Prevalence of HPV DNA in cervical lesions in patients from Ecuador and Japan

Prevalence of human papillomavirus genotypes in women of different ethnicity from rural northwestern Ecuador

BACKGROUND

In Ecuador, cervical cancer is the third most common cancer among women and the second most common cause of cancer-related death in women. Although HPV represents a serious public health problem worldwide, the information about its prevalence and genotypes in remote communities of Ecuador is limited. The aim of this study was to determine the distribution of HPV genotypes among ethnic minority women from two remote communities of the northwestern region of Ecuador: Afro-Ecuadorians and Chachis (Amerindian group).

METHODS

We included 291 women who responded to a short survey and were screened for HPV by the amplification of the L1 gene and a nested multiplex PCR to detect 14 high risk (HR) genotypes. A survey collected information on ethnicity, age, community access, and sexual and gynecological history. We identified risk factors associated with HPV infection and co-infection using multivariate logistic regression to calculate odds ratio (OR) and Wald 95% confidence intervals (CI).

RESULTS

Overall, HPV prevalence in the study cohort was 56%, and the five most common HR-HPV genotypes were HPV-58, -16, -68, -39, and -43; however, the distribution of HPV genotypes varied according to ethnicity. We identified lineage A (European variant) for HPV-16 and sublineage A2 for HPV-58 in both ethnic groups. Adjusting for ethnicity, age, community access, and number of sexual partners, we found that Afro-Ecuadorian women were less likely to have an HPV infection than Chachi women (OR: 0.49, 95% CI: 0.25, 0.96), and that participants in communities only accessible by river had 64% less chances of an HPV infection when compared to women in communities accessible by road (OR: 0.36, 95% CI: 0.19, 0.71), and women with 2 to 3 sexual partners had 2.47 times the odds of HPV infection than participants with 0-1 partners (OR: 2.47, 95% CI: 1.32, 4.6). Similar associations were observed with prevalence of co-infection.

CONCLUSIONS

This study provides baseline knowledge regarding the prevalence and distribution of HPV genotypes in ethnic groups of the northwestern coastal Ecuador and essential information for the implementation of appropriate HPV testing and vaccination program to prevent cervical cancer.

Frequency and distribution of HPV genotypes in 800 genital samples of Ecuadorian men and women from the city of Guayaquil

Even though there are data published on HPV epidemiology in Ecuador, the distribution of genotypes in Guayaquil, the largest city in the country, has not been previously determined in a study including including both, men and women. The present study aimed to determine the distribution of 37 HPV genotypes in genital samples from Ecuadorian men and women living in the city of Guayaquil. Genital samples included in daily diagnostic routine were analyzed by the 37 HPV GenoArray Diagnostic Kit (Hybribio^® Ltd., Sheung Wan, Hong Kong). The relative frequency of detectable genotypes was determined. HPV relative frequency according to sample characteristics, including sex and age groups, was compared using c² test. From the 800 samples (400 men and 400 women), 411 (51.38%) were positive for HPV DNA. The obtained frequency was higher among samples from men (253/400 or 63.25%) in comparison to samples from women (158/400 or 39.50%), with a p value <0.05. Samples from men showed a higher frequency of HPV genotypes 6, 16, 18 and 11, while among samples from women genotypes 39, 16, 6 and 58 were the most frequent. Considering male and female samples together, genotypes 6, 16, 39 and 11 presented the highest frequencies. HPV DNA was detected in half of the studied samples, with a higher frequency among samples from men. Genotype 39 was the most frequent among women, and ranked third when samples from men and women are analyzed together.

