Comparison of transformation zone sampling rates— a potentially useful indicator of smear taker performance

Retrospective analysis of 18555 routinely collected smears from women in the age range 20-50 years reveals that there is a statistically significant relationship between the overall transformation zone sampling rate achieved in general practice and the detection rates for cervical abnormality. Similar analysis comparing unsatisfactory smear rates with rates for the detection of abnormality demonstrates a negative correlation which fails to achieve statistical significance. Comparison of transformation zone sampling rates achieved by smear takers sending samples to the same laboratory is proposed as a potentially useful performance indicator for smear takers.     

The inadequate smear: does it matter?

The objective of this study was to quantify the incidence of underlying cervical intraepithelial neoplasia (CIN) among women referred for colposcopy with three consecutive inadequate smears. The design was a retrospective cohort study analysing data from a regional colposcopy database at Cervical Screening Wales. Women who were referred to all the colposcopy clinics in Wales with three consecutive inadequate smears, the third inadequate smear being taken between 1 April 2001 and 31 March 2002 constituted the study population. The results of the fourth smear taken at the colposcopy clinic after three consecutive inadequate smears, the worst biopsy results from any of the subsequent colposcopies and the relationship between the result of the fourth smear taken at colposcopy clinic and any histology result were the main outcome measures. The accuracy of the colposcopic opinion was also examined. Of the 433 women identified as having been referred because of three consecutive inadequate smears, 302 were linked to either a subsequent smear and/or a biopsy result. An adequate smear result was available for 85% of these women when the smear was taken in the colposcopy clinic; 77% were reported as negative and 8% were abnormal. Of the 347 women seen in the colposcopy clinic, high-grade CIN was seen in 3% and low-grade lesion in 8%. The sensitivity and specificity of the fourth inadequate smear test in predicting underlying CIN were 15% and 84% respectively, with a positive predictive value of 8%. The sensitivity and specificity of colposcopy in predicting histological CIN among patients with three inadequate smears was 70% and 49%, respectively, and the positive predictive value was 44%. This study raises the question as to whether three consecutive inadequate smears should be considered as an indication for colposcopy, or merely for a further smear to be taken in circumstances where there is a greater likelihood getting an adequate result.     

Survey of smear taking practice in the former North Thames region

One hundred and seventy-seven doctors and 161 nurses from 230 clinics responded to a questionnaire on smear taking practice. The responses show that 66% of smear takers use the Aylesbury spatula and 30% use the Ayre spatula. A total of 53% use a cytobrush for selected cases. Training of smear takers and preparation of smears was satisfactory. Most (but not all) smear takers routinely record clinical information on the request form. Only 20 cytology laboratories in the North Thames region (70%) provide additional feedback to the smear takers about the quality of their smears apart from the information on the request form. Our study shows that feedback is an area where interaction between the laboratory and smear taker could be encouraged.     

Evidence for direct learning curve for technique on change of cervical sampling device

The recommended sampling device within the NHS Cervical Screening Programme is the Aylesbury spatula. A local decision was taken to decrease brush usage (either alone or in combination) by 50% from an initial level of 41.8%, with an initial inadequate smear rate of 9.93%. This was managed by controlling smear taking equipment through provision of smear taking kits. The monthly inadequate rate unexpectedly rose to 17.8% before dropping back to previous levels. Brush usage overall fell to 35.2%, with a corresponding increase in spatula use. The possible reasons for this are discussed. The facts suggest that these changes were directly linked, and that there is a learning curve with change of sampling device and that a rise in the inadequate rate should be expected under these circumstances.     

The cervical smear test: does timing have an effect on sample adequacy?

