Gloria Inés Sánchez

Human papillomavirus genotype attribution in invasive cervical cancer: a retrospective cross-sectional worldwide study

BACKGROUND Knowledge about the distribution of human papillomavirus (HPV) genotypes in invasive cervical cancer is crucial to guide the introduction of prophylactic vaccines. We aimed to provide novel and comprehensive data about the worldwide genotype distribution in patients with invasive cervical cancer. METHODS Paraffin-embedded samples of histologically confirmed cases of invasive cervical cancer were collected from 38 countries in Europe, North America, central South America, Africa, Asia, and Oceania. Inclusion criteria were a pathological confirmation of a primary invasive cervical cancer of epithelial origin in the tissue sample selected for analysis of HPV DNA, and information about the year of diagnosis. HPV detection was done by use of PCR with SPF-10 broad-spectrum primers followed by DNA enzyme immunoassay and genotyping with a reverse hybridisation line probe assay. Sequence analysis was done to characterise HPV-positive samples with unknown HPV types. Data analyses included algorithms of multiple infections to estimate type-specific relative contributions. FINDINGS 22,661 paraffin-embedded samples were obtained from 14,249 women. 10,575 cases of invasive cervical cancer were included in the study, and 8977 (85%) of these were positive for HPV DNA. The most common HPV types were 16, 18, 31, 33, 35, 45, 52, and 58 with a combined worldwide relative contribution of 8196 of 8977 (91%, 95% CI 90-92). HPV types 16 and 18 were detected in 6357 of 8977 of cases (71%, 70-72) of invasive cervical cancer. HPV types 16, 18, and 45 were detected in 443 of 470 cases (94%, 92-96) of cervical adenocarcinomas. Unknown HPV types that were identified with sequence analysis were 26, 30, 61, 67, 69, 82, and 91 in 103 (1%) of 8977 cases of invasive cervical cancer. Women with invasive cervical cancers related to HPV types 16, 18, or 45 presented at a younger mean age than did those with other HPV types (50·0 years [49·6-50·4], 48·2 years [47·3-49·2], 46·8 years [46·6-48·1], and 55·5 years [54·9-56·1], respectively). INTERPRETATION To our knowledge, this study is the largest assessment of HPV genotypes to date. HPV types 16, 18, 31, 33, 35, 45, 52, and 58 should be given priority when the cross-protective effects of current vaccines are assessed, and for formulation of recommendations for the use of second-generation polyvalent HPV vaccines. Our results also suggest that type-specific high-risk HPV-DNA-based screening tests and protocols should focus on HPV types 16, 18, and 45.

Worldwide genomic diversity of the high-risk human papillomavirus types 31, 35, 52, and 58, four close relatives of human papillomavirus type 16

ABSTRACT Among the more than one hundred formally described human papillomavirus (HPV) types, 18 are referred to as high-risk HPV types due to their association with anogenital cancer. Despite pathogenic similarities, these types form three remotely related taxonomic groups. One of these groups is called HPV species 9 and is formed by HPV-16, the most common and best-studied type, together with HPV-31, -33, -35, -52, -58, and -67. Previous worldwide comparisons of HPV-16 samples showed about 2% nucleotide diversity between isolates, which were subsequently termed variants. The distribution of divergent variants has been found to correlate frequently with the geographic origin and the ethnicity of the infected patients and led to the concept of unique African, European, Asian, and Native American HPV-16 variants. In the current study, we address the question of whether geography and ethnicity also correlate with sequence variations found for HPV-31, -35, -52, and -58. This was done by sequencing the long control region in samples derived from Europe, Asia, and Africa, and from immigrant populations in North and South America. We observed maximal divergence between any two variants within each of these four HPV types ranging from 1.8 to 3.6% based on nucleotide exchanges and, occasionally, on insertions and deletions. Similar to the case with HPV-16, these mutations are not random but indicate a relationship between the variants in form of phylogenetic trees. An interesting example is presented by a 16-bp insert in select variants of HPV-35, which appears to have given rise to additional variants by nucleotide exchanges within the insert. All trees showed distinct phylogenetic topologies, ranging from dichotomic branching in the case of HPV-31 to star phylogenies of the other three types. No clear similarities between these types or between these types and HPV-16 exist. While variant branches in some types were specific for Europe, Africa, or East Asia, none of the four trees reflected human evolution and spread to the extent illustrated by HPV-16. One possible explanation is that the rare HPV types that we studied spread and thereby diversified more slowly than the more abundant HPV-16 and may have established much of todays variant diversity already before the worldwide spread of humans 100,000 years ago. Most variants had prototypic amino acid sequences within the E6 oncoprotein and a segment of the L1 capsid protein. Some had one, two, or three amino acid substitutions in these regions, which might indicate biological and pathogenic diversity between the variants of each HPV type.

