the other hand the rate of HPV infection in chronic cervicitis cases was much higher than cases reported by previous studies. This necessitates more attention to the role of human papillomaviruses in the their induction in the studied area.

Oral contraceptive use and risk of breast, cervical, colorectal, and endometrial cancers: a systematic review

Oral contraceptives may influence the risk of certain cancers. As part of the AHRQ Evidence Report, Oral Contraceptive Use for the Primary Prevention of Ovarian Cancer, we conducted a systematic review to estimate associations between oral contraceptive use and breast, cervical, colorectal, and endometrial cancer incidence. We searched PubMed, Embase, and Cochrane Database of Systematic Reviews. Study inclusion criteria were women taking oral contraceptives for contraception or ovarian cancer prevention; includes comparison group with no oral contraceptive use; study reports quantitative associations between oral contraceptive exposure and relevant cancers; controlled study or pooled patient-level meta-analyses; sample size for nonrandomized studies ≥100; peer-reviewed, English-language; published from January 1, 2000 forward. Random-effects meta-analyses were conducted by estimating pooled ORs with 95% confidence intervals (CIs). We included 44 breast, 12 cervical, 11 colorectal, and 9 endometrial cancers studies. Breast cancer incidence was slightly but significantly increased in users (OR, 1.08; CI, 1.00-1.17); results show a higher risk associated with more recent use of oral contraceptives. Risk of cervical cancer was increased with duration of oral contraceptive use in women with human papillomavirus infection; heterogeneity prevented meta-analysis. Colorectal cancer (OR, 0.86; CI, 0.79-0.95) and endometrial cancer incidences (OR, 0.57; CI, 0.43-0.77) were significantly reduced by oral contraceptive use. Compared with never use, ever use of oral contraceptives is significantly associated with decreases in colorectal and endometrial cancers and increases in breast cancers. Although elevated breast cancer risk was small, relatively high incidence of breast cancers means that oral contraceptives may contribute to a substantial number of cases.

Prevalence and distribution of high-risk human papillomavirus genotypes in invasive carcinoma of the uterine cervix in Uruguay

OBJECTIVES

Persistent infection with specific genotypes of human papillomaviruses (HPVs) is the main cause of invasive cervical cancer (ICC). Only a few of the various HPV types account for most of the cases worldwide, and geographical differences in their distribution are evident. Data from locally prevalent genotypes are essential in view of introduction of HPV type-specific prophylactic vaccines.

METHODS

In this work, we have investigated HPV type distribution in samples of ICC cases that occurred in Uruguayan women. DNA extracted from ICC treated in Centro Hospitalario Pereira Rossell of Montevideo between 1999 and 2007 were analyzed. Search and typing were performed by polymerase chain reaction using generic GP5+/GP6+ primers and specific primers for HPV types 16, 18, 33, and 45. Positive GP5+/GP6+ samples, which were negative for all 4 high-risk HPV-specific types screened were further analyzed by sequencing.

RESULTS

Human papillomavirus DNA sequences were found in 163 (92.6%) of 176 cases. The most prevalent genotypes were HPV16 (67.6%) and HPV18 (8.5%) followed by HPV45 (6.8%) and HPV33 (3.4%), as single or mixed infection. Other less frequent genotypes were HPV31, HPV35, HPV39, HPV51, HPV52, HPV58, HPV66, and HPV73. The viral type could not be determined (HPV X) in 1 case (0.6%) of the HPV DNA-positive cervical cancers and double infections were found in 1.7% of the cases. The higher percentage of most aggressive HPV (16/18/45) genotypes was detected in cases diagnosed at younger than 60 years old, whereas these genotypes were less frequent in older patients.

CONCLUSION

We conclude that HPV types 16, 18, and 45 have a very high prevalence in ICC of Uruguayan women. Results provide evidence that 16 of 18 infections are more aggressive, but most cancers could be vaccine preventable.

Type-specific HPV prevalence in cervical cancer and high-grade lesions in Latin America and the Caribbean: systematic review and meta-analysis

Background

Cervical cancer is a major public health problem in Latin America and the Caribbean (LA&C), showing some of the highest incidence and mortality rates worldwide. Information on HPV type distribution in high-grade cervical lesions (HSIL) and invasive cervical cancer (ICC) is crucial to predict the future impact of HPV16/18 vaccines and screening programmes, and to establish an appropriate post-vaccinal virologic surveillance. The aim was to assess the prevalence of HPV types in HSIL and ICC in studies in LA&C.

Methods and Findings

We performed a systematic review, following the MOOSE guidelines for systematic reviews of observational studies, and the PRISMA statement for reporting systematic reviews and meta-analyses. Inclusion criteria were at least ten cases of HSIL/ICC, and HPV-type elicitation. The search, without language restrictions, was performed in MEDLINE, Cochrane Library, EMBASE, LILACS from inception date to December 2009, proceedings, reference lists and consulting experts. A meta-analysis was performed using arc-sine transformations to stabilize the variance of simple proportions. Seventy-nine studies from 18 countries were identified, including 2446 cases of HSIL and 5540 of ICC. Overall, 46.5% of HSIL cases harbored HPV 16 and 8.9% HPV18; in ICC, 53.2% of cases harbored HPV 16 and13.2% HPV 18. The next five most common types, in decreasing frequency, were HPV 31, 58, 33, 45, and 52.

Study's limitations comprise the cross-sectional design of most included studies and their inherent risk of bias, the lack of representativeness, and variations in the HPV type-specific sensitivity of different PCR protocols.

Conclusions

This study is the broadest summary of HPV type distribution in HSIL and ICC in LA&C to date. These data are essential for local decision makers regarding HPV screening and vaccination policies. Continued HPV surveillance would be useful, to assess the potential for changing type-specific HPV prevalence in the post-vaccination era in Latin America.

Human papillomavirus infection in female sex workers in Lima, Peru

OBJECTIVES

To determine the prevalence and risk factors for human papillomavirus (HPV) infection in female sex workers (FSW) in Lima, Peru.

METHODS

Cross-sectional study of 87 FSW. Information regarding demographics, sex work practices, and genital and blood specimens was collected.

RESULTS

Forty-four (50.6%) of 87 FSW had HPV detected in cervical swabs. The prevalence of coinfection by two or more HPV types was 39.1%. Thirty-one (35.6%) were infected by at least one high-risk HPV type, representing 70.5% of women with HPV infection. HPV infection was associated with younger age but not with any demographic or sexual characteristics.

