Liquid-based cytology improves productivity in cervical cytology screening

Comparison of Liquid-Based Preparations with Conventional Smears in Thyroid Fine-Needle Aspirates: A Systematic Review and Meta-Analysis

BACKGROUND

To compare conventional smears (CSs) and liquid-based preparations (LBPs) for diagnosing thyroid malignant or suspicious lesions.

METHODS

Studies in the PubMed, SCOPUS, Embase, Web of Science, and Cochrane database published up to December 2023. We reviewed 17 studies, including 15,861 samples.

RESULTS

The diagnostic odds ratio (DOR) for CS was 23.6674. The area under the summary receiver operating characteristic curve (AUC) was 0.879, with sensitivity, specificity, negative predictive value, and positive predictive value of 0.8266, 0.8668, 0.8969, and 0.7841, respectively. The rate of inadequate specimens was 0.1280. For LBP, the DOR was 25.3587, with an AUC of 0.865. The sensitivity, specificity, negative predictive value, and positive predictive value were 0.8190, 0.8833, 0.8515, and 0.8562. The rate of inadequate specimens was 0.1729. For CS plus LBP, the AUC was 0.813, with a lower DOR of 9.4557 compared to individual methods. Diagnostic accuracy did not significantly differ among CS, LBP, and CS plus LBP. Subgroup analysis was used to compare ThinPrep and SurePath. The DORs were 29.1494 and 19.7734. SurePath had a significantly higher AUC.

CONCLUSIONS

There was no significant difference in diagnostic accuracy or proportion of inadequate smears between CS and LBP. SurePath demonstrated higher diagnostic accuracy than ThinPrep. Recommendations for fine-needle aspiration cytology should consider cost, feasibility, and accuracy.

Stability, integrity, and recovery rate of cellular nucleic acids preserved in a new liquid-based cytology medium

BACKGROUND

Liquid-based cytology (LBC) has replaced the conventional Papanicolaou test in cervical cancer screening. The cervical swab specimens collected in LBC media can also be used for additional analyses including high-risk HPV (HR-HPV) test, DNA methylation analysis, and HPV E6/E7 mRNA test.

METHODS

The stability, integrity, and recovery rate of cellular DNA and RNA after storage at different conditions were evaluated by a quantitative real-time PCR (qPCR) based HR-HPV test, reverse transcription qPCR (RT-qPCR), and agarose gel electrophoresis. Cervical swab specimens collected in a newly developed LBC medium, VersaMedium, and ThinPrep PreservCyt medium were processed on Hologic ThinPrep 5000 instrument.

RESULTS

Cervical exfoliative cells fixed by VersaMedium exhibited good cellular morphology with intact membranes and delineated chromatin structures. Cellular DNA preserved in VersaMedium exhibited high level of stability at both room temperature and 4°C, and remained mostly intact at 4°C for up to 28 days. Cellular RNA preserved in VersaMedium maintained higher level of stability and integrity at 4°C than at room temperature. VersaMedium also showed no apparent adverse effect on the recovery rate of nucleic acids.

CONCLUSION

In addition to maintaining cellular morphology, when stored at 4°C, VersaMedium preserves cellular nucleic acids and PreservCyt medium without noticeable adverse effects on the recovery rate during purification. Therefore, VersaMedium is an appropriate LBC medium for the collection and preservation of cervical swab specimens. And VersaMedium preserved cellular nucleic acids are of such high quality that they are suitable for HR-HPV qPCR test and RT-qPCR analyses.

Intravoxel Incoherent Motion Diffusion-Weighted Magnetic Resonance Imaging of Cervical Cancer With Different b-Values

OBJECTIVE

The aims of this study were to evaluate the dependence of diffusion parameters on the b values adopted for intravoxel incoherent motion diffusion-weighted magnetic resonance imaging and to investigate the application value of multiple diffusion parameters obtained from monoexponential and biexponential models in subjects with a normal cervix and in cervical cancer patients.

METHODS

A total of 120 female patients with cervical cancer and 21 female control subjects with a normal cervix underwent diffusion-weighted magnetic resonance imaging with 13 b values (0-2000 s/mm) at 3 T. The standard apparent diffusion coefficient (Dst), diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) were calculated by fitting with monoexponential and biexponential models at 2 different ranges of b values: 0 to 1000 and 0 to 2000 s/mm. A univariate analysis was performed to identify factors that could distinguish cervical carcinoma from normal cervical tissue. Parameters that correlated with the pathological grade and stage of cervical cancer were also evaluated. Receiver operating characteristic curves were used to evaluate the diagnostic efficiency of every parameter.

