Liquid-based cytology can improve efficiency of cervical smear readers: evidence from timing surveys in two NHS cytology laboratories

OBJECTIVE: Cervical screening programmes in England and Wales were advised by the National Institute for Clinical Excellence in 2003 to adopt liquid-based cytology (LBC) in place of conventional Papanicolaou (Pap) cytology to facilitate laboratory efficiency. Pilot evaluations in England and Scotland monitored daily or weekly workloads of smear readers and concluded that LBC could increase hourly throughput rates. This study, instead, used timing surveys to determine screening rates. METHODS: Two National Health Service cytology laboratories in Manchester and Stockport were partially converted to the LBC ThinPrep process for a cervical screening trial. Three 1-week timing surveys were conducted over 7 months. The surveys covered all LBC-trained staff. The first survey in Manchester also covered staff undertaking conventional Pap screening. The smear readers used timers to record time taken for examining and reporting each slide. RESULTS: In Manchester, in the first survey, nearly 1 minute per slide was saved by the LBC method during primary microscopy. In both laboratories, the mean microscopy time for primary screening of LBC slides was reduced by almost 1 minute between the first and second surveys. There was no difference between the second and third surveys. Microscopy by cytopathologists was also 1 minute per slide quicker with LBC than conventional Pap. The LBC inadequate rates for both laboratories were <2.0%. Organizational factors impacted on the hourly LBC primary screening rates in the laboratories, the rate for Stockport being higher than the rates in the pilot evaluations. CONCLUSIONS: The timing surveys confirm that the LBC ThinPrep technology can improve laboratory efficiency. However, decision-makers should also consider the overall costs and benefits of introducing the technology in screening programmes, including the capital investment and workforce implications.     

Comparison of cytology and histology results in English cervical screening laboratories before and after liquid‐based cytology conversion: do the data provide evidence for a single category of high‐grade dyskaryosis?

R. G. Blanks and R. S. Kelly
Comparison of cytology and histology results in English cervical screening laboratories before and after liquid‐based cytology conversion: do the data provide evidence for a single category of high‐grade dyskaryosis? Objective: To determine whether the difference between the positive predictive value (PPV) for cervical intraepithelial neoplasia (CIN) grade 2 or worse (CIN2+) of referral from moderate dyskaryosis and from severe dyskaryosis was reduced after laboratories converted from conventional to liquid‐based cytology (LBC). Furthermore, to explore the cytology/histology agreement after LBC conversion, and to determine post‐LBC whether there was increased support for the use of one single category of high‐grade dyskaryosis (equivalent to high‐grade squamous intraepithelial lesion). Methods: The association between cytology and histology has been examined using annual Korner return data (KC61 returns) collected by laboratories from the English National Health Service cervical screening programme. The study compares return data before and after LBC conversion. Results: The study examined data from 102 laboratories that converted from conventional cytology to LBC. Before conversion the PPV for CIN2+ of severe dyskaryosis was 88% and after increased to 90% (P = 0.003). For moderate dyskaryosis the PPV for CIN2+ increased from 70% to 72% (P = 0.06). The absolute difference of 18% between severe and moderate dyskaryosis was therefore the same pre‐ and post‐LBC conversion. The PPV of mild dyskaryosis for CIN2+ before and after conversion reduced from 23% to 19% (P < 0.001). The agreement between cytology and histology measured using a weighted Kappa statistic increased from 0.52 to 0.60 after conversion to LBC because of small increases in the proportions of severe dyskaryosis or worse with CIN3+ outcomes and mild dyskaryosis with CIN1 or less outcomes. Conclusions: Following LBC conversion there was evidence of a modest increase in the agreement between cytology and histology but no evidence of a change in the absolute difference in PPV for CIN2+ between moderate and severe dyskaryosis. The data support the conclusion that women referred with moderate dyskaryosis will on average have a lower risk of progression to invasive cancer than women referred with severe dyskaryosis. If the data were considered to support the categories of high‐grade dyskaryosis (moderate) and high‐grade dyskaryosis (severe) before LBC conversion then it can be strongly argued that they also support these categories after conversion.     

