Liquid-based cervical cytology

Usefulness of Liquid-Based Cytology in Diagnosing Biliary Tract Cancer Compared to Conventional Smear and Forceps Biopsy

BACKGROUND/AIMS

Liquid-based cytology (LBC) has been shown to improve the diagnostic efficacy of brush cytology for thyroid, cervical and pancreatic cancer. To evaluate the diagnostic performance of LBC for biliary tract cancer, we compared it with conventional smears and forceps biopsies.

METHODS

A retrospective study was conducted of all consecutive patients who underwent brush cytology under ERCP from January 2010 to April 2020. The primary outcome was the diagnostic efficacy of conventional smears and LBC. The difference between the two groups was corrected using inverse probability weighting (IPW). The secondary outcome was the sensitivity and specificity of brush cytology and forceps biopsy. The secondary outcome was evaluated in patients who underwent both methods.

RESULTS

Among 162 patients, conventional smears were performed in 70 patients and LBC was performed in 92 patients. In the primary analysis using IPW, the sensitivity of conventional smears and LBC was 56.00% and 78.26% respectively (P = 0.009). The specificity was 100% for both methods. The accuracy was 66.15% for conventional smears and 83.33% for LBC (P = 0.012). In the secondary analysis, the sensitivity of conventional smears versus forceps biopsies was 62.16% versus 78.38% (P = 0.034) and 81.16% for both LBC and forceps biopsies. The specificity of both cytological examination and forceps biopsies was 100%.

CONCLUSIONS

Liquid-based cytology demonstrated better sensitivity and accuracy than conventional smears. Moreover, its diagnostic performance was close to that of forceps biopsies.

False Negative Results in Cervical Cancer Screening-Risks, Reasons and Implications for Clinical Practice and Public Health

False negative (FN) results in cervical cancer (CC) screening pose serious risks to women. We present a comprehensive literature review on the risks and reasons of obtaining the FN results of primary CC screening tests and triage methods and discuss their clinical and public health impact and implications. Misinterpretation or true lack of abnormalities on a slide are the reasons of FN results in cytology and p16/Ki-67 dual-staining. For high-risk human papillomavirus (HPV) molecular tests, those include: truly non-HPV-associated tumors, lesions driven by low-risk HPV types, and clearance of HPV genetic material before sampling. Imprecise disease threshold definition lead to FN results in visual inspection with acetic acid. Lesions with a discrete colposcopic appearance are a source of FN in colposcopic procedures. For FAM19A4 and hsa-miR124-2 genes methylation, those may originate from borderline methylation levels. Histological misinterpretation, sampling, and laboratory errors also play a role in all types of CC screening, as well as reproducibility issue, especially in methods based on human-eye evaluation. Primary HPV-based screening combined with high quality-assured immunocytochemical and molecular triage methods seem to be an optimal approach. Colposcopy with histological evaluation remains the gold standard for diagnosis but requires quality protocols and assurance measures.

Comparison of Cervical Cytopathological Diagnosis Using Innovative Qi Brush and Traditional Cervex-Brush® Combi

Objectives: To compare the effectiveness between Qi brush and Cervex-Brush® Combi for the diagnosis of cervical lesions.

Methods: After we registered a random-control clinical trial on the Chinese Clinical Trial Registry (No. XJTU1AF2017LSK-25), cervical cell samples were successively collected with both Qi brush and Cervex-Brush® Combi before undergoing colposcope. Colposcopy with biopsy was performed later. Histological diagnosis was regarded as the gold standard in this study. The following indices of the two brushes were compared: sampling degree of satisfaction and presence rate of metaplastic cells, together with sensitivity (Se), specificity (Sp), false positives (FP), false negatives (FN), positive predictive value (PPV), and negative predictive value (NPV). The kappa value was used to measure the inter-rater agreement of the Qi brush and Cervex-Brush® Combi in diagnosing cervical lesions.

Results: In total, 74 patients were enrolled in this study. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Qi brush were 57.14, 86.84, 76.19, and 73.33%, respectively. For the Cervex-Brush® Combi, they were 26.92, 88.89, 63.63, and 62.75%, respectively. In addition, the Qi brush had a higher satisfied sampling rate (89.19%) than the Cervex-Brush® Combi (83.78%), and the P-value was 0.336 using Chi-square test. The kappa value was 0.444, which indicated a medium agreement between these two brushes, and the sensitivity of the Qi brush was higher than that of the Cervex-Brush® Combi, with significant statistical difference (P = 0.039<0.05).

Conclusions: The Qi brush was more effective than the Cervex-Brush® Combi for sampling and also had a slightly higher accuracy in diagnosing in cytology. In terms of social and economic benefits, the Qi brush may be a better cervical cytology collector.

Detection of transformation zone cells in liquid-based cytology and its comparison with conventional smears

BACKGROUND

To compare the differences between liquid-based cytology (LBC) and conventional cytology in respect of the detection of transformation zone cells (TZC) by age group and to assess test performance by correlating results with cytological abnormalities.

METHODS

A retrospective study assessing the results of cervical-vaginal cytology smears collected at a private laboratory in São Paulo (Brazil) between January 2010 and December 2015.

RESULTS

A total of 1 030 482 cytology tests were performed; of these, 3811 (0.36%) unsatisfactory samples were excluded. Cytology sampling in the patients studied was performed using the conventional technique in 394 879 (38.5%) cases and the liquid-based techniques in 631 792 (61.5%) cases. The proportion of samples with TZC for interpretation was 73.2% (288 956 samples) in conventional cytology and 52.7% (333 115 samples) in LBC (P < .001). The presence of TZC rate declined in both groups with age, but was consistently lower for LBC (P < .001). The presence of endocervical and metaplastic cells was associated with higher high-grade intraepithelial lesion detection rates.

CONCLUSION

Low representation of the transformation zone was found in the samples collected using the LBC technique, particularly in the over 50 age group. Conventional cytology was associated with a higher rate of detection of high-grade lesions.

Cervical cancer screening by molecular Pap-transformation of gynecologic cytology

BACKGROUND

Cervical cancer is one of the common cancers in women accounting for 7.9% of all cancers. In India it is the second commonest cancer in women. The immortality of the cancer cell and the relatively long time frame from acquisition of infection to development of cervical cancer was established. As major advancements like LBC, HPV testing were introduced in the recent years, screening has taken a new avatar, the Molecular pap!! The objectives of this study were: To compare gynecologic cytology and abnormal results with respect to conventional and LBC. To study the role of HPV cotesting and ancillary tests performed, that is, HPV CISH, and p16ink4a by IHC.

METHODS

About 71 924 Conventional and LBC samples were included from August 2009 to December 2017. Cases for HPV testing along the conventional smears were 1539. HPV can be tested from the same LBC vial as the sample remains stable at room temperature for 6 weeks. HPV DNA PCR was carried out in our laboratory for High and Low risk genotypes. Cytology findings were also correlated with histology.

RESULTS

Detection rate of SILs in LBC samples were higher (2.20%). The commonest abnormality was LSIL in LBC and ASCUS in conventional smears. Commonest HR HPV and LR HPV detected was 1 61 856 and 61 142.

CONCLUSION

LBC with HPV cotesting improves sensitivity and specificity and reduces ambiguous results; allows better compliance, as a negative result of both tests allows patients to get screening every 5 years, thereby increasing screening intervals, important in a resource limited situation.

