Estimation of disease severity in the NHS cervical screening programme. Part II: quantitative methods of estimating disease severity and progression potential

R. G. Blanks Estimation of disease severity in the NHS cervical screening programme. Part II: quantitative methods of estimating disease severity and progression potential Objective: This is the second of a two‐part paper exploring the use of a more quantitative approach to both cytology and histology disease severity measurements. In Part I the problem of artificial cut‐off points was discussed and a semi‐quantitative solution to the problem proposed. In Part II quantitative methods are proposed that are used to predict the estimated progression probability (EPP) to invasive cancer. Methods: Based on models derived from published data the grade number (GN) is related to the EPP to invasive cancer over the next 10 years for both cytology (CEPP) and histology (HEPP) using a look‐up table. CEPP and HEPP are then adjusted by other factors such as age, persistence, HPV result, number of cells and lesion size to obtain the adjusted CEPP and HEPP (ACEPP and (AHEPP). The two factors can be combined to produce an adjusted weighted estimated progression potential using the formula AWEPP ((ACEPP + AHEPP)/2) × AHEPP) using a two to one bias in favour of the histology. Results: As an example of the methodology consider a slide estimated as showing a 60% probability of moderate dyskaryosis (HSIL favouring CIN2) and 40% probability of mild dyskaryosis (LSIL favouring CIN1). The GN number would be 1.6 (as described in Part I) and the EPP over the next 10 years 0.78%. For a woman aged 52 years (correction factor ×2.0) with a second mildly dyskaryotic smear (correction factor ×1.25) and >50 dyskaryotic cells (correction factor 1.5) the ACEPP would be 0.78 × 2.00 × 1.25 × 1.5 = 2.9%. If the HEPP on histology was 50:50 between CIN1 and CIN2, the AHEPP can be calculated as 1.4%. The AWEPP would be ((2.9 + 1.4)/2 × 1.4) = 1.7%. The final estimate of disease progression potential based on both cytology and histology is 1.7% over 10 years. Conclusions: These quantitative approaches based on adjusted and weighted EPP provide a framework suitable for research, audit and comparison between screening centres, and for tailoring criteria for colposcopy referral and treatment. Further research is required to improve the estimates given in the paper.     

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.     

Borderline nuclear change,high‐grade dyskaryosis not excluded: current concepts and impact on clinical practice

S. S. Hoo, A. Patel, H. Buist, K. Galaal, J. D. Hemming and R. Naik Borderline nuclear change, high‐grade dyskaryosis not excluded: current concepts and impact on clinical practice Objective: Borderline nuclear change, high‐grade dyskaryosis not excluded (B/HG) is a subcategory of the borderline category recommended by the British Society for Clinical Cytology as warranting direct referral to colposcopy. This subcategory is equivalent to the Bethesda category of atypical squamous cells, cannot exclude high‐grade squamous intraepithelial lesion (ASC‐H). The purpose of this study was to determine the validity and accuracy of using B/HG to identify potential cervical intraepithelial neoplasia (CIN) grade 2 or worse (CIN2+). Methods: Data were collected from the hospital pathology database for borderline, B/HG and high‐grade cytology (moderate dyskaryosis and above), and their respective histological and colposcopic outcomes. SPSS was used for data analysis. Results: Of the 84 799 total cytology samples screened between July 2006 and December 2009, 5225 (6.1%) were reported as borderline, 309 (0.4%) as B/HG and 1222 (1.4%) as high‐grade cytology. Thus, B/HG comprised 5.9% of the overall borderline category, in keeping with national guidelines (<10%). CIN2+ was confirmed in 86.6% of high‐grade, 40.8% of B/HG and 3.0% of borderline cytology. Of 309 women reported with B/HG cytology, 239 had colposcopy. Colposcopic appearances showed a positive predictive value (PPV) of 71.8% for detecting CIN2+ and a negative predictive value of 60.7%. Conclusions: The B/HG category was associated with a significantly higher incidence of CIN2+ compared with borderline cytology as a whole. This refining performance justifies its existence. Colposcopic appearances had a high PPV for detecting CIN2+. Therefore, colposcopy is recommended in patients with B/HG cytology and treatment should be offered if high‐grade colposcopic changes are seen.     