The evaluation of human papillomavirus genotyping in cervical liquid-based cytology specimens; using the Roche Linear Array HPV genotyping assay

Objective:  To ascertain the usefulness of the Roche Linear Array human papillomavirus (HPV) genotyping assay for assessing HPV genotypes in liquid-based cytology (LBC) samples and to evaluate this methodology within a cytopathology laboratory. These tests are of importance as persistent infection with high-risk HPV genotypes is considered a causal factor in the development of cervical cancer.
Methods:  A total of 175 cervical LBC samples were tested using the Roche Linear Array HPV genotyping test. The suitability of the assay use in routine cytopathology laboratory was considered. HPV genotypes were matched to the cervical cytology results, which included negative, borderline nuclear abnormalities, mild, moderate and severe dyskaryosis.
Results:  The assay could be applied to screening samples with the combined result available at the reporting stage. There were no test failures. All samples used after cytological analysis had sufficient DNA for testing. The results were reproducible and easily read and there was concordance of results between biomedical scientists. The results of the assay showed co-infection with multiple HPV genotypes was common in both high-grade and low-grade cytology samples. The percentage of HPV+ samples in the normal cytology samples (although in this grouping the number of samples was low) was 37%. In the cytology samples reported as severe dyskaryosis the HPV genotypes most commonly found were HPV16 and HPV51.
Conclusion:  The assay was able to detect multiple HPV infection with a wide range of genotypes in LBC samples sent for routine cytological analysis. It would be suitable for use in a cytopathology laboratory. The results of the assay show that the genotype profile has some variation from other geographical regions, and more work is needed to determine population prevalence, to ascertain the impact of the HPV vaccine, to evaluate test for cure and HPV triage management.     

Comparison of the conventional cervical smear and liquid-based cytology: results of a controlled, prospective study in the Abruzzo Region of Italy

OBJECTIVE: To compare conventional cervical testing (CCT) and liquid-based cytology (LBC) within a randomized trial performed during 2001-2002 in the Abruzzo Region of Italy, including a cost-outcome comparative analysis. STUDY DESIGN: Study subjects were recruited in the framework of a controlled, randomized study organized in the Abruzzo Region. Women aged 2 6-64 years were randomized to an active arm (LBC) or control arm (CC1). The particip ating laboratories had no previous ex perience with LBC. RESULTS: The inadequacy rate was 4.3% in CCT and 1.3% in the LBC arm (D < 0.001). Atypical squamous cells of undetermined sign ifi cance and atypical glands of undetermined significance reports were more frequent at CCT vs. LBC. A small, insignificant excess of low grade squamous intraepithelial lesions or high grade squamous epithelial lesions+ reports was observed in the LBC arm. The cervical intraepithelial neoplasia 2+ (CIN2+) detection rate was not statistically different in the 2 arms (CCT=0.54%, LBC= 0.66%, p = 0.28). In the overall series positive predictive value was slightly but not significantly higher in the LBC arm. LBC increased costs by 4.2% per both screened women and CIN2+ detected. CONCLUSION: The study reflects the introductory phase of LBC in laboratories without prior LBC experience. In this setting LBC reduced the inadequacy rate and decreased reading and was at least as sensitive as and more specific than CCT. Utilization of LBC in organized screening programs will be based on local feasibility, considering that the high cost of LBC is only partially compensated for by other benefits, such as residual cellular material, available for molecular testing, including human papillomavirus testing.     

Using a quality control approach to define an 'adequately cellular' liquid-based cervical cytology specimen

Objective:  To define a minimum acceptable total squamous cellularity for (ThinPrep^®) liquid-based cervical cytology (LBC) specimens using quality control techniques.
Methods:  Two hundred LBC preparations were made containing varying numbers (<200) of severely dyskaryotic squamous cells and with varying total cellularities.
Results:  Ninety-eight per cent of the LBC preparations that were missed by one or more of three cytoscreeners had fewer than 16 abnormal objects (single dyskaryotic cells or clumps of cells) and 87 dyskaryotic cells. The minimum ratio of dyskaryotic to total squamous cells that, in a preparation of 5000 squamous cells has a probability of at least 0.98 that 87 or more dyskaryotic cells will be present is 1 : 47. Twenty-three preparations diagnosed as abnormal had ratios of dyskaryotic to total squamous cells of between 1 : 2.5 and 1 : 4596. There is thus no feasible minimum acceptable squamous cellularity that will give an acceptable probability of detection of all specimen vials containing abnormal cells in the observed proportions.
Conclusions:  It is suggested that the minimum acceptable cellularity for LBC specimens is set pragmatically by the screening programme to give a feasible percentage of repeat tests.     