A comparison of liquid-based cytology with conventional Papanicolaou smears in cervical dysplasia diagnosis

Background:

Due to the high number of women affected by cervical cancer and the importance of an early diagnosis, combined with the frequent incidence of false-negative Papanicolaou (Pap) smear screening results for this disease, several studies have been conducted in recent years in order to find better tests. Liquid-based cytology (LBC) tests, including the liquid-based thin layer method, have demonstrated the highest potential for reducing false-negative cases and improved sample quality. This study aimed to compare the strength of the Pap smear test with fluid cytology and conventional tests in detecting cervical dysplasia.

Materials and Methods:

This descriptive-analytic study was conducted on 366 women who attended private laboratories for a Pap smear. The Pap smear sampling was conducted simultaneously using two methods: conventional Pap (CP) smear and LBC), from the cervix.

Results:

The mean age of the participants was 32 ± 8.8 years. Diagnostic results of endocervical cells, epithelial cells, vaginitis cells, and metaplastia were consistent with both conventional and liquid cytology smears, and the kappa coefficient was determined to be significant (P < 0.001). In total, 40.5% of diagnostic cases indicated bacterial inflammation 80.3% of the diagnoses in both methods were P1 and 3.9% of cases diagnosed were P2, the overall diagnostic consistency was 83.9% between the two sampling methods. The inflammation diagnosis was 40.5% and this was consistent in both methods of LBC and CP. There was one case of a false-negative diagnosis in the LBC method and 14 cases in the CP method.

Conclusion:

Results showed that the LBC may improve the sample's quality and reduce the number of unsatisfactory cases more than with the CP method.

Unsatisfactory rate in liquid-based cervical samples as compared to conventional smears: A study from tertiary care hospital

Background:

Developed countries adopted liquid-based cytology (LBC) cervical cytology, partly because of its lower proportions of unsatisfactory (U/S)/inadequate samples. This study was carried out to evaluate effect on the rate of U/S samples after introduction of LBC in our laboratory.

Materials and Methods:

An audit of U/S cervical samples was performed, which included split samples (n = 1000), only conventional Pap smear (CPS) smears (n = 1000), and only LBC samples (n = 1000). The smears were reviewed by two observers independently, and adequacy for the samples was assessed as per The Bethesda System 2001. The reasons for U/S rate in split samples were categorized into various cytologic and/or technical reasons.

Results:

U/S rate was far less in only LBC samples (1.2%) as compared to only CPS (10.5%) cases. Cases in the satisfactory but limited category were also less in only LBC (0.4%) as compared to only CPS (3.2%) samples. The main reasons for U/S smears in split samples were low cell count (37.2% in CPS; 58.8% in LBC). The second main reason was low cellularity with excess blood and only excess blood in CPS samples.

Conclusion:

There was a significant reduction of U/S rate in LBC samples as compared to CPS samples, and the difference was statistically significant. The main cause of U/S samples in LBC was low cellularity indicating a technical fault in sample collection. The main cause of U/S rate in CPS was low cellularity followed by low cellularity with excess blood. Adequate training of sample takers and cytologists for the precise cell count to determine adequacy in smears can be of great help in reducing U/S rate.

Comparing SurePath, ThinPrep, and conventional cytology as primary test method: SurePath is associated with increased CIN II+ detection rates

Purpose

Within the last decade, SurePath and ThinPrep [both liquid-based cytology (LBC) tests] have replaced conventional cytology (CC) as primary test method in cervical cancer screening programs of multiple countries. The aim of our study was to examine the effect in the Dutch screening program.

Methods

All primary smears taken within this program from 2000 to 2011 were analyzed using the nationwide registry of histo- and cytopathology (PALGA) with a follow-up until March 2013. The percentage of smears classified as borderline/mildly dyskaryotic (BMD) and >BMD as well as CIN and cervical cancer detection rates were compared between SurePath and ThinPrep versus CC by logistic regression analyses (adjusted for age, screen region, socioeconomic status, and calendar time).

Results

We included 3,118,685 CC, 1,313,731 SurePath, and 1,584,587 ThinPrep smears. Using SurePath resulted in an increased rate of primary smears classified as >BMD [odds ratio (OR) = 1.12 (95% confidence interval (CI) 1.09–1.16)]. CIN I and II⁺ detection rates increased by 14 % [OR = 1.14 (95% CI 1.08–1.20)] and 8 % [OR = 1.08 (95% CI 1.05–1.12)]. Cervical cancer detection rates were unaffected. Implementing ThinPrep did not result in major alterations of the cytological classification of smears, and it did not affect CIN detection rates. While not significant, cervical cancer detection rates were lower [OR = 0.87 (95% CI 0.75–1.01)].

Conclusions

The impact of replacing CC by LBC as primary test method depends on the type of LBC test used. Only the use of SurePath was associated with increased CIN II⁺ detection, although it simultaneously increased the detection of CIN I.

[Early detection of cervical cancer in Germany: evidence and implementation]

Cervical cancer is the third most common cancer among women worldwide, with an estimated 529,000 new cases in 2008. The incidence of cervical cancer in Germany is still among the highest in Western Europe. For more than 40 years women in Germany have had legal and free access to a conventional cytologic smear test starting at the age of 20 years. The introduction of the Pap smear subsequently led to a reduction in the incidence and mortality of cervical cancer. However, the low sensitivity of the Pap smear and the evidence regarding human papillomavirus (HPV) in the context of cervical cancer have led to a critical view of the existing early detection of cervical cancer. In the meantime, new screening methods have been developed and different HPV tests, liquid-based cytology, and novel biomarkers have become available. Several randomized studies have investigated HPV testing as a primary cervical cancer screening test, generating a large body of evidence. It is expected that a combination of HPV testing and cytology will improve cervical cancer screening. In the near future, the early detection of cervical cancer in Germany will be restructured on the basis of the German National Cancer Plan as well as the new Cancer Screening and Registers Act (KFRG). The European guidelines for quality assurance in cervical cancer screening will be taken into account, and an organized, population-based, and quality-assured cervical cancer screening program will be implemented.

Diagnostic value of HMGB1 immunostaining on cell blocks from residual liquid-based gynecologic cytology specimens

Aberrant expression of high mobility group box 1 (HMGB1) is associated with tumor development and progression. The current study was conducted to evaluate the significance of HMGB1 immunostaining on cell block (CB) preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix. The CBs were prepared from 157 residual liquid-based gynecologic cytology specimens which were collected from women whose cervical lesions had been confirmed by histopathology. The expression of HMGB1 and p16INK4A (p16) was visualized by immunocytochemistry on the CB preparations, and the association of their expression patterns was correlated with the severity of cervical lesions. HeLa cells were used as positive control. HMGB1 expression was observed in dysplastic and neoplastic cells and increased along with the progression of cervical neoplasia. The rates of positive staining for HMGB1 in cervical intraepithelial neoplasia 1 (CIN-1), CIN-2, CIN-3, and invasive squamous cell carcinomas (ISCCs) were 69.4, 96.9, 100.0, and 100.0%, respectively. The differences between positive rates of patients with chronic cervicitis and various CINs as well as ISCCs were significant (P < 0.005). The differences in positive staining rates between each two CIN groups, and differences between CIN-1/2 and ISCCs, were also significant (P < 0.005). The expression pattern of HMGB1 was generally correlated with that of p16 (P < 0.001). HMGB1 staining was observed in some p16-negative specimens. HMGB1 immunostaining on a CB from gynecologic cytology specimens is potentially valuable for the screening of cervical lesions in cases with questionable cytology.

Pooled analysis of the performance of liquid-based cytology in population-based cervical cancer screening studies in China

BACKGROUND

Liquid-based cytology (LBC) has been widely used for cervical cancer screening. Despite numerous studies and systematic reviews, to the authors' knowledge few large studies to date have focused on biopsy-confirmed cervical lesions and controversy remains concerning its diagnostic accuracy. The objective of the current study was to assess LBC for detecting biopsy-confirmed cervical intraepithelial neoplasia (CIN) and cancer.