Nuevos paradigmas y desafíos en la prevención y control del cáncer de cuello uterino en América Latina

El cancer de cuello uterino sigue siendo un problema de salud publica en Latinoamerica. El uso de la citologia para la deteccion de lesiones pre-cancerosas no ha tenido mayor impacto en las tasas de incidencia y mortalidad, que aun se mantienen altas en la region. La disponibilidad de nuevas tecnicas de tamizaje para la deteccion de lesiones pre-cancerosas y de vacunas altamente eficaces que previenen casi todas las lesiones relacionadas con VPH-16 y VPH-18 en mujeres no expuestas previamente al virus representan una gran oportunidad para la prevencion del cancer de cuello uterino en la region. En este manuscrito resumimos la evidencia cientifica y la experiencia de la region en i) el uso de pruebas de VPH y de la inspeccion visual despues del acido acetico (IVAA) en tamizaje primario, y ii) la implementacion de programas de vacunacion en adolescentes. Finalmente enumeramos una serie de recomendaciones adecuadas para distintos escenarios. La factibilidad de implementar un programa nacional de prevencion de cancer de cuello uterino exitoso y sostenible en paises latinoamericanos dependera de las prioridades de salud, la infraestructura y personal de salud disponible, determinadas luego de un riguroso analisis situacional local.

Integration of Human Papillomavirus Vaccination and Cervical Cancer Screening in Latin America and the Caribbean

Despite substantial efforts to control cervical cancer by screening, most Latin American and Caribbean countries continue to experience incidence rates of this disease that are much higher than those of other Western countries. The implementation of universal human papillomavirus (HPV) vaccination for young adolescent women is the best prospect for changing this situation. Even though there are financial challenges to overcome to implement such a policy, there is broad political support in the region for adopting universal HPV vaccination. The costs of implementing this policy could be largely alleviated by changing cervical cancer control practices that rely on inefficient use of resources presently allocated to cytology screening. In view of the strong evidence base concerning cervical cancer prevention technologies in the region and the expected impact of vaccination on the performance of cytology, we propose a reformulation of cervical cancer screening policies to be based on HPV testing using validated methods followed by cytologic triage. This approach would serve as the central component of a system that plays the dual role of providing screening and surveillance as integrated and complementary activities sharing centralized resources and coordination.

Knowledge of Pap screening and human papillomavirus among women attending clinics in Medellín, Colombia.

This study evaluated Pap screening and human papillomavirus (HPV) knowledge in a population of Colombian women as a possible contributing factor of low cervical cancer screening success. This is a descriptive, cross-sectional analysis of 454 women who were approached in five different hospitals and clinics throughout Medellín, Colombia. Of them, 449 females agreed to participate and answered a standardized face-to-face questionnaire regarding Pap screening and HPV knowledge. Using logistic regression, predictors of both Pap and HPV knowledge were examined. Overall, 76.3% of the participants exhibited a high level of Pap screening knowledge, while only 7.8% showed high level of HPV knowledge. Of the 449 women, 71.5% reported that it had been 1 year or less since their last Pap test, while 7.8% reported never having had a Pap test or not having had a recent test. Factors influencing Pap screening knowledge included education level and insurance; factors influencing HPV knowledge included education level and age. The high level of Pap screening knowledge and use do not explain the high cervical cancer rates in Colombia. The results of this study suggest that educational efforts should be focused on increasing womens knowledge and awareness of HPV in anticipation of the availability of HPV vaccines and HPV tests for screening