Finnish cytotechnologists' views on the competencies of newly graduated biomedical scientists in clinical cytology

Objective

This study asked 40 cytotechnologists for their views on the competencies of newly graduated biomedical scientists in clinical cytology during the national conference of the Finnish Association of Cytotechnologists in November 2015.

Methods

The questionnaire mainly consisted of statements that were scored on a five‐point Likert‐scale, where 1 was not important and 5 was very important. It covered five sections of clinical cytology: sampling and techniques, gynaecological screening, non‐gynaecological screening, safety and quality management, and miscellaneous.

Results

Of the 40 delegates approached to complete the questionnaire, 37 (92.5%) agreed. Respondents felt that important sampling and technique competencies were specimen fixation, with a mean score of 4.9 out of 5.0, types of specimens (4.7), Papanicolaou smear collection (4.7), Papanicolaou smear request information (4.7) and evaluation of specimen sufficiency (4.6). Less important competencies were examining FNAs (2.0) and nasopharyngeal specimens (2.2). The respondents had many expectations about how education in cytology could be developed, for example more theoretical lessons, more practice in microscope use, and consistent criteria for training and cooperation between cytology laboratories and universities of applied sciences.

Conclusions

The cytotechnologists who took part in our survey expected newly graduated biomedical scientists to have basic competencies in cytology. These were sampling and techniques, laboratory safety and quality management, specimen adequacy and identifying normal cells taken during gynaecological screening. They were also keen to develop education in cytology.     

Comparison of SurePath® and ThinPrep® liquid‐based cervical cytology using positive predictive value,atypical predictive value and total predictive value as performance indicators

P. K. Wright, J. Marshall and M. Desai Comparison of SurePath ^® and ThinPrep ^® liquid‐based cervical cytology using positive predictive value, atypical predictive value and total predictive value as performance indicators Objective: Two liquid‐based cytology (LBC) systems are in widespread use in the UK: ThinPrep^® and SurePath^®. A number of studies have now compared LBC with conventional cytology in cervical screening. However, to date, we are aware of no studies that have compared ThinPrep^® with SurePath^® LBC. As the selection and use of specific diagnostic systems in a laboratory has significant clinical and economic implications, there is a clear need to compare directly existing LBC technology. The objective of this study was to compare ThinPrep^® with SurePath^® LBC in a single cytology laboratory using performance indicators. Methods: Data were collected for all cervical cytology samples processed at Manchester Cytology Centre over a 1‐year period. ThinPrep^® LBC was compared with SurePath^® LBC using positive predictive value (PPV), atypical predictive value (APV) and total predictive value (TPV), reflecting outcome of cervical intraepithelial neoplasia (CIN) grade 2 or worse for high‐grade dyskaryosis (PPV), low‐grade dyskaryosis or borderline (atypical) cytology (APV) and all (total) abnormal cytology (TPV). Results: 2287 (out of 56 467) (ThinPrep^®) and 586 (out of 22 824) (SurePath^®) samples showed borderline or worse cytology after exclusion criteria. PPV, APV and TPV were within acceptable ranges for both ThinPrep^® and SurePath^®. Conclusions: ThinPrep^® and SurePath^® were equivalent based on three performance indicators. We suggest that APV and TPV should be used as an adjunct to PPV and other methods of quality assurance for cervical screening.     

A comparison of variability in Papanicolaou and liquid-based cytology inadequacy rates using Shewhart control charts

OBJECTIVE: To use Shewhart control charts to compare variability in inadequacy rates from Papanicolaou (Pap) and liquid-based cytology (LBC). DESIGN: Retrospective analysis of quality assurance data. SETTING: Eleven Welsh cytology laboratories. METHODS: Shewhart 'p' charts were plotted for proportions of slides reported as inadequate. Charts were compared for statistical control. MAIN OUTCOME MEASURES: Evidence of statistical control in the processes. RESULTS: Control charts allowed easy interpretation of patterns in the data. Variability in inadequacy rates was much lower for LBC than for Pap cytology. CONCLUSION: Monitoring inadequate rates with Shewhart charts provides more information than tabular monitoring reports, assisting in quality improvement. With respect to inadequacy rates, LBC is less variable than Pap cytology.     

