Transformation zone sampling rate is a useful performance indicator for practitioners collecting cervical samples using SurePathTM liquid-based cytology system

An analysis of the reports of 53 982 liquid-based cytology (LBC) samples processed at the Royal Victoria Infirmary, Newcastle, reveals a significant relationship between the transformation zone (TZ) sampling rate observed in specimens submitted from different practices and their overall detection rate for dyskaryosis. The observed correlation (R = 0.184; P = 0.033, CI = 0.017 to 0.397) is very similar to that described previously using conventional cervical smears and confirms the potential relevance of TZ sampling rates as an indicator of consistently effective specimen collection. The correlation between unsatisfactory sample rates and detection rates for high-grade dyskaryosis (R = -0.188, P = 0.030, CI = -0.865 to -0.045) also shows a significant relationship for LBC samples which was not previously seen in conventional smears. The essential role of smear taker feedback, the use of transformation zone sampling and unsatisfactory smear rates as key indicators and the practical issues relating to routine reporting of transformation zone components are discussed.     

Inadequate cervical cytology—the need to audit individual smear takers'' inadequate rates

In order to assess the performance of individual smear takers, their rates of inadequate smears, due to insufficient material, were monitored between 1992 and 1996. Although the yearly average clinic inadequate rates were all at acceptable levels, there was great variation of rates between smear takers, ranging from 0% to 19.5%. Identification of individuals with unacceptably high inadequate rates allowed them to undergo further training. Continuous monitoring of these inadequate rates can be used to measure levels of performance amongst all smear takers, but is particularly useful for new smear takers, or those who have required retraining.     

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.     

Analysis of five sampling methods for the preparation of cervical smears

The quality of the cervical smear, a decisive factor in the efficacy of population screening, can depend on the sampling method utilized. An analysis was made of the performance of five sample takers in a screening program, each of whom had made approximately 5,000 smears, and of the five sampling methods each had used: spatula alone (method A), Cytobrush plus spatula (method B), Cytopick (method C), cotton swab plus spatula (method D) and Cervex brush (method E). The differences between the sample takers and the sampling methods were significant in both the detection of grade III cervical intraepithelial neoplasia (CIN III) (P less than .01) and in the production of smears containing endocervical cells (EC+) (P less than .018). The data obtained firmly establish the importance of the presence of endocervical cells for smear adequacy. The results of this study indicate that (1) method B (Cytobrush plus spatula) and method C (Cytopick) give superior results in the preparation of EC+ smears and in the detection of CIN III and thus should be used in population screening programs, and (2) methods A and D should not be used for cervical cytologic sampling in such programs.     

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.     

The post-LLETZ cervical smear: influence of time interval from LLETZ

OBJECTIVE: To determine the effect of the time interval between large loop excision through the transformation zone (LLETZ) and the first subsequent cervical smear on the adequacy of the smear for cytologic interpretation and cytologic abnormality rates. STUDY DESIGN: A retrospective, case-note analysis of women attending a colposcopy clinic between May 1, 1999, and March 31, 2002, who had high grade histologic lesions on their LLETZ biopsy, irrespective of the referral indication. RESULTS: A total of 771 women were included in the study. Negative smears were reported in 639 (82.9%); 82 (10.6%) were abnormal and 50 (6.5%) unsatisfactory. The post-LLETZ smear was performed at a median interval of 105 days (range, 48-829). A univariate logistic regression analysis did not reveal any relationship between the rate of unsatisfactory or abnormal smears and the interval since having LLETZ (p = 0.935). CONCLUSION: These data do not support the traditionally held concept that performing the post-LLETZ smear before 6 months increases the rate of unsatisfactory or abnormal smears.     

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.     

European guidelines for quality assurance in cervical cancer screening: recommendations for collecting samples for conventional and liquid-based cytology.

The current paper presents an annex in the second edition of the European Guidelines for Quality Assurance in Cervical Cancer Screening. It provides guidance on how to make a satisfactory conventional Pap smear or a liquid-based cytology (LBC) sample. Practitioners taking samples for cytology should first explain to the woman the purpose, the procedure and how the result will be communicated. Three sampling methods are considered as acceptable for preparing conventional Pap smears: (i) the cervical broom; (ii) the combination of a spatula and an endocervical brush; and (iii) the extended tip spatula. Smear takers should take care to sample the entire circumference of the transformation zone, to quickly spread the cellular material over a glass slide, and to fix the preparation within a few seconds to avoid drying artefacts. According to local guidelines, one of these three methods may be preferred. Sampling with a cotton tip applicator is inappropriate. Similar procedures should be followed for sampling cells for LBC, but only plastic devices may be used. The collected cells should be quickly transferred into a vial with fixative liquid according to the instructions of the manufacturer of the LBC system. Subsequently, the slide or vial and the completed request form are sent to the laboratory for cytological interpretation.     