CONCLUSIONS

Our study confirms the high prevalence of HPV infection in FSW reported by other groups and suggests that brothel-based FSW may be at lower risk for acquiring high-risk HPV infection.

HPV prevalence in Colombian women with cervical cancer: implications for vaccination in a developing country

Human Papillomavirus (HPV) vaccines have been considered potentially cost-effective for the reduction of cervical cancer burden in developing countries; their effectiveness in a public health setting continues to be researched. We conducted an HPV prevalence survey among Colombian women with invasive cancer. Paraffin-embedded biopsies were obtained from one high-risk and one low-middle-risk regions. GP5+/GP6+ L1 primers, RLB assays, and E7 type specific PCR were used for HPV-DNA detection. 217 cases were analyzed with 97.7% HPV detection rate. HPV-16/18 prevalence was 63.1%; HPV-18 had lower occurrence in the high-risk population (13.8% versus 9.6%) allowing for the participation of less common HPV types; HPV-45 was present mainly in women under 50 and age-specific HPV type prevalence revealed significant differences. Multiple high-risk infections appeared in 16.6% of cases and represent a chance of replacement. Age-specific HPV prevalence and multiple high-risk infections might influence vaccine impact. Both factors highlight the role of HPVs other than 16/18, which should be considered in cost-effectiveness analyses for potential vaccine impact.

Differences in the risk of cervical cancer and human papillomavirus infection by education level

BACKGROUND

Cervical cancer risk is associated with low education even in an unscreened population, but it is not clear whether human papillomavirus (HPV) infection follows the same pattern.

METHODS

Two large multicentric studies (case-control studies of cervical cancer and HPV prevalence survey) including nearly 20 000 women. GP5+/GP6+ PCR was used to detect HPV.

RESULTS

Education level was consistently associated with cervical cancer risk (odds ratio (OR) for 0 and >5 years vs 1-5 years=1.50, 95% confidence interval (CI): 1.25-1.80 and 0.69, 95% CI: 0.57-0.82, respectively, P for trend <0.0001). In contrast, no association emerged between education level and HPV infection in either of the two IARC studies. A majority of the women studied had never had a Pap smear. The association between low education level and cervical cancer was most strongly attenuated by adjustment for age at first sexual intercourse and first pregnancy. Parity and screening history (but not lifetime number of sexual partners, husband's extramarital sexual relationships, and smoking) also seemed to be important confounding factors.

CONCLUSION

The excess of cervical cancer found in women with a low socio-economic status seems, therefore, not to be explained by a concomitant excess of HPV prevalence, but rather by early events in a woman's sexually active life that may modify the cancer-causing potential of HPV infection.

Cervical carcinoma and sexual behavior: collaborative reanalysis of individual data on 15,461 women with cervical carcinoma and 29,164 women without cervical carcinoma from 21 epidemiological studies

High-risk human papillomavirus (HPV) types cause most cervical carcinomas and are sexually transmitted. Sexual behavior therefore affects HPV exposure and its cancer sequelae. The International Collaboration of Epidemiological Studies of Cervical Cancer has combined data on lifetime number of sexual partners and age at first sexual intercourse from 21 studies, or groups of studies, including 10,773 women with invasive cervical carcinoma, 4,688 women with cervical intraepithelial neoplasia grade 3 (CIN3)/carcinoma in situ, and 29,164 women without cervical carcinoma. Relative risks for invasive cancer and CIN3 were estimated by conditional logistic regression. Risk of invasive cervical carcinoma increased with lifetime number of sexual partners (P for linear trend <0.001). The relative risk for > or =6 versus 1 partner, conditioned on age, study, and age at first intercourse, was 2.27 [95% confidence interval (95% CI), 1.98-2.61] and increased to 2.78 (95% CI, 2.22-3.47) after additional conditioning on reproductive factors. The risk of invasive cervical carcinoma increased with earlier age at first intercourse (P for linear trend <0.001). The relative risk for age at first intercourse < or =14 versus > or =25 years, conditioned on age, study, and lifetime number of sexual partners was 3.52 (95% CI, 3.04-4.08), which decreased to 2.05 (95% CI, 1.54-2.73) after additional conditioning on reproductive factors. CIN3/carcinoma in situ showed a similar association with lifetime number of sexual partners; however, the association with age at first intercourse was weaker than for invasive carcinoma. Results should be interpreted with caution given the strong correlation between sexual and reproductive factors and the limited information on HPV status.

HPV genotyping from invasive cervical cancer in Chile

OBJECTIVE

To determine the prevalence rates of the different HPV types in cervical cancer lesions in Chile to facilitate the development of prophylactic human papillomavirus (HPV) vaccines effective for that country.

METHOD

Biopsy samples of 312 cervical cancer lesions were assessed for HPV type by reverse-line blotting assay.

RESULTS

HPV DNA was found in 94.2% of the lesions, 67.2% harboring 1 viral type and the remainder harboring more than 1 type. HPV-16 was the most frequent type in single infections (50.5%), followed by HPV-18 (7.8%), HPV-31 (2.4%), and HPV-45 (2.0%). HPV-16 was also present in 98.7% of dual and multiple infections, its most frequent association being with HPV-18.

CONCLUSIONS

HPV types 16, 18, 31, and 45, alone or combined with other types, were observed in the biopsy samples of up to 80.5% of cervical cancer lesions.

Risk factors for human papillomavirus exposure and co-factors for cervical cancer in Latin America and the Caribbean

The incidence of cervical cancer in Latin America and the Caribbean (LAC) is among the highest in the world. Because there are major demographic shifts happening in LAC countries (population growth, urbanization and ageing) cervical cancer incidence and mortality will likely continue to be a significant public health problem. Overall human papillomavirus (HPV) prevalence in the LAC general population has been found to be 2-fold higher than the average worldwide prevalence. The large HPV and cancer burden may be explained by the highly prevalent HPV variants of HPV types -16 and 18, which have an increased oncogenic potential. Given the major mode of transmission of genital HPV is sexual, certain, patterns of sexual behaviour (early age at first sexual intercourse, number of sexual partners and sexual behaviour of the partner) are associated with an increased risk of HPV genital acquisition. Although HPV infection is necessary for carcinogenesis, certain co-factors (high parity, long term use of oral contraceptives, smoking and co-infection with the human immunodeficiency virus (HIV)) help in the progression from infection to cancer. Many studies that have contributed to this evidence have been carried out in LAC and are reviewed and summarised in this article. Since HPV vaccines will likely take years to implement, and many more years to show impact on disease, cervical cancer screening programmes remain as the key intervention to control disease in LAC in the years to come.

