Evaluation of thin-layer methods in urine cytology

Conventional cytospin smears prepared from urinary tract specimens were compared with two new thin layer techniques, i.e. ThinPrep and AutoCyte PREP. Cellularity, cell preservation, background features, detection rate, screening time and ease of preparation were evaluated. Thin-layer techniques when applied to urine cytology were found to improve cell yield and cell preservation, and reduce background artefact. The reporting rate for abnormal urothelial cells was comparable to conventional cytospin smears, as was screening time. Laboratory staff found the methodologies to be practicable and easily incorporated into a large routine diagnostic service. We conclude that a one-slide thin-layer urine preparation is comparable to four cytospin slides in the detection of urothelial abnormalities, and that both ThinPrep and AutoCyte PREP have comparable features.     

Use of automated primary screening on liquid-based, thin-layer preparations

OBJECTIVE: To evaluate the accuracy of the AutoPap System (TriPath Imaging, Inc., Burlington, North Carolina, U.S.A.) (TriPath) in screening AutoCyte PREP liquid-based, thin-layer preparations by comparing the final cytologic diagnoses with instrument slide classification results. STUDY DESIGN: A total of 9,665 AutoCyte PREP thin-layer slides were first independently screened to establish a final cytologic diagnosis (reference diagnosis). The slides were then processed on the AutoPap System. Each slide successfully processed was reported into result categories. The generated report gave a ranking score for each slide designated for "review." Slides designated "no further review" (NFR) were also listed in the report. The reported results were then compared to the reference cytologic diagnoses. RESULTS: Of 9,665 slides initially submitted to the AutoPap, 8,688 (90.8%) were qualified for scanning, and 884 (9.2%) were definitely classified as process review or rerun and excluded from the study. Of high grade squamous intraepithelial lesions and greater (HSIL+), 85.2% were ranked in the first rank, 12.7% in the second, one (2.1%) in the third, none in the fourth and fifth and none in the NFR category. Of low grade squamous intraepithelial lesions, 47.4% were ranked in the first rank, 20.8% in the second, 10.6% in the third, 10.1% in the fourth, 5.3% in the fifth and 5.8% in NFR. Of atypical squamous cells of undetermined significance and atypical glandular cells of undetermined significance, 53.6% were ranked in the first rank, 22.5% in the second, 12.4% in the third, 5.4% in the fourth, 3.8% in the fifth and 2.3% in NFR. Considering a cutoff value at < or = 3rd rank, 84% of cervical abnormalities (RR 6.52, 95% CI 4.96-8.66) and 100% of HSIL+ were identified. CONCLUSION: The AutoPap demonstrates a high capability for detecting cervical abnormalities on AutoCyte PREP thin-layer slides. HSIL+ was associated with the highest instrument scores.     

Accuracy of thin-layer cytology in patients undergoing cervical cone biopsy

OBJECTIVE: To compare the accuracy of thin-layer cytology with Autocyte PREP (TriPath Imaging Inc., Burlington, North Carolina, U.S.A.) with conventional smears in 500 women undergoing cervical cone biopsy. STUDY DESIGN: The study was performed among 500 consecutive women presenting for cone biopsy for high grade cervical intraepithelial neoplasia (CIN) on biopsy in 350 (70%) and discrepant cytology/colpohistology in 150 (30%). Before performing a cone biopsy, two cervical samples were collected for conventional smears and thin-layer cytologic slides, with randomization of the order. Conventional smears were stained and diagnosed at Pasteur Cerba, while thin-layer cytologic slides were processed at a local TriPath office (Meylan, France) and sent in a masked fashion for screening at Pasteur Cerba. Any slides initially read as normal were reviewed again and reported without knowledge of the other cytologic or cone biopsy data. The final cytologic diagnoses for the two methods were compared with histopathology of the cone biopsy. RESULTS: The conventional smear was unsatisfactory in 58 (11.6%) of cases, while there were 4 (0.8%) unsatisfactory thin-layer cytologic slides (P < .001). Endocervical cells were missing from 31 (6.2%) of conventional smears and 34 (6.8%) of thin-layer cytologic slides. For the pooled data, sensitivities of conventional smear and thin layer for detecting high grade CIN (0.82% and 0.86%, respectively) were similar as were specificities (0.40% and 0.43%, respectively). When first samples were compared, the sensitivities of the conventional smear and thin layer for high grade CIN were 0.79% and 0.89%, respectively (P = .02), with corresponding specificities of 0.41% and 0.36% (P < .01). CONCLUSION: When controlled for sample order, the sensitivity of thin-layer cytology for detecting high grade CIN was significantly higher than that of conventional smears in patients with previous abnormal cytology, but at the expense of specificity.     