Posters. P11 Positive predictive values for high and low‐grade cytological abnormalities as surrogates for specificity and sensitivity

Introduction Positive predictive value (PPV), measuring the percentage of moderate dyskaryosis or worse confirmed as CIN2 or worse, is used as a measure of accuracy in cervical screening. However, it relates more to specificity than sensitivity because the denominator includes false positives rather than false negatives. Low values reflect over‐reporting of high‐grade dyskaryosis but high values may reflect under‐reporting. Sensitivity is impossible to measure from correlation of cytology with outcome because women with negative cytology are rarely referred for colposcopy. Rates of CIN3 resulting from referrals for low‐grade cytology may be used as a surrogate for sensitivity, as high values may reflect under‐reporting (ref). Study design Outcome of colposcopy referrals was monitored during a period of 4 years, using a fail‐safe database. Results PPV at Guy's & St Thomas rose from 54% in 1998/1999 to 69% in 2001/2002. The former was below the NHSCSP recommended range. During the same period of time CIN1 rates for moderate dyskaryosis fell from 37% to 24%, reflecting the main source of discrepancy. While specificity increased (as reflected by increasing PPV) sensitivity remained constant in that CIN3 rates for mild dyskaryosis and borderline remained below 6%: average rates in England have fallen over the last 3 years and were 7.4% in 2000/2001 (ref). CIN2 rates for mild dyskaryosis also remained constant at 11% to 12%. Conclusion Correlation of biopsy results with high‐ and low‐grade cytological abnormalities is a useful method of monitoring accuracy of cytology reporting, and can be used to measure over‐ and under‐reporting as surrogates for specificity and sensitivity.     

Koilocytosis; an indication for conservative management

The management of women with mild dyskaryosis continues to be the subject of debate. The management of cases with such smears could be improved if additional morphological features were found to be indicative of low/high grade cervical intraepithelial neoplasia (CIN). Our own experience in the routine audit of the diagnostic accuracy of cervical smears had suggested that cases of dyskaryosis with koilocytosis were associated with a low risk of CINIII. Two hundred and forty-four cervical smears reported as showing evidence of wart virus infection were reviewed and their subsequent histories noted. Of these smears, 173 demonstrated clear evidence of koilocytosis. Irrespective of the initial grade of dyskaryosis, only 28 cases (16.2%) had underlying CIN or had progressed to CIN over a minimum follow-up period of 21 months. Only two cases (1.2%) showed evidence of CINIII. Koilocytosis is associated with a low risk of CIN and an especially low risk of CINIII. The management of women with koilocytic smears should be modified accordingly.     

Koilocytosis; an indication for conservative management

The management of women with mild dyskaryosis continues to be the subject of debate. The management of cases with such smears could be improved if additional morphological features were found to be indicative of low/high grade cervical intraepithelial neoplasia (CIN). Our own experience in the routine audit of the diagnostic accuracy of cervical smears had suggested that cases of dyskaryosis with koilocytosis were associated with a low risk of CINIII. Two hundred and forty-four cervical smears reported as showing evidence of wart virus infection were reviewed and their subsequent histories noted. Of these smears, 173 demonstrated clear evidence of koilocytosis. Irrespective of the initial grade of dyskaryosis, only 28 cases (16.2%) had underlying CIN or had progressed to CIN over a minimum follow-up period of 21 months. Only two cases (1.2%) showed evidence of CINIII. Koilocytosis is associated with a low risk of CIN and an especially low risk of CINIII. The management of women with koilocytic smears should be modified accordingly.     