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.

Human Papillomavirus type distribution in invasive cervical cancer in Uganda

Background

We conducted a study aiming to describe Human Papillomavirus (HPV) type distribution in invasive cervical carcinoma in Uganda.

Methods

191 archival cervical carcinoma samples diagnosed in the Department of Pathology, Makerere University in Kampala between 1968 and 1992 were analysed using a sensitive PCR-Reverse Hybridization Line Probe Assay.

Results

Out of the 186 cases of confirmed invasive cervical cancer in the study paraffin blocks, 114 were positive for HPV DNA. Specific HPV genotypes were identifiable in 109 cases: HPV 16, 18, 31, 35, 39, 44, 45, 51, 52 and 70. These occurred as single infections in 105 cases (96.3%) and as multiple infections in 4 cases (3.7%). HPV 16 or 18 accounted for 80% (84/105) of cases with single infection.

Conclusion

The results of this study confirm the role of HPV 16 and 18 in cervical cancer pathogenesis in the Ugandan population. The results suggest that the currently available HPV vaccines against HPV 16 and 18 could possibly prevent the majority of invasive cervical cancers in Uganda.

Cervical cancer and hormonal contraceptives: collaborative reanalysis of individual data for 16,573 women with cervical cancer and 35,509 women without cervical cancer from 24 epidemiological studies

BACKGROUND

Combined oral contraceptives are classified by the International Agency for Research on Cancer as a cause of cervical cancer. As the incidence of cervical cancer increases with age, the public-health implications of this association depend largely on the persistence of effects long after use of oral contraceptives has ceased. Information from 24 studies worldwide is pooled here to investigate the association between cervical carcinoma and pattern of oral contraceptive use.

METHODS

Individual data for 16,573 women with cervical cancer and 35,509 without cervical cancer were reanalysed centrally. Relative risks of cervical cancer were estimated by conditional logistic regression, stratifying by study, age, number of sexual partners, age at first intercourse, parity, smoking, and screening.

FINDINGS

Among current users of oral contraceptives the risk of invasive cervical cancer increased with increasing duration of use (relative risk for 5 or more years' use versus never use, 1.90 [95% CI 1.69-2.13]). The risk declined after use ceased, and by 10 or more years had returned to that of never users. A similar pattern of risk was seen both for invasive and in-situ cancer, and in women who tested positive for high-risk human papillomavirus. Relative risk did not vary substantially between women with different characteristics.

INTERPRETATION

The relative risk of cervical cancer is increased in current users of oral contraceptives and declines after use ceases. 10 years' use of oral contraceptives from around age 20 to 30 years is estimated to increase the cumulative incidence of invasive cervical cancer by age 50 from 7.3 to 8.3 per 1000 in less developed countries and from 3.8 to 4.5 per 1000 in more developed countries.

Carcinoma of the cervix and tobacco smoking: collaborative reanalysis of individual data on 13,541 women with carcinoma of the cervix and 23,017 women without carcinoma of the cervix from 23 epidemiological studies

Tobacco smoking has been classified as a cause of cervical cancer, but the effect of different patterns of smoking on risk is unclear. The International Collaboration of Epidemiological Studies of Cervical Cancer has brought together and combined individual data on 13,541 women with and 23,017 women without cervical carcinoma, from 23 epidemiological studies. Relative risks (RRs) and 95% confidence intervals (CIs) of carcinoma of the cervix in relation to tobacco smoking were calculated with stratification by study, age, sexual partners, age at first intercourse, oral contraceptive use and parity. Current smokers had a significantly increased risk of squamous cell carcinoma of the cervix compared to never smokers (RR = 1.60 (95% CI: 1.48-1.73), p<0.001). There was increased risk for past smokers also, though to a lesser extent (RR = 1.12 (1.01-1.25)), and there was no clear trend with time since stopping smoking (p-trend = 0.6). There was no association between smoking and adenocarcinoma of the cervix (RR = 0.89 (0.74-1.06) and 0.89 (0.72-1.10) for current and past smokers respectively), and the differences between the RRs for smoking and squamous cell and adenocarcinoma were statistically significant (current smoking p<0.001 and past smoking p = 0.01). In current smokers, the RR of squamous cell carcinoma increased with increasing number of cigarettes smoked per day and also with younger age at starting smoking (p<0.001 for each trend), but not with duration of smoking (p-trend = 0.3). Eight of the studies had tested women for cervical HPV-DNA, and in analyses restricted to women who tested positive, there was a significantly increased risk in current compared to never smokers for squamous cell carcinoma (RR = 1.95 (1.43-2.65)), but not for adenocarcinoma (RR = 1.06 (0.14-7.96)). In summary, smokers are at an increased risk of squamous cell but not of adenocarcinoma of the cervix. The risk of squamous cell carcinoma increases in current smokers with the number of cigarettes smoked per day and with younger age at starting smoking.

Prevalence of human papillomavirus genotypes and their variants in high risk West Africa women immigrants in South Italy

BACKGROUND

The distribution of human papillomaviruses (HPVs) varies greatly across populations and HPV surveys have been performed in different geographical regions in order to apply appropriate vaccine strategies. Little information, however, exists regarding HPV genotypes distribution in immigrant women from countries at high incidence for cervical cancer. The aim of this study was to determine the spectrum of HPVs and their variants among HIV-positive and HIV-negative women immigrants in South Italy mainly from West Africa and with a history of prostitution.

RESULTS

Cervical cytological samples have been collected from 14 HIV-positive and 31 HIV-negative immigrants (38 out of 45 were born in Nigeria), attending a gynecological outpatient clinic in the Campania region. Human papillomaviruses were detected by broad spectrum consensus-primer-pairs MY09/MY11 and GP5+/GP6+-based polymerase chain reaction and characterized by nucleotide sequence analysis. Altogether, 42.2% (19/45) of samples were HPV positive with detection rates of 57.1% (8/14) in HIV-positive and 35.5% (11/31) in HIV-negative women. Among the twelve different viral genotypes identified, HPV33, 58, 70 and 81 were the prevalent genotypes with a frequency of 6.7% each, followed by HPV16, 35, 42, 54, 31, 52, 56 and 67, in descending order of prevalence. Sequence homology studies performed on the L1 amplified fragments of HPV16, 52 and 58 isolates allowed the identification of nucleotide changes distinctive of non-European variants.