Evaluation of the FocalPoint GS system performance in an Italian population-based screening of cervical abnormalities

OBJECTIVE: To evaluate the FocalPoint Location-Guided Screening (FPGS) performance in computer-assisted primary screening of Papanicolaou-stained cervicovaginal smears. STUDY DESIGN: A total of 37,306 routine consecutive conventional Pap slides were prospectively processed on the FPGS. Each slid designated by the instrument as Review was reported according to results obtained using a GS Review Station. Subsequently, all slides under went conventional manual rapid screening and reported results were compared. RESULTS: Of the slides initially submitted to the FPGS, 34,004 (91.15%) were qualified for scanning. Within these slides, the system classified 7,399 (21.8%) as needing No Further Review and ranked to Review the remaining 26,605 (78.2%). Of the 418 cellular abnormalities found, 409 were classified for Review by FPGS and 9 minor grade lesions were classified in the "No Further Review" population. Overall, 352 (86%) of atypical squamous cell (ASC)+ were ranked in high-score quintiles, including 96 (94%) of the 102 high-grade squamous intraepithelial lesion (HSIL) or worse. Location-guided software identified cellular abnormalities, in the automatically selected fields of view, in 378 (92%) of the ranked abnormal slides, showing a sensitivity > 95% on SILs. CONCLUSION: Slide ranking and location-guided screening features are of value in detecting and triaging abnormal smears.     

Rapid cervicovaginal smear screening: method of quality control and assessing individual cytotechnologist performance

AIM: To validate the method of rapid screening (RS) in the detection of cervical lesions and false-negative results as well as in quality control of cytotechnologist performance. MATERIAL AND METHODS: The RS method was validated on Papanicolaou-stained and initially conventionally analysed vaginal, cervical and endocervical (VCE) smears collected in an opportunistic programme for the detection of cervical carcinoma. The study included 3680 VCE smears from the Department of Gynaecologic Cytology, University Department of Gynaecology and Obstetrics, Zagreb University Hospital Center, Zagreb and from the Department of Clinical Cytology, Osijek University Hospital, Osijek. Histologically verified abnormal findings accounted for 10% of the study samples. Thirteen cytotechnologists, with no previous experience in RS, performed the test. Each slide was examined using the 'step' technique for 1.5 minutes, the findings were classified as negative or abnormal, and the abnormal ones were also classified according to differential cytological diagnosis. The results were compared with those obtained on initial screening. Abnormal findings from a group of initially negative findings were reanalysed using conventional methods to make definitive cytological diagnosis. RESULTS: RS yielded a sensitivity of 83.7%, specificity of 93.7%, positive predictive value of 62.4%, negative predictive value of 97.9% and diagnostic accuracy of 92.6%. Relative to the initial abnormal differential cytological diagnosis, the diagnostic value of RS increased with lesion severity [54.8%, 68.0% and 91.3% for cervical intraepithelial neoplasia (CIN) I, CIN II and CIN III respectively]. RS detected 38 additional positive findings; 94.2% of these were atypical squamous cells of undetermined significance (ASCUS)/abnormal glandular cells undetermined significance (AGUS) and CIN I. The rate of additional positive findings was 1.14% (38/3135). The false-negative rate of initial screening was 9.4% (38/406), and individual cytotechnologist sensitivity was 60.0-100.0%. CONCLUSION: RS could be introduced as an efficient method of quality control to improve the sensitivity of cytological screening as well as for quality control of cytotechnologist performance.     

Quality assurance in cervical smears: 100% rapid rescreening vs. 10% random rescreening

OBJECTIVE: To compare 100% rapid rescreening of cervical smears with 10% random rescreening as a method of quality assurance. STUDY DESIGN: A total of 5215 smears, randomly selected from smears reported as negative by cytotechnologists during routine screening, underwent 100% rapid rescreening by senior cytotechnologists. Ten percent of these smears, selected at random, were rescreened by other senior cytotechnologists. The gold standard was defined by cytopathologists, who rescreened all 5215 smears. After excluding unsatisfactory smears detected by cytopathologists, 4271 were included in the analysis. RESULTS: The 100% rapid rescreening method identified 69.9%, 95.7% and 100%, respectively, of atypical squamous cells of undetermined significance, low grade squamous intraepithelial lesion and high grade squamous intraepithelial lesion cases reported by the cytopathologists. The 100% rapid rescreening method showed a sensitivity of 73.5% and specificity of 98.6%. The 10% rescreening method showed sensitivity of 40.9% and specificity of 98.8%. CONCLUSION: One hundred percent rapid rescreening is an efficient method of internal quality assurance in cervical smear diagnosis. It can reduce the false negative rate and therefore can provide greater certainty to women who have received negative results. Well-trained cytotechnologists are able to identify abnormal smears in 1-minute rapid rescreening.     

Evaluation of a centrifuge method and thin-layer preparation in urine cytology

OBJECTIVE: To evaluate and compare the quality and cost of urine cytology using the Cytospin method (Shandon, ThermoElectron Corporation, Waltham, Massachusetts, U.S.A.) and the AutoCyte PREP (TriPath Imaging, Burlington, North Carolina, U.S.A.) in a general laboratory. STUDY DESIGN: A study of differences between the Cytospin method and AutoCyte PREP in the areas of specimen preparation, staining, number and quality of diagnostic cells, background, screener preference, and cost was undertaken over a 3-month period in 2000. Sixty fresh voided urine samples from 25 patients with known transitional cell carcinoma were prepared by the Cytospin method and the AutoCyte PREP according to the manufacturers' instructions. RESULTS: The Cytospin method had longer preparation time but shorter screening time than the AutoCyte PREP. The number of diagnostic cells was higher in the Cytospin method. Fixation quality and staining clarity were better in the Cytospin method. Qualitative assessment of cell arrangements, cell and nuclear size and shape, nuclear/cytoplasmic ratio and nuclear membrane irregularity showed no significant differences between the 2 methods. Cellular details and nuclear chromatin patterns were clearer and better preserved in the Cytospin method, but the AutoCyte PREP showed less blood and inflammatory cells and debris. CONCLUSION: In the majority of cases the screeners preferred the Cytospin method due to its better overall cytologic quality. However, the amount of blood, inflammation and debris was much lower in the AutoCyte PREP. This reduced the need to make a second, diluted specimen and made turnaround time faster. The AutoCyte PREP was 7 times more expensive than the Cytospin method.     

Comparison of TriPath thin-layer technology with conventional methods on nongynecologic specimens

OBJECTIVE: To evaluate the use of the TriPath PREP (previously called AutoCyte) TriPath Inc., Burlington, North Carolina, U.S.A.) in nongynecologic cytologic material by performing side-by-side comparison of conventional preparations with TriPath-prepared slides. STUDY DESIGN: An initial study of 613 cases (set A) was conducted to compare the TriPath PREP system with conventional methods for the evaluation of nongynecologic specimens, including urine, body cavity effusions, cerebrospinal fluid, pulmonary and gastrointestinal specimens. Paired cases were evaluated for cellularity, staining quality, preservation and representation of diagnostic material. Subsequent changes in the automated technique warranted reevaluation of the TriPath method. The follow-up study of 259 cases (set B) was conducted with the same design as set A. Results of evaluated parameters were analyzed using the chi 2 test. RESULTS: Results of the two sets were strikingly different. Prior to technical changes made by the laboratory, the TriPath method was significantly inferior. In the second set, the preferred material was most commonly the TriPath-prepared material. In particular, the majority of urine samples were prepared better by the automated, thin-layer system. CONCLUSION: The TriPath PREP system offers a reliable preparation of urine and has potential for other nongynecologic specimens, provided that careful attention is paid to technical details and some adjustments are made to account for specimen variability.     

Processing liquid-based gynecologic specimens: comparison of the available techniques.

OBJECTIVE: To develop a cytopreparation protocol suitable for satisfactory processing by the AutoCyte PREP System with the gynecologic specimens collected in PreservCyt fluid for the ThinPrep machine. STUDY DESIGN: The residue of a number of gynecologic specimens collected in PreservCyt and processed by ThinPrep were processed by AutoCyte PREP. Some modifications were made in the cytopreparatory protocol in order to obtain satisfactory specimens. RESULTS: The ThinPrep and AutoCyte PREP specimens were examined independently. The results were comparable, with a high degree of concordance between the two techniques. CONCLUSION: Gynecologic specimens collected in PreservCyt and following the ThinPrep specimen collection protocol can be processed using the AutoCyte PREP System. Minor protocol modifications provided comparable diagnostic material. Additional studies are needed to explore the feasibility of this approach and fulfill the various U.S. regulatory agency requirements for the liquid-based Pap test.     