Improved endocervical sampling and HPV viral load detection by Cervex-Brush® Combi

OBJECTIVE: Liquid-based cytology (LBC) for cervical screening is becoming increasingly used. Together with SurePath LBC, various collecting devices can be utilized, among which the Cervex-Brush is the most widely used. The new Rovers Cervex-Brush Combi combines the advantages of the Cervex-Brush with the EndoCervex-Brush increasing sampling of the endocervical canal. The objective of this study was to analyse and to compare the Cervex-Brush Combi with the Cervex-Brush for the collection of squamous and endocervical cells, human papillomavirus (HPV) typing/quantification and disease detection in SurePath LBC. METHODS: Using either the Cervex-Brush or the Cervex-Brush Combi 100 consecutive SurePath LBC samples were collected using each brush type. All 200 slides were read by the FocalPoint and screened by guided screening using slide wizards. The viral load of HPV type 16 E7, 18 E7, 31 E6, 33 L1, 33 E6, 35 E4, 39 E7, 45 E7, 51 E6, 52 L1, 52 E7, 53 E6, 56 E7, 58 L1, 58 E6, 59 E7, 66 E6 and 68 E7 was determined using a TaqMan-based real-time quantitative PCR analysis. RESULTS: The mean number of sampled squamous cells did not differ between the two brush types (54 963 versus 54 595 cells). The use of the Cervex-Brush Combi, however, resulted in a two- to threefold increase in the number of sampled endocervical cells (P < 0.00001). Using the Cervex-Brush Combi slightly more lesions were detected (three versus two low-grade squamous intraepithelial lesions), and resulted in the detection of more atypical squamous cells of undetermined significance (six versus three). In the Cervex-Brush group, 60% (3/5) of abnormal smears were positive for oncogenic HPV types, whereas 66.7% (6/9) of abnormal smears in the Cervex-Brush Combi group tested positive. The median HPV viral load for samples taken with the Cervex-Brush Combi was 0.1825 copies/cell and was significantly higher than in samples taken with the Cervex-Brush (0.0042 copies/cell) (P = 0.02). CONCLUSION: Sampling with the Cervex-Brush Combi resulted in the collection of the same amount of squamous cells, but in a two to threefold harvest of endocervical cells. This led to the detection of a higher viral load for oncogenic HPV and an increase in the number of detected abnormal smears.     

Endometrial carcinoma detected with SurePath liquid-based cervical cytology: comparison with conventional cytology

Introduction: Conventional Pap smears (CPS) have little impact on the detection of endometrial carcinoma. Although liquid‐based cytology (LBC) is replacing CPS in the UK, experience with identification of endometrial cancers with this technique is limited. Aim: To compare the accuracy of the SurePath LBC with that of CPS for detection of endometrial cancers. Methods: Our study group comprised SurePath LBC samples reported as atypical endometrial cells and endometrial adenocarcinoma (classified respectively as borderline, code 8 and ?glandular neoplasia, code 6 for the NHS Cervical Screening Programme statistics) in 2004–2005. CPS reported as atypical endometrial cells or adenocarcinoma in 1993–1998 comprised the control group. Histological follow‐up was obtained. Results: Endometrial abnormalities were reported in 95 (0.073%) of 130 352 LBC samples, comprising 75 (0.058%) atypical endometrial cells and 20 (0.015%) endometrial adenocarcinoma reports. Of 409 495 CPS, 117 (0.029%) were diagnosed as endometrial abnormalities, comprising 59 (0.014%) atypical endometrial cells and 58 (0.014%) endometrial adenocarcinoma reports. Thus, the endometrial adenocarcinoma reporting rate was similar in both groups, but that for atypical endometrial cells was higher with LBC (P < 0.001). The positive predictive value for endometrial cancer of endometrial adenocarcinoma and atypical endometrial cell reports in the LBC group was 73.3 and 18.8%, respectively, compared with 42.3 and 6.7% in the CPS group. The endometrial adenocarcinoma patients in CPS group were older (mean age 62.5 years versus 56.5 years) and most (22/25) were symptomatic, whereas most (13/17) patients in the LBC group were asymptomatic at the time of sampling (P < 0.001). Conclusion: SurePath LBC is at least as accurate a method for detecting endometrial cancer as CPS. SurePath LBC demonstrates enhanced identification of endometrial pathology in asymptomatic women in the cervical screening programme.     