CONCLUSION

The overall HPV prevalence (42.2%) was high in this immigrant women group with the most common viral types other than HPV16 and 18, against which current vaccine strategies have been developed. The distribution of HPV genotypes and their variants in high-risk immigrants reflects that of their original countries. The surveillance of risk groups that may act as viral reservoirs of uncommon genotypes within different countries are necessary to determine the severity of HPV infection with the different viral types and to monitor a possible shift of prevalent strains following vaccination.

Prevalence of the most common high-risk HPV genotypes among women in three new independent states of the former Soviet Union

Type distribution of HPV has been studied in different geographic regions, but the data are scanty from the new independent states of the former Soviet Union. Here the HPV prevalence and distribution of the most frequent high-risk HPV types among 3,187 women at different risk for HPV and cervical intraepithelial neoplasia in Russia, Belarus, and Latvia is reported. HPV detection, type distribution and viral load analysis in DNA samples from cervical scrapes were done with real-time PCR-based assay detecting HPV types 16, 18, 31, 33, 35, 39, 45, 52, and 58. The overall HPV prevalence was 31.2%, HPV16 was the most prevalent type followed by HPV31 and HPV33 group. The overall HPV prevalences in Russia, Belarus and Latvia were 33.4%, 27.5%, and 26.2%. The type distributions were similar in these countries, except for Latvia where HPV39 was the third prevalent genotype. HPV prevalence was highest (40.8%) among women from sexually transmitted disease clinic, followed by 30.9% among gynecological outpatients and 27.2% in screening patients. HPV detection increased with cytological abnormality (P = 0.0001) and lesion grade in the biopsy (P = 0.0001), from 27% to 72% in normal samples to cancer, and from 64% to 77% in cervical intraepithelial neoplasia 1 to cancer. The normalized viral loads varied greatly between and among different HPV-types. The mean log HPV33 group copies/cell increased from negative for intraepithelial lesions to cancer (P = 0.049). Distribution of the most common high-risk HPV-types seems to be similar in these countries as reported in other major geographical regions.

Cervical screening by visual inspection, HPV testing, liquid-based and conventional cytology in Amazonian Peru

Cervical cancer is an important public health problem in many developing countries, where cytology screening has been ineffective. We compared four tests to identify the most appropriate for screening in countries with limited resources. Nineteen midwives screened 5,435 women with visual inspection (VIA) and collected cervical samples for HPV testing, liquid-based cytology (LBC) and conventional cytology (CC). If VIA was positive, a doctor performed magnified VIA. CC was read locally, LBC was read in Lima and HPV testing was done in London. Women with a positive screening test were offered colposcopy or cryotherapy (with biopsy). Inadequacy rates were 5% and 11% for LBC and CC respectively, and less than 0.1% for VIA and HPV. One thousand eight hundred eighty-one women (84% of 2,236) accepted colposcopy/cryotherapy: 79 had carcinoma in situ or cancer (CIS+), 27 had severe- and 42 moderate-dysplasia on histology. We estimated a further 6.5 cases of CIS+ in women without a biopsy. Sensitivity for CIS+ (specificity for less than moderate dysplasia) was 41.2% (76.7%) for VIA, 95.8% (89.3%) for HPV, 80.3% (83.7%) for LBC, and 42.5% (98.7%) for CC. Sensitivities for moderate dysplasia or worse were better for VIA (54.9%) and less favourable for HPV and cytology. In this setting, VIA and CC missed the majority of high-grade disease. Overall, HPV testing performed best. VIA gives immediate results, but will require investment in regular training and supervision. Further work is needed to determine whether screened-positive women should all be treated or triaged with a more specific test.

Comparison of risk factors for invasive squamous cell carcinoma and adenocarcinoma of the cervix: Collaborative reanalysis of individual data on 8,097 women with squamous cell carcinoma and 1,374 women with adenocarcinoma from 12 epidemiological studies

Squamous cell carcinomas account for about 80% of cancers of the uterine cervix, and the majority of the remainder are adenocarcinomas. There is limited evidence on the extent to which these histological types share a common etiology. The International Collaboration of Epidemiological Studies of Cervical Cancer has brought together and combined individual data on 8,097 women with invasive squamous cell carcinoma, 1,374 women with invasive adenocarcinoma and 26,445 women without cervical cancer (controls) from 12 epidemiological studies. Compared to controls, the relative risk of each histological type of invasive cervical cancer was increased with increasing number of sexual partners, younger age at first intercourse, increasing parity, younger age at first full-term pregnancy and increasing duration of oral contraceptive use. Current smoking was associated with a significantly increased risk of squamous cell carcinoma (RR = 1.50, 95% CI: 1.35-1.66) but not of adenocarcinoma (RR = 0.86 (0.70-1.05)), and the difference between the two histological types was statistically significant (case-case comparison p < 0.001). A history of screening (assessed as having had at least one previous nondiagnostic cervical smear) was associated with a reduced risk of both histological types, but the reduction was significantly greater for squamous cell carcinoma than for adenocarcinoma (RR = 0.46 (0.42-0.50) and 0.68 (0.56-0.82), respectively; case-case comparison, p = 0.002). A positive test for cervical high-risk HPV-DNA was a strong risk factor for each histological type, with 74% of squamous cell carcinomas and 78% of adenocarcinomas testing positive for HPV types 16 or 18. Squamous cell and adenocarcinoma of the cervix share most risk factors, with the exception of smoking.

Worldwide human papillomavirus etiology of cervical adenocarcinoma and its cofactors: implications for screening and prevention

BACKGROUND

Most cancers of the uterine cervix are squamous cell carcinomas. Although the incidence of such carcinomas of the uterine cervix has declined over time, that of cervical adenocarcinoma has risen in recent years. The extent to which human papillomavirus (HPV) infection and cofactors may explain this differential trend is unclear.

METHODS

We pooled data from eight case-control studies of cervical cancer that were conducted on three continents. A total of 167 case patients with invasive cervical adenocarcinoma (112 with adenocarcinoma and 55 with adenosquamous carcinoma) and 1881 hospital-based control subjects were included. HPV DNA was analyzed in cervical specimens with the GP5+/6+ general primer system followed by type-specific hybridization for 33 HPV genotypes. Blood samples were analyzed for chlamydial and herpes simplex virus 2 (HSV-2) serology. Multivariable unconditional logistic regression modeling was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs). All tests of statistical significance were two-sided.

