Clinical relevance of human papillomavirus testing in cytopathology

Cancer of the uterine cervix is the second most common cancer in women worldwide. Currently, cervical screening is based on cytology alone. Because infection with high-risk human papillomavirus types (hrHPVs) is a necessary cause of cervical cancer, it has been postulated that screening might become more efficient when it is based on combined cytology and hrHPV testing. In this review we will discuss the advantages of added HPV tests in cervical cancer screening, as a quality control for false-negative smears, in triage of women with equivocal smears, in follow-up of women treated for CIN3 or cervical cancer and for the detection of cervical adenocarcinoma.     

HPV检测早期筛查宫颈癌的临床意义——附妇科门诊2761例宫颈拭子HPV分析

目的探讨女性HPV DNA检测在宫颈癌防治方面的意义。方法应用DNA杂交技术对2 761例妇科门诊就诊者基因分型检测。结果 2 761例样本中,HPV感染有768例,阳性率27.82%,HPV感染人次972人次。检测高危型HPV（16,18,31,33,35,39,45,51,52,56,58,59,68）813人次,占感染总人次的83.64%;检出低危型HPV（6,11,42,43,44）73人次,占感染总人次7.51%;中国人群常见型HPV（53,66,CP8304）86人次,占感染总人次的8.85%。165例样本中包含了25种亚型的感染。结论 DNA杂交技术检测HPV基因分型,可一次检测多种亚型,有利于对HPV多重感染的诊断和宫颈癌的防治,可作为宫颈癌筛查的手段。     

Ensuring quality in cervical screening programmes based on molecular human papillomavirus testing

The increased use of human papillomavirus testing within cervical screening programmes necessarily brings about changes to the laboratory services required to support them. A crucial element of such services is to demonstrate initial and ongoing quality of the test (and associated processes). In this review, we outline some of the quality considerations and challenges with an emphasis on the laboratory including assay and platform validation, internal quality control selection and strengths and weaknesses of external quality assurance schemes. The influence and role of key external entities, including regulatory agencies, guideline groups, programme commissioners and commercial providers, are also discussed.     

Quality assurance issues and PACS

Quality assessment and assurance is a growing concern in all areas of health care. The concern is fueled by a body of evidence that indicates that quality of care is not optimal, and in many instances, is unacceptably low. Although different standards for quality have been proposed, health outcome is the ultimate standard, since improving health is the goal of the health care system. The effects of PACS on health outcome are not known. A PAC system has the potential to improve quality, especially if it makes the diagnostic process more efficient, but evidence that such improvement actually occurs is so far lacking.     

Quality assurance in cervical cancer screening

Objectives. to examine the effectiveness of introducing External Quality Assessment (EQA) into all laboratories which undertake gynaecological cytopathology. to assess pathologists and cytotechnologists regularly for their competence to screen cervical smears, regardless of their standing in the laboratory hierarchy or their experience of gynaecological cytopathology.
Methods. Each participant was asked to screen and report on 10 slides during a 2 h period. the assessment was carried out by a facilitator under the direction of a specially appointed EQA Committee. A maximum score of 20 points was awarded for a completely correct set of answers. A minus score was awarded for a missed abnormal smear. Seventeen pathology laboratories in North West Thames Regional Health Authority participated; 146 cytologists were assessed.
Results. A pilot and four rounds of EQA have been completed and a total 5350 smears examined. Out of 2568 dyskaryotic (abnormal) smears screened, 0.7% were not identified correctly. of the 146 cytologists taking part in the assessment, 95% achieved a score of 17 or more. Three participants were identified who did not reach an acceptable level of competence and appropriate remedial action was taken.
Conclusion. the EQA scheme detected unacceptable levels of performance which can be quickly rectified. Participation of 100% has been maintained on a voluntary basis, and 4 years experience of the scheme confirms that a very high standard of screening prevails in the Region. the study illustrates that voluntary self-regulation is acceptable in the NHS, and the introduction of similar EQA schemes on a national scale will go a long way to establishing confidence in the cervical cancer screening programme.     

