Cytological distinction between high-risk and low-risk human papillomavirus infections in SurePath liquid-based cell preparations

New biological research and understanding of Papanicolaou's test

The development of the Papanicolaou smear test by Dr. George Nicholas Papanicolaou (1883-1962) is one of the most significant achievements in screening for disease and cancer prevention in history. The Papanicolaou smear has been used for screening of cervical cancer since the 1950s. The test is technically straightforward and practical and based on a simple scientific observation: malignant cells have an aberrant nuclear morphology that can be distinguished from benign cells. Here, we review the scientific understanding that has been achieved and continues to be made on the causes and consequences of abnormal nuclear morphology, the basis of Dr. Papanicolaou's invention. The deformed nuclear shape is caused by the loss of lamina and nuclear envelope structural proteins. The consequences of a nuclear envelope defect include chromosomal numerical instability, altered chromatin organization and gene expression, and increased cell mobility because of a malleable nuclear envelope. HPV (Human Papilloma Virus) infection is recognized as the key etiology in the development of cervical cancer. Persistent HPV infection causes disruption of the nuclear lamina, which presents as a change in nuclear morphology detectable by a Papanicolaou smear. Thus, the causes and consequences of nuclear deformation are now linked to the mechanisms of viral carcinogenesis, and are still undergoing active investigation to reveal the details. Recently a statue was installed in front of the Papanicolaou's Cancer Research Building to honor the inventor. Remarkably, the invention nearly 60 years ago by Dr. Papanicolaou still exerts clinical impacts and inspires scientific inquiries.

Significance of the Cytological Signs of Human Papillomavirus Infection in Anal Pap Smears of Human Immunodeficiency Virus-Infected Japanese Men Who Have Sex with Men

Purpose: The incidence of invasive anal cancer (IAC) has been increasing among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). Although cytological diagnosis is the modality of choice for screening cases of IAC, it is associated with lower sensitivity and specificity. Therefore, the present study aimed to evaluate new cytological signs of human papillomavirus (HPV) infection that may contribute to improving anal cytology. Methods: Anal cytology and HPV testing were performed using SurePath liquid-based cytology on samples obtained from 37 HIV-positive Japanese MSM. Subsequently, a histological biopsy based on high-resolution anoscopy was performed in MSM with abnormal cytological findings indicative of atypical squamous cells of undetermined significance (ASC-US) +. Also, anal Papanicolaou (Pap) smears were performed to determine cellularity, presence of dysplastic squamous cells, and other cytological signs of HPV infection. Results: Of the 37 MSM who underwent anal cytology, six tested negative for intraepithelial lesion or malignancy, three cases exhibited ASC-US, 17 exhibited low-grade squamous intraepithelial lesion (LSIL), nine exhibited high-grade squamous intraepithelial lesion (HSIL), and two remained undiagnosed. The anal Pap smears of 28 (96.6%) of the 29 MSM with abnormal cytological findings of ASC-US+ exhibited anal intraepithelial neoplasia (AIN), as revealed by histological biopsy. The median value (minimum–maximum) of the cellularity of anal Pap smears was 12 (0–70.5) nsc/hpf. In 26 MSM with LSIL and HSIL, the median dysplastic squamous cells count was 14 (2–152) dsc/smear and the cytological sign of HPV infection was 11 (2–71) hpv/smear. Of all anal Pap smears that revealed ASC-US+, 96.6% exhibited cytological signs of HPV infection. Compression-positive binucleated cells were the most prevalent among all cytological signs of HPV infection. Conclusion: For anal cytology, instead of considering a small number of dysplastic squamous cells, screening based on cytological signs of HPV infection may be beneficial for improving the diagnosis of AIN.

Significance of Compression in Binucleation while Differentiating Reactive Cellular Changes Between Human Papillomavirus and Candida Infections

Purpose:

Binucleation is a reactive cellular change (RCC) in Pap smears due to Candida infection. However, the origin of these binucleated cells as RCCs remains unclear. The purpose of this study was to examine binucleation in patients negative for intraepithelial lesion or malignancy (NILM) and infected with Candida and those infected with high-risk human papillomavirus (hr-HPV) and to clarify the origin of the binucleated cells.

Methods:

A total of 115 endocervical swab specimens with a combined diagnosis of NILM, Candida infection, and RCCs were used for this study. Pap smears were used to identify binucleated cells and then separate them into two groups, compression-positive and compression-negative. In addition, hr-HPV was detected using polymerase chain reaction (PCR) with a specific primer on the DNA extracted from the remaining residual cytology specimens. To make the hr-HPV-infected binucleated cells visible, an in situ PCR assay was performed on the Pap smear.

Result:

Of the 115 specimens, 69.6% contained binucleated cells, 26 (32.5%) showed only the compressed form, 35 (43.8%) showed only the non-compressed form, and 19 showed both the compressed and non-compressed forms of binucleated cells. Also, 34 specimens (29.6%) were positive for hr-HPV. The sensitivity and specificity of compression-positive binucleated cells were 91.2% and 82.7% (p < 0.001), but they were not significant in the compression-negative group (p = 0.156). Also, 34 cases with hr-HPV contained 99 compression-positive and 24 compression-negative cells. The hr-HPV-positive cells accounted for 68 (68.7%) of the 99 compression-positive and 2 (8.3%) of the 24 compression-negative binucleated cells as determined by an in situ PCR assay for hr-HPV. The relationship between compression and hr-HPV was statistically significant (p < 0.001).