OBJECTIVE: The aim of this study was to determine the effect of timing of the cervical smear test on sample adequacy. METHODS: Inadequate and negative smears from pre-menopausal women, with a regular menstrual cycle and who were not undertaking any hormone therapy, were selected and re-screened. The inadequate smears were then categorized according to the reasons for the inadequate result. The time of the cycle that the smear was taken was recorded for both inadequate and negative smears. The expected frequency of smears per phase was compared with the observed frequency per phase using the chi-squared statistical test. RESULTS: There was no significant difference between the overall observed and expected rate of the inadequate smears of nine general practitioner (GP) practices (P = 0.886), of GP practice 4 (lowest inadequate rate) (P = 0.610), or GP practice 6 (highest inadequate rate) (P = 0.621) at any phase of the cycle. CONCLUSION: Results show that there is no optimum phase for adequate sample collection, therefore it is suggested that there is no effect of timing of the cervical smear test on sample adequacy, that timing is not a relevant factor in reducing the inadequate smear rate, and restricting smear taking to mid-cycle is unnecessary. (The information regarding last menstrual period/length of cycle from which these conclusions were reached relied upon the accuracy of patient information given to the smear taker.).     

The quality of smear taking training for hospital medical trainees

INTRODUCTION: Training for cervical smear takers in primary care is well established. We aimed to assess the adequacy of training in cervical smear taking among hospital medical trainees. METHOD: An anonymous questionnaire survey was conducted among hospital medical trainees within the North West region of England. The questionnaire assessed the trainees' level of confidence in their knowledge and skills in the theoretical and practical aspects of cervical smear taking, and the training they had received. The standards used were as stated in the National Health Service Cervical Screening Programme Resource Pack for Training Smear Takers (July 1998). These included practical smear taking, pre- and post-test counselling, the background to cervical screening, the National Health Service Cervical Screening Programme, the role of the Health Authority and the laboratory, provision for women with special needs, acceptability, accountability and quality assurance. RESULTS: Seventy-eight per cent of trainees returned the questionnaires. Although all the trainees were confident about taking smears, a significant percentage was concerned about the theoretical and specific issues associated with smear taking such as the care of women with special needs. Only 60.7% had received formal training in practical smear taking. Furthermore, only 48.3% had been formally trained in the clinical management of smears. CONCLUSION: There appears to be an urgent need for formal training in the theory and practice of smear taking and for the standardization of the course content. The introduction of training in liquid-based cytology provides us with a golden opportunity to address this deficit.     

Cervical disease in women referred to colposcopy following inadequate smears

The aim of this audit was to determine if inadequate cervical smears are associated with significant cervical pathology. Case records for 52 women with three consecutive inadequate smears referred for colposcopy to the Leicester Royal Infirmary (LRI) were retrieved. Sixteen women underwent large loop excision of the transformation zone (LLETZ) and cervical intraepithelial neoplasia (CIN) was identified in six cases. There were no cases of inadequate smears initiating the diagnosis in 100 consecutive women with invasive cervical cancer. Inadequate smears are associated with high rates of treatment for a low yield of CIN. To reduce morbidity associated with colposcopy it may be acceptable to repeat an inadequate smear after 6 months rather than arranging immediate recall.     

The influence of sample takers on the cellular composition of cervical smears

In a population-based cervical cancer screening program, the performances of five sample takers and their influence on the cellular composition of the smears and the numbers of epithelial abnormalities diagnosed were analyzed. As measured by the presence of endocervical columnar cells, there were remarkable variations in the quality of the smears between sample takers and between years of sampling. There was also a positive relationship between the presence of endocervical columnar cells in the smear and the number of epithelial abnormalities found. A lower quality of smear was reflected by a lower incidence of epithelial atypical changes found, both between sample takers and by a single sample taker over a period of time. These findings show that sample takers influence the cellular composition of smears and, therefore, the diagnostic outcome of smear screening. Their competence in executing their tasks must be frequently reviewed.     

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.     

The influence of the cervix on smear quality. I: Atrophy. An audit of cervical smears taken post‐colposcopic management of intraepithelial neoplasia

Out of 951 smears taken from women attending a hospital cytology clinic, 122 were found to be of poor quality. Twenty‐eight percent of these were associated with clinical and/or cytological atrophy, and in 91% of these the main adverse factor affecting smear quality was scantiness. The relative risk of obtaining a scanty smear was found to be 4.8 times greater in women in whom clinical atrophy was identified when compared with those with no atrophy. It is suggested that a reduction in the number of scanty, and hence potentially inadequate, smears in the screening programme may be achieved by the use of more appropriate sampling implements in all women in whom there is clinical evidence of atrophy. Further review of alternative sampling methods is indicated.     