Prospective parallel randomized trial of the MultiCyte™ ThinPrep® imaging system: the Scottish experience

T.J. Palmer, S.M. Nicoll, M.E. McKean, A.J. Park, D. Bishop, L. Baker and J.E.A. Imrie
Prospective parallel randomized trial of the MultiCyte? ThinPrep^® imaging system: the Scottish experience Background: Computer‐assisted screening of cervical liquid‐based cytology (LBC) preparations using the ThinPrep® Imaging System (TIS) has shown improved qualitative and quantitative gains. The use of Multicyte? has not been described in a well‐established national screening programme with a low incidence of high‐grade dyskaryosis. Objectives: To assess the impact of computer‐assisted screening within the Scottish Cervical Screening Programme (SCSP). Methods: Two groups of three laboratories, each sharing a ThinPrep® Imager, screened 79 366 slides randomized to test and 90 551 to control arms by laboratory accession. Screeners were not blinded. Standard laboratory reporting profiles of the SCSP, sensitivity, specificity and false‐negative rates of all grades of LBC abnormalities with respect to final cytology reports, predictive value for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) on histology; and screening rates were compared for both arms. Results: Inadequate and negative reporting rates were significantly lower and low‐grade reporting rates significantly higher in the imager arm. Imager‐assisted screening showed significantly better specificity than manual screening with respect to the final cytology result. There was no evidence of a significant difference in the detection of CIN2 + or CIN3 + . Positive, abnormal and total predictive values (high‐grade, low‐grade and all abnormal cytology found to be CIN2 + , respectively) were similar in both arms. Productivity was significantly higher in the imager arm. Conclusion: Computer‐assisted screening in a well established screening programme showed significantly improved productivity without loss of quality. These findings should inform future policy for cervical screening programmes.     

Use of liquid-based cytology in serous fluids: a comparison with conventional cytopreparatory techniques

OBJECTIVE: To examine the performance of liquid-based cytology (LBC) on body cavity fluids as compared with conventional cytopreparatory techniques. STUDY DESIGN: Slides from a total of 592 serous fluids, effusions as well as intraoperative washings, were reviewed. Of these fluids, 301 were collected before and 291 after the introduction of the PrepStain LBC (TriPath Imaging, Burlington, North Carolina, U.S.A.) in our laboratory. RESULTS: PrepStain thin layers showed excellent morphology on a clear background, with preservation of 3-dimensional configurations and a sufficient amount of extracellular material to allow an accurate diagnosis. Cytopreparation, screening and interpretation of LBC were less time consuming. Moreover, when the performance of the various cytopreparatory techniques in malignant fluids was studied, PrepStain thin layers excelled over conventional cytopreparatory methods in showing a significantly lower false negative rate (P=.0414). CONCLUSION: Our findings indicate that in body fluid cytology, thin layers can safely replace other types of wet-fixed preparations, resulting in enhanced specimen quality and diminished false negative rates.     

Test characteristics of various screening modalities for cervical cancer: a feasibility study to develop an alternative strategy for resource-limited settings

OBJECTIVE: To determine test characteristics - sensitivity, specificity, positive and negative predictive values - of different screening modalities to detect cervical precancerous and cancerous lesions in order to devise an effective alternative strategy for cervical cancer screening in resource-poor settings. METHODS: A total of 472 women presenting with nonspecific gynecologic symptoms were screened by cytology, visual inspection with acetic acid application (VIA), VIA with magnification (VIAM) and human papillomavirus (HPV)-DNA testing. Colposcopic examination was performed in all and on-site biopsy was taken if any grade I and above lesion was detected on colposcopy (230). On histopathological examination, 105 showed cervical intraepithelial neoplasia II and above lesions. Sensitivity, specificity and predictive values for each test were calculated taking colposcopy and or directed biopsy as the gold standard. Comparisons were made with cytology in order to assess the feasibility of alternative strategies in resource-poor settings. RESULTS: VIA was less sensitive (86.7% versus 91.4%) but more specific (90.7% versus 86.6%) than cytology at low grade squamous intraepithelial lesion (LSIL) threshold but the difference was not statistically significant (P > 0.01). HPV testing improved the sensitivity over cytology (97.1% versus 91.4%) but there was a nonsignificant loss of specificity (84.2% versus 86.6%). Results of VIAM were more or less similar to VIA. CONCLUSION: VIA can be used as a mass screening tool for cervical cancer in resource-poor settings.     