RESULTS

The adjusted overall odds ratio for cervical adenocarcinoma in HPV-positive women compared with HPV-negative women was 81.3 (95% CI = 42.0 to 157.1). HPV 16 and HPV 18 were the two most commonly detected HPV types in case patients and control subjects. These two types were present in 82% of the patients. Cofactors that showed clear statistically significant positive associations with cervical adenocarcinoma overall and among HPV-positive women included never schooling, poor hygiene, sexual behavior-related variables, long-term use of hormonal contraception, high parity, and HSV-2 seropositivity. Parity had a weaker association with adenocarcinoma and only among HPV-positive women. Use of an intrauterine device (IUD) had a statistically significant inverse association with risk of adenocarcinoma (for ever use of an IUD compared with never use, OR = .41 [95% CI = 0.18 to 0.93]). Smoking and chlamydial seropositivity were not associated with disease.

CONCLUSIONS

HPV appears to be the key risk factor for cervical adenocarcinoma. HPV testing in primary screening using current mixtures of HPV types and HPV vaccination against main HPV types should reduce the incidence of this cancer worldwide.

Cervical carcinoma and reproductive factors: Collaborative reanalysis of individual data on 16,563 women with cervical carcinoma and 33,542 women without cervical carcinoma from 25 epidemiological studies

The International Collaboration of Epidemiological Studies of Cervical Cancer has combined individual data on 11,161 women with invasive carcinoma, 5,402 women with cervical intraepithelial neoplasia (CIN)3/carcinoma in situ and 33,542 women without cervical carcinoma from 25 epidemiological studies. Relative risks (RRs) and 95% confidence intervals (CIs) of cervical carcinoma in relation to number of full-term pregnancies, and age at first full-term pregnancy, were calculated conditioning by study, age, lifetime number of sexual partners and age at first sexual intercourse. Number of full-term pregnancies was associated with a risk of invasive cervical carcinoma. After controlling for age at first full-term pregnancy, the RR for invasive cervical carcinoma among parous women was 1.76 (95% CI: 1.53-2.02) for > or => or =7 full-term pregnancies compared with 1-2. For CIN3/carcinoma in situ, no significant trend was found with increasing number of births after controlling for age at first full-term pregnancy among parous women. Early age at first full-term pregnancy was also associated with risk of both invasive cervical carcinoma and CIN3/carcinoma in situ. After controlling for number of full-term pregnancies, the RR for first full-term pregnancy at age <17 years compared with > or => or =25 years was 1.77 (95% CI: 1.42-2.23) for invasive cervical carcinoma, and 1.78 (95% CI: 1.26-2.51) for CIN3/carcinoma in situ. Results were similar in analyses restricted to high-risk human papilloma virus (HPV)-positive cases and controls. No relationship was found between cervical HPV positivity and number of full-term pregnancies, or age at first full-term pregnancy among controls. Differences in reproductive habits may have contributed to differences in cervical cancer incidence between developed and developing countries.

The influence of smoking and other cofactors on the time to onset to cervical cancer in a southern European population

Cervical cancer is a complex and multifactorial disease. Although there are substantial data supporting the causative role of persistent human papillomavirus (HPV) infection in the development of cervical cancer, the complete course of the disease has never been completely understood. Several risk cofactors have been suggested with controversial results. Portugal has the highest incidence of squamous cell carcinoma (SCC) within western Europe and there are no known studies regarding the role of cofactors in SCC. The aim of our study was to evaluate the role of smoking, sexual behaviour, reproductive and contraceptive history, in the time-to-onset (TTO) of severe cervical lesions (HGSIL/SCC) in the Portuguese population. We verified that age of first sexual intercourse under 18 years (odds ratio (OR) 2.8), pregnancy (OR 2.9), first pregnancy under 21 years (2.6), number of pregnancies (OR 2.3-5.4) and parity (OR 1.9-5.7) are risk factors in the development of cervical neoplasia. Smoke exposure index (SEI) was significantly different (P=0.002) between cases and controls. Our results regarding time-to-onset demonstrate that smoking (P<0.001, log rank test), number of sexual partners (P<0.001, log rank test) and use of oral contraceptives (P<0.001, log rank test) are important determinants in the earlier onset of severe cervical lesions. Using this approach, our findings may help to clarify the role of smoking and other cofactors in the persistence and progression of cervical lesions.

Screening for breast and cervical cancer in a large German city: participation, motivation and knowledge of risk factors

BACKGROUND

Few data exist on attendance for cervical and breast cancer screening, breast self-examination and knowledge about risk factors for cervical cancer among German women. A population-based survey was performed in the city of Bielefeld in Germany.

METHOD

A questionnaire was mailed to 1500 randomly selected women age 25 to 75. Of those, 540 questionnaires were returned and 532 were analysed.

RESULTS

Women participating in the survey considered themselves well informed about possibilities for early detection of breast cancer (84.0%). Most information was received from office-based gynaecologists (82.4%). 82.8% had a breast examination by a medical doctor annually and 43.1% practised breast self-examination every month. 55.5% of the women had had a mammography, 72.5% gave screening as a reason for a mammogram. Age at first mammography was associated with social class (p<0.001). Cytological smears for early detection of cervical cancer were common and obtained frequently. Age at first Pap smear was associated with social class (p<0.001). 69.9% of the women considered themselves insufficiently informed on risk factors for cervical cancer. Women were poorly informed about risk factors for cervical cancer. Only 3.2% knew that infection with human papillomavirus (HPV) is a risk factor for cervical cancer. Giving a correct answer was associated with social class (p<0.001) but not with age.

CONCLUSION

Rates of opportunistic mammography screening were high in the study population. Information on risk factors for cervical cancer was scarce. Efforts should be made to improve women's knowledge about risk factors for cervical cancer.

KEY POINTS

What do German women know about screening for breast and cervical cancer offered annually by health insurances at no cost? Most women participating in the survey considered themselves well informed about possibilities for early detection of breast cancer. Over two third of the women considered themselves insufficiently informed on risk factors for cervical cancer. Only 3.2% of the women knew that infection with human papillomavirus (HPV) is a risk factor for cervical cancer. There is a pressing need in Germany for better education of the general public on risk factors for cervical cancer.

Comparison of type-specific human papillomavirus data from self and clinician directed sampling

OBJECTIVE(S)

To compare the type-specific human papillomavirus (HPV) recovery from physician and patient-collected samples.

METHODS

Three hundred thirty-four (334) women attending colposcopy clinics in three countries were enrolled in this cross-sectional study. Cervicovaginal samples were collected by patients and physicians and processed with polymerase chain reaction and reverse line blot genotyping. McNemar's Chi-squared tests and Kappa statistics were utilized to determine statistical associations between physician- versus patient-collected samples.