RESULTS

All the tested parameters, except the D* of the 2 different ranges of b value groups, significantly differed between the patients with cervical carcinoma and control subjects (P < 0.01). D2000, Dst2000, and D1000 showed comparable diagnostic value, with an area under the curve of 0.923, 0.909, and 0.907, respectively. Dst2000, D2000, Dst1000, and D1000 differed significantly among the 3 degrees of cervical stromal infiltration depth (P < 0.05).

CONCLUSIONS

D2000 and Dst2000 tended to outperform D1000 in terms of diagnostic efficiency, but there was no significant difference in their ability to differentiate cervical carcinoma from normal cervix. Cervical cancers with lower Dst and D values tended to have greater infiltration depth.

[Who performs gynecological cytology and how?]

Since 1971 German women aged 20 years and older can annually participate in the gynecological cancer screening program free of charge. As part of this program a cervical smear is taken for testing. The Federal Joint Committee (Gemeinsamer Bundesausschuss, GBA) is planning to change this system so that women aged over 30 years can either choose to continue with annual cytological screening using a cervical smear or can primarily opt for a human papillomavirus (HPV) test every 5 years. Women who are HPV positive will receive a supplementary cytological examination as a triage method. In Germany classification of the cytological results is based on the third revision of the Munich nomenclature (Münchner Nomenklatur, MN III), which has been in operation since 1 January 2015. The number of accredited cytology institutions and of cytologists has changed considerably since 2008. There has been a marked increase in the number of pathologists by 28.4%, which is a promising trend. The number of tests carried out has remained relatively constant; however, an increasing number of tests are now being performed in large laboratories.

The advantages of incorporating liquid-based cytology (TACAS™) in mass screening for cervical cancer

We incorporated liquid-based cytology (LBC) in population-based screening for cervical cancer. The usefulness of using LBC in mass screening for cervical cancer was examined. From 2009 to 2014, 157,061 individuals underwent mass screening for cervical cancer in Aomori Prefecture. From 2009 to 2011, cells were collected from 82,218 individuals and the specimens were conventionally prepared (CP). From 2012 to 2014, cells were collected from 74,843 individuals and the specimens were prepared using LBC (TACAS™). Cytology results for the 2 sets of specimens were compared and differences in cytologic features were examined. ASC-US and more severe lesions were detected at a rate of 1.13 % by CP and 1.44 % by LBC, so LBC had a 1.3-fold higher rate of detection. LBC had a 1.6-fold higher rate of LSIL detection and a 1.2-fold higher rate of HSIL detection. CP detected cancer in 20 cases at a rate of 0.024 % while LBC detected cancer in 18 cases at a rate of 0.024 %. Cytodiagnosis of the 18 cases of SCC that LBC identified revealed that 7 were SCC, 8 were HSIL, and 3 were ASC-H. Atypical cells tended to be smaller with TACAS™. LBC reduced the time needed for microscopic examination of a single specimen by 42 % in comparison to CP. LBC using TACAS™ allowed the detection of slight lesions and slight changes in cells. LBC can lessen the burden on medical personnel and may lead to improved accuracy.

Conventional smears versus liquid-based preparations for thyroid fine-needle aspirates: a systematic review and meta-analysis

INTRODUCTION

Thyroid fine-needle aspiration has traditionally been prepared using conventional smears (CS). Liquid-based preparations (LBP) have grown in popularity and yet, there is a lack of consensus about which method is superior. This review compared CS and LBP as an intervention in the management of thyroid nodules.

MATERIALS AND METHODS

Medline, EMBASE, Scopus and ClinicalTrials.gov were searched to locate relevant studies. Observational studies comparing CS and LBP of consecutive thyroid fine-needle aspirations were included. Two reviewers independently screened, extracted, and entered data. Double data extraction included the following outcomes: (1) the proportion of inadequate smears and (2) the proportion of indeterminate smears. Studies were also assessed for risk of bias and heterogeneity.

RESULTS

From 599 unique studies, title/abstract screening identified 136 studies, and full text screening identified 13 studies. The 13 studies included 24,307 fine-needle aspirations from 19,433 patients and had high clinical, methodological, and statistical heterogeneity with low risk of bias. For CS and LBP, a meta-analysis of 12 studies showed no difference in the proportion of inadequate smears (risk difference: -0.00; 95% confidence interval [CI]: -0.04-0.04); 13 studies showed no difference in the proportion of indeterminate smears (risk difference: -0.02; 95% CI: -0.05-0.01). Sensitivity analysis of studies with low risk of bias had similar results.

CONCLUSIONS

There is no difference between CS and LBP in the proportion of inadequate and indeterminate smears. Recommendations of one method over the other should be based on cost, feasibility, and accuracy, all of which require further study.