METHODS

A pooled analysis of LBC using data from 13 population-based, cross-sectional, cervical cancer screening studies performed in China from 1999 to 2008 was performed. Participants (n = 26,782) received LBC and human papillomavirus testing. Women found to be positive on screening were referred for colposcopy and biopsy. The accuracy of LBC for detecting biopsy-confirmed CIN of type 2 or worse (CIN2+) as well as CIN type 3 or worse (CIN3+) lesions was analyzed.

RESULTS

Of 25,830 women included in the analysis, CIN2+ was found in 107 of 2612 with atypical squamous cells (4.1%), 142 of 923 with low-grade squamous intraepithelial neoplasia (15.4%), 512 of 784 with high-grade squamous intraepithelial neoplasia (65.3%), 29 of 30 with squamous cell carcinoma (96.7%), 4 of 27 with atypical glandular cells (14.8%), and 85 of 21,454 with normal cytology results (0.4%). No invasive cancers were found to have atypical squamous cells, atypical glandular cells, or cytologically normal slides. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of LBC for detecting CIN2+ were 81.0%, 95.4%, 38.3%, 99.3 %, and 94.9%, respectively. Although Hybrid Capture 2 was more sensitive than LBC, the specificity, positive predictive value, and overall accuracy of LBC were higher than those of Hybrid Capture2 at 85.2%, 18.6%, and 85.5%, respectively.

CONCLUSIONS

The results of the current study indicate that the performance of LBC can effectively predict the risk of existing CIN2+ and may be a good screening tool for cervical cancer prevention in a developing country.

A randomized trial comparing conventional cytology to liquid-based cytology and computer assistance

Liquid-based cytology (LBC) has replaced conventional cytology (CC) for cervical cancer screening in some countries. However, it remains unclear whether LBC is superior to CC. A randomized controlled trial was conducted between August 2007 and March 2009 in Germany to compare LBC, alone and in combination with computer-assisted imaging technology (CAS), to CC in the detection of histologically confirmed cervical intraepithelial neoplasia (CIN). The main outcome measures were detection rates, relative sensitivities, positive predictive values (PPVs) and relative PPVs comparing LBC without and with CAS to CC. Primary histological outcome was CIN2 or higher. Included were 20,627 women participating in opportunistic cervical cancer screening at 20 gynecologic practices. The practices were randomized weekly to use LBC (n = 11,331) or CC (n = 9,296). Patients with positive findings were invited to expert colposcopy. The relative sensitivity of LBC versus CC using the CIN2+ cut-off was 2.74 (95% confidence interval [CI] 1.66-4.53). The relative sensitivity of LBC/CAS versus CC for CIN2+ was 3.17 (95% CI 1.94-5.19). The PPV of LBC and CC for CIN2+ was 48% and 38%, respectively. The PPV ratio did not differ significantly from unity. Differences between LBC and CC were smaller in some sensitivity and subgroup analyses; however, relative sensitivity of LBC remained increased. LBC without and with CAS compared with CC under the field conditions of an opportunistic screening system had a significantly higher sensitivity for the detection of CIN without deterioration of PPVs. Additional use of CAS did not further improve sensitivity of LBC. © 2012 Wiley Periodicals, Inc.

Histological correlation of glandular abnormalities in cervical liquid-based cytology

Conventional Papanicolaou smear method is still commonly used for cervical cancer screening in Japan, despite the liquid-based cytology (LBC) that has become a global tendency in the world recently. One of the obstacles in the way of popularization of this method seems to be the confusion as to diagnosis upon cervical glandular lesions. We performed comparison study between LBC and conventional Papanicolaou smear about cytological diagnosis using split-sample method in 4522 patients. In 13 cases analyses, which were reported with either AGC or adenocarcinoma by either method, LBC tends to be milder than that by conventional smear, however, the credibility of LBC is considered to be near to that of conventional smear with regard to screening for glandular abnormalities. These results indicate that cervical cancer screening should shift to LBC under the enough experience and appropriate dealing with the cytological diagnosis.

Patients with cervical cancer: why did screening not prevent these cases?

OBJECTIVE

The objective of the study was to assess the screening history of women with cervical cancer and review normal cervical smears 5 years preceding the diagnosis.

STUDY DESIGN

Cytological and histological results of 401 women treated for invasive cervical cancer between 1991 and 2008 at the Radboud University Nijmegen Medical Center were studied. Ninety-eight normal smears were reviewed.

RESULTS

Of the 401 women, 269 (67%) received at least 1 invitation for the national screening program for cervical cancer (NCSP). One- third fell outside the target age of the NCSP. Seventeen percent never responded to the invitation(s). Twenty-one percent had 1 or more normal smears within 5 years preceding the diagnosis. After review, only 39% of those smears were reviewed as a normal smear.

CONCLUSION

Half of the women with cervical cancer were never screened because of the limited target age range or nonattendance. Twenty-one percent had a normal smear within 5 years preceding the diagnosis, caused by interpretation and/or sampling errors.

Detection of HPV by in situ hybridization in thin-layer (ThinPrep) cervicovaginal samples

We have studied an automated in situ hybridization (ISH) method as a possible alternative approach for detecting high-risk human papillomavirus (HPV) in monolayer (ThinPrep) cervico-vaginal samples, comparing the results with those obtained by polymerase chain reaction (PCR) using consensus primers and studying the relationship between the ISH staining pattern and the viral integration in HPV 16-positive cases. Eighty atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL) cases were used for our purposes. The patients were monitored through periodic cytologies. ISH with was performed with an automated Ventana System, analysis by PCR was performed with consensus primers and integration of HPV16 was performed by realtime PCR analyzing E2 and E6 genes. Additionally, 27 HSIL cases were also studied to observe the ISH staining patterns. HPV infection was detected by ISH in 21.7% of the ASCUS cases and 55.8% of the LSIL cases. Two distinct staining patterns were observed: multipunctated (MP) and diffuse (DI). In some cases, a mixed pattern (MP + DI) was observed and these cases were considered as MP. The MP pattern increased with the degree of lesion and seemed to have a prognostic value in ASCUS/LSIL cases. The lesion in MP pattern cases persisted throughout the entire study in 77% of cases, whereas in cases with a DI staining pattern, only 41% of them showed persistence of the lesion (p <0.001). No correlation was found between HPV integration and the ISH staining pattern. Given the lower sensitivity and negative predictive value of ISH and its incapacity to demonstrate the integration of high-risk HPV in ASCUS and LSIL cases using liquid-based cytology, we do not recommend this technique for the triage of ASCUS and LSIL cases.

Early detection in head and neck cancer - current state and future perspectives

Survival and quality of life in head and neck cancer are directly linked to the size of the primary tumor at first detection. In order to achieve substantial gain at these issues, both, primary prevention and secondary prevention, which is early detection of malignant lesions at a small size, have to be improved. So far, there is not only a lack in the necessary infrastructure not only in Germany, but rather worldwide, but additionally the techniques developed so far for early detection have a significance and specificity too low as to warrant safe implementation for screening programs. However, the advancements recently achieved in endoscopy and in quantitative analysis of hypocellular specimens open new perspectives for secondary prevention. Chromoendoscopy and narrow band imaging (NBI) pinpoint suspicious lesions more easily, confocal endomicroscopy and optical coherence tomography obtain optical sections through those lesions, and hyperspectral imaging classifies lesions according to characteristic spectral signatures. These techniques therefore obtain optical biopsies. Once a "bloody" biopsy has been taken, the plethora of parameters that can be quantified objectively has been increased and could be the basis for an objective and quantitative classification of epithelial lesions (multiparametric cytometry, quantitative histology). Finally, cytomics and proteomics approaches, and lab-on-the-chip technology might help to identify patients at high-risk. Sensitivity and specificity of these approaches have to be validated, yet, and some techniques have to be adapted for the specific conditions for early detection of head and neck cancer. On this background it has to be stated that it is still a long way to go until a population based screening for head and neck cancer is available. The recent results of screening for cancer of the prostate and breast highlight the difficulties implemented in such a task.