RESULTS

Oncogenic HPV infection was identified in 23.2% of patient-collected specimens compared to 34.9% of physician-collected specimens. Physician sampling detected significantly more infections with type 16 and 52 than did self-sampling and significantly more oncogenic HPV infection overall. For non-oncogenic HPV detection, there was no statistical difference between physician- and patient-collected samples.

CONCLUSION(S)

Patient sampling for HPV using a single vaginal brush does not identify all oncogenic HPV subtypes.

Role of human papillomavirus in the carcinogenesis of squamous cell carcinoma and adenocarcinoma of the cervix

Human papillomavirus (HPV) infection is the most common sexually transmitted disease, with more than 80% of the population infected at some time in their life. In rare cases, this infection may lead to cervical cancer. Virtually all squamous cell carcinomas and the overwhelming majority of adenocarcinomas of the cervix are HPV positive. HPV integration in the genome will lead to inactivation of the p53 pathway and the Rb pathway. Integration is essential for the onset of cervical carcinogenesis, but is probably not sufficient for progression to invasive cervical cancers. It is likely that several cofactors, such as environmental, viral and host-related factors, are necessary for the development of cervical cancer. There are several similarities and differences between the two major histological types. This article will address the role of HPV in cervical carcinogenesis as well as the molecular biology involved in the process.

Chlamydia trachomatis and invasive cervical cancer: a pooled analysis of the IARC multicentric case-control study

To determine whether Chlamydia trachomatis infection is consistently associated with an increased risk of invasive cervical carcinoma (ICC) after accounting for the strong effect of human papillomavirus (HPV) infection, a case-control study of 1,238 cases of ICC and 1,100 control women from 7 countries was carried out (hospital-based studies in Thailand, the Philippines, Morocco, Peru, Brazil and population-based studies in Colombia and Spain, all coordinated by the International Agency for Research on Cancer, Lyon, France). C. trachomatis serum antibody detection was made by means of a microfluorescence assay. Among HPV DNA-positive cases and controls, the risk of squamous cell ICC was elevated in C. trachomatis seropositive women (OR = 1.8; 95% CI = 1.2-2.7) after adjustment for age, center, oral contraceptive use, history of Pap smears, number of full-term pregnancies and herpes simplex virus 2 seropositivity. The effect of C. trachomatis seropositivity on squamous cell ICC risk increased with increasing C. trachomatis antibody titers and was higher in women under 55 years of age. C. trachomatis antibodies were not associated with adeno- or adenosquamous cell carcinoma (OR = 1.0; 95% CI = 0.53-1.9) in HPV DNA-positive women. An association of C. trachomatis with squamous cell ICC was found among all cases and control women with or without adjustment for HPV.

Human papillomavirus and cervical cancer: issues for biobehavioral and psychosocial research

There is now overwhelming evidence that high-risk, sexually transmitted types of human papillomavirus (HPV) are the main causal agent in cervical cancer. Biobehavioral and psychosocial research is uniquely capable of addressing many of the issues raised by HPV and its link with cervical cancer. In this article we review current findings in this area and identify issues for future research. The first of the three sections explores issues associated with the introduction of HPV testing for the detection and management of cervical abnormalities and the impact of growing public awareness of the sexually transmitted nature of cervical cancer. The implications for public understanding of cervical cancer, psychosocial issues associated with screening, and the potential impact on screening uptake are discussed. The second section addresses the role of biobehavioral factors in the persistence and progression of HPV infection as well as possible interventions to minimize the risk of persistence. Finally, primary prevention of HPV is discussed.

Against which human papillomavirus types shall we vaccinate and screen? The international perspective

At least 15 types of HPV have been associated with cervical cancer, but current HPV vaccines confer only type-specific immunity. To determine geographic variations in the HPV type distribution in cervical cancer, we carried out a pooled analysis of data from an international survey of HPV types in cervical cancer and from a multicenter case-control study, both co-coordinated by the IARC. Study cases were 3,607 women with incident, histologically confirmed cervical cancer recruited in 25 countries. HPV DNA detection and typing in cervical cells or biopsies were centrally done using PCR assays. Estimates of the potential number of cases prevented by HPV type-specific vaccines and changes in the validity of different HPV screening cocktails were calculated. HPV DNA was detected in 96% of specimens, and 30 different types were detected. The 15 most common types were, in descending order of frequency, 16, 18, 45, 31, 33, 52, 58, 35, 59, 56, 39, 51, 73, 68 and 66. Higher than average proportions of type 16 were found in northern Africa, of type 18 in south Asia, of type 45 in sub-Saharan Africa and of type 31 in Central/South America. A vaccine including types 16 and 18 could potentially prevent 71% of cervical cancers worldwide, but its impact with regard to the percentage of cases potentially prevented would be higher in Asia and Europe/North America. In contrast, a vaccine containing the 7 most common HPV types would prevent about 87% of cervical cancers worldwide, with little regional variation. The impact of modifying the number of types in the screening cocktail tests would be small and probably irrelevant for screening programs.

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.

Severe cervical glandular cell lesions and severe cervical combined lesions

BACKGROUND

The purpose of the current study was to determine the accuracy of routinely screened cervical smears to predict a glandular cell lesion in histologically confirmed cases of cervical adenocarcinoma in situ (AIS), invasive adenocarcinoma (ADCA), adenosquamous carcinoma (ADSQCA), and severe combined glandular and squamous cell lesions.

METHODS

Between 1989-2000, a total of 1,141 women with a histologic diagnosis of cervical AIS, ADCA, ADSQCA, and combined lesions (glandular cell lesion with a coexistent squamous cell lesion) were registered in the Dutch National Pathology Archive (PALGA). In 1054 of these 1,141 histologic cases, an additional conventional Papanicolaou (Pap) smear diagnosis was registered from the same patient. Material was evaluated with regard to the accuracy of cytologic diagnosis, the percentage of combined lesions, the mean age of the patients, and the time interval between AIS and ADCA.

RESULTS

Of 1,141 registered histologic cases, 57.5% were registered as having an "intraepithelial" lesion, whereas 42.5% were registered as having an "invasive" process. A combined process was diagnosed in 63.2% of cases. From the same patients, a cytologic diagnosis of a severe cervical epithelial lesion was registered in PALGA for 91.2% (n = 961) of 1054 cases. A cytologic registration of a severe glandular cell lesion (with or without a squamous cell component) was made in 547 cases (51.9%). Prediction of a severe glandular cell lesion on the Pap smear was found to be more accurate in cases of histologically confirmed pure glandular cell abnormalities than in cases with a histologic diagnosis of a combined lesion. The cytologic prediction was found to be correct in 75.2% of cases of pure AIS and 47.3% of cases of AIS with coexistent high-grade squamous intraepithelial lesion (HGSIL) (cervical intraepithelial lesion [CIN] type 2 [CIN 2] or CIN 3). The mean ages of the patients with AIS and AIS + HGSIL were 37.3 years and 34 years, respectively, whereas the mean age of the patients with ADCA and ADCA + HGSIL was 41.9 years and 38.1 years, respectively. The interval between the average ages of patients with AIS and ADCA and those with AIS + HGSIL and ADCA + HGSIL was 4.6 years and 4.1 years, respectively.

CONCLUSIONS

On the basis of a data search of the PALGA registry, it can be concluded that in a relatively large number of cases a severe cervical glandular cell lesion was not diagnosed on the Pap smear. Furthermore, data demonstrated that the prediction of a glandular abnormality is less accurate in cases of combined squamoglandular cell lesions than in pure glandular cell lesions.

Prevalence and determinants of Chlamydia trachomatis infections in women from Bogota, Colombia

OBJECTIVES

Chlamydia trachomatis infection in the cervix and uterus has been hypothesised to be a co-factor for cervical cancer. We performed a cross sectional study in Bogota, Colombia, where cervical cancer rates are high, to determine the prevalence and determinants of C trachomatis infection, and in particular its association with human papillomavirus (HPV).

METHODS

1829 low income sexually active women were interviewed and tested for C trachomatis, using an endogenous plasmid PCR-EIA, and for 37 HPV types, using a general primer GP5+/6+ mediated PCR-EIA.

RESULTS

The overall prevalence of C trachomatis was 5.0%, and it did not differ substantially between women with normal (5.0%) and those with abnormal (5.2%) cervical cytology. Women infected with any HPV type (15.1%) had a slightly increased risk of being simultaneously infected with C trachomatis (adjusted OR 1.3, 95% CI: 0.8 to 2.4). This association was stronger when multiple HPV infections (adjusted OR 2.5, 95% CI: 1.1 to 5.9) were present. No other lifestyle or reproductive characteristics were clearly associated with risk of C trachomatis infection.

CONCLUSIONS

HPV infected women, particularly women with multiple HPV infections, are at increased risk of being infected with C trachomatis.

Risk factors for adenocarcinoma and squamous cell carcinoma of the cervix in women aged 20-44 years: the UK National Case-Control Study of Cervical Cancer

We report results on risk factors for invasive squamous cell and adenocarcinomas of the cervix in women aged 20–44 years from the UK National Case–Control Study of Cervical Cancer, including 180 women with adenocarcinoma, 391 women with squamous cell carcinoma and 923 population controls. The risk of both squamous cell and adenocarcinoma was strongly related to the lifetime number of sexual partners, and, independently, to age at first intercourse. The risk of both types of cervical cancer increased with increasing duration of use of oral contraceptives, and this effect was most marked in current and recent users of oral contraceptives. The risk of squamous cell carcinoma was associated with high parity and the risk of both squamous cell and adenocarcinoma increased with early age at first birth. Long duration smoking (20 or more years) was associated with a two-fold increase in the risk of squamous cell carcinoma, but smoking was not associated with the risk of adenocarcinoma. Further studies are needed to confirm the suggestion from this and other studies of differences in risk related to smoking between squamous cell and adenocarcinomas of the cervix.

Cervical cytological screening and human papillomavirus DNA testing in Flanders

The causal relationship between genital human papillomavirus (HPV) infection and cervical dysplasia/carcinoma has been recognised for some time. The aim of this study was to document the occurrence and distribution of HPV infection in the five provinces of the Flemish region in Belgium and to correlate the HPV DNA test results with the cytological results on simultaneously performed thin layer preparations of cervical cells. Out of a total screened group of 105107 samples, 1978 samples with cytological abnormalities were tested for HPV DNA using the MY09/MY11 consensus PCR. The mean age of the whole group was 36.9 years. The LSIL group, with a mean age of 33.6 years, was significantly younger than the other groups. There was no significant difference in HPV prevalence among the provinces. In four out of five provinces the HPV prevalence reached 100% in high-grade lesions. There is a significant increase in predominance of high-risk HPV types, with increasing abnormal cytology (17.9% WNL < 51.1% ASCUS < 83.8% LSIL < 97.2% HSIL). Three peaks of HPV DNA positivity were observed, a first at 22 yrs (82%), a second at 47 yrs (60%) and a third in women older than 65 yrs (52%). These results shed more light on HPV prevalence in Flanders and show that the MY09/MY11 consensus primer based detection system is very suitable for the detection of HPV infections in Flanders.

Cervical cancer and use of hormonal contraceptives: a systematic review

BACKGROUND

Human papillomavirus (HPV) is believed to be the most important cause of cervical cancer. Recent studies suggest that long duration use of oral contraceptives increases the risk of cervical cancer in HPV positive women.

METHODS

Results from published studies were combined to examine the relationship between invasive and in situ cervical cancer and duration and recency of use of hormonal contraceptives, with particular attention to HPV infection.

FINDINGS

28 eligible studies were identified, together including 12531 women with cervical cancer. Compared with never users of oral contraceptives, the relative risks of cervical cancer increased with increasing duration of use: for durations of approximately less than 5 years, 5-9 years, and 10 or more years, respectively, the summary relative risks were 1.1 (95% CI 1.1-1.2), 1.6 (1.4-1.7), and 2.2 (1.9-2.4) for all women; and 0.9 (0.7-1.2), 1.3 (1.0-1.9), and 2.5 (1.6-3.9) for HPV positive women. The results were broadly similar for invasive and in situ cervical cancers, for squamous cell and adenocarcinoma, and in studies that adjusted for HPV status, number of sexual partners, cervical screening, smoking, or use of barrier contraceptives. The limited available data suggest that the relative risk of cervical cancer may decrease after use of oral contraceptives ceases. However, study designs varied and there was some heterogeneity between study results.

INTERPRETATION

Although long duration use of hormonal contraceptives is associated with an increased risk of cervical cancer, the public health implications of these findings depend largely on the extent to which the observed associations remain long after use of hormonal contraceptives has ceased, and this cannot be evaluated properly from published data.

Epidemiologic classification of human papillomavirus types associated with cervical cancer

BACKGROUND

Infection with human papilloma virus (HPV) is the main cause of cervical cancer, but the risk associated with the various HPV types has not been adequately assessed.