Five-year follow-up of women with borderline and mildly dyskaryotic cervical smears

This study investigated the 5-year follow-up status of women with cervical smears showing borderline nuclear changes (BNC) or mild dyskaryosis and the effect of koilocytosis on the outcome. Thirteen per cent of women with cervical smears showing BNC had high-grade cervical intraepithelial neoplasia (CIN). In contrast, 28% of women with cervical smears showing mild dyskaryosis had high-grade CIN. The presence of koilocytosis (24% for borderline smears and 34% for mild dyskaryotic smears) did not appear to influence the risk of developing high-grade CIN. Our results suggest that the simultaneous implementation of the British Society for Clinical Cytology proposed terminology and the colposcopy guidelines from the British Society for Colposcopy and Cervical Pathology could have an impact on colposcopy services.     

P‐21POSITIVE PREDICTIVE VALUE OF CERVICAL SMEARS REPORTED AS MILD DYSKARYOSIS

Objective: Recent national guidelines (NHSCSP Document 20) recommend the referral of patients having the first occurrence of mild dyskaryosis. We evaluated the usefulness of this guideline and determined the positive predictive value (PPV) of conventional smears (CS) and ThinPrep samples (TP) reported as the first occurrence of mild dyskaryosis. Methods: This was a retrospective study where we looked at the cases of mild dyskaryosis from January’05 to June’05 received at our laboratory. Of these, the cases of mild dyskaryosis at the first instance were only taken into consideration. Histological diagnosis of these cases where available were retrieved from the laboratory database and were correlated with the cytological findings. Results: There were 1016 cases, which were reported as mild dyskaryosis. Out of them, 51.1% (519 cases) were first report of mild dyskaryosis: 61.8% (321 cases) and 38.2% (198 cases) were CS and TP respectively. Of these, 181 CS (56.4%) and 120 TP (60.6%) had a histological follow up. The results showed that 54.1% CS and 56.7% TP had a low‐grade outcome, 26.0% CS and 25.8% TP had a high‐grade outcome and 19.9% CS and 17.5% TP had a normal outcome. The PPV of mild dyskaryosis for CIN1 or worse result was 53.0% and 50.0% in CS and TP respectively. The PPV of mild dyskaryosis for CIN1 only was 27.1% and 24.2% in CS and TP respectively. Discussion: The difference in PPV for both systems is statistically insignificant. This result endorses usefulness of colposcopic referral after the first report of mild dyskaryosis.     

Outcome of SurePath™ cervical samples reported as borderline nuclear change by cytological subtype and high‐risk HPV status

N. Gupta, N. Dudding, J. Crossley, S.J. Payyappilly and J.H.F. Smith
Outcome of SurePath? cervical samples reported as borderline nuclear changes by cytological subtype and high‐risk HPV status Background: The average borderline rate in cervical cytology samples for English laboratories was 3.8% with the range being 2.0–6.8% at the time of the present study, which was undertaken in order to determine the association between different subtypes of borderline nuclear change (BNC), high‐grade cervical intraepithelial neoplasia (CIN) and high‐risk human papillomavirus (hrHPV) status. Materials and methods: Of 68 551 SurePath^TM cervical samples reported in one laboratory over a period of 2 years, 2335 (3.4%) were reported as BNC. hrHPV status was known in 1112 cases (47.6%). The outcome was known only for women with hrHPV‐positive BNC, who were recommended for colposcopy under the National Health Service Cervical Screening Programme sentinel site protocol. Women with hrHPV‐negative BNC were returned to 3‐yearly recall. The cases were subdivided into BNC, high‐grade dyskaryosis cannot be excluded (B‐HG; 105 cases); BNC with koilocytosis (B‐K; 421 cases); BNC with other features of HPV (B‐HPV; 160 cases); and BNC, not otherwise specified (B‐NOS; 426 cases) and were correlated with the histological outcome where available. Results: The study population age ranged from 23 to 65 years. Cases that tested positive for hrHPV by Qiagen HCII assay comprised 78.1%, 81.0%, 73.1% and 67.8% of B‐HG, B‐K, B‐HPV and B‐NOS categories, respectively. CIN2 or worse (CIN2+) was found in 64.6%, 10.0%, 19.7% and 20.1% of hrHPV‐positive cases of B‐HG, B‐K, B‐HPV and B‐NOS, respectively, which was significantly higher in the B‐HG category (P < 0.001) and lower in the B‐K category compared with B‐NOS (p < 0.001) and B‐HPV (p = 0.006) respectively. CIN3+ comprised 55.6%, 6.3%, 26.3% and 19.1% of biopsies in the same categories, respectively. Conclusions: Subtyping BNC is useful, especially B‐K and B‐HG, which, respectively, had the lowest and highest rates of detection of both CIN2+ and CIN3+, confirming that koilocytosis is likely to be associated with transient HPV infection. Women with B‐HG should be referred to colposcopy in the absence of HPV triage.     

P‐26CONVENTIONAL V THIN LAYER TECHNIQUES: A COMPARATIVE STUDY OF BRONCHIAL SPECIMENS USING CONVENTIONAL AND TWO LBC METHODS,THINPREP AND SUREPATH

Introduction: There is ongoing debate about the terminology used in the classification of dyskaryosis, including whether BNA smears should be classified according to whether koilocytes are present or not. We explored the effect of koilocytosis in the management experiences and clinical outcomes of women with a single BNA smear. Methods: This study includes 410 women aged 20–59 years, resident in Tayside who had an ‘baseline’ BNA smear between 31/10/1999 and 31/10/2002 who were eligible for the TOMBOLA trial but who did not participate. Recommended follow‐up for these women was a repeat smear in six months. Up to three‐years follow‐up data was collected on subsequent cytological smears, colposcopy examinations and any related histology. The baseline smear was re‐read for the presence or absence of koilocytes. Women were classified according to their clinical outcomes during their three years. Results: 47% (192/410) of women were classified as having koilocytosis at baseline. The mean age was lower among these women (25 years) compared to those without koilocytosis (35 years). 55% (105/192) of women with koilocytosis at baseline had one or more negative smears and no further abnormal smears, compared to 63% (137/218) of those without koilocytosis, the difference was not statistically significant. 28% (53/192) of women with koilocytosis at baseline were referred to colposcopy after subsequent low‐grade or high‐grade smears compared to 19% (42/218) of those without koilocytosis; the difference was statistically significant. 14% (27/192) of women with koilocytosis at baseline were diagnosed with CIN2/3 or worse during follow‐up compared to 10% (21/218) of women without koilocytosis; the difference was not statistically significant. Discussion: Our results suggest that the presence or absence of koilocytosis has little impact on the clinical outcomes of women with a BNA smear.     

Cervical intraepithelial neoplasia grade III (CIN III) and invasive cervical carcinoma: the yawning gap revisited and the treatment of risk

In a 3-year study of the population of Southampton and south-west Hampshire there were 10 times as many cases of CIN III compared with invasive squamous carcinoma (700 compared with 70). The peak incidence of CIN III per 1000 screened women years was in those aged 25-29 years, which was 20 years earlier than the peak incidence of invasive cervical cancer per 1000 women years at risk. Ninety percent of CIN III was diagnosed in women under 50 years. There were 14 cases of cervical glandular intraepithelial neoplasia grade III (CGIN III), three coexisting with CIN III, all in women aged under 50 years: the gap between intraepithelial and invasive lesions was not seen for glandular neoplasia. Although referral was for at least moderate dyskaryosis in 86.8% of women with CIN III or CGIN III, most had been screened previously, either having had mild abnormalities requiring repeat cytology (39.8%) or negative cytology (34.5%). Only 12 women aged > or = 50 years had previous negative cytology: 21.4% compared with 35.6% of women aged < 50 years (P = 0.034). The results of this study suggest that the best opportunity for preventing invasive squamous cell carcinoma lies in screening women aged 20-39 years when the incidence of CIN III in the screened population is highest and before the peak incidence of invasive disease. The results also indicate the importance of repeated screening and follow up of minor cytological abnormalities in the detection of CIN III. The benefit of screening must be regarded as a treatment of risk, since it is almost certain that a high proportion of CIN III regresses or persists unchanged.     