Diagnostic value of p16INK4A, Ki-67, and human papillomavirus L1 capsid protein immunochemical staining on cell blocks from residual liquid-based gynecologic cytology specimens

BACKGROUND

This study was conducted to evaluate the reliability and role of cell block preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix and to improve the value of cell block preparations in diagnosing and predicting the prognosis of cervical lesions through immunostaining of p16INK4A (p16), Ki-67, and human papillomavirus (HPV) L1 capsid protein (HPV L1).

METHODS

In total, 138 specimens were diagnosed on liquid-based cytology (LBC) and cell block preparations, and 63 specimens were subjected subsequently to tissue follow-up and immunostaining for p16, Ki-67, and HPV L1 on cell block sections.

RESULTS

In 42 specimens that were diagnosed as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion (HSIL), and squamous cell carcinoma (SCC) on cell blocks, 38 specimens (90.5%) were confirmed by histopathologic reports, and there was slightly better than 81.6% agreement between LBC and tissue follow-up. Immunointensity and cells that were positive for p16 were enhanced according to increased pathologic grade and differed statistically between cervical intraepithelial neoplasia 1 (CIN-1) and CIN-2/CIN-3 as well as SCC. The positive rates of HPV L1 decreased gradually according to the severity of cervical neoplasia, and HPV L1/p16 expression patterns were related to the severity of cervical lesions.

CONCLUSIONS

The cell block preparation technique was complementary to LBC, and the authors concluded that the application of LBC combined with cell block preparations may improve the diagnostic accuracy of cytology. Immunostaining for p16 and Ki-67 on cell block preparations can help to improve the diagnostic accuracy of HSIL and SCC. A combined expression pattern of p16 and HPV L1 may serve as a valuable index for predicting prognosis and follow-up of cervical dysplastic lesions.

A Shandon PapSpin liquid-based gynecological test: A split-sample and direct-to-vial test with histology follow-up study

BACKGROUND

Studies for liquid-based Papanicolaou (Pap) tests reveal that liquid-based cytology (LBC) is a safe and effective alternative to the conventional Pap smear. Although there is research on ThinPrep and SurePath systems, information is lacking to evaluate the efficiency and effectiveness of systems based on cytocentrifugation. This study is designed to determine the sensitivity and specificity of the Shandon PapSpin (ThermoShandon, Pittsburgh, Pennsylvania, USA) liquid-based gynecological system. We used split-sample and direct-to-vial study design.

MATERIALS AND METHODS

2,945 women referred to prophylactic check-up were enrolled in this study. Split sample design was used in 1,500 women and residual cervical cytology specimen from all these cases was placed in fluid for PapSpin preparation after performing conventional smear. The direct-to-vial study was carried out in another cohort of 1,445 women in whom the entire cervical material was investigated using only the PapSpin technique. Follow up histological diagnoses for 141 women were obtained from both study arms following 189 abnormal cytology cases. 80 LBC cases from the split sample group and 61 LBC cases in the direct-to-vial group were correlated with the histology results. The sensitivity and secificity of the conventional smear and PapSpin tests in both study arms were compared.

RESULTS

In the split sample group, conventional smears showed a higher proportion of ASC-US (atypical cells undetermined significance): 31 (2.1%) vs 10 (0.7%) in PapSpin (P = 0.001). A higher proportion of unsatisfactory samples was found in the conventional smear group: 25 (1.7%) vs 6 (0.4%) cases (P = 0.001). In the split sample group, the sensitivity of the conventional and PapSpin tests was 68.7% vs 78.1%, and the specificity 93.8% vs 91.8%, respectively. In the direct to vial group PapSpin sensitivity was 75.9% and specificity 96.5%. The differences in sensitivity and specificity were not significant. The positive predictive values for the conventional and PapSpin methods were not different in the split sample group: 88.0% vs 86.2% and 95.7% in the direct-to-vial group. Also, no differences were found for negative predictive value (82.1, 86.8% and 80.0% respectively).

CONCLUSIONS

PapSpin showed good qualitative results in both study arms, even after the material splitting in the first study arm, and is a good alternative to the conventional Pap smear. Additionally, the PapSpin method offers several advantages such as the opportunity to prepare duplicate slides, option for HPV DNA testing and cell block preparations from residual material. Microscopic evaluation of thinner cell preparations is less time consuming than the conventional Pap smears.

Liqui-Prep® versus conventional Papanicolaou smear to detect cervical cells abnormality by split-sample technique: a randomized double-blind controlled trial

To assess the diagnostic performances of LiquiPrep® (LP) to detect cervical cellular abnormality in comparison to Papanicolaou (Pap) smear in 194 women with abnormal cervical cytology who were scheduled for colposcopy at the institution between January 2008 and November 2008. The women were randomized to undergo a repeated cervical cytologic evaluation by Pap smear followed by LP, or the two methods in alternating order. The pathologist was blinded to previous cytologic diagnosis and the pair of slides assigned for each woman. Cytologic results from each method were compared to subsequent histopathology. Mean screening time for each LP and Pap slides were 4.3 ± 1.2 minutes and 5.4 ± 1.1 minutes, respectively (P < 0.001). From 194 cases, ASC or AGC were diagnosed in 72 cases (37.1%) from LP and 68 cases (35.1%) from Pap smear. After excluding the ASC/AGC group, the overall cytologic diagnostic agreement between the two tests were 69 of 87 cases (73.6%) while the agreements with histologic diagnoses were 39/87 cases from LP (44.8%) and 41 (47.1%) from Pap smear (P = 0.824). The accuracy of LP was not significantly different from Pap test, 43.4% (95% confidence interval [CI]: 34.8-52.1%) compared to 44.4% (95% CI: 35.7-53.1%). LP did not have superior performance over Pap test to detect high-grade lesions (≥ cervical intraepithelial neoplasia II) using ASC/AGC as the threshold with the sensitivity of 70.5% (95% CI: 64.0-76.9%) versus 77.3% (95% CI: 71.4-83.2%), respectively.

Cytologic detection of cervical abnormalities using liquid-based compared with conventional cytology: a randomized controlled trial

OBJECTIVE

To compare test positivity rates of liquid-based and conventional cytology.

METHODS

This study was a cluster randomized controlled trial with family practice as the unit of randomization, performed within the Dutch national cervical screening program. Women aged 30-60 years (n=89,784) recruited from 246 family practices were included. One-hundred twenty-two practices (49,222 individuals) were randomly assigned to the experimental arm, and 124 practices (40,562 participants), to the conventional arm. Inclusion was performed during a 3-year period between April 2003 and July 2006. Cytologic test positivity rates of liquid-based compared with conventional cytology was compared in terms of crude and adjusted odds ratios, applying a per-protocol analysis.