Consequences of the introduction of combined spatula and Cytobrush sampling for cervical cytology. Improvements in smear quality and detection rates

One of the most important yardsticks for evaluating sampling for the detection of premalignant and malignant cervical lesions is the percentage of smears that contain cells from the transformation zone. Until February 1985, all smears made by around 500 different general practitioners were taken with a modified Ayre spatula. In the period February to October 1985, 24,496 smears of spatula samples and 5,716 smears prepared by combined spatula-Cytobrush sampling were analyzed. With the introduction of the combined spatula-Cytobrush method, the rate of smears containing cells from the transformation zone (adequate smears) rose from 84% to 98%. With the spatula-alone method, there were large differences between the rates of adequate smears from the various doctors; with the combined spatula-Cytobrush method, all participating doctors were without exception highly successful. The positive cytology rate was significantly higher in the combined spatula-Cytobrush smears (0.75%) as compared with the spatula-alone smears (0.38%). There was also a change in the diagnostic pattern in that more premalignant changes of the glandular epithelium of the endocervix were detected. One case of early invasive adenocarcinoma of the endocervix, in which the combined spatula-Cytobrush smears was positive and the repeat spatula-alone smear made by the gynecologist was negative, is discussed in detail. We anticipate that, with the large-scale introduction of the Cytobrush sampling method, fewer repeat smears will be required and, in addition, the observed relative increase of endocervical adenocarcinoma of the endocervix will be halted. In addition, there will be fewer false-negative smears.     

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.     

Use of the Cytobrush for cervical sampling after cryotherapy

The presence of endocervical cells in routine gynecologic smears (prepared from spatula and cotton swab samples) and Cytobrush smears was analyzed in 52 patients with a history of prior cryotherapy. These cases represented 11% of the 491 women evaluated using both techniques between August 1, 1987, and January 31, 1990. The routine smear contained endocervical cells in 25 (48%) of the 52 cases while the Cytobrush smear contained endocervical cells in 49 (94%) of the cases. The use of the Cytobrush for cervical cytologic screening thus appears to be of value in patients with a prior history of cryotherapy, which frequently renders the transformation zone less accessible to routine sampling.     

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.     

Analytical solution for vacuum preloading considering the nonlinear distribution of horizontal permeability within the smear zone

The vacuum preloading is an effective method which is widely used in ground treatment. In consolidation analysis, the soil around prefabricated vertical drain (PVD) is traditionally divided into smear zone and undisturbed zone, both with constant permeability. In reality, the permeability of soil changes continuously within the smear zone. In this study, the horizontal permeability coefficient of soil within the smear zone is described by an exponential function of radial distance. A solution for vacuum preloading consolidation considers the nonlinear distribution of horizontal permeability within the smear zone is presented and compared with previous analytical results as well as a numerical solution, the results show that the presented solution correlates well with the numerical solution, and is more precise than previous analytical solution.     

The preparation of additional smears from a cervical scrape: impact on the rate of detection of cervical neoplasia

The preparation of additional smears from a cervical scrape: impact on the rate of detection of cervical neoplasia It has been known for some time that only a proportion of the cells on the smear-taking device is transferred to the slide. This can give rise to errors in reporting although the smear may have been taken correctly. This study was undertaken to identify a quick and simple method of improving the accuracy of the Papanicolaou test. A conventional smear and five additional smears were obtained from 62 women attending a Genito-Urinary Medicine clinic. The cell content of the conventional smears and the additional smears was compared. Dyskaryotic cells were detected both in the conventional smear and in the first and second additional smears from 22 women. Dyskaryotic cells were detected in the first and second additional smears only in five women. Thus, the conventional smear failed to detect biopsy-confirmed cervical abnormality in these women. A cell count of the first additional smear in the five cases where the conventional smear was negative showed that they contained, on average, 310 dyskaryotic cells. The preparation of one additional cervical smear per cervical scrape could significantly increase the accuracy of the cervical smear test by 11% (P=0.025, McNemar's test).     

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 Cervex: an ectocervical brush sampler

The performance of a new ectocervical brush sampler--the Cervex--was compared with the Ayre spatula in 280 paired cervical smears. The Cervex smears were superior in quality of spread, transformation zone sampling in all degrees of cervical patency and in detection of histologically proven epithelial abnormalities, with a false negative rate of 10.9% compared with 20% for the Ayre. Improvement in predictive value was noted in atrophic samples, with increased cellularity and transformation zone representation. Difficulty has been encountered in obtaining adequate samples from the older woman and from those with iatrogenic scarring of the cervix. Although two-sampler techniques may be used, submission of high quality pan-cervical material from a single sampler onto one slide is economically and organizationally attractive. The Cervex seems capable of producing such samples and deserves further evaluation for routine screening.     

Multicommutated flow-through optosensors implemented with photochemically induced fluorescence: determination of flufenamic acid

This article describes a multicommutated flow injection-solid phase spectroscopy system implemented with photochemically induced fluorescence for the determination of flufenamic acid (FFA). A strongly fluorescent photoproduct is generated when FFA is irradiated online under UV light in a strong sulfuric medium. The photoproduct generated is retained on C(18) silica gel (which fills the detection area of the flow cell) and directly monitored on the active solid support at 258/442 nm (lambda(ex)/lambda(em)). After maximum signal recording, the sensing zone is regenerated by eluting the retained photoproduct with an appropriate H(2)SO(4)/MeOH solution. The sensor, completely automated, is based on the use of three-way solenoid valves conveniently operated by a homemade multicommutation software written in Java language. The system is calibrated at 10 and 60s for sampling time, showing detection limits of 1.28 x 10(-9) and 5.33 x 10(-10) molL(-1) and sampling rates of 38 and 28 h(-1), respectively, with relative standard deviations of 0.9 and 1.2%. The applicability of the method is demonstrated for the determination of FFA in human serum, human urine, and a pharmaceutical preparation without any pre-treatment. Good recovery levels were achieved between 90.5 and 103.7%.