Inadequate cervical smears: results of an educational slide exchange scheme

Fifty-six slides, predominantly inadequate and of varying difficulty, were circulated to 12 laboratories as an educationally based slide exchange scheme. Three slides failed to achieve an agreed majority consensus opinion. Seventy percent of participants agreed with the consensus opinion in 80% of slides. Of the slides originally reported as inadequate, the consensus diagnosis was inadequate in 78%, negative in 12% and abnormal in 10%. The latter included two cases of high-grade dyskaryosis. There was good agreement for the two most frequent causes of inadequacy in submitted slides (obscured and poor cellularity). There was poor consistency in reporting the presence or absence of endocervical and immature squamous metaplastic cells, to an extent that questions their use in the assessment of smear adequacy. Three inadequate slides on consensus opinion were associated with subsequent cervical intraepithelial neoplasia (grade III) or invasive squamous cell carcinoma. In the latter case, the slide had originally been reported as negative by the submitting laboratory.     

Liquid-based cytology and conventional smears compared over two 12-month periods.

BACKGROUND AND OBJECTIVE: Liquid based cytology (LBC) was introduced across the Scottish Cervical Screening Programme in 2003-2004. The objective of this study was to compare in a large cytopathology laboratory the results of cervical samples over two twelve-month periods, 2001-2002, when the great majority of smears were conventional, with 2003-2004, when all were LBC. METHODS: The results of smears in both periods were analysed to give overall reporting profiles, and correlated with results of cervical biopsies. The numbers of patients referred for colposcopy were compared. RESULTS: The percentage of unsatisfactory smears fell from 13.6% to 1.9%. Colposcopic referrals for repeated unsatisfactory smears fell from almost 25% to 0.5%. There was a decrease in overall smear numbers, but despite this there was an increase in the number of smears reported as showing dyskaryosis of any grade. There was an increase in positive predictive value for moderate dyskaryosis and above, from 79.5% to 86.1%. The outcome of biopsies from patients referred with mild dyskaryosis showed no decrease in accuracy of predicting a low grade histological lesion. Workload in the laboratory decreased, due to fewer smears received overall, more rapid primary screening times and fewer multi-slide cases. Primary screening backlogs all but disappeared, and reporting times greatly improved. CONCLUSIONS: Introduction of liquid based cytology led to improvements in unsatisfactory smear rates, with significant benefits to colposcopic referrals and laboratory turnaround times. Pick-up rates of dyskaryosis were maintained, and the positive predictive value of a dyskaryotic smear report was improved.     

Interlaboratory Reproducibility In Reporting Inadequate Cervical Smears—A Multicentre Multinational Study

