Joellen Klaustermeier

Bio: Joellen Klaustermeier is an academic researcher. The author has contributed to research in topics: Cervical cancer & HPV vaccines. The author has an hindex of 14, co-authored 16 publications receiving 1120 citations.

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

Abstract: 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.

p16 overexpression identifies HPV-positive vulvar squamous cell carcinomas.

Abstract: Two types of vulvar squamous cell carcinomas (VSCCs) are recognized according to their relationship to human papillomavirus (HPV). Basaloid or warty carcinomas are considered HPV-associated tumors, whereas differentiated keratinizing neoplasms are considered non-HPV-associated. Recently, immunohistochemical detection of p16 and p53 has been proposed to differentiate these 2 types of VSCCs. We conducted a histologic study with immunohistochemical evaluation of p16 and p53 and HPV detection and typing by polymerase chain reaction using 2 different sets of primers in 92 cases of VSCCs to evaluate the usefulness of immunohistochemistry in the classification of VSCCs and to describe the clinico-pathologic characteristics of both types of VSCCs. HPV was detected in 16/92 (17.4%) specimens, HPV16 being identified in 75% of positive cases. A significant number of discrepancies between histology and HPV detection were observed, with 37.5% of HPV-positive tumors being keratinizing and 9.2% of HPV-negative carcinomas showing basaloid or warty features. Diffuse positivity for p16 and p53 was observed in 100% and 6.2% of HPV-positive tumors and in 2.3% and 64.5% of HPV-negative neoplasms, respectively. The sensitivity and specificity of p16 immunostaining to detect HPV-associated carcinomas (100% and 98.7%, respectively) were better than those of histologic criteria (93.8% and 35.5%) and of p53 negative stain (62.5% and 93.4%). Vulvar intraepithelial neoplasia grade 3 of basaloid/warty type was identified in 53.8% HPV-positive tumors, including 3 keratinizing tumors. All these cases were p16 positive and p53 negative. Vulvar intraepithelial neoplasia grade 3 of differentiated type was observed in 45.6% of HPV-negative cases; 90.8% of them were positive for p53 but all were negative for p16. No differences in age, stage, or development of recurrence were observed between HPV-positive and negative tumors. In summary, the current morphologic criteria to discriminate HPV-positive and negative VSCCs have a significant overlap. Immunostaining for p16 is a reliable marker for HPV-positive VSSCs, which improves the results of histologic classification.

The basaloid cell is the best tissue marker for human papillomavirus in invasive penile squamous cell carcinoma: a study of 202 cases from Paraguay.

Abstract: Human papillomavirus (HPV) has been reported in 12-82% of penile squamous cell carcinomas (SCC). There is an association of the virus with basaloid and warty carcinomas but the reported prevalence is variable. The causes of these variations are not clear. They may be owing to geographic differences, the use of different techniques to detect HPV, the status of the original paraffin blocks, or to variable criteria in tumor classification. The aims of the study were to determine the prevalence of HPV in penile SCC and subtypes using a sensitive technique, to investigate genotypes involved, and to search for other morphologic features associated with the virus from a series of cases from Paraguay. HPV detection was done by SPF-10 polymerase chain reaction followed by DNA enzyme-immunoassay and genotyping by LIPA 25 (version 1). Samples were tested at Catalan Institute of Oncology, Barcelona, and cross testing was carried out at the Delft Diagnostic Laboratories in The Netherlands. HPV was detected in 64 of 202 cases (32%). Thirteen tumors had multiple HPV genotypes. Most prevalent genotypes were HPV-16 (46 cases), HPV-6 (6 cases), and HPV-18 (4 cases), either in single or in multiple infections. HPV was preferentially associated with warty-basaloid (82%), basaloid (76%), and warty (39%) carcinomas and not detected in verrucous, mixed verrucous-papillary, pseudohyperplastic, and pseudoglandular SCCs. There was a strong association between HPV and higher histologic grade. Basaloid cells were more frequently found in HPV positive tumors (72%) and this association was statistically significant in univariate and multivariate analyses. Cells with koilocytotic features and keratinizing squamous cells were also present but to a much lesser degree (47% and 19%, respectively). In summary, HPV was found in a third of the cases and the most common genotype was HPV-16. Low-risk genotypes were rarely found in single infections, representing 4 cases among all analyzed (2%). There was an association between HPV presence and higher histologic grade and with basaloid, warty-basaloid, and warty carcinomas. Our results also suggest that, in penile SCC, the basaloid cell is the best tissue marker for oncogenic HPV infection.