RESULTS

Crude ratios of the odds of test positivity rates of liquid-based compared with conventional cytology for atypical squamous cells of undetermined significance or more severe, low-grade squamous intraepithelial lesion or more severe, and high-grade squamous intraepithelial lesion or more severe were 0.95 (95% confidence interval [CI] 0.82-1.10), 1.00 (95% CI 0.83-1.20), and 0.97 (95% CI 0.77-1.22), respectively. Liquid-based cytology resulted in fewer unsatisfactory tests (odds ratio 0.30, 95% CI 0.23-0.38). The results did not change when the odds ratios were adjusted for age, study site, study period, and urbanization level. Of 128 women screened with liquid-based cytology, one unsatisfactory preparation is avoided.

CONCLUSION

This study found no statistically significant difference in cytologic test positivity rates between liquid-based and conventional cytology. However, liquid-based cytology resulted in significantly fewer unsatisfactory tests.

CLINICAL TRIAL REGISTRATION

Nederlands Trial Register, www.trialregister.nl, NTR1032

LEVEL OF EVIDENCE

I.

Superior performance of liquid-based versus conventional cytology in a population-based cervical cancer screening program

OBJECTIVE

Liquid-based cytology may offer improvements over conventional cytology for cervical cancer screening. The two cytology techniques were compared in a group of 86,469 women who participated in a population-based screening program. Using a nation-wide pathology database containing both cervical cytology and histology records for all patients, we compared the outcome of the two screenings methods with regard to the detection rate of histological proven abnormalities and the determination of the true false-negative rates for both methods.

METHODS

Two cohorts of women living in the same geographical region were used. Cohort 1 (n=51,154 women) was analysed using conventional cytology (conventional cohort) and cohort 2 (liquid cohort) (n=35,315 women) was analysed using liquid-based cytology (SurePath). The samples were processed in one laboratory. The results of histological follow up were available via a central database.

RESULTS

The rate of unsatisfactory slides was significantly lower using liquid-based cytology (0.13% vs. 0.89%, p<0.0001). Detection of ASCUS+ (Atypical squamous cells of unknown significance or higher abnormalities) was significantly higher using liquid-based cytology (2.97% vs. 1.64%, p<0.0001), mainly due to the increase in the ASCUS category. The percentage of histological abnormalities within the ASCUS samples was approximately equal in both cohorts, indicating that more true abnormal cases were detected using liquid-based cytology. The sensitivity for detection of a histological proven lesion is significantly higher in the liquid cohort compared to the conventional cohort (96.2% vs. 92.0%), with only a slight difference in specificity (97.8% vs. 98.2%).

CONCLUSION

This population study confirmed previous institution-based reports of decreased numbers of unsatisfactory samples based on liquid-based cytology and showed an increased sensitivity for the detection of cytological abnormalities that was validated by subsequent histological investigation.

Cervical cancer screening: from molecular basis to diagnostic practice, going through new technologies

In the era of Human Papillomavirus (HPV) vaccination, a lot of misunderstanding still exists among healthcare professionals and patients regarding HPV infection. The purpose of this review is to synthesize the clinical molecular mechanisms that contribute to HPV-mediated cervical carcinogenesis, as well as to appraise the current status of new biomarkers and technologies in terms of available data on clinical applications and future promises.

The current and future role of screening in the era of HPV vaccination

With the introduction of cervical screening programs, the incidence and mortality of cervical cancer has been drastically reduced. Techniques such as the traditional Papanicolaou test and the newer liquid-based cytology allow for the early detection of cervical abnormalities prior to the development of invasive cervical cancer. As oncogenic human papillomavirus (HPV) infection is necessary for cervical cancer, HPV-DNA testing has also been proposed as a routine screening method for the general population. Screening limitations, such as adherence, test sensitivity and specificity, access, and cost-effectiveness are reflected in current screening guidelines. The development of prophylactic cervical cancer vaccines is a major milestone in cervical cancer prevention. These vaccines protect against the initial infection of certain oncogenic HPV types, and therefore prevent the development of cervical dysplasia, precancerous lesions, and cervical cancer. Considering routine cervical cancer vaccination in adolescent girls, screening guidelines must adapt in order to retain efficient and cost-effective prevention measures. Although the true epidemiological and economic impact of cervical cancer vaccines cannot be immediately realized, mathematical models predict various scenarios in which vaccination, in addition to cervical screening, will be cost-effective and further reduce cervical cancer disease.

Evaluation of p16INK4a as a diagnostic tool in the triage of Pap smears demonstrating atypical squamous cells of undetermined significance

BACKGROUND

P16(INK4a) (p16) has emerged as a biomarker for the detection of high-risk human papillomavirus (HR-HPV) in Papanicolaou (Pap) smears. Many studies have confirmed a strong correlation between p16 immunohistochemical positivity and high-grade squamous intraepithelial lesions (HSIL) of the cervix. Because p16 is predictive of HR-HPV and HSIL, it seems plausible that p16 could be used as a diagnostic tool to triage atypical squamous cells of undetermined significance (ASCUS) Pap smears. In this way, Pap smears with no p16 staining could be recategorized as negative for intraepithelial lesion or malignancy (NILM) before final case disposition, thus preventing unnecessary and costly follow-up.

METHODS

p16 immunostains were performed on 178 ThinPrep (Cytyc, Marlborough, Mass) Pap smears signed out as ASCUS among 5 cytopathologists. p16 stains were independently scored between 0 (no staining) and 4 (staining in cells with nuclear aberration) by either 2 or 3 pathologists. The p16 score was compared with both Hybrid Capture 2 (hc(2)) (Digene, Gaithersburg, Md) and follow-up (Pap smear and tissue) results.

RESULTS

The sensitivity and specificity of p16 immunohistochemistry compared with both hc(2) and follow-up were not statistically significant, with both data subsets having P-values greater than .05.

CONCLUSIONS

Statistical significance was not demonstrated in any of the data subsets, indicating that the p16 score alone cannot be used to recategorize Pap smears from ASCUS to NILM as a means to prevent unnecessary and expensive follow-up. Although not meeting criteria for statistical significance, the sensitivity and positive predictive value of p16 scores versus tissue follow-up only were more statistically favorable, suggesting that p16 has better correlation with tissue follow-up than results of hc(2). In addition, p16 staining was identified consistently in atrophic Pap smears, including 23 of 25 additional NILM atrophic smears stained, indicating that p16 cannot be used as a marker to triage atypical atrophic smears.

[Cytomics and predictive medicine for oncology]

One hundred and fifty years after Virchow introduced his fundamental concept of cellular pathology, we now have tools that allow us to unravel the mechanisms of single living cells on a previously unprecedented level of detail. By exploring the molecular cellular phenotype, multiparametric cytometry not only detects specific cellular functions in general but also offers insights into the interaction of single subunits of proteins (e.g., growth factor receptors). Several quantitative and objective techniques allow analysis of single-cell preparations as well as tissue sections to obtain data on different cellular parameters. This opens the way to quantitative and objective histology, which in the future may be possible even without blood or the need to make an incision. To use this huge amount of data for treatment decisions in an individual patient, novel bioinformatic concepts are needed in order to predict the individual course of a disease. The concept of cytomics centers on the cell as the integral unit of all life and explores diseases starting from the cell and going to subcellular units (top-down analysis).

Accuracy of herpes simplex virus detection in liquid-based (SurePath) Papanicolaou tests: a comparison with polymerase chain reaction

A review of our institution's Papanicolaou test records over an 11-yr period showed that liquid-based Papanicolaou tests (LBPTs) had a significantly higher frequency of diagnoses of Herpes simplex virus (HSV)-related cellular changes compared to conventional Papanicolaou smears (77/302,841, 0.026% vs. 56/376,173, 0.015%, P = 0.002). To investigate the accuracy of the diagnosis of HSV by LBPT, we performed conventional polymerase chain reaction (PCR) on the residual samples from 258 prospectively collected LBPT and real-time PCR using a different primer set on a subset of 40 LBPT. Conventional PCR was positive in 22 of 22 cases diagnosed of HSV, 1 of 2 cases diagnosed as suspicious for HSV, and none of 234 LBPT without a cytologic HSV diagnosis. Real-time PCR was positive in 8 of 8 cases diagnosed as HSV and none of the 32 controls. We conclude that LBPT allows an increased detection of HSV that is highly accurate.

Liquid compared with conventional cervical cytology: a systematic review and meta-analysis

OBJECTIVE

To compare test performance characteristics of conventional Pap tests and liquid-based cervical cytology samples.

DATA SOURCES

Eligible studies, published between 1991 and 2007, were retrieved through PubMed/EmBase searching and completed by consultation of other sources.

METHODS OF STUDY SELECTION

Studies were selected if a conventional and a liquid-based sample were prepared from the same woman or when one or the other type of sample was taken from a separate but similar cohort. The current systematic review and meta-analysis is restricted to studies where all subjects were submitted to gold standard verification, based on colposcopy and histology of colposcopy-targeted biopsies, allowing computation of absolute and relative test validity for cervical intraepithelial neoplasia grade 2 or worse. Randomized trials were selected as well if all test-positive cases were verified with the same gold standard, allowing computation of the relative sensitivity. Impact of study characteristics on accuracy was assessed by subgroup meta-analyses, meta-regression, and summary receiver operating characteristic curve regression.

TABULATION, INTEGRATION, AND RESULTS

The relative sensitivity, pooled from eight studies, with complete gold standard verification and from one randomized clinical trial, did not differ significantly from unity. Also, the specificity, considering high-grade and low-grade squamous intraepithelial lesions as cutoff, was similar in conventional and liquid cytology. However, a lower pooled specificity was found for liquid-based cytology when presence of atypical squamous cells of undetermined significance was the cutoff (ratio 0.91, 95% confidence interval 0.84-0.98). Differences in study characteristics did not explain interstudy heterogeneity.

CONCLUSION

Liquid-based cervical cytology is neither more sensitive nor more specific for detection of high-grade cervical intraepithelial neoplasia compared with the conventional Pap test.

Comparative sensitivities of ThinPrep and Papanicolaou smear for adenocarcinoma in situ (AIS) and combined AIS/high-grade squamous intraepithelial lesion (HSIL): comparison with HSIL

BACKGROUND

Despite the historic belief that cytologic screening offers little protection against cervical adenocarcinoma (CAC), there is emerging evidence that, by detecting the precursor lesion, adenocarcinoma in situ (AIS), cervical screening may reduce the incidence of CAC as it has for cervical squamous carcinoma. Because liquid-based cytology is fast replacing the conventional Papanicolaou smear (PS), it is important to establish that it is at least as effective in detecting AIS.

METHODS

The authors calculated the sensitivities of PS and ThinPrep (TP) for 100 women with histologic AIS (from 160 PS slides and 60 TP slides), for 94 women with AIS+high-grade squamous intraepithelial lesion (HSIL) (from 151 PS slides and 50 TP slides), and for 558 women with HSIL (from 788 PS slides and 383 TP slides). All smears were taken up to 36 months before the histologic diagnosis.

RESULTS

In no category was there a significant difference between PS sensitivity and TP sensitivity. The HSIL category had a significantly higher overall sensitivity than the other categories. However, when sensitivity was defined as cytologic detection of high-grade disease, there was no difference between any of the categories. For the detection of a high-grade glandular lesion, the presence of a concurrent histologic HSIL was associated with reduced sensitivity for the detection of AIS.

CONCLUSIONS

The current results indicated that it may prove possible for cervical screening, with either PS or TP, to reduce the incidence of CAC.

The effect of continuous monitoring of cytologic-histologic correlation data on cervical cancer screening performance

CONTEXT

The use of Papanicolaou (Pap) test cytologic-histologic correlation in quality improvement activities is not well studied.

OBJECTIVE

To determine if continuous monitoring of correlation data improves performance.

DESIGN

Participants in the College of American Pathologists Q-Tracks program (213 laboratories) self-reported the number of Pap test-histologic biopsy correlation discrepancies every quarter for up to 8 years. A mixed linear model determined if the length of participation in the Q-Tracks program was associated with improved performance. Main outcome measures were predictive value of a positive Pap test, Pap test sensitivity, sampling sensitivity, and proportion of positive histologic diagnoses following a Pap test diagnosis of atypical squamous cells or atypical glandular cells.

RESULTS

Institutions evaluated 287,570 paired Pap test-histologic correlation specimens and found 98,424 (34.2%) true-positive Pap test correlations, 19,006 (6.6%) false-positive Pap test correlations, and 6575 (2.3%) false-negative Pap test correlations. The mean predictive value of a positive Pap test, sensitivity, screening and interpretive sensitivity, sampling sensitivity, and proportion of positive histologic diagnoses following a Pap test diagnosis of atypical squamous or glandular cells were 83.6%, 93.7%, 99.2%, 94.2%, 60.3%, and 38.8%, respectively. Longer participation was significantly associated with a higher predictive value of a positive Pap test (P = .01), higher Pap test sensitivity (P = .002), higher Pap test sampling sensitivity (P = .03), and higher proportion of positive histologic diagnoses for a Pap test diagnosis of atypical squamous cells (P < .001).

CONCLUSIONS

Long-term monitoring of cytologic-histologic correlation is associated with improvement in cytologic-histologic correlation performance.

Exposure to alcohol or tobacco affects the pattern of maturation in oral mucosal cells: a cytohistological study

OBJECTIVE

To assess the maturation pattern of oral mucosal cells of patients exposed to tobacco and alcohol.

METHODS

(i) Group without lesions. Smears obtained from the lower lip, border of the tongue and floor of the mouth of 31 control individuals (group I), 49 tobacco users (group II) and 27 tobacco/alcohol users (group III) were stained using the Papanicolaou method. The first 100 cells counted on each smear determined the maturation pattern and the keratinization index (KI). Analysis of variance (ANOVA) and the Tukey multiple comparison test were used for statistical analysis, at a 5% significance level. (ii) Group with lesions. Cytopathological and histopathological studies were conducted for 15 patients: eight with leucoplakia without epithelial dysplasia, two with epithelial dysplasia and five with squamous cell carcinoma.

RESULTS

(i) Group without lesions. Statistical analysis revealed a smaller number of superficial cells with nuclei in all sites of the group of tobacco/alcohol users (group III) when compared to the control group (group I), and this difference was statistically significant (P<0.005). (ii) Group with lesions. The severity of histopathological findings increased with the increase in the number of cells of the deeper epithelial layers, with a statistically significant difference in the number of intermediate (P=0.013) and parabasal cells (P=0.049), which increased with the severity of the epithelial maturation disorder: leucoplakias with dysplasia had a greater number of intermediate and parabasal cells than leucoplakias without dysplasia; and the number in squamous cell carcinomas was greater than in leucoplakias with dysplasia.

CONCLUSION

The maturation pattern of cells in the three anatomic sites showed changes that may be associated with the synergistic effect of tobacco and alcohol. Also, the severity of histopathological findings was associated with the increase in the number of cells in the deeper epithelial layers.

Accuracy of liquid based versus conventional cytology: overall results of new technologies for cervical cancer screening: randomised controlled trial

OBJECTIVE

To compare the accuracy of conventional cytology with liquid based cytology for primary screening of cervical cancer.

DESIGN

Randomised controlled trial.

SETTING

Nine screening programmes in Italy.

PARTICIPANTS

Women aged 25-60 attending for a new screening round: 22 466 were assigned to the conventional arm and 22 708 were assigned to the experimental arm.