A set of 300 vaginal smears was interpreted by 13 cytologists from six European laboratories, who were requested to report inadequate and suboptimal smears. the set had been appropriately seeded to reach approximately 10% inadequate and 20% suboptimal smear frequency. According to the majority report, 230 smears were classified as adequate (76.7%), 43 as inadequate (14.3%), and 27 as suboptimal (9.0%). Agreement with the majority report ranged from 52% to 91% (average 78%). Kappa statistics for reporting inadequate smears showed a high level of agreement for five cytologists, and fair to good agreement for eight. In contrast, K statistics for reporting suboptimal smears showed fair to good agreement with the majority report only in five instances, whereas agreement was poor for eight cytologists. ‘Inadequate smear’rates may be used to compare the quality of smears received in different laboratories, as there is a high level of agreement among cytologists as to what constitutes an inadequate smear. However, this is not true for ‘suboptimal smear’ rates, and more precise reporting criteria must be defined and tested if an intermediate category is to be retained to report poor quality smears: more precise reporting criteria must be defined and tested if an intermediate category is to be retained to report poor quality smears. Une série de 300 frottis cervico-vaginaux a été examinee par 13 cytologistes appartenant à 6 laboratoires européens auxquels il avait été demandé de signaler les frottis inadéquats et sub-optimaux. Cette série de frottis a été constituée de façon à atteindre approximativement une fréquence de 10% de frottis inadéquats et de 20% de frottis sub-optimaux. Si I'on considère les réponses faites par la majorité des cytologistes, 230 frottis ont été classés adéquats (76,7%), 43 classés inadéquats (14,3%), et 27 comme sub-optimaux (9,0%). La concordance avec les réponses de la majorité des cytologistes varie de 52%à 91% (moyenne 78%). Concernant le signalement des frottis inadéquats, le test Kappa est excellent pour 5 cytologistes et moyen à bon pour les 8 autres. Au contraire, pour le signalement des frottis sub-optimaux, le test Kappa montre un accord moyen à bon avec les réponses de la majorité seulement dans 5 cas alors que I'agrément est mauvais pour 8 cytologistes. La fréquence des frottis inadéquats peut être utilisée pour comparer la qualité de prélèvement du frottis dans différents laboratoires, alors que les comparaisons de la fréquence des frottis sub-optimaux sont discutables, du fait d'un biais de diagnostic évident. Des critéres plus précis pour le signalement des frottis sub-optimaux doivent étre définis et testés si cette catégorie doit être retenue pour rapporter les frottis de mauvaise qualité. 300 Abstriche wurden durch 13 Zytologen aus 6 europäischen Laboratorien hinsichtlich der Kriterien ‘unbrauchbar’und ‘suboptimal’beurteilt. Die Sammlung enthielt etwa 10% unbrauchbare und 20% suboptimale Präparate. Mehrheitlich wurden 230 Abstriche als auswertbar (76,7%), 43 als unbrauchbar (14,3%) und 27 als suboptimal (9,0%) bezeichnet. Die Statistik ergab hinsichtlich der unbrauchbaren Abstriche eine ausgezeichnete Ûbereinstimmung für 5 und eine gute Ûbereinstim-mung für 8 Zytologen. Demgegenüber zeigte sich hinsichtlich der Beurteilung suboptimal nur 5mal eine gute und 8mal eine schlechte Ûbereinstimmung. Damit ist die Kategorie suboptimal ungeeignet zum Vergleich und bedarf einer genaueren Definition wenn sie für die Qualitätskontrolle eingesetzt werden soll.     

Review of negative and low‐grade cervical smears in women with invasive cervical cancer after the first 3 years of the national cervical screening programme in Slovenia

A. Repše‐Fokter, A. Pogačnik, V. Snoj, M. Primic‐Žakelj and M. S. Fležar
Review of negative and low‐grade cervical smears in women with invasive cervical cancer after the first 3 years of the national cervical screening programme in Slovenia Objective: The purpose of the study was to perform a national review of negative, low‐grade and inadequate smears reported during the latest screening period before cervical cancer diagnosis in 2006, after the first 3 years of the screening programme. Methods: Among 162 new cervical cancer cases there were 47 (29%) without previous cytology, 47 (29%) with one high‐grade smear prior to diagnosis and 68 (42.0%) with at least one previous negative, low‐grade, atypical or inadequate smear 1–40 months before diagnosis. Of the latter 68 cases, 37 patients with 59 smears (together with 118 control slides) were included in the review as 31 had smears reported at laboratories no longer operating. Findings were related to the last cytology report before diagnosis as well as to histological type and stage of the cancer. Results: In our study group, 19 (51%) of 37 patients had squamous cell carcinoma, 15 (41%) adenocarcinoma and 3 (8%) adenosquamous carcinoma, compared with 121 (75%), 26 (16%), 12 (7%), respectively, and 3 (2%) other types, for all carcinomas. Twenty‐one of 37 women also had high‐grade cytology prior to diagnosis of cancer. Women with previous cytology (with or without recent high‐grade smears) were more likely to have stage I cancers than those without cytology (P < 0.0001). The expert group upgraded 17/33 smears in the patients with squamous carcinomas, which was more than in those with adeno‐ and adenosquamous carcinomas (5/24, P < 0.05). Conclusion: As expected, a higher proportion of smears preceding adenocarcinomas were true negative. Under‐diagnosed smears were not related to cancer stage or last cytology report before diagnosis.     