Classification of cervical smears with discordance between the cytologic and/or histologic ratings

The problems of diagnostic variability between certified cytotechnologists was studied. Three cytology laboratories submitted a total of 28 cervical smears that had a discordance between the cytologic and/or histologic ratings. Eight independent cytotechnologists provided blind readings on each slide, expressed as "absence of cervical intraepithelial neoplasia (CIN)" to "CIN III." The median rating was absence of CIN or CIN I for 8 slides, CIN II for 5 and CIN III for 15. With a kappa value greater than 0 reflecting agreement beyond chance expectation and a value of 0.40 indicating fair agreement, the kappa value for 8 X 28 ratings was 0.36 (P = .0001), with a 90% confidence interval (CI) between 0.34 and 0.37. The kappa value was 0.14 (P = .10), with a 90% CI between 0.10 and 0.18, on a subsample of nine smears with two or more positive cytology diagnoses but a negative histology. Sixteen of the 28 slides represented cases of histologically proven cancer. Treating cytologic diagnoses of CIN II and CIN III as positive, the sensitivity of the cytologist with reference to histology varied between 71% and 86% while the specificity ranged from 18% to 62%. The positive predictive value was 1/2.5 to 1/1 and the negative predictive value was 1/6 to 1/1. The predictive power (true positives/false positives) ranged from 1.0 to 2.2. The cytodiagnosis of these cervical smears from cases of discordance thus exhibited limited reliability. Standardization of the relevant cytologic knowledge and its routine application is needed to improve the level of performance.     

A comparative study: conventional preparation and ThinPrep® 2000 in respiratory cytology

In order to compare and contrast conventional preparation (CP) with ThinPrep 2000 (TP) in respiratory cytology, 207 samples were divided equally and processed by the two different preparation methods, generating three CP and one TP slide per sample. No lesion identified by CP was missed by TP and there were no significant differences between TP and CP in the diagnostic categories. However, two cases of squamous cell carcinoma were detected on TP which had been classified as unsatisfactory and moderate squamous dyskaryosis, respectively, on CP. ThinPrep was found to be superior to CP in many respects as it provided standardized preparations in a greater proportion of cases and problems such as cell overlapping and background debris were markedly reduced. In several instances the diagnostic accuracy in CP was compromised by smears that were either too thick, too thin, or too scanty. Cell preservation was also better on TP when compared with CP, facilitating more accurate diagnosis and significantly reducing the primary screening and reporting time, especially of sputum samples. A major advantage of TP methodology is the fact that it facilitates optimal use of skilled cytotechnologists and streamlines the workflow in the laboratory.     

Issues for application of virtual microscopy to cytoscreening,perspectives based on questionnaire to Japanese cytotechnologists

To clarify the issues associated with the applications of virtual microscopy to the daily cytology slide screening, we conducted a survey at a slide conference of cytology. The survey was conducted specifically to the Japanese cytology technologists who use microscopes on a routine basis. Virtual slides (VS) were prepared from cytology slides using NanoZoomer (Hamamatsu Photonics, Japan), which is capable of adjusting focus on any part of the slide. A total of ten layers were scanned from the same slides, with 2 micrometer intervals. To simulate the cytology slide screening, no marker points were created. The total data volume of six slides was approximately 25 Giga Bytes. The slides were stored on the Windows 2003 Server, and were made accessible on the web to the cytology technologists. Most cytotechnologists answered "Satisfied" or "Acceptable" to the VS resolution and drawing speed, and "Dissatisfied" to the operation speed. To the ten layered focus, an answer "insufficient" was slightly more frequent than the answer "sufficient", while no one answered "fewer is acceptable" or "no need for depth". As for the use of cytology slide screening, answers "usable, but requires effort" and "not usable" were about equal in number. In a Japanese cytology meeting, a unique VS system has been used in slide conferences with markings to the discussion point for years. Therefore, Japanese cytotechnologists are relatively well accustomed to the use of VS, and the survey results showed that they regarded VS more positively than we expected. Currently, VS has the acceptable resolution and drawing speed even on the web. Most cytotechnologists regard the focusing capability crucial for cytology slide screening, but the consequential enlargement of data size, longer scanning time, and slower drawing speed are the issues that are yet to be resolved.     