Molecular epidemiology and phylogenetic analysis of human papillomavirus infection in women with cervical lesions and cancer from the coastal region of Ecuador

The aim of the present study was to gather information regarding the molecular epidemiology of Human papillomavirus (HPV) and related risk factors in a group of women with low- and high-grade cervical lesions and cancer from the coastal region of Ecuador. In addition, we studied the evolution of HPV variants from the most prevalent types and provided a temporal framework for their emergence, which may help to trace the source of dissemination within the region. We analyzed 166 samples, including 57 CIN1, 95 CIN2/3 and 14 cancer cases. HPV detection and typing was done by PCR-sequencing (MY09/MY11). HPV variants and estimation of the time to most recent common ancestor (tMRCA) was assessed through phylogeny and coalescence analysis. HPV DNA was found in 54.4% of CIN1, 74.7% of CIN2/3 and 78.6% of cancer samples. HPV16 (38.9%) and HPV58 (19.5%) were the most prevalent types. Risk factors for the development of cervical lesions/cancer were the following: three or more pregnancies (OR=4.3), HPV infection (OR=3.7 for high-risk types; OR=3.5 for HPV16), among others. With regard to HPV evolution, HPV16 isolates belonged to lineages A (69%) and D (31%) whereas HPV58 isolates belonged only to lineage A. The period of emergence of HPV16 was in association with human populations (tMRCA=91052 years for HPV16A and 27000 years for HPV16D), whereas HPV58A preceded Homo sapiens evolution (322257 years). This study provides novel data on HPV epidemiology and evolution in Ecuador, which will be fundamental in the vaccine era.

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 and its association with cervical dysplasia in Ecuadorian women attending a private cancer screening clinic

Women living in Latin American countries bear a disproportionate burden of cervical cancer, a condition caused by infection with the human papillomavirus (HPV). We performed a study in Santa Elena, Guayas (currently Santa Elena Province), Ecuador, to determine how often HPV could be detected in women attending a private cancer screening clinic. Participants underwent a Pap test, and vaginal and cervical swabs were performed for HPV testing by the polymerase chain reaction (PCR). Each participant completed a verbally administered survey. The mean age of 302 participants was 37.7 years (range 18 to 78 years). The majority of cervical and vaginal specimens contained sufficient DNA to perform PCR. Overall, 24.2% of the participants had either a cervical or vaginal swab that tested positive for HPV. In general, there was a good correlation between the HPV types detected in the cervical and vaginal swabs from the participants, but vaginal swabs were more likely to contain HPV DNA than were cervical swabs. The high-risk HPV types 16, 52, 58, and 59 and the low-risk HPV types 62, 71, 72, and 83 were the most frequently detected HPV types. The number of lifetime sexual partners was positively associated with detection of any HPV type, detection of oncogenic HPV, and abnormal Pap smears. Further studies are needed to determine if these results are representative of all Ecuadorian women and to determine if cervical cancers in Ecuadorian women are caused by the same HPV types found in the swab specimens obtained in this study.

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.

Retrospective Analysis of Concurrent Chemoradiation with the Combination of Bleomycin, Ifosfamide and Cisplatin (BIP) for Uterine Cervical Cancer

Combination chemotherapy consisting of bleomycin, ifosfamide, and ciplatin (BIP) is recognized as one of the most effective chemotherapies for uterine cervical cancer. However, there have been no reports that evaluate concurrent use of radiation with BIP. The objective of this study was to evaluate the toxicity and response of the combination of BIP concurrent with radiation in patients with squamous cell carcinoma of the uterine cervix. Eligibility criteria included patients who underwent radical hysterectomy (Type III hysterectomy) as a primary treatment and revealed lymph node metastases or deep myometrial invasion (stage IB and IIA) and patients who were previously untreated (stage IIB-IV). All of the patients had biopsy-proven squamous cell carcinoma of the uterine cervix. The patients received three courses of BIP chemoradiation, and the response and toxicity were evaluated. From January 2000 to December 2003, 30 patients met study eligibility criteria. All but three patients completed 3 courses of planned chemotherapy. The frequency of severe (grade 3 and 4) toxicity was as follows: anemia, 46.7%; neutrocytopenia, 73.3%; thrombocytopenia, 16.7%; and nausea and vomiting, 23.3%. Among 30 patients, 22 cases were evaluated for response. Complete response was achieved in 16 (72.7%) of patients, with a response rate of 90.9%. In conclusion, BIP chemoradiation seems to be superior to previously reported chemoradiation regimens, and has a potential as an optimal combination chemotherapy concurrent with radiation.