Outcome analysis of 4 years' follow-up of patients referred for colposcopy with one smear showing mild dyskaryosis

Objective: To assess the 4‐year outcome of patients after one smear showing mild dyskaryosis with respect to smear regression rate, prevalence of cervical intraepithelial neoplasia (CIN) and the effect of age. Methods: Retrospective analysis of patients diagnosed with initial mildly dyskaryotic smear during the year 2000 with a follow‐up period of 48 months. These women had not had any previous abnormal smears. Settings: Cytopathology Department and Colposcopy Unit, King’s College Hospital, London, UK. Results: We identified 524 patients of whom 375 patients with complete follow‐up data are included. The age range was 19–67 years with a median of 29 years. There were 207 patients aged 35 years or less (55%). At 6 months, 258 smears were performed and 47.8% of them were negative (95% CI: 41.6–54.0%). The total number of negative follow‐up smears in the first year was 198 out of a total of 397 smears performed (50%). This proportion has significantly increased between 1 and 4 years’ follow‐up to 67.5% (RR: 1.24; 95% CI: 1.14–1.35). Over the 4‐year period, 791 smears were performed and 477 were negative (60.3%; 95% CI: 56.9–63.7%). Of the 477 negative smears there were only 61 smears (12.8%; 95% CI: 10–16%), in 54 patients (14%; 95% CI: 11–18%) that reverted back to low‐grade cytological abnormality. In only one case the repeat smear showed high‐grade abnormality after initial negative follow‐up; however, on biopsy, histology showed CIN I. Out of the 375 patients, 70 required treatment with excisional biopsy (19%; 95% CI: 15.0–22.9%). Histology confirmed high‐grade CIN in only 41 cases giving a prevalence of 11% (95% CI: 8.1–14.5%). There were no cases of microinvasive or invasive cancer detected. Age (≤35 years versus >35 years) did not significantly affect either cytological or histological outcome. Conclusion: Sixty per cent of follow‐up smears after initial mild dyskaryosis subsequently became negative; of them 87.2% remained negative over the 4 year follow‐up. Treatment was only required in 19% of patients, with 11% prevalence of high‐grade CIN. Age did not affect the outcome. These results are reassuring and indicate that colposcopic referral may not be necessary after only one mildly dyskaryotic smear.     

Proffered Papers 10.30–11.15 Monday 15 September 2003 3 5 year outcome of women with borderline and mild dyskaryosis smears 3 5 year outcome of women with borderline and mild dyskaryosis smears

Aims

• 1 To identify the outcome status of women with borderline and mild dyskaryosis smears.
• 2 To determine whether the presence or absence of koilocytosis influences the outcome status.
• 3 To identify the proportion of women with borderline smears showing koilocytosis.

Materials and methods Borderline and mild dyskaryosis cervical smears diagnosed during January to March 1997 were identified from the laboratory database. Each slide was reviewed by two researchers independently, who then agreed a final consensus diagnosis. All slides were classified according to the presence or absence of koilocytosis. Slides were excluded from the study if the review diagnosis was negative, inadequate or high‐grade dyskaryosis. The outcome status was classified according to the worst lesion identified histologically and/or cytologically during the 5‐year follow‐up period. Results 1974 women were identified with borderline or mild dyskaryosis cervical smears of which 1597 were included in the study. Table 1 shows the outcome status of these women.

Table 1. . The outcome status of these women

BSCC,Bethesda or other? Terminology in cervical cytology European panel discussion

The European panel agreed that reproducibility and translatability of terminology in cervical cytology were essential, arguing well for harmonization of reporting systems. The majority at this meeting use a modification of the Bethesda system (BS). Local modifications involved reporting subcategories within high grade and low grade lesions, which would not alter the overall translatability of their systems both with each other and BS. The majority agree that low grade lesions with and without koilocytosis should be managed similarly as should high grade lesions (moderate dysplasia/CIN2 or worse). Those systems linking moderate dysplasia with mild rather than severe dysplasia would need to define moderate dysplasia as such, if their results were to be translatable, which would be preferable to their using a different definition of low grade and high grade lesions. Translation between systems might anyway be facilitated by reporting moderate dysplasia as a subcategory within high grade, which was favoured by most of those present. Therefore, there is no need for exact agreement of terminology if broad principles are agreed. This useful discussion adds weight to the British Society for Clinical Cytology recommendation that the new classification should be adopted by the UK National Health Service Cervical Screening Programme. If the new classification is adopted, the UK would join the European consensus opinion on terminology.     