How do liquid-based preparations of thyroid fine-needle aspiration compare with conventional smears? An analysis of 5475 specimens

BACKGROUND

Fine-needle aspiration (FNA) plays a pivotal role in the initial evaluation of patients with thyroid nodules. Traditionally, aspirated material is expelled directly onto the microscope slide to make a conventional smear (CS). Recently, liquid-based preparations (LBP) have gained in popularity. This study compares the accuracy of these two preparation techniques in diagnosing thyroid nodules.

METHODS

A clinical database containing 5475 thyroid cytology consults from 2009 to 2013 was queried to identify 5169 CS and 306 LBP cases. Cytological diagnostic frequency rendered before and after second review were compared between LBP and CS. Correlation with the histology diagnosis was also calculated for each preparatory technique.

RESULTS

Age, sex, and nodule size were comparable between patients who had FNA processed by LBP and CS. More LBP cases than CS cases were inadequate (17% vs. 10%; p<0.001). LBP cases had fewer benign diagnoses (39% vs. 47%; p=0.003) and tended to have more malignant diagnoses (16% vs. 12%; p=0.09) when compared to CS. Indeterminate and suspicious categories were comparable between LBP and CS. Correlation with histology was also comparable between both techniques.

CONCLUSION

LBP was associated with a significantly higher proportion of inadequate and a lower proportion of benign diagnoses. Thus, universal adoption of LBP may introduce more inadequate samples. Future investigations should explore the lack of on-site evaluation with LBP as a potential source for the high inadequate rate.

Cytological Evaluation and REBA HPV-ID HPV Testing of Newly Developed Liquid-Based Cytology, EASYPREP: Comparison with SurePath

Background

The objective of this study was to evaluate a newly-developed EASYPREP liquid-based cytology method in cervicovaginal specimens and compare it with SurePath.

Methods

Cervicovaginal specimens were prospectively collected from 1,000 patients with EASYPREP and SurePath. The specimens were first collected by brushing for SurePath and second for EASYPREP. The specimens of both methods were diagnosed according to the Bethesda System. Additionally, we performed to REBA HPV-ID genotyping and sequencing analysis for human papillomavirus (HPV) on 249 specimens.

Results

EASYPREP and SurePath showed even distribution of cells and were equal in cellularity and staining quality. The diagnostic agreement between the two methods was 96.5%. Based on the standard of SurePath, the sensitivity, specificity, positive predictive value, and negative predictive value of EASYPREP were 90.7%, 99.2%, 94.8%, and 98.5%, respectively. The positivity of REBA HPV-ID was 49.4% and 95.1% in normal and abnormal cytological samples, respectively. The result of REBA HPV-ID had high concordance with sequencing analysis.

Conclusions

EASYPREP provided comparable results to SurePath in the diagnosis and staining quality of cytology examinations and in HPV testing with REBA HPV-ID. EASYPREP could be another LBC method choice for the cervicovaginal specimens. Additionally, REBA HPV-ID may be a useful method for HPV genotyping.

Diagnostic value of liquid-based (Liqui-PREP) preparations and interobserver reproducibility in fine needle aspiration cytology of the nodular thyroid lesions

The aim of this study is to define the diagnostic role of Liqui-Prep (LP) technique for the diagnosis of thyroid lesions and to assess interobserver variabilities. In all, 98 thyroid FNA (fine needle aspiration) cytology samples from 83 patients for preoperative evaluation of thyroid nodules, prepared by the LP, were examined. The LP slides were independently evaluated by three pathologists and they were classified into the five categories according to the Bethesda system. The histopathologic diagnoses were grouped as follows: benign, follicular neoplasm, and malignant. Agreements between LP and histopathologic diagnoses were investigated using kappa values. Marginal homogenity and kappa tests were used for statistical analysis for the evaluation of the agreement between the pathologists and the interobserver variability of the thyroid aspiration cytology results. The presence of nucleoli, nuclear grooving, overlapping, intranuclear inclusion, and nuclear irregularity were recorded and scored on each case based on LP slide review. Concurrences between LP and the histologic diagnoses for the three pathologists were almost perfect (k = 0.798; k = 0.826; k = 0.880). When the observers were paired there was no significant difference from the diagnostic point of view. Interobserver agreement among the three pathologists was moderate. Initially diagnostic difficulties may occur because of the inadequate experience of the pathologists concerning the evaluation of the cytologic changes associated with this new technique. Liqui-Prep technique is useful for the cytologic diagnosis of the thyroid nodules. The nuclear irregularity was the most essential feature for the differentiation of malignant lesions from follicular neoplasm by the LP method.

Comparison of conventional and liquid-based cytology, and human papillomavirus testing using SurePath preparation in Japan

We compared the detection rate of cervical neoplasias between a liquid-based cytology (LBC) method using SurePath and the conventional method. We also studied the feasibility of human papillomavirus (HPV) typing by linear array assay. Cytological specimens from 1551 Japