Prophylactic cancer vaccines: development and challenges for HBV and HPV vaccines in Latin America.

Vaccines against hepatitis B virus (HBV) and human papillomaviruses (HPV) are two safe and highly effective vaccines that were developed at the end of the 20th century and can prevent human cancer. HBV vaccine prevents liver cancer, and HPV prevents cervical and other HPV-related cancers. Starting with the immunogen identification, 15 years were necessary to reach the industrial production of HBV vaccine, and 20 years, for the HPV vaccines. However, while HBV vaccines have been commercially available for over 40 years and are used in most countries, there are still significant challenges to achieve universal childhood immunization against hepatitis B. Similarly, HPV vaccines have been commercially available for 17 years, and yet, countries with higher cervical cancer still have the lowest HPV vaccination rates. We describe the development of HBV and HPV vaccines and discuss the challenges to reaching equitable access to these vaccines in Latin America.

Genetic polymorphisms in the cag pathogenicity island of Helicobacter pylori and risk of stomach cancer and high-grade premalignant gastric lesions.

Helicobacter pylori (Hp) infects the stomach of about half of the human population and is strongly associated with the risk of gastric cancer (GC) and its premalignant precursors. The cag pathogenicity island (cagPAI) is a region of the Hp genome encoding for key molecular machinery involved in the infection process. Following a sequencing study, we selected 50 genetic polymorphisms located in seven cagPAI genes and tested their associations with the risk of advanced gastric premalignant lesions and GC in 1220 subjects from various Latin American populations showing the whole spectrum of phenotypes from gastritis to GC. We found that three polymorphisms of cagA are associated with the risk of advanced gastric premalignant lesions (incomplete intestinal metaplasia [ie, Type 2 and 3] or dysplasia), and that six polymorphisms located in cagA, cagL and cagI were associated with risk of GC. When corrected for multiple testing none of the associations were statistically significant. However, scores built by integrating the individual polymorphisms were significantly associated with the risk of advanced gastric premalignant lesions and GC. These results have the potential of establishing markers for risk stratification in the general population, in view of targeting Hp eradication to high-risk population groups.

Persistence of Immunity When Using Different Human Papillomavirus Vaccination Schedules and Booster-Dose Effects 5 Years After Primary Vaccination.

Background: There are limited data regarding the duration of immunity induced by different human papillomavirus (HPV) vaccination schedules and the immunogenicity of a booster dose of both bivalent HPV vaccine (bHPV) or quadrivalent HPV vaccine (qHPV). Methods: Follow-up of a nonrandomized clinical trial to evaluate the 5-year antibody persistence of the bHPV in girls (age, 9-10 years) and women (age, 18-24 years). Noninferiority of the 2-dose versus 3-dose schedule among girls was evaluated at months 54 (n = 639) and 64 (n = 990). Girls vaccinated with a 2-dose schedule of bHPV or qHPV received a booster dose of either vaccine at month 61. Immunogenicity was measured using a virus-like particle-based enzyme-linked immunosorbent assay. Geometric mean titers (GMTs) for HPV16/18 were estimated after stratification by vaccination schedule and age group. Results: At months 54 and 64, the 2-dose schedule remained noninferior to the 3-dose schedule. GMTs remained above natural infection levels across all age groups up to 64 months. After the booster, anti-HPV16/18 GMTs increased exponentially with the same pattern, regardless of vaccine administered. No safety concerns were identified with the booster dose. Conclusions: A 2-dose schedule is highly immunogenic in girls, suggesting a high immune memory. Thus, a booster dose is likely to be unprofitable, considering the low global immunization coverage. Clinical Trials Registration: NCT01717118.

Impact and Effectiveness of the Quadrivalent Human Papillomavirus Vaccine: A Systematic Review of 10 Years of Real-world Experience.

Prophylactic human papillomavirus (HPV) vaccination programs constitute major public health initiatives worldwide. We assessed the global effect of quadrivalent HPV (4vHPV) vaccination on HPV infection and disease. PubMed and Embase were systematically searched for peer-reviewed articles from January 2007 through February 2016 to identify observational studies reporting the impact or effectiveness of 4vHPV vaccination on infection, anogenital warts, and cervical cancer or precancerous lesions. Over the last decade, the impact of HPV vaccination in real-world settings has become increasingly evident, especially among girls vaccinated before HPV exposure in countries with high vaccine uptake. Maximal reductions of approximately 90% for HPV 6/11/16/18 infection, approximately 90% for genital warts, approximately 45% for low-grade cytological cervical abnormalities, and approximately 85% for high-grade histologically proven cervical abnormalities have been reported. The full public health potential of HPV vaccination is not yet realized. HPV-related disease remains a significant source of morbidity and mortality in developing and developed nations, underscoring the need for HPV vaccination programs with high population coverage.

Human papillomavirus DNA prevalence and type distribution in anal carcinomas worldwide.

Knowledge about human papillomaviruses (HPV) types involved in anal cancers in some world regions is scanty. Here, we describe the HPV DNA prevalence and type distribution in a series of invasive anal cancers and anal intraepithelial neoplasias (AIN) grades 2/3 from 24 countries. We analyzed 43 AIN 2/3 cases and 496 anal cancers diagnosed from 1986 to 2011. After histopathological evaluation of formalin-fixed paraffin-embedded samples, HPV DNA detection and genotyping was performed using SPF-10/DEIA/LiPA25 system (version 1). A subset of 116 cancers was further tested for p16(INK4a) expression, a cellular surrogate marker for HPV-associated transformation. Prevalence ratios were estimated using multivariate Poisson regression with robust variance in the anal cancer data set. HPV DNA was detected in 88.3% of anal cancers (95% confidence interval [CI]: 85.1-91.0%) and in 95.3% of AIN 2/3 (95% CI: 84.2-99.4%). Among cancers, the highest prevalence was observed in warty-basaloid subtype of squamous cell carcinomas, in younger patients and in North American geographical region. There were no statistically significant differences in prevalence by gender. HPV16 was the most frequent HPV type detected in both cancers (80.7%) and AIN 2/3 lesions (75.4%). HPV18 was the second most common type in invasive cancers (3.6%). p16(INK4a) overexpression was found in 95% of HPV DNA-positive anal cancers. In view of the results of HPV DNA and high proportion of p16(INK4a) overexpression, infection by HPV is most likely to be a necessary cause for anal cancers in both men and women. The large contribution of HPV16 reinforces the potential impact of HPV vaccines in the prevention of these lesions.

Time trends of human papillomavirus types in invasive cervical cancer, from 1940 to 2007.

Contribution over time of human papillomavirus (HPV) types in human cancers has been poorly documented. Such data is fundamental to measure current HPV vaccines impact in the years to come. We estimated the HPV type-specific distribution in a large international series of invasive cervical cancer (ICC) over 70 years prior to vaccination. Paraffin embedded ICC cases diagnosed between 1940 and 2007 were retrieved from eleven countries in Central-South America, Asia and Europe. Included countries reported to have low-medium cervical cancer screening uptake. Information on age at and year of diagnosis was collected from medical records. After histological confirmation, HPV DNA detection was performed by SPF-10/DEIA/LiPA25 (version1). Logistic regression models were used for estimating the adjusted relative contributions (RC) of HPV16 and of HPV18 over time. Among 4,771 HPV DNA positive ICC cases, HPV16 and HPV18 were the two most common HPVs in all the decades with no statistically significant variations of their adjusted-RC from 1940-59 to 2000-07 (HPV16-from 61.5 to 62.1%, and HPV18-from 6.9 to 7.2%). As well, the RC of other HPV types did not varied over time. In the stratified analysis by histology, HPV16 adjusted-RC significantly increased across decades in adenocarcinomas. Regarding age, cases associated to either HPV16, 18 or 45 were younger than those with other HPV types in all the evaluated decades. The observed stability on the HPV type distribution predicts a high and stable impact of HPV vaccination in reducing the cervical cancer burden in future vaccinated generations.

Epidemiology of cervical cancer in Colombia.

OBJECTIVE: To describe the incidence, mortality, time trends and prognostic factors for cervical cancer in Cali, Colombia, and to review the molecular epidemiological evidence showing that HPV is the major and necessary cause of cervical cancer and the implications of this discovery for primary and secondary prevention. MATERIALS AND METHODS: Incidence rates of cervical cancer during a 45-year period (1962-2007) were estimated based on the population-based cancer registry of Cali and the mortality statistics from the Municipal Health Secretariat of Cali. Prognostic factors were estimated based on relative survival. Review of the molecular epidemiological evidence linking HPV to cervical cancer was focused on the studies carried out in Cali and in other countries. RESULTS: Incidence rates of squamous cell carcinoma (SCC) declined from 120.4 per 100 000 in 1962-1966 to 25.7 in 2003-2007 while those of adenocarcinoma increased from 4.2 to 5.8. Mortality rates for cervical cancer declined from 18.5 in 1984-1988 to 7.0 per 100 000 in 2009-2011. Survival was lower in women over 65 years of age and in clinical stages 3-4. Review of the molecular epidemiological evidence showed that certain types of HPV are the central and necessary cause of cervical cancer. CONCLUSIONS: A decline in the incidence and mortality of SCC and an increase in the incidence of adenocarcinoma during a 45-year period was documented in Cali, Colombia.

Risk of advanced gastric precancerous lesions in Helicobacter pylori infected subjects is influenced by ABO blood group and cagA status.

A higher incidence of stomach cancer in ABO blood type A individuals than in those with blood type O has been known for a long time. We studied this association in relation to Helicobacter pylori (Hp) of different cagA status. For our study, we used baseline gastric histopathology data and DNAs from frozen gastric biopsies of 2,077 subjects enrolled in a chemoprevention trial for gastric precancerous lesions in Venezuela. We analyzed six single nucleotide polymorphisms in the ABO gene, and we assessed the presence of the Hp cagA gene. Odds ratios (ORs) for risk of advanced precancerous gastric lesions were calculated using individuals with normal gastric epithelium or non-atrophic gastritis as a reference. Among individuals carrying a cagA negative Hp infection or no Hp infection, those with blood type A had a lower risk of intestinal metaplasia (IM) and dysplasia than those with blood type O (OR=0.60; 95% CI 0.38-0.94). In carriers of cagA positive Hp strains, individuals with blood type A had a higher risk of IM or dysplasia than those with blood type O (OR=1.42, 95% CI 1.09-1.86) and a higher risk if compared to subjects carrying cagA negative strain and non-A blood group (OR=3.82, 95% CI=2.80-5.20). The interaction between Hp cagA status and blood type was statistically significant (p=0.0006). We showed that SNPs in the ABO gene, predictive of ABO blood groups, are associated with risk of advanced precancerous gastric lesions in individuals infected with Hp, but the assessment of the risk is strictly dependent on cagA status.

Epidemiologic profile, sexual history, pathologic features, and human papillomavirus status of 103 patients with penile carcinoma.

PURPOSE: The incidence of penile cancer is four times higher in Paraguay than in the United States or Europe. There are no adequate scientific explanations for this geographical variation. The goal of this study was to evaluate the interplay among risk factors, morphology of the primary tumor, and HPV status. METHODS: Information on socioeconomic status, education level, habits, and sexual history was obtained in 103 Paraguayan patients with penile cancer. All patients were then treated by surgery, and specimens were evaluated histopathologically. RESULTS: Patients usually dwelled in rural/suburban areas (82%), lived in poverty (75%), had a low education level (91%), and were heavy smokers (76%). Phimosis (57%), moderate/poor hygienic habits (90%), and history of sexually transmitted diseases (74%) were frequently found. Patients with >10 lifetime female partners had an odds ratio of 3.8 (95% CI 1.1, 12.6; P-trend = .03) for presenting HPV-positive tumors when compared to patients with <6 partners. However, this trend was not significant when the number of sexual partners was adjusted for age of first coitus and antecedents of sexually transmitted diseases. HPV-related tumors (found in 36% of the samples) were characterized by a warty and/or basaloid morphology and high histological grade in most cases. CONCLUSIONS: In our series, patients with penile cancer presented a distinctive epidemiologic and pathologic profile. These data might help explaining the geographical differences in incidence and aid in the design of strategies for cancer control in Paraguay.

Clinical characteristics and HPV type in recurrent respiratory papillomatosis in Colombia.

OBJECTIVE: Describe factors associated with aggressive forms of recurrent respiratory papillomatosis (RRP). MATERIALS AND METHODS: One hundred eighty-nine RRP cases diagnosed between 1985 and 2009 were identified in pathological records. HPV was detected by the SPF-10 method with broad spectrum primers, (version 1). RESULTS: 113 patients had only one surgery (less aggressive) and 76, two or more interventions (more aggressive). The likelihood of aggressive lesions decreased with increasing age at diagnosis and HPV-11 was associated with no significant increase in the risk of aggressiveness. CONCLUSIONS: The age at diagnosis was the main determinant of RRP aggressiveness.

Prevention and control of HPV and HPV-related cancers in France: the evolving landscape and the way forward - a meeting report.

Misinformation regarding HPV vaccine safety and benefits has resulted in low coverage within the eligible French population. HPV vaccination is safe and efficacious in preventing HPV infections in adolescents. However, reaching optimal coverage in countries such as France is challenging due to misinformation, among other factors. Moreover, disparities exist in cervical cancer screening programs. To support the government health promotion policy aimed at improving prevention and control of HPV-related cancers in France, the Human Papillomavirus Prevention and Control Board (HPV-PCB), in collaboration with local experts, held a meeting in Annecy, France (December 2021).HPV-PCB is an independent, multidisciplinary board of international experts that disseminates relevant information on HPV to a broad array of stakeholders and provides guidance on strategic, technical and policy issues in the implementation of HPV control programs.After a one-and-a-half-day meeting, participants concluded that multi-pronged strategies are required to expand vaccination coverage and screening. Vaccine acceptance could be improved by: 1) strenghtening existing trust in clinicians by continuous training of current and upcoming/pre-service healthcare professionals (HCPs), 2) improving health literacy among adolescents and the public through school and social media platforms, and 3) providing full reimbursement of the gender-neutral HPV vaccine, as a strong signal that this vaccination is essential.The discussions on HPV infections control focused on the need to: 1) encourage HCPs to facilitate patient data collection to support performance assessment of the national cervical cancer screening program, 2) advance the transition from cytology to HPV-based screening, 3) improve cancer prevention training and awareness for all HCPs involved in screening, including midwives, 4) identifying patient barriers to invitation acceptance, and 5) promoting urine or vaginal self-sampling screening techniques to improve acceptability, while establishing appropriate follow-up strategies for HPV-positive women. This report covers some critical findings, key challenges, and future steps to improve the status of HPV prevention and control measures in the country.

Penile intraepithelial neoplasia: Distribution of subtypes, HPV genotypes and p16INK4a in 84 international cases.

There are few pathologic or molecular studies of penile precancerous lesions, and the majority refers to lesions associated with invasive carcinomas. Penile Intraepithelial Neoplasia (PeIN) is classified in two morphologically and distinctive molecular groups, non-HPV and HPV-related with special subtypes. The primary purpose of this international series was to classify PeIN morphologically, detect HPV genotypes and determine their distribution according to PeIN subtypes. A secondary aim was to evaluate the p16INK4a immunostaining as a possible HPV surrogate for high-risk HPV infection in penile precancerous lesions. Samples consisted of 84 PeIN cases, part of a retrospective cross-sectional analysis of 1095 penile carcinomas designed to estimate the HPV DNA prevalence in penile cancers using PCR and p16INK4a immunostaining. Penile Intraepithelial Neoplasia (PeIN) was classified in HPV-related (basaloid, warty-basaloid, warty, hybrid, and mixed subtypes) and non-HPV-related (differentiated), the former being the most frequent. PeIN subtypes were differentiated (non-HPV-related) and basaloid, warty-basaloid, warty, hybrid and mixed (HPV-related). Basaloid PeIN was the most commonly diagnosed subtype, and HPV16 was the most frequent HPV genotype detected. Warty-basaloid and warty PeIN showed a more heterogeneous genotypic composition. Most HPV genotypes were high-risk but low-risk HPV genotypes were also present in a few cases (4%). A single HPV genotype was detected in 82% of HPV positive cases. In contrast, multiple genotypes were detected in the remaining 18% of cases. The findings in this study support the paradigm that penile in situ neoplasia, like its invasive counterparts, is HPV dependent or independent and has distinctive morphological subtypes readily identified in routine practice. Considering that HPV16 is clearly the predominant type, and that the three available vaccines have HPV16, all of them will be suitable for vaccination programs; the price of the vaccines will be probably the main determinant to choose the vaccine.