Proposed Sheffield quantitative criteria in cervical cytology to assist the grading of squamous cell dyskaryosis, as the British Society for Clinical Cytology definitions require amendment

OBJECTIVE: In 1986, the British Society for Clinical Cytology (BSCC) published quantitative criteria to assist diagnosis in a three-tier grading system of squamous cell dyskaryosis. In dyskaryotic cells, area nuclear to cytoplasmic (NC) ratios below 50%, between 50% and 66% and over 66% were defined as equating with mild, moderate and severe grades respectively. Following the Terminology Conference in 2002, however, the BSCC recommended on their website that the three-tier model should be replaced by a new two-tier system of low- and high-grade squamous abnormalities. The latter broadly equate with the two-grade Bethesda System (TBS) for reporting squamous intraepithelial lesions. The purpose of this study was to assess the accuracy and reproducibility of the BSCC three-tier quantitative definitions, to investigate if they were applicable to liquid-based cytology (LBC) and to see how they related to the proposed new two-tier BSCC system. METHODS: Quantitative image analysis was undertaken on illustrations from the 1986 BSCC terminology publication and on microscope slides from external quality assessment and Cytology Training Centre teaching sets. RESULTS: Analysis of mean NC ratios showed that mild, moderate and severe dyskaryosis exist as statistically different populations. Overlap of NC ratio ranges, however, limits their practical application in the three-tier model, although interestingly no overlap was noted between mild and severe dyskaryosis. No grade of dyskaryosis had a mean area NC ratio over 50%, indicating that the BSCC quantitative definitions are incorrect. The mean diameter NC ratios for mild, moderate and severe dyskaryosis were found to be 40%, 49% and 66% respectively. Accordingly it is possible that those reporting cervical cytology could be interpreting the BSCC NC ratios as meaning diameter rather than area. Amalgamation of the three-tier results into the proposed two-tier model shows that the resulting mean NC area and diameter ratios identify statistically different low- and high-grade populations. The reduced degree of overlap, however, of NC ratio ranges in the two-tier model implies that NC ratios could have a useful practical role in the separation of the low- and high-grade categories. The two categories were reasonably well separated by mean area and diameter NC ratios of 25% and 50% respectively. A two-tier model combining mild with moderate rather than severe dyskaryosis was found to be a statistically valid alternative but gave rise to NC ratios that would be difficult to use in practice. Except for moderate dyskaryosis, no significant differences were identified between the mean NC ratios of either conventional and LBC preparations or LBC preparations using two different commercial methodologies (SurePath and ThinPrep). Differences, however, were noted in area measurements between SurePath and ThinPrep and this has potential implications for classifications (such as TBS) using area comparisons as their basis. In addition, it was found that the increased NC ratio, associated with higher grades of dyskaryosis is more a consequence of progressive cytoplasmic area reduction rather than nuclear area increase. The similar NC ratios of borderline nuclear changes associated with human papilloma virus and mild dyskaryosis support the BSCC proposal that these can be combined to constitute a low-grade category. This study shows that the BSCC area NC ratio criteria of grading squamous cell dyskaryosis require amendment. In addition, this study supports the new BSCC recommendation of low- and high-grade squamous cell categories. CONCLUSIONS: The study proposes Sheffield quantitative criteria to assist the grading of squamous cell abnormalities. Quantitative diameter NC ratio measurements, however, must always be accompanied by detailed assessment of qualitative morphological features and in particular those relating to nuclear chromatin. This is equally relevant to both two- and three-tier models.     