Is a liquid‐based cytology more sensitive than a conventional Pap smear?

K. Sigurdsson
Is a liquid‐based cytology more sensitive than a conventional Pap smear? Background: The comparative sensitivity of liquid‐based cytology (LBC) test and conventional Papanicolaou (Pap) smears is controversial. Material and methods: This study analyses the distribution of cytology, histology, colposcopy and large loop excision of the transformation zone among women screened in Iceland with LBC at the Cancer Detection Clinic in Reykjavik and with a conventional Pap smear outside the Detection Clinic in 2007–2011. The study material included 42 654 LBC tests from 20 439 women and 103 909 Pap smears from 61 574 women. The period 2000–2004 is used to correct for potential bias as a result of unequal distribution of the studied parameters between the study sites before the introduction of LBC. Results: The observed results indicated that women screened with an LBC sample had significantly decreased detection rates of inadequate smears, increased detection of low‐grade squamous intraepithelial lesion (LSIL)/atypical cytology and referrals to colposcopy, and an increased detection rate of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) irrespective of age. LBC increased significantly the detection rates of high‐grade squamous intraepithelial lesion or worse (HSIL+) cytology and CIN3+ histology only in women under 40 years of age. Taking into consideration the unequal prevalence of the studied parameters between the study sites in 2000–2004 indicated, however, that LBC only affected the rate of inadequate and low‐grade cytology tests under the age of 40 years. Positive predictive values for CIN2+ were not significantly different between the tests. Conclusions: The study results support the view that LBC is no more sensitive than Pap smears for the detection of HSIL+ and CIN2+ irrespective of age. LBC decreased the rate of inadequate smears, but increased the rate of low‐grade cytology under the age of 40 years and decreased the total rate of abnormal smears over the age of 40 years.     

O‐110 YEAR AUDIT OF GLANDULAR CYTOLOGY REPORTS WITH SPECIAL REGARD TO THE EFFECT OF CONVERSION TO LBC

Objectives: A randomised trial in screening to improve cytology (ARTISTIC Trial) was set up to evaluate the effectiveness of human papilloma virus (HPV) testing in primary cervical screening. Design: Women attending the NHS Cervical Screening Programme in Greater Manchester were screened for HPV in addition to routine cytological testing with ThinPrep Liquid‐Based Cytology (LBC). 25 020 women aged 20–64 were screened at entry and 3 years later. Participants were randomised in a 3 : 1 ratio between those whose HPV test result was revealed and acted upon and those in whom it was concealed. Results: A total of 24 510 women (18 386 revealed and 6124 concealed) had adequate cytology and HPV results. Cytology results at entry were: 87% normal, 11% borderline or mild, 1.1% moderate and 0.6% severe dyskaryosis or worse. Prevalence of HPV decreased sharply with age, from 40% at age 20–24 to 12% at 35–39 and 7% or less above age 50, and increased with cytological grade, from 10% (normal cytology) to 31% (borderline), 70% (mild), 86% (moderate), and 96% (severe or worse). Only 60% of women with severe dyskaryosis showed HPV 16 and / or 18 infection. Conclusion: The ARTISTIC Trial has provided the largest collection of LBC samples with HPV typing in Greater Manchester population. It has shown that the HPV testing is practicable in routine screening in women aged over 30. HPV 16 and 18 are more predictive for underlying disease, but other HPV types account for 30% of high‐grade disease.     

P-9A COMPARISON OF THE REPORTING MORPHOLOGICAL FEATURES OF GLANDULAR NEOPLASIA FOR CONVENTIONAL AND LIQUID BASED CYTOLOGY FOR CERVICAL SAMPLES