The use of screening episodes linked to CIN3 and invasive cancer registrations to study outcomes from the NHS Cervical Screening Programme

Objective: To examine how NHS cervical screening data can be collected and analysed in order to evaluate women’s screening histories as episodes rather than as individual smears. Design: Analysis of routine cervical screening data grouped into screening episodes for a cohort of women regarding episodes starting in a given year. Setting: NHS Cervical Screening Programme. Population: Data from four Health Authorities (now eight Primary Care Trusts) from the NHS Cervical Screening Programme with primary smears (first in an episode) taken between 1 April 1999 and 31 March 2000. Methods: Cytology information obtained from the call/recall (‘Exeter’) computer system was linked to cervical intraepithelial neoplasia (CIN) 3 and invasive cancer outcome information obtained from cancer registries. Screening histories were divided into episodes, each starting with a primary smear that was followed up to episode closure or, for episodes still open followed for an average 4.25 years, from the primary smear. The episode was divided into two parts (up to referral to colposcopy and following the referral). The outcomes of the episodes are described including referral rate to colposcopy and CIN3 and invasive cancer rates by factors such as age. Main outcome measures: Episode histories and rates of referral to colposcopy, CIN3 and invasive cancer. Results: There were 176 923 episodes from 176 319 women (1.003 episodes per woman) followed up to March 2004, the date at which the first phase of information accrual ceased. Of these episodes, 172 100 (97.3%) were closed either by a negative smear referring the woman back to routine recall or by default (defined as no smear recorded within 21 months following a smear requiring an action of repeat or refer to colposcopy). The remaining 4823 (2.7%) of episodes were still open, of which in 3121 (1.8%) the woman had been referred to colposcopy and in 1702 (1.0%) no referral decision had been made. Referral rates to colposcopy varied by age from 5.7% in women aged 20–24 years down to 0.9% in women aged 60–64 years. The overall efficiency of screening was highest for woman aged about 30 years, with a CIN3 detection rate of eight per 1000 women and a positive predictive value (for CIN3 or worse) of referral to colposcopy of 21%. Conclusion: The study has shown that routinely collected NHS cervical screening data can be combined to give information on complete episodes, allowing important performance measures to be studied. We suggest that in future information in the NHS screening system should be structured to facilitate such analysis and to allow cytology and histology information to be readily linked.     

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.     

Should the laboratory assess the sampling adequacy of cervical smears?

Should the laboratory assess the sampling adequacy of cervical smears? The results of a questionnaire answered by 14 out of the 18 NHS laboratories in Scotland reporting cervical smears showed that, since the publication of Guidelines for Judging the Adequacy of a Cervical Smear, by the British Society for Clinical Cytology (BSCC), rates of unsatisfactory smears had risen from a mean of 3.3% to 6.5%, with some laboratories reporting rates of over 10%. Four laboratories followed the guidelines closely in requiring the presence of two indicators of sampling of the transformation zone, i.e. endocervical cells, metaplastic cells or endocervical mucus. Seven laboratories required one indicator either in all smears or in a subset, whilst three did not require any indicator at all. The laboratories observing the guidelines closely had a higher mean unsatisfactory rate than those partially observing them. The main impediment to the full implementation of the BSCC guidelines appeared to be fear of an unmanageably high unsatisfactory smear rate. The accuracy of the assessment of adequacy is questioned, as is the cost effectiveness of doing so.     

How predictive is a cervical smear suggesting invasive squamous cell carcinoma?