Improved rate of high-grade cervical intraepithelial neoplasia detection in human papillomavirus DNA hybrid capture testing

BACKGROUND: Numerous studies have established a link between human papillomavirus (HPV), squamous intraepithelial lesions (SIL) and carcinoma of the cervix. Testing for HPV DNA in addition to cytology in screening programs for cervical cancer has been suggested to increase detection rates. STUDY DESIGN: HPV DNA testing (performed by hybridization antibody capture assay I or II), cytology and biopsy (performed within 1 month of each other) were retrospectively reviewed for a series of 155 women. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of HPV testing vs. cytology were calculated using biopsy as the gold standard. These values were also calculated in a subgroup of 37 individuals older than 35 years. RESULTS: The sensitivity, specificity, PPV and NPV of DNA hybrid capture HPV testing for detecting high-grade cervical intraepithelial neoplasia (CIN) were 86%, 44%, 26% and 93%, respectively. The respective values for cytology detection of high-grade CIN were 17%, 97%, 56% and 82%. CONCLUSION: HPV testing was significantly more sensitive for detecting high-grade CIN than cytology (86% vs. 17%). Our data support immediate colposcopy and biopsy, rather than follow-up Papanicolaou testing, if the test for HPV DNA is positive for an intermediate- to high-risk type.     

A prospective study of human papillomavirus (HPV) testing to resolve uncertainty in colposcopy

J. Bowring, R. Albrow, A. Fisher, G. Downey, J. Cullimore, J. Patnick, P.G. Walker and H.C. Kitchener
A prospective study of human papillomavirus (HPV) testing to resolve uncertainty in colposcopy Objective: UK colposcopy services are seeing increased workloads, a large proportion of which are follow‐up appointments. The English Cervical Screening Programme HPV Special Interest Group identified five subcategories of colposcopy clinic patients who often require prolonged follow‐up regimes for low‐grade abnormalities. Human papillomavirus (HPV) testing has a high negative predictive value, meaning that HPV‐negative women are at very low risk of underlying disease. Our objectives were to quantify the number of HPV‐negative women in each study subcategory and to evaluate the number who could potentially be discharged from colposcopy on the basis of their results. Methods: Four colposcopy clinics prospectively identified women according to five categories over 12 months. All women underwent cytological testing and high‐risk HPV (hrHPV) testing using the Hybrid Capture 2 test. Management outcomes and decisions based on a knowledge of the HPV status were recorded. Results: Data available on 755 women showed that 422/755 (55.9%) and 260/755 (34.4%) had persistent cervical intraepithelial neoplasia grade 1 (CIN1) (Category 1) or a minor abnormality following treatment (Category 2), respectively. In Categories 1 and 2, 51.7% and 60.2%, respectively, were hrHPV negative. The rates with biopsies of CIN2 or worse (CIN2+) across the two categories were 3/355 (0.8%) and 21/291 (7.0%) for hrHPV‐negative and hrHPV‐positive women, respectively. Conclusion: The incorporation of hrHPV testing within organized cervical screening programmes has been widely accepted. hrHPV testing for the clinical scenarios outlined in this study detects women who are hrHPV negative and therefore at low risk of underlying disease, potentially reducing anxiety and inconvenience for women and costs to colposcopy services.     

Quality assurance for polychromatic flow cytometry

This protocol outlines a three-part quality assurance program to optimize, calibrate and monitor flow cytometers used to measure cells labeled with five or more fluorochromes (a practice known as polychromatic flow cytometry). The initial steps of this program (system optimization) ensure that the instrument's lasers, mirrors and filters are optimally configured for the generation and transmission of multiple fluorescent signals. To determine the sensitivity and dynamic range of each fluorescence detector, the system is then calibrated by measuring fluorescence over a range of photomultiplier tube (PMT) voltages by determining the PMT voltage range and linearity (Steps 2-10) and validating the PMT voltage (Steps 11-17). Finally, to ensure consistent performance, we provide procedures to monitor the precision, accuracy and sensitivity of fluorescence measurements over time. All three aspects of this program should be performed upon installation, or whenever changes occur along the flow cytometer's optical path. However, only a few of these procedures need to be carried out on a routine basis.     