Conclusion:

Compression-positive binucleated cells may be present as a result of hr-HPV infection and not RCC, which is caused due to inflammation in NILM cases infected with Candida.

Human papillomavirus testing versus repeat cytology for triage of minor cytological cervical lesions

BACKGROUND

Atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intra-epithelial lesions (LSIL) are minor lesions of the cervical epithelium, detectable by cytological examination of cells collected from the surface of the cervix of a woman.Usually, women with ASCUS and LSIL do not have cervical (pre-) cancer, however a substantial proportion of them do have underlying high-grade cervical intra-epithelial neoplasia (CIN, grade 2 or 3) and so are at increased risk for developing cervical cancer. Therefore, accurate triage of women with ASCUS or LSIL is required to identify those who need further management.This review evaluates two ways to triage women with ASCUS or LSIL: repeating the cytological test, and DNA testing for high-risk types of the human papillomavirus (hrHPV) - the main causal factor of cervical cancer.

OBJECTIVES

Main objective To compare the accuracy of hrHPV testing with the Hybrid Capture 2 (HC2) assay against that of repeat cytology for detection of underlying cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) or grade 3 or worse (CIN3+) in women with ASCUS or LSIL. For the HC2 assay, a positive result was defined as proposed by the manufacturer. For repeat cytology, different cut-offs were used to define positivity: Atypical squamous cells of undetermined significance or worse (ASCUS+), low-grade squamous intra-epithelial lesions or worse (LSIL+) or high-grade squamous intra-epithelial lesions or worse (HSIL+).Secondary objective To assess the accuracy of the HC2 assay to detect CIN2+ or CIN3+ in women with ASCUS or LSIL in a larger group of reports of studies that applied hrHPV testing and the reference standard (coloscopy and biopsy), irrespective whether or not repeat cytology was done.

SEARCH METHODS

We made a comprehensive literature search that included the Cochrane Register of Diagnostic Test Accuracy Studies; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (through PubMed), and EMBASE (last search 6 January 2011). Selected journals likely to contain relevant papers were handsearched from 1992 to 2010 (December). We also searched CERVIX, the bibliographic database of the Unit of Cancer Epidemiology at the Scientific Institute of Public Health (Brussels, Belgium) which contains more than 20,000 references on cervical cancer.More recent searches, up to December 2012, targeted reports on the accuracy of triage of ASCUS or LSIL with other HPV DNA assays, or HPV RNA assays and other molecular markers. These searches will be used for new Cochrane reviews as well as for updates of the current review.

SELECTION CRITERIA

Studies eligible for inclusion in the review had to include: women presenting with a cervical cytology result of ASCUS or LSIL, who had undergone both HC2 testing and repeat cytology, or HC2 testing alone, and were subsequently subjected to reference standard verification with colposcopy and colposcopy-directed biopsies for histologic verification.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data from the selected studies, and obtained additional data from report authors.Two groups of meta-analyses were performed: group I concerned triage of women with ASCUS, group II concerned women with LSIL. The bivariate model (METADAS-macro in SAS) was used to assess the absolute accuracy of the triage tests in both groups as well as the differences in accuracy between the triage tests.

MAIN RESULTS

The pooled sensitivity of HC2 was significantly higher than that of repeat cytology at cut-off ASCUS+ to detect CIN2+ in both triage of ASCUS and LSIL (relative sensitivity of 1.27 (95% CI 1.16 to 1.39; P value < 0.0001) and 1.23 (95% CI 1.06 to 1.4; P value 0.007), respectively. In ASCUS triage, the pooled specificity of the triage methods did not differ significantly from each other (relative specificity: 0.99 (95% CI 0.97 to 1.03; P value 0.98)). However, the specificity of HC2 was substantially, and significantly, lower than that of repeat cytology in the triage of LSIL (relative specificity: 0.66 (95% CI 0.58 to 0.75) P value < 0.0001).

AUTHORS' CONCLUSIONS

HPV-triage with HC2 can be recommended to triage women with ASCUS because it has higher accuracy (significantly higher sensitivity, and similar specificity) than repeat cytology. When triaging women with LSIL, an HC2 test yields a significantly higher sensitivity, but a significantly lower specificity, compared to a repeat cytology. Therefore, practice recommendations for management of women with LSIL should be balanced, taking local circumstances into account.

Testing for human papillomavirus in cervical cancer screening: a review of indications and methodology

High-risk human papillomavirus (hrHPV) testing has become an integral component of cervical cancer screening, given that persistent infection with hrHPV was recognized as a significant risk factor for most precancers and cancers of the cervix. Particularly, testing for hrHPV types (in conjunction with cervical cytology) has been approved for primary screening in women over 30 years of age and for cost-effective triaging of equivocal cervical cytology results. HPV was a small double-stranded DNA virus that cannot be cultured in vitro; so, different types of tests have been developed to detect its presence. Various molecular techniques were available for detecting the presence and/or quantity of hrHPV. In this review, the testing options for hrHPV and its surrogates, with an emphasis on those approved by the US Food and Drug Administration (FDA), were detailed. Cancer (Cancer Cytopathol) 2011;. © 2011 American Cancer Society.