Cost analysis of PAPNET-assisted vs. conventional Pap smear evaluation in primary screening of cervical smears

OBJECTIVE: To assess the difference in costs between PAPNET-assisted and conventional microscopy of cervical smears when used as a primary screening tool. STUDY DESIGN: We performed time measurements of the initial screening of smears by four cytotechnologists in one laboratory. Time was measured in 816 conventionally screened smears and in 614 smears with PAPNET-assisted screening. Data were collected on the components of initial screening, clerical activities and other activities in the total work time of cytotechnologists in the routine situation and on resource requirements for both techniques. RESULTS: PAPNET saved an average of 22% on initial screening time per smear. Due to costs of processing and additional equipment, the costs of PAPNET-assisted screening were estimated to be $2.85 (and at least $1.79) higher per smear than conventional microscopy. The difference in costs is sensitive to the rate of time saving, the possibility of saving on quality control procedures and the component of the initial screening time in the total work time of cytotechnologists. CONCLUSION: Although PAPNET is time saving as compared with conventional microscopy, the associated reduction in personnel costs is outweighed by the costs of scanning the slides and additional equipment. This conclusion holds under a variety of assumptions. Using PAPNET instead of conventional microscopy as a primary screening tool will make cervical cancer screening less cost-effective unless the costs of PAPNET are considerably reduced and its sensitivity and/or specificity are considerably improved.     

Rapid pre-screening is more sensitive in liquid-based cytology than in conventional smears

Rapid pre-screening (RPS) is a useful tool to measure and improve performance in the cytology laboratory. Whether RPS is more or less effective in liquid-based cytology than in conventional smears is unknown. We compared the estimated sensitivity in a laboratory of 11 cytotechnologists which converted from conventional smears to SurePath? (Becton Dickinson, Franklin Lakes, N.J., USA) liquid based cytology. In the 9 months prior to conversion, 23,286 smears were screened compared with 30,610 smears in the 12 months immediately after conversion. The estimated sensitivity of rapid pre-screening for 90 s improved significantly with liquid based cytology for all abnormalities (58.7 vs. 68.7%, p<0.001), atypical squamous cells of undetermined significance+low-grade squamous intra-epithelial lesion (52.6 vs. 63.1%, p<0.001), and high-grade squamous intra-epithelial alone (76.2 vs. 85%, p<0.001). Histologic follow up for 156 cases identified by rapid pre-screening of SurePath slides showed 32 (21%) cases of CIN1 or greater and 18 cases (12%) with CIN3 or worse. We conclude that rapid pre-screening is significantly more sensitive in liquid-based cytology compared with conventional smears, and detects significant lesions that are missed by routine screening.     

Implementation and evaluation of a new automated interactive image analysis system

OBJECTIVE: To compare automated interactive screening using the ThinPrep Imaging System with independent manual primary screening of 12,000 routine ThinPrep slides. STUDY DESIGN: With the first 6,000 cases, the Review Scopes (RS) screening results from the 22 fields of view (FOV) only were compared to independent manual primary screening. In the next 6,000 cases, any abnormality detected in the 22 FOV resulted in full manual screening on the cytotechnologist's own microscope. Sensitivity and specificity together with their 95% CIs were calculatedfor each method. RESULTS: In the first set of 6, 000 cases, diagnostic sensitivity and specificity of the imager were 85.19% and 96.67%, respectively. The diagnostic sensitivity and specificity of manual primary screening were 89.38% and 98.42%. This highersensitivity and specificity of manual primary screening were found to be statistically significant. The second set of 6,000 cases demonstrated no significant statistical difference in sensitivity or specificity between the sets of data. CONCLUSION: The results from our study show that the sensitivity and specificity of the imager technology are equivalent to those of manual primary screening. The system is ideally suited to the rapid screening of negative cases, allowing increased laboratory productivity and greater throughput of cases on a daily basis.     

Quality control of cervical cytology in high-risk women. PAPNET system compared with manual rescreening