Quality assurance and risk reduction guidelines

Cervical cancer continues to be a major cause of death in women worldwide. The major problem facing most women is the unavailability of screening Pap tests in poor and underdeveloped countries. While rates of cancer deaths have decreased 60-80% in developed countries since the Pap test became available, the accuracy of Paps was challenged recently. In order to instill public confidence and promote optimal patient care, measures to improve the quality of the entire screening process should be undertaken. Continuous quality improvement processes are more appropriate than traditional quality assurance monitors. Although no standards can be defined that are applicable to all laboratory settings and nations, this document provides current views on universal quality procedures and risk reduction. Procedure/policy manuals, workload assessment, hierarchic/peer review, discrepancy analysis, rescreening studies and cytohistologic correlation are examples of universally applicable quality tools. The variability in practices in different parts of the world is also discussed.     

Comparison of conventional and liquid-based cytology, and human papillomavirus testing using SurePath preparation in Japan

We compared the detection rate of cervical neoplasias between a liquid-based cytology (LBC) method using SurePath and the conventional method. We also studied the feasibility of human papillomavirus (HPV) typing by linear array assay. Cytological specimens from 1551 Japanese women were prepared using the conventional and SurePath methods; the cytological and histological results from biopsy samples were compared. HPV typing using an HPV linear array assay was carried out on residual specimens using the SurePath method. The cytodiagnostic results showed a concordance rate of 85.3% (Κ= 0.46) between the two methods. The sensitivity of lesions histopathologically diagnosed as CIN1 or above was not significantly different between the two methods (P = 0.575-1.000). The receiver operating characteristic curve analysis of the detectability in CIN2 or above revealed no significant difference between the two methods (P = 0.096). Among the 44 patients who underwent HPV typing using a linear array assay, 33 samples were eligible for HPV testing and were stored at ambient temperature. In conclusion, the SurePath and conventional methods have equivalent abilities for detecting cervical lesions. After preparation for cytological diagnosis, use of the remaining cells from the SurePath specimens to perform HPV typing using the linear array method could be feasible.     

Genital human papillomavirus testing by in situ hybridization in liquid atypical cytologic materials and follow-up biopsies

OBJECTIVE: To describe cases of HPV testing by DNA in situ hybridization performed on atypical cervicovaginal samples collected by a liquidsed method that were negative for HPV DNA on cytology but revealed cervical intraepithelial neoplasia on follow-up biopsies. STUDY DESIGN: Three hundred ninety-five consecutive SurePath atypical squamous cells of undetermined significance (ASC-US) cytologic samples from asymptomatic, reproductive-age women were tested for human papillomaviruses (HPVs) by the in situ hybridization (ISH) method (Ventana Inform HPV Test, Tucson, Arizona, U.S.A). One hundred (25%) cases underwent follow-up colposcopic biopsy within 3 months of cytology. All the tests (cytology, ISH, histology) were independently evaluated without knowledge of the other tests. RESULTS: One hundred twenty-two (33%) cytologic samples were positive for HPVs. Of a total of 100 (HPV positive and negative) follow-up biopsies, 55 were positive for cervical intraepithelial neoplasia (CIN). Fourteen cases of biopsy-proven CIN tested negative for all HPV types in the prior cytologic samples. Retesting of the 14 CIN tissues by ISH was negative in 10, positive for HPV in 2 and inconclusive in 2. CONCLUSION: There is a small but significant (14%) false negative rate with HPV testing by the Ventana ISH method. Clinically suspicious cases should be followed even if an HPV test is negative.