Phylogenetic origin of Helicobacter pylori pathogenicity island and risk of stomach cancer and high-grade premalignant gastric lesions.

Infection by Helicobacter pylori (Hp) has been causally linked to risk of gastric cancer (GC). The coevolution of Hp and humans shaped the risk of GC as our species left Africa and migrated to the other continents. Latin America (LatAm) is a high GC incidence region where Hp evolved uniquely in the 500 years since European colonization. Differential virulence of the Hp cagA -pathogenicity island (cagPAI) by ancestral origin has been reported. We hypothesized that Hp phylogenetic origin might play a role in determining GC risk in LatAm. We used genotypes of 50 Hp genetic variants mapping to the Hp cagPAI, studied in 1220 subjects from Venezuela, Colombia, Mexico and Paraguay, who were infected with cagA-positive Hp, including 150 GC, 177 high-grade premalignant lesions (HGPMLs) and 893 low-grade premalignant lesions. We estimated the phylogenetic origin of Hp cagPAI in all study subjects by use of the STRUCTURE software and principal component analysis (PCA) and tested whether the estimated African ancestry percentage was associated with the risk of GC or HGPML. African ancestral component estimates by STRUCTURE and PCA were highly correlated. STRUCTURE-based African origin estimate was not significantly associated with the risk of HGPML, but it was inversely associated with GC risk: the OR associated with the continuous values of African component was 0.09 (95% CI, 0.01-0.85; P = 0.035). Similar trends were observed for GC with PCA-based estimates, but the association was not statistically significant. These results suggest that Hp ancestral origin may play a role in gastric carcinogenesis.

Detection of variable genotypes in common human papillomavirus-associated invasive penile squamous cell carcinomas: a study of 177 human papillomavirus-positive cases.

Human papillomavirus (HPV) is detected in 30-50% of invasive penile carcinomas, and it is frequently associated with basaloid and warty morphological features. Based on this heterogeneity and different clinical behaviors, we hypothesized a variation in their HPV genotypic composition. To test this, we evaluated 177 HPV-positive cases: basaloid (114), warty-basaloid (28), and warty (condylomatous) (35) invasive carcinomas. HPV DNA detection and genotyping was performed using the SPF-10/DEIA/LiPA25 system. Nineteen HPV genotypes were detected. High-risk HPVs predominated (96%), and low-risk HPVs were rarely present. Most common genotype was HPV16 followed by HPVs 33 and 35. According to the genotypes identified, 93% of the cases would be covered with current vaccination programs. There was a significant variation in the distribution of HPV16 and non-HPV16 genotypes according to histological subtype. HPV16 was significantly frequent in basaloid (87%) and was less frequent in warty carcinomas (61%). This molecular difference, along with their distinctive macro-microscopic and prognostic features, makes basaloid and warty carcinomas unique. The gradual decreasing frequency of HPV16 demonstrated in basaloid, warty-basaloid, and warty carcinomas suggest that the basaloid cell, present in those types in decreasing proportions, may be responsible for the differences.

Prevalence and genotype distribution of human papillomavirus infection of the cervix in Spain: the CLEOPATRE study.