INTERVENTIONS

Conventional cytology compared with liquid based cytology and testing for human papillomavirus.

MAIN OUTCOME MEASURE

Relative sensitivity for cervical intraepithelial neoplasia of grade 2 or more at blindly reviewed histology, with atypical cells of undetermined significance or more severe cytology considered a positive result.

RESULTS

In an intention to screen analysis liquid based cytology showed no significant increase in sensitivity for cervical intraepithelial neoplasia of grade 2 or more (relative sensitivity 1.17, 95% confidence interval 0.87 to 1.56) whereas the positive predictive value was reduced (relative positive predictive value v conventional cytology 0.58, 0.44 to 0.77). Liquid based cytology detected more lesions of grade 1 or more (relative sensitivity 1.68, 1.40 to 2.02), with a larger increase among women aged 25-34 (P for heterogeneity 0.0006), but did not detect more lesions of grade 3 or more (relative sensitivity 0.84, 0.56 to 1.25). Results were similar when only low grade intraepithelial lesions or more severe cytology were considered a positive result. No evidence was found of heterogeneity between centres or of improvement with increasing time from start of the study. The relative frequency of women with at least one unsatisfactory result was lower with liquid based cytology (0.62, 0.56 to 0.69).

CONCLUSION

Liquid based cytology showed no statistically significant difference in sensitivity to conventional cytology for detection of cervical intraepithelial neoplasia of grade 2 or more. More positive results were found, however, leading to a lower positive predictive value. A large reduction in unsatisfactory smears was evident.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN81678807 [controlled-trials.com].

[Comparison of the ThinPrep monolayer technique and conventional cervical Pap smears in a high-risk population using the Munich II nomenclature]

OBJECTIVE

In this prospective study using the Munich II nomenclature for cervical cytology. Pap smear results obtained by the ThinPrep monolayer technique and those obtained by the conventional method were compared.

METHODS

Pap smears were obtained from 1,000 women using an Ayre spatula/endocervical brush combination. Following transfer of the cell sample onto a slide, the same collection devices were rinsed in a liquid medium and processed using ThinPrep-2000 processor (split-sample technique).

RESULTS

Specimen inadequacies due to drying artefacts, cell overlap or low number of epithelial cells were rare with both methods without any significant differences. However, ThinPrep slides were significantly less often compromised by red or white blood cells or by cytolysis. In contrast, endocervical cells were missing in 11.6% of slides compared to only 2.3% in conventional Pap smears. ThinPrep yielded results of unknown significance (Pap III) significantly less often (4.2 vs 6.3%).

CONCLUSIONS

ThinPrep slides are less frequently compromised by blood components or cytolysis. Inconclusive results of Pap III are slightly less frequent when using ThinPrep. However, there is a significant percentage of slides lacking the endocervical component. Using a combination of spatula and cytobrush, this may not necessarily be due to non-representative cell sampling.

Ontario Cervical Cancer Screening Clinical Practice Guidelines

OBJECTIVE

To develop clinical practice guidelines for cervical screening and the primary management of abnormal cytology in Ontario, using an established methodological process.

DATA SOURCES

Primary data sources were relevant articles listed in the Medline (1998 to July 2004), Embase (1998 to July 2004), and Cochrane Library (2004, Issue 2) databases.

STUDY SELECTION

Studies addressing quality or the optimization of cervical screening were considered eligible in the systematic review of the evidence. Specifically, clinical practice guidelines, technology assessments, systematic reviews, and randomized controlled trials were of primary interest. Given the variability of the data, other information sources were considered eligible if there was a demonstrated gap in the published literature.

DATA EXTRACTION

Data were identified and extracted by a methodologist and reviewed by four authors. Results were reviewed and discussed by members of an expert working group consisting of a diverse group of health professionals with expertise in cervical cancer. Data audits were conducted by independent reviewers.

DATA SYNTHESIS

recommendations with evidence ratings were developed through a review of the evidence with expert consensus and were approved by more than 80% of 40 external practitioners who reviewed the document and responded to a standardized survey.

CONCLUSION

The development of comprehensive recommendations on cervical screening in Ontario was feasible using a rigorous methodological process. Recommendations for practice are provided.

Liquid-based cytology for cervical cancer screening

In multiple studies during the last decade, liquid-based cytology for cervical cancer screening has been shown to increase the detection rate for preneoplastic squamous intraepithelial lesions equal to or greater than the conventional Papanicolaou (Pap) smear method. Liquid-based collection and processing provide more representative cervical sampling than conventional smearing of the specimen on a glass slide. Currently, there are two test methodologies that are widely marketed and available to clinical laboratories, health systems and clinicians that undertake cervical cytology. The purpose of this article is to provide an overview of the methodology and performance of SurePath Liquid-Based Pap Test in cervical cytology screening. The SurePath liquid-based Pap test significantly reduces the unsatisfactory rate of Pap test slides, and detects a significantly higher number of low- and high-grade squamous lesions when compared with the conventional Pap smear technique. Biopsy confirmation shows that this increased detection does not come at a cost of decreasing specificity, and sensitivity for histologic dysplasia is equal to or greater than the best available data for the conventional Pap method. The SurePath collection vial provides residual cellular material for adjunctive out-of-the-vial molecular testing, including sexually transmitted diseases and oncologic biomarkers associated with cervical carcinoma. Finally, SurePath slides can be placed on an automated cervical cytology screening device (FocalPoint), thus providing improved disease detection and enhanced laboratory productivity.

A three-armed trial of the ThinPrep Imaging System

We compared the performance of the ThinPrep (TP) Imaging System (TIS) with manual reading of TP slides (TPM) and with manual reading of the paired conventional Pap smear (PS) in terms of sensitivity for and positive predictive value (PPV) of high-grade disease and productivity. The study consisted of 11,416 routine PS and paired TP slides as well as 103 confirmed abnormal TP slides. In terms of sensitivity for the detection of biopsy-confirmed high-grade disease, overall there was no statistically significant difference between TIS-screened TP (TPI) and TPM (81.1% vs. 86.8%). For the routine cases, TPI was significantly more sensitive than PS (73.4% vs. 57.8%). In terms of PPVs for the cytologic prediction of high-grade disease, there was no statistically, significant difference among TPI, TPM, and PS (75.6%, 73.9%, and 84.6%). For cytologic reports of possible high-grade disease, the PPVs were equivalent for TPI (45.0%) and TPM (37.0%) and there was no significant difference in PPVs between TPI and PS (61.3%). For TP slides, TIS screening showed a 27% productivity gain when compared with manual screening and a 54% productivity gain when compared with manual screening of PS slides. Use of TIS showed productivity benefits when compared with TPM and both productivity and sensitivity benefits over use of PS.

Usefulness of combining testing for p16 protein and human papillomavirus (HPV) in cervical carcinoma screening

OBJECTIVE

To evaluate the value of the combination of p16 and HPV detection in the screening for cervical cancer.

METHODS

186 patients with previous abnormal cervical lesion were studied. After colposcopic examination, two conventional Pap slides were prepared: the first was Papanicolaou-stained and examined by cytologist; the second was immunocytochemically stained for p16. Cervical cells were collected by brush using for HPV detection by Hybrid Capture II. Biopsy of any colposcopically abnormal lesions was performed.