Cervical Human Papillomavirus Prevalence in 5 Continents: Meta-Analysis of 1 Million Women with Normal Cytological Findings

Abstract: BACKGROUND: Baseline information on human papillomavirus (HPV) prevalence and type distribution is highly desirable to evaluate the impact of prophylactic HPV vaccines in the near future. METHODS: A meta-analysis was performed of studies published between 1995 and 2009 that used polymerase chain reaction or Hybrid Capture 2 for HPV detection in women with normal cytological findings. RESULTS: The analysis included 194 studies comprising 1016719 women with normal cytological findings. The estimated global HPV prevalence was 11.7% (95% confidence interval 11.6%-11.7%). Sub-Saharan Africa (24.0%) Eastern Europe (21.4%) and Latin America (16.1%) showed the highest prevalences. Age-specific HPV distribution presented with a first peak at younger ages ( /=45 years). Among the women with type-specific HPV data ([Formula: see text]) the 5 most common types worldwide were HPV-16 (3.2%) HPV-18 (1.4%) HPV-52 (0.9%) HPV-31 (0.8%) and HPV-58 (0.7%). CONCLUSIONS: Although the prevalence of HPV in women with normal cytological findings is high and variable across world regions HPV types 16 18 31 52 and 58 are consistently found among the 10 most common types in all of them. These results represent the most comprehensive assessment of HPV burden among women with normal cytological findings in the pre-HPV vaccination era worldwide.

The Lower Anogenital Squamous Terminology Standardization Project for HPV-Associated Lesions: Background and Consensus Recommendations from the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology

Abstract: The terminology for human papillomavirus(HPV)–associated squamous lesions of the lower anogenital tract has a long history marked by disparate diagnostic terms derived from multiple specialties. It often does not reflect current knowledge of HPV biology and pathogenesis. A consensus process was convened to recommend terminology unified across lower anogenital sites. The goal was to create a histopathologic nomenclature system that reflects current knowledge of HPV biology, optimally uses available biomarkers, and facilitates clear communication across different medical specialties. The Lower Anogenital Squamous Terminology (LAST) Project was co-sponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology and included 5 working groups; 3 work groups performed comprehensive literature reviews and developed draft recommendations. Another work group provided the historical background and the fifth will continue to foster implementation of the LAST recommendations. After an open comment period, the draft recommendations were presented at a consensus conference attended by LAST work group members, advisors, and representatives from 35 stakeholder organizations including professional societies and government agencies. Recommendations were finalized and voted on at the consensus meeting. The final, approved recommendations standardize biologically relevant histopathologic terminology for HPV-associated squamous intraepithelial lesions and superficially invasive squamous carcinomas across all lower anogenital tract sites and detail the appropriate use of specific biomarkers to clarify histologic interpretations and enhance diagnostic accuracy. A plan for disseminating and monitoring recommendation implementation in the practicing community was also developed. The implemented recommendations will facilitate communication between pathologists and their clinical colleagues and improve accuracy of histologic diagnosis with the ultimate goal of providing optimal patient care.

Carcinogenic human papillomavirus infection.

Abstract: Infections with human papillomavirus (HPV) are common and transmitted by direct contact. Although the great majority of infections resolve within 2 years, 13 phylogenetically related, sexually transmitted HPV genotypes, notably HPV16, cause - if not controlled immunologically or by screening - virtually all cervical cancers worldwide, a large fraction of other anogenital cancers and an increasing proportion of oropharyngeal cancers. The carcinogenicity of these HPV types results primarily from the activity of the oncoproteins E6 and E7, which impair growth regulatory pathways. Persistent high-risk HPVs can transition from a productive (virion-producing) to an abortive or transforming infection, after which cancer can result after typically slow accumulation of host genetic mutations. However, which precancerous lesions progress and which do not is unclear; the majority of screening-detected precancers are treated, leading to overtreatment. The discovery of HPV as a carcinogen led to the development of effective preventive vaccines and sensitive HPV DNA and RNA tests. Together, vaccination programmes (the ultimate long-term preventive strategy) and screening using HPV tests could dramatically alter the landscape of HPV-related cancers. HPV testing will probably replace cytology-based cervical screening owing to greater reassurance when the test is negative. However, the effective implementation of HPV vaccination and screening globally remains a challenge.