Human papillomavirus (HPV) infection is a necessary cause of cervical cancer. The aim of this study was to estimate the prevalence of cervical HPV infection and HPV type-specific distribution among women attending cervical cancer screening in Spain during 2007 and 2008. Women aged 18-65 years were recruited according to an age-stratified sampling method. Liquid-based cervical samples were collected and analyzed for cytology, HPV detection, and genotyping. HPV genotyping was determined using the INNO-LiPA HPV Genotyping Extra Reverse Hybridization Line Probe Assay. Prevalence estimates were age-standardized using 2001 Spanish census data. The present study included 3,261 women. Age-standardized HC2-based HPV prevalence was 14.3% (95% CI, 13.1-15.5) among women aged 18-65 years, and 28.8% (26.6-31.1) among women aged 18-25 years. High-risk HPV types were detected in 12.2% (95% CI, 11.1-13.4) of HPV-tested women, representing 84.0% of HPV-positive samples. Multiple infections were present in 4.1% (95% CI, 3.4-4.8) of HPV-tested women (25.0% of HPV-positive samples). The most common high-risk HPV-types among HPV-tested women were 16 (2.9%), 52 (1.8%), 51 (1.6%), 31 (1.3%), and 66 (1.2%). HPV-type 16 was present in 16.9% of HPV-positive samples. One or more of the HPV vaccine types 6/11/16/18 were detected in 3.8% of HPV-tested women (22.1% of HPV-positive samples). Though not a true population-based survey, this study provides valuable baseline data for future assessment of the impact of current HPV vaccination programs in Spain. The high prevalence of HPV infection among young women may reflect recent changes in sexual behavior.

Type-specific human papillomavirus distribution in invasive cervical carcinomas in Paraguay. A study of 432 cases.

Cervical carcinoma is the most common malignant tumor among woman in Paraguay. Cytological screening programs have not been successful and a plan for human papillomavirus (HPV) based-screening program and/or vaccination is under evaluation. This study aimed to identify the contribution of HPV genotypes in invasive cervical cancer in Paraguay to provide essential background data to guide and assess the introduction and impact of new preventive strategies based on HPV. Four hundred thirty two histologically confirmed cases (1960-2004) were analyzed. HPV detection in paraffin blocks was performed at the Catalan Institute of Oncology using PCR with SPF-10 broad spectrum primers followed by DNA enzyme immunoassay and genotyping with a reverse hybridization line probe analysis. The majority of cases were squamous cell carcinoma (92.8%). Mean patients age was 48 years old. HPV DNA was detected in 73.1% of the cases and single infections were predominant (97.8%). The most common HPV single types were 16, 18, 45, 33, 31, 52, 35, and 39. 73.1% of HPV positive cases had an HPV 16, 18 as single infection. HPV16 was frequent in SCC whereas HPV 18 and 45 were prevalent in glandular tumors. Significant decrease of HPV 16 with age groups (P-trend = 0.022) and increase in other HPV types (P-trend > 0.001) were observed. The potential impact of HPV 16 and 18 for a vaccination program was 73.1%. The study provide a profile of the HPV situation in the country, with robust clinical, pathological and virological data which would permit a better cervical cancer screening and vaccination programs.

Human papillomavirus genotype distribution in cervical cancer cases in Spain. Implications for prevention.

OBJECTIVE: Human papillomavirus (HPV) genotype distribution in invasive cervical cancer (ICC) is critical to guide the introduction and to assess the impact of HPV prophylactic vaccines. This study aims to provide specific information for Spain. METHODS: 1043 histological confirmed ICC cases diagnosed from 1940 to 2007 from six Spanish regions were assembled. HPV DNA detection was performed by SPF(10) broad-spectrum PCR followed by deoxyribonucleic acid enzyme immunoassay and genotyping by reverse hybridization line probe assay (LiPA(25)) (version 1). RESULTS: Of 1043 ICC cases, 904 were HPV DNA positive (adjusted prevalence: 89.1%). The eight most common types, in decreasing order, were HPV 16, 18, 33, 31, 45, 35, 52 and 56, accounting for more than 90% of cases. HPV 16 and 18 contributed to 72.4% of all HPV positive ICC cases. In cervical adenocarcinomas, this contribution increased up to 94%. HPV 16 and 18 relative contributions showed a stable pattern over the 60 year study period. HPV 45, 18 and 16-positive ICC cases presented at younger ages than cases with other HPV types (adjusted mean age: 43.8, 45.2, 52.6 and 57.7 years, respectively). CONCLUSIONS: HPV 16 and 18 accounted together for a 72.4% of positive cases, with no statistically significant changes in their relative contributions over the last decades. In 94% of cervical adenocarcinomas we identified at least one of the two HPV types included in the current vaccines (HPV 16/18). Results suggest a major impact of HPV vaccines on reduction of ICC burden in Spain in the HPV vaccinated cohorts.