RESULTS

The 186 cervical samples were classified cytologically as normal (148), ASCUS (13), low-grade (11), high-grade (12) dysplasia and squamous cell carcinoma (2). P16 and HPV were found in all high-grade dysplasia and SCC, and in 64% and 27% of low-grade dysplasia, 62% and 0% of ASCUS and 7.4% and 3.4% of normal, respectively. 18 of p16-positive cases (11%) were HPV-negative, 14 of them in the ASCUS and normal group. Compared to histological results, all of the p16-positive cases of squamous metaplasia, CIN II/III and SCC were HR-HPV-positive. Therefore, the cases that were positive for both with normal cytology (5 cases) or low-grade dysplasia (3 cases) may comprise a high-risk group for neoplastic change.

CONCLUSION

The combination of p16 and HPV detection may be useful in cervical cancer screening to identify high-risk patients requiring early and proper management.

Comparison of conventional Papanicolaou smear and SurePath liquid-based cytology in the Copenhagen population screening programme for cervical cancer

OBJECTIVE

To compare diagnostic performance of conventional Papanicolaou smear with SurePath liquid-based cytology in a population screening programme.

METHODS

A retrospective comparison was performed on data from two 18-month periods of the screening programme for cervical cancer in the municipality of Copenhagen with conventional Papanicolaou technique (n = 82,116) and liquid-based cytology (n = 84,414).

RESULTS

After the conversion to liquid-based cytology the percentage of unsatisfactory samples decreased from 2.3% to 0.3% (P < 0.001), whereas the number of normal cervical samples lacking an endocervical component increased from 8.5% to 8.9% (P < 0.005). The percentage of samples with atypical cells and cells suspicious for malignancy increased from 3% to 4.2% (P < 0.001) and from 1.9% to 2.4% (P < 0.001), respectively. The subsequent histological follow-up showed normal findings decreased from 70.5% to 68.9% and from 28.0% to 26.1%, respectively. However, in relation to the entire screening populations, there was an increase of normal findings from 2.12% to 2.89% after primary atypical diagnosis and from 0.53% to 0.62% after diagnosis of suspicious cells after conversion to the liquid-based technique.

CONCLUSIONS

This study showed the number of unsatisfactory samples to be significantly reduced with the liquid-based technique. The data suggest that there is an increased detection rate of cervical precancerous lesions with liquid-based cytology, but the number of false positive tests is still high. The specificity of the two tests seems similar, but this cannot be ascertained exactly, because of the fact that follow-up of negative cases is unavailable.

The significance of certification in liquid-based cytology and performance in the college of american pathologists interlaboratory comparison program in cervicovaginal cytopathology

CONTEXT

Morphology training and certification provided by the manufacturer is required before laboratories are allowed to prepare and interpret liquid-based cytology (LBC) gynecologic slides. Whether this certification is associated with improved LBC interpretation performance is not known.

OBJECTIVE

To determine whether LBC certification correlates with performance.

DESIGN

The results of the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytopathology for the year 2004 were reviewed. During this year a question on the answer form asked participants whether they were certified in LBC preparations. Participant responses were analyzed at 2 levels of agreement with the reference diagnosis of unknown glass slides mailed quarterly.

RESULTS

For cytotechnologists and pathologists, participants who were LBC certified had a significantly lower total discordant rate to series than participants who were not certified for validated LBC ThinPrep (Cytyc Corp, Marlborough, Mass) preparations (P < .001 for both groups). The results were similar for validated conventional preparations for pathologists but not for cytotechnologists. The differences were present across most individual diagnostic series. Differences were most striking for low-grade squamous intraepithelial lesions. In addition, cytotechnologists and pathologists who were certified had a significantly lower total discordant rate to the exact diagnosis for validated LBC ThinPrep slides than those who were not certified (discordant rates for cytotechnologists, 14.14% and 23.36%, respectively, P < .001; for pathologists, 15.99% and 24.07%, respectively, P < .001).

CONCLUSION

Although not all confounding factors were excluded in this study, LBC certification is associated with a significantly lower discordant rate to both series and exact diagnosis for validated LBC ThinPrep preparations.

Dutch solutions for liquid-based cytology: analysis of unsatisfactory slides and HPV testing of equivocal cytology

The liquid-based techniques to obtain microscopy slides for cervical screening have replaced conventional smears almost completely in the USA, but not in all European countries. The decision making process to use liquid-based cytology (LBC) for nationwide screening programs depends on the health system. In a pilot study of over 7,000 screenees, we analyzed the unsatisfactory LBC slides and tested the equivocal cytologies for HPV by using the LiPA test. For comparison over 48,000 conventional screening data were used. Compared to conventional smears, the LBC slides were highly cellular, the state of fixation was much better, and obscuring blood did not exist. The unsatisfactory rate showed an increase from 262/100,000 (conventional smears) to 357/100,000 (LBC slides) due to too thick, undiagnosable epithelial fragments on the LBC slides. HPV testing of the equivocal cytology leads to a better patient management and less unnecessary referrals.

A comparative study of two devices used for cervical cell sampling raises some doubts about liquid-based cytology

The objective of this study was to compare the quality of smears obtained by a newly designed cervical cell sampler (the implement) to those obtained with the cervex brush, using liquid-based cytology (LBC). A prospective randomized controlled trial with the approval of the local ethics committees after informing the Medical Devices Agency in the UK was used in this study. The study was carried out in colposcopy clinics in two district general NHS Trust Hospitals in London. A total of 200 women were recruited (100 from each hospital). The women were randomized into two groups, each of them having two smears at the same time. One hundred (50%) of the women had their first smear with the new implement, and the other 100 (50%) had their first smear with the cervex brush. The main outcome of this study is good-quality smears, assessed by evidence of effective sampling of the transformation zone, including immature metaplastic cells and also endocervical cells. Eighty-five percent of the smears taken by the new implement showed good-quality smears compared to 91% of those taken by the cervex brush, a statistically marginally nonsignificant result, with P value = 0.052 (McNemar exact test). A larger number of good-quality smears, judged by evidence of sampling of transformation zone, were obtained with the cervex brush, though the difference was statistically marginally nonsignificant, using the British society for clinical cytology criteria. Surprisingly, despite the use of LBC, there was a higher rate of inadequate smears obtained with both the devices (8% with each) compared to our previous study using the conventional slide test (1.3% with the new implement and 1.8% with the Jordan's spatula).

Evaluation of cervical screening strategies with adjunct high-risk human papillomavirus testing for women with borderline or mild dyskaryosis

The management of women with a smear read as borderline/mild dyskaryosis (BMD) found by cervical cancer screening is still under discussion as only few of these cases are associated with high-grade lesions. To determine the optimal screening strategy for these women, a simulation model of cervical cancer development was used that is based on high-risk human papillomavirus (hrHPV) infection. The current strategy of repeat cytological testing at 6 and 18 months after BMD was compared to strategies with adjunct hrHPV testing. Calculations were done for both conventional and liquid-based cytology as the primary screening tool. In comparison to current screening, adjunct hrHPV testing was more effective in preventing cancer and more woman-friendly (reduction in colposcopy referrals with outcome < cervical intraepithelial neoplasia (CIN2) of up to 56% and in repeat smears of 30-100%). In combination with conventional cytology, cost-effective strategies were the ones in which a sample for high-risk human papillomavirus (hrHPV) testing is collected at a return visit within 1 month or in which hrHPV testing is restricted to repeat smears taken at 6 and 18 months. For these strategies, co-collection of samples for hrHPV testing at baseline is not necessary which has organizational and cost advantages. In combination with liquid-based cytology, it was cost-effective to perform a reflex hrHPV test at baseline from the liquid-based specimen. Liquid-based screening was more effective than conventional screening, but annual diagnosis costs were euro5 million higher (population size 16 million). In conclusion, our calculations indicate that implementation of hrHPV testing for the management of women with borderline or mild dyskaryosis (BMD) is feasible both in settings where conventional and liquid-based cytology is current practice.