METHODS

We pooled data from 11 case-control studies from nine countries involving 1918 women with histologically confirmed squamous-cell cervical cancer and 1928 control women. A common protocol and questionnaire were used. Information on risk factors was obtained by personal interviews, and cervical cells were collected for detection of HPV DNA and typing in a central laboratory by polymerase-chain-reaction-based assays (with MY09/MY11 and GP5+/6+ primers).

RESULTS

HPV DNA was detected in 1739 of the 1918 patients with cervical cancer (90.7 percent) and in 259 of the 1928 control women (13.4 percent). With the GP5+/6+ primer, HPV DNA was detected in 96.6 percent of the patients and 15.6 percent of the controls. The most common HPV types in patients, in descending order of frequency, were types 16, 18, 45, 31, 33, 52, 58, and 35. Among control women, types 16, 18, 45, 31, 6, 58, 35, and 33 were the most common. For studies using the GP5+/6+ primer, the pooled odds ratio for cervical cancer associated with the presence of any HPV was 158.2 (95 percent confidence interval, 113.4 to 220.6). The odds ratios were over 45 for the most common and least common HPV types. Fifteen HPV types were classified as high-risk types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82); 3 were classified as probable high-risk types (26, 53, and 66); and 12 were classified as low-risk types (6, 11, 40, 42, 43, 44, 54, 61, 70, 72, 81, and CP6108). There was good agreement between our epidemiologic classification and the classification based on phylogenetic grouping.

CONCLUSIONS

In addition to HPV types 16 and 18, types 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82 should be considered carcinogenic, or high-risk, types, and types 26, 53, and 66 should be considered probably carcinogenic.

Prognostic factors in neuroendocrine small cell cervical carcinoma: a multivariate analysis

BACKGROUND

The purpose of this study was to evaluate the clinical and pathologic factors associated with survival in patients with neuroendocrine (NE) cervical carcinoma.

METHODS

All patients with NE cervical carcinoma diagnosed between 1979-2001 were identified from tumor registry databases at two hospitals. Data were collected from hospital charts, office records, and tumor registry files. The impact of clinical and pathologic risk factors on the survival of patients with small cell NE carcinoma of the cervix was evaluated using Kaplan-Meier life table analyses and log-rank tests. The independent prognostic factors found to be predictive of survival in univariate analysis were evaluated using Cox regression. All tests were two-tailed with P values < 0.05 considered significant.

RESULTS

Thirty-four patients (median age, 42 years) were diagnosed with neuroendocrine cervical carcinoma, which included 21 with International Federation of Gynecology and Obstetrics (FIGO) Stage I disease, 6 with FIGO Stage II disease, 5 with FIGO Stage III disease, and 2 with FIGO Stage IV disease. Seventeen patients underwent a radical and 6 patients underwent a simple hysterectomy. Fourteen women received adjuvant therapy with pelvic radiation and/or cisplatin-based chemotherapy. Ten women received primary radiotherapy with (n = 5) or without (n = 4) chemotherapy and the remaining patient refused therapy. Women with early-stage (Stage I-IIA) disease had median survival rates of 31 months compared with 10 months in the advanced-stage (Stage IIB-IVB) group (P = 0.002). In univariate analysis, advanced stage (P = 0.002), tumor size >2 cm (P = 0.02), margin involvement (P = 0.016), pure versus a mixed histologic pattern (P = 0.04), margin status (P = 0.016), and smoking (P = 0.04) were considered poor prognostic factors. In multivariate analysis, smoking for early-stage patients and stage of disease in the overall population remained as independent prognostic factors of survival.

CONCLUSIONS

Smoking and advanced stage are reported to be poor prognostic factors for survival in patients with NE small cell carcinoma of the cervix. Only those with early lesions amenable to extirpation are cured. The role of primary or postoperative radiation with or without chemotherapy is unclear and yields uniformly poor results, particularly in patients with advanced lesions. Clinical trials are needed.

Follow-up care of women with an abnormal cytology in a low-resource setting

STUDY PURPOSE

We ascertained the follow-up care after an abnormal cytology (Papanicolaou) screening in the San Marti;n region of Perú and assessed the status of women who had not received adequate care.

BASIC PROCEDURES

We identified women with an abnormal cytology and assessed their medical records, laboratory registries, death certificates and interviewed them at home. Re-screening, diagnosis and treatment were offered.

MAIN FINDINGS

Only 46 (25%) of the 183 women identified received appropriate follow-up care. At re-screening 31 (34%) had a normal result, 9 (10%) were diagnosed with CIN1 and 50 (56%) had CIN2 or worse.

PRINCIPAL CONCLUSIONS

In this setting, follow-up care after an abnormal cytology was very poor and could explain the lack of impact of cervical cancer screening. Women with an abnormal cytology constitute a high-risk group that should be a priority for health services.

P53 codon 72 polymorphism and susceptibility to development of human papilloma virus-associated cervical cancer in Indian women

BACKGROUND

Infection with human papilloma virus (HPV) is an important etiological factor in the development of cervical cancer and it has been proposed that individuals homozygous for Arg/Arg at codon-72 of p53 are seven times more susceptible to HPV-mediated cancer. In this study, we have analyzed the genetic predisposition of the India population to HPV infection and cervical carcinogenesis.

METHODS

We investigated 71 cases of squamous cell carcinoma of the cervix, 14 cases of low-grade squamous intraepithelial lesions, 25 cases of high-grade squamous intraepithelial lesions and 29 noncancer controls for presence of HPV16/18 infections by L-1-specific PCR assay and Southern hybridization, and its association with polymorphism at p53 codon 72.

RESULTS

We observed that 69.1% (76/110) of the cervical cancer patients were HPV positive, among which the presence of HPV16, 18 and 16/18 coinfection was 40.9%, 8.2% and 13.6%, respectively. The allele frequencies of the three p53 genotypes Arg/Arg, Arg/Pro and Pro/Pro in the HPV-positive tumour samples were 0.34, 0.57 and 0.09 in comparison with frequencies of 0.18, 0.44 and 0.38 for HPV-negative tumours. Hence, there is a significant difference in the allelic frequency of p53 Arg/Arg in high-risk HPV-infected cervical carcinoma cases (0.34) and HPV-negative carcinomas (0.18).

CONCLUSION

Our results indicate a striking over-representation of homozygous arginine at codon 72 of p53 in HPV-associated cervical carcinogenesis. We conclude that women with Arg/Arg homozygous allele are more prone to infection by HPV16/18, which leads to cervical carcinomas having poor prognosis.