Long‐term cytological and histological outcomes in women managed with loop excision treatment under local anaesthetic for high‐grade cervical intraepithelial neoplasia

Y. L. Woo, C. Badley, E. Jackson and R. Crawford Long‐term cytological and histological outcomes in women managed with loop excision treatment under local anaesthetic for high‐grade cervical intraepithelial neoplasia Objective: This study examines the impact of excision margin status after large loop excision of the transformation zone (LLETZ) under local anaesthetic for high‐grade cervical intraepithelial neoplasia (HG‐CIN) on the cytological and histological outcomes up to 5 years after treatment. Methods: Prospective cytological and histological data were obtained by examination of the colposcopy database at Addenbrooke’s Hospital, Cambridge, UK. All women aged between 19 and 50 years who underwent treatment for HG‐CIN by LLETZ under local anaesthetic were included in the study. Patients without follow‐up data were excluded from the study. The excision margin status was correlated with the subsequent cytological and histological outcomes. Results: A series of 967 women with CIN2 and CIN3 underwent LLETZ excision under local anaesthetic. Overall, 42% of women had disease present at the excision margin following LLETZ. Women with CIN3 were more likely than those with CIN2 to have an involved excision margin (P < 0.0001). Cytological recurrence was highest at 12 months (16%) and did not correlate with the CIN grade or excision margin status. Histological recurrence/persistence was also highest at 12 months follow‐up (15%) and this correlated with grade of CIN and margin status (P < 0.0001). Conclusions: Histological recurrence/persistence correlates with grade of CIN and excision margin status. Management of HG‐CIN in an outpatient setting under local anaesthetic is safe, cost effective and yields a favourable long‐term outcome.     

ABC3 Part II: a review of the new criteria for evaluating cervical cytology in England

R.G. Blanks
ABC3 Part II: a review of the new criteria for evaluating cervical cytology in England The new Achievable Standards, Benchmarks for Reporting, and Criteria for Evaluating Cervical Cytopathology, 3rd edn (ABC3) includes radical changes in the criteria for evaluating cervical cytology. First, they include a new mission statement ‘the objective of cervical screening is to reduce cervical cancer incidence and mortality by screening with a high sensitivity for the detection of CIN2 or worse, whilst maintaining a high specificity’. Second, the original four performance measurement criteria where laboratories were examined further if they were below the 10th or above the 90th percentile has been changed to three and laboratories are only mandatorily examined if they fall below the 5th or above the 95th percentile. The old criteria related to the percentage of samples that were inadequate, the percentage of all adequate samples reported as moderate dyskaryosis or worse (equivalent to high‐grade squamous intraepithelial lesion or cancer), the percentage of adequate samples reported as mild dyskaryosis or borderline (equivalent to low‐grade squamous intraepithelial lesion or atypical squamous/glandular cells) and the positive predictive value. The new criteria are percentage of inadequate samples, positive predictive value and a new measure termed referral value. These changes mean that far fewer laboratories will require mandatory examination. Third, a raft of optional performance measures have been introduced to help laboratories examine their annual statistical return to the Department of Health in comparison with other laboratories. These measures have been designed to produce a more uniform national programme, and to help laboratories decide whether they are maximizing the benefit of screening while minimizing the harm, which is the goal of all screening programmes. This review examines in detail the new criteria and explains in more detail some of the thinking behind them.     

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.     

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.     

Assessment of the Accuracy of Cytology In Women Referred For Colposcopy and Biopsy: the Results of a 1 Year Audit

The results of weekly colposcopy review meetings have been audited for 1 year and cases where there was a discrepancy between the referral cervical smear and the initial colposcopy biopsy have been analysed. New referrals (n = 476) for colposcopy were studied. In the final outcome 80% of 326 women referred for moderate or severe dyskaryosis were found to have cervical intraepithelial neoplasia (CIN) grade II or III or invasive carcinoma. Three women found to have invasive carcinoma had been referred for severely dyskaryotic smears. Twenty women were referred for smears with cell changes suggesting glandular neoplasia: five were found to have adenocarcinoma in situ, whereas eight had CIN and seven had negative biopsies. The results justify the referral policy and demonstrate the need for further investigation when initial colposcopic biopsies are negative.