Predictors of human papillomavirus infection in women undergoing routine cervical cancer screening in Spain: the CLEOPATRE study.

BACKGROUND: Human papillomavirus (HPV) is a sexually transmitted infection that may lead to development of precancerous and cancerous lesions of the cervix. The aim of the current study was to investigate socio-demographic, lifestyle, and medical factors for potential associations with cervical HPV infection in women undergoing cervical cancer screening in Spain. METHODS: The CLEOPATRE Spain study enrolled 3 261 women aged 18-65 years attending cervical cancer screening across the 17 Autonomous Communities. Liquid-based cervical samples underwent cytological examination and HPV testing. HPV positivity was determined using the Hybrid Capture II assay, and HPV genotyping was conducted using the INNO-LiPA HPV Genotyping Extra assay. Multivariate logistic regression was used to identify putative risk factors for HPV infection. RESULTS: A lifetime number of two or more sexual partners, young age (18-25 years), a history of genital warts, and unmarried status were the strongest independent risk factors for HPV infection of any type. Living in an urban community, country of birth other than Spain, low level of education, and current smoking status were also independent risk factors for HPV infection. A weak inverse association between condom use and HPV infection was observed. Unlike monogamous women, women with two or more lifetime sexual partners showed a lower risk of infection if their current partner was circumcised (P for interaction, 0.005) and a higher risk of infection if they were current smokers (P for interaction, 0.01). CONCLUSION: This is the first large-scale, country-wide study exploring risk factors for cervical HPV infection in Spain. The data strongly indicate that variables related to sexual behavior are the main risk factors for HPV infection. In addition, in non-monogamous women, circumcision of the partner is associated with a reduced risk and smoking with an increased risk of HPV infection.

Intrauterine device use, cervical infection with human papillomavirus, and risk of cervical cancer: a pooled analysis of 26 epidemiological studies.

BACKGROUND: Intrauterine device (IUD) use has been shown to reduce the risk of endometrial cancer, but little is known about its association with cervical cancer risk. We assessed whether IUD use affects cervical human papillomavirus (HPV) infection and the risk of developing cervical cancer. METHODS: We did a pooled analysis of individual data from two large studies by the International Agency for Research on Cancer and Institut Català d'Oncologia research programme on HPV and cervical cancer; one study included data from ten case-control studies of cervical cancer done in eight countries, and the other included data from 16 HPV prevalence surveys of women from the general population in 14 countries. 2205 women with cervical cancer and 2214 matched control women without cervical cancer were included from the case-control studies, and 15,272 healthy women from the HPV surveys. Information on IUD use was obtained by personal interview. HPV DNA was tested by PCR-based assays. Odds ratios and 95% CIs were estimated using multivariate unconditional logistic regression for the associations between IUD use, cervical HPV DNA, and cervical cancer. FINDINGS: After adjusting for relevant covariates, including cervical HPV DNA and number of previous Papanicolaou smears, a strong inverse association was found between ever use of IUDs and cervical cancer (odds ratio 0·55, 95% CI 0·42-0·70; p<0·0001). A protective association was noted for squamous-cell carcinoma (0·56, 0·43-0·72; p<0·0001), adenocarcinoma and adenosquamous carcinoma (0·46, 0·22-0·97; p=0·035), but not among HPV-positive women (0·68, 0·44-1·06; p=0·11). No association was found between IUD use and detection of cervical HPV DNA among women without cervical cancer. INTERPRETATION: Our data suggest that IUD use might act as a protective cofactor in cervical carcinogenesis. Cellular immunity triggered by the device might be one of several mechanisms that could explain our findings. FUNDING: Instituto de Salud Carlos III; Agència de Gestió d'Ajuts Universitaris i Recerca; Marató TV3 Foundation; Bill & Melinda Gates Foundation; International Agency for Research on Cancer; European Community; Fondo de Investigaciones Sanitarias, Spain; Preventiefonds, Netherlands; Programa Interministerial de Investigación y Desarrollo, Spain; Conselho Nacional de Desenvolvimiento Cientifico e Tecnologico, Brazil; and Department of Reproductive Health & Research, WHO.