New Approaches to Cervical Cancer Screening in Latin America and the Caribbean

Cervical cancer remains an important public health problem in the Latin America and Caribbean region (LAC), with an expected significant increase in disease burden in the next decades as a result of population ageing. Prophylactic human papillomavirus (HPV) vaccine is currently unaffordable in LAC countries. However, even if vaccination was implemented, an additional two decades will be required to observe its impact on HPV related disease and cancer. With some exceptions, cytology-based screening programs have been largely ineffective to control the problem in the region, and there is a need for new approaches to the organization of screening and for use of newly developed techniques. Several research groups in LAC have conducted research on new screening methods, some of which are summarized in this paper. A recommendation to reorganize screening programs is presented considering visual inspection for very low resource areas, improvement of cytology where it is operating successfully and HPV DNA testing followed by visual inspection with acetic acid (VIA) or cytology as soon as this method becomes technically and economically sustainable. This could be facilitated by the incorporation of new, low-cost HPV DNA testing methods and the use of self-collected vaginal specimens for selected groups of the population. An important requisite for screening based on HPV testing will be the quality assurance of the laboratory and the technique by validation and certification measures.

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.

Human papillomavirus genotype detection in recurrent respiratory papillomatosis (RRP) in Colombia.

Knowledge on human papillomavirus (HPV) genotype distribution in recurrent respiratory papillomatosis (RRP) is essential to assess the impact of HPV vaccine. It is provided information for Colombia.

Genótipos de vírus de papiloma humano em carcinoma de células escamosas de cabeça e pescoço na Colômbia

UNLABELLED Estimating the type-specific prevalence of human papillomavirus (HPV) in head and neck cancer (HNSCC) is helpful in predicting the impact of HPV immunization. OBJECTIVE To estimate the overall prevalence, and gender and age-specific prevalence of HPV in HNSCC. METHOD This cross sectional retrospective study was carried out in four pathology laboratories of Medellin, Colombia. HPV testing was performed by GP5+/6+ PCR-based RLB and HPV 16 and 18 type-specific PCR. RESULTS 175 primary HNSCC cases consecutively diagnosed between 1999 and 2008 with confirmed diagnosis and amplifiable DNA were included. Overall HPV prevalence was 18.9%. HPV was found in 23.9%, 17.5% and 13.3% of the oral cavity, larynx and oropharynx cases respectively. Among HPV positive cases, 82% were HPV 16 and 18% were HPV 18. No other HPV genotypes were identified. Most patients were males. Male patients were younger that their female counterparts, particularly in oral cavity cancer cases. CONCLUSION HPV 16 and 18 genotypes were found in nearly 20% of HNSCC cases in Colombian patients. The impact of HPV vaccination for the prevention of HNSCC in this population deserves further evaluation.

Higher Micronutrient Intake Is Associated With Human Papillomavirus-Positive Head and Neck Cancer: A Case-Only Analysis

No studies have investigated dietary differences between head and neck squamous cell carcinoma (HNSCC) patients with human papillomavirus (HPV)-positive tumors and patients with HPV-negative tumors. This study was designed to investigate the relationship between diet and HPV status in HNSCC patients. Cases of HNSCC were recruited from 2 clinical centers participating in the University of Michigan Head and Neck Specialized Program of Research Excellence (SPORE). HPV tissue genotyping was performed, and epidemiological and dietary data collected. Multivariable logistic regression tested whether pretreatment consumption of 12 selected micronutrients was significantly associated with HPV-positive status in 143 patients newly diagnosed with cancer of the oral cavity or pharynx. After controlling for age, sex, body mass index, tumor site, cancer stage, problem drinking, smoking, and energy intake, significant and positive associations were observed between vitamin A, vitamin E, iron, β-carotene, and folate intake and HPV-positive status (P trend < 0.05), suggesting that diet may be a factor in the improved prognosis documented in those with HPV-positive HNSCC. Dietary differences by HPV status should be considered in prognostic studies to better understand the influence of diet on HNSCC survival.