How predictive is a cervical smear suggesting invasive squamous cell carcinoma? Features have been described in severely dyskaryotic cervical smears that suggest frankly invasive or microinvasive squamous cell carcinoma. These are reported in three separate categories in our department. The aim of the current study was to assess the positive predictive value of these categories for invasive disease on histology. All smears reported in these categories over a five year period were correlated with the histology results. 527 smears were assessed. The positive predictive value of a smear suggesting frank invasion was 55.7% for all invasive squamous carcinomas and 40% for stage IB or above. Smears suspicious of invasion or microinvasion predicted invasive disease in 22.3% and 17.2%, respectively, most carcinomas being stage IA. Invasive squamous cell carcinoma may be predicted to a limited degree by cervical cytology especially when the smear suggests frank invasion.     

P‐4TRANSFORMATION ZONE COMPONENT IN LIQUID BASED CERVICAL CYTOLOGY

Introduction: Quality assurance guidelines for the UK cervical screening programme recommend that more than 80% of cervical samples from women aged 20–50 years should contain adequate numbers of Transformation zone (TZ) cells i.e. 10 or more endocervical or squamous metaplastic cells. This study was conducted to assess the frequency of TZ component in Liquid Based Cytology (LBC) both for ThinPrep (TP) and SurePath (SP) LBC. Also to assess the degree to which this is recorded by individual screeners and to determine the percentage of samples with evidence of TZ component for the different smear takers. Method: All LBC cervical specimens received at a tertiary cytology centre in the year 2004 from women aged 20–50 years were included in the study. Evidence of TZ sampling was recorded as: TP = TZ present (10 or more TZ cells)TA = TZ absentTS = TZ scanty (less than 10 TZ cells)TN = atrophic smears, TZ cells not recognisable Results: The total number of LBC cervical cases was 7445. TP = 4300 (mostly primary care) and SP = 3145 (mostly colposcopy). Overall TZ sampling rate in LBC was 82%. TP = 77.17%; SP = 88.24%. When scanty TZ was included, the standard was met for both systems (TP = 93.7%; SP = 88.24%). Presence/absence of TZ component was recorded in 6370 cases (85.1%); range 0%–97.79%. 56.7% of smear takers achieved the minimum standard for TZ sampling. Discussion: The percentage of ThinPrep samples containing adequate TZ cells was 77.17% compared to SurePath, which was 88.24%. This may be due to different patient populations i.e. primary care versus colposcopy. Screeners recorded TZ sampling in approximately 85% of samples. 56.7% of smear takers met the standard for TZ sampling.     

P-5AN UNUSUAL FORM OF THYROID PAPILLARY CARCINOMA: COLUMNAR CELL VARIANT WITH NEUROENDOCRINE FEATURES

Introduction:  Quality assurance guidelines for the UK cervical screening programme recommend that more than 80% of cervical samples from women aged 20–50 years should contain adequate numbers of Transformation zone (TZ) cells i.e. 10 or more endocervical or squamous metaplastic cells. This study was conducted to assess the frequency of TZ component in Liquid Based Cytology (LBC) both for ThinPrep (TP) and SurePath (SP) LBC. Also to assess the degree to which this is recorded by individual screeners and to determine the percentage of samples with evidence of TZ component for the different smear takers.
Method:  All LBC cervical specimens received at a tertiary cytology centre in the year 2004 from women aged 20–50 years were included in the study. Evidence of TZ sampling was recorded as: TP = TZ present (10 or more TZ cells)TA = TZ absentTS = TZ scanty (less than 10 TZ cells)TN = atrophic smears, TZ cells not recognisable
Results:  The total number of LBC cervical cases was 7445. TP = 4300 (mostly primary care) and SP = 3145 (mostly colposcopy). Overall TZ sampling rate in LBC was 82%. TP = 77.17%; SP = 88.24%. When scanty TZ was included, the standard was met for both systems (TP = 93.7%; SP = 88.24%). Presence/absence of TZ component was recorded in 6370 cases (85.1%); range 0%–97.79%. 56.7% of smear takers achieved the minimum standard for TZ sampling.
Discussion:  The percentage of ThinPrep samples containing adequate TZ cells was 77.17% compared to SurePath, which was 88.24%. This may be due to different patient populations i.e. primary care versus colposcopy. Screeners recorded TZ sampling in approximately 85% of samples. 56.7% of smear takers met the standard for TZ sampling.