Cervical cancer accounts for approximately 15% of cancer diagnosed in women worldwide with up to 190 000 deaths per annum. One of the major causes of cervical cancer is the infection of human papillomavirus (HPV), a DNA virus. This virus is epidermotropic; there are over 75 subtypes and subtypes 16, 18, 31 and 33 are associated with cervical intraepithelial neoplasia (CIN) and carcinomas. Since the start of the cervical screening in mid 1960s, the cervical cancer rate has decreased. There are two techniques used for slide preparation and staining: conventional cytology and liquid based cytology (LBC). Due to the differences in sample collection and preparation, certain aspects of cell morphology, architecture and patterns will present differently from each other on the slide. The study was conducted in a County Hospital. Twenty conventional slides and eight LBC slides already reported as ? Glandular neoplasia were reviewed and assessed with regards to their morphological features. Moreover, conventional slides were compared with LBC slides to determine the differences in their cell morphology, sensitivity and specificity. Furthermore, a semi-quantitative method was used and also true-positive and false-positive rates were evaluated using positive predictive value (PPV). The findings indicated that despite the differences in cell morphology there are many similarities between the two techniques. The study also showed that it was difficult to distinguish between abnormal glandular cells and abnormal squamous cells, which may end in a false positive result and over reporting of glandular neoplasia. Finally, it showed that LBC slides were easier to screen and also had a higher positive predictive value (PPV) resulting in higher sensitivity and specificity. In conclusion, the LBC technique is more accurate and conversion to this technique is the positive step in the screening program.     

Proficiency testing in cytology laboratories in Ontario, Canada: a decade of experience. I. Introduction and description of the testing model

There are few formally documented proficiency testing programs for cytology laboratories, and those that have been documented are not entirely comparable in format. The first of three papers documenting a mandatory universal proficiency testing program for cytology laboratories in the Province of Ontario, Canada, presents data on the structure and function of the participating laboratories (including a comparison of the data for 1974 and 1980) and on the organization of the testing model (including selection of terminology, construction and use of the survey and assessment of responses). In 1980, of the 463 medical laboratories in Ontario, 91 of 222 hospital laboratories and 65 of 216 nonhospital laboratories were licensed in cytology. In that year, the 156 cytology laboratories processed 1.48 million cytology specimens, 92% of which were gynecologic. Hospital laboratories processed 87.5% of the nongynecologic cytology specimens and 30% of the gynecologic cytology specimens. These proportions have been virtually constant for several years. Between 1974 and 1980, there was a trend in Ontario to fewer laboratories processing less than 5,000 cytology specimens per annum. Subsequent papers in this series describe the results of the initial surveys in this program and a precision study to evaluate the consistency of reporting by individual laboratories.     

O‐4CHARACTERISTICS OF FALSE NEGATIVE LBC SAMPLES

Background: Liquid based cytology (LBC) is the method of choice for the processing of samples in the cervical screening programme in England and Wales. Two LBC systems are in use; ThinPrep® and SurePath®. The manufacturers of SurePath® recommend that slides are screened in two separate directions perpendicular to each other (bidirectional screening) during the initial learning period. There is currently no evidence to evaluate whether this method is superior to screening in one direction only (unidirectional). Objectives: To compare the detection rate of high‐grade dyskaryosis in SurePath® preparations between screeners who used a unidirectional method and screeners who used a bidirectional method, to see if the screening method influenced detection rate. Methods: A questionnaire was sent to 23 screening staff at our Cytology Centre in October 2005, enquiring as to the method they used to screen SurePath® slides, as well as the grade of staff and the number of years experience they had screening cervical cytology slides. The staff were divided into two groups based on whether they screened unidirectionally or bidirectionally. A retrospective computerised search of all the slides screened by the staff for the period September 2004 to August 2005 was carried out, and the high‐grade detection rate at primary screening for the groups were calculated. Further analysis was carried out to determine the statistical significance of any difference between the two groups, as well as to account for potential confounding factors. Results: Initial results suggesting a statistically significant difference between the screening methods were later shown to be confounded by experience. Critical analysis of the data and study design reveal that no firm conclusions can be made on the basis of this work. Conclusion: No firm conclusions on screening method can be drawn due to fundamental limitations and confounding factors in this retrospective work‐based study. Recommendations for further studies are made, controlling for confounding factors.     

Application of liquid-based preparation to fine needle aspiration cytology in breast cancer

OBJECTIVE: To examine the performance of liquid-based cytology (LBC) in breast cytology to confirm the diagnosis of carcinoma. STUDY DESIGN: Using cell clusters directly scratched from surgically removed tumor masses, we examined the immunocytochemistry, molecular biology and cytomorphology of the specimens. RESULTS: LBC was very useful for gene analysis and evaluating the immunocytochemistry. The cytologic features of LBC were slightly different from those ofa conventional aspiration cytology smear. CONCLUSION: LBC is a promising method for improving the standardization ofpreparations in breast cytology, although care should be taken to account for its characteristic cytologic features. The quantitative analysis of HER-2 mRNA correlated with the results of immunohistochemistry.