OBJECTIVE: To compare the effectiveness of the PAPNET System with conventional rescreening of negative cervical smears in a high-risk population. STUDY DESIGN: Three thousand ninety-seven negative cervical smears from women with past history of cervical abnormalities were rescreened manually and with the PAPNET System. There were two reviews of PAPNET images: the first by two cytotechnologists with limited exposure to the instrument, and the second, limited to smears with discrepant diagnoses, by an expert in the use of the system. The remaining discrepant smears were submitted to a blinded microscopic review by a third party. The a priori consensus diagnosis was arbitrarily established when the result of two of the three reviews--manual, PAPNET and the independent third review--were concordant. The results of rescreening were compared with available biopsies. RESULTS: On manual rescreening of the 3,097 smears, 2,901 (93.66%) were reported as negative and 170 (5.49%) as abnormal. On the first PAPNET review, 2,938 (94.87%) were reported as negative and 150 (4.84%) as abnormal. There were 144 smears with discrepant diagnoses. After the second PAPNET review of these discrepant smears, the agreement between manual and PAPNET rescreening rose from 94.27% to 95.58%. A final, blinded review of 89 residual discrepant smears was used to establish consensus diagnoses. The diagnoses made by PAPNET-assisted rescreening agreed much better with the consensus diagnoses than did manual rescreening (Kappa = .61 vs. Kappa = -.32, P < .001). When compared with the results of 50 available biopsies, PAPNET-assisted rescreening also had a somewhat lower false negative rate (sensitivity 58.82% vs. 41.18%, P = .17) and a statistically significant lower false positive rate (specificity 63.64% vs. 36.36%, P = .01). CONCLUSION: PAPNET-assisted rescreening, when carried out by an experienced person, is more efficient than manual rescreening.     

Effect of cellularity on the sensitivity of detecting squamous lesions in liquid-based cervical cytology

OBJECTIVE: To evaluate the effect of cellularity on the sensitivity of both screening and diagnosis in a liquid-based cervical sample. STUDY DESIGN: SurePath samples (TriPath Imaging Inc., Burlington, North Carolina, U.S.A.) with known diagnoses were selected, including 18 negative, 16 low grade squamous intraepithelial lesion (LSIL) and 12 high grade squamous intraepithelial lesion (HSIL) cases. Through a serial dilution technique, samples of varying cellularity were prepared. The 275 slides were assigned random numbers and were routinely screened by 1 of 2 senior cytotechnologists, blinded to the reference diagnosis. Specimens with a screening diagnosis of atypical squamous cells of undetermined significance (ASCUS) or higher were reviewed by two pathologists, resulting in a final consensus diagnosis. Using a grid counting system, cellularity was determined for each slide. RESULTS: There was a clear demarcation in sensitivity between specimens with a cellularity of < 5,000 or > or = 5,000 squamous cells. This applied to both the sensitivity for screening and to the final consensus diagnosis. For cases with a reference diagnosis of LSIL+, at a cytotechnologist screening level of ASCUS or greater, sensitivity increased from 72.8% (< 5,000 cells) to 98.1% (> or = 5,000 cells) and for a reference diagnosis of HSIL from 85.7% to 100%, respectively. Similarly, for the consensus diagnosis, sensitivity rose from 78.5% (< 5,000 cells) to 96.6% (> or = 5,000 cells) for LSIL+ and from 82.9% to 100%, respectively, for HSIL. These differences were statistically significant (P < .001). CONCLUSION: A minimum cellularity of 5,000 squamous cells is recommended for SurePath liquid-based cervical preparations.     

Human papillomavirus DNA detection in women with primary abnormal cytology of the cervix: prevalence and distribution of HPV genotypes

OBJECTIVES: In this study, we focus on the prevalence and occurrence of different anogenital human papillomavirus (HPV) genotypes in a first abnormal cervical screening test, and correlate HPV genotyping with the cytological diagnosis on thin-layer liquid-based preparations in routine gynaecological screening. METHODS: Out of 780 abnormal smears, 513 tested positive for HPV. All 25 different HPV types were identified by Line Probe Assay. RESULTS: The prevalence of high-risk HPV types increased from 72% in atypical squamous cell of undetermined significance to 94.5% in high-grade intra-epithelial lesion (HSIL). Co-infection with multiple HPV types was predominantly found in HSIL (35.8%). In the HSIL group the most common HPV types were 16, 52, 51 and 31; type 18 was rarely present. CONCLUSION: The role of types 31, 51 and 52 should be considered in future studies on vaccine development.     

Prospective study of PAPNET: review of 25656 Pap smears negative on manual screening and rapid rescreening

In this prospective study, 27,014 Pap smears were selected for PAPNET review on the request of the referring practitioner or patient. Smears that were negative on routine manual screening were submitted for rapid rescreening. Smears considered normal after these two manual screens (n = 25,656) were reviewed using the PAPNET testing system. Routine manual screening identified 1340 (4.96%) of the smears as abnormal, and a further 18 (0.07%) abnormalities were detected by rapid rescreening. PAPNET review identified an additional 102 (0.4%) abnormal smears, including 10 histologically confirmed high grade lesions. The use of PAPNET testing following routine manual screening and rapid rescreening in tandem, enables cytologists to detect additional diagnostically significant abnormalities and reduce the rate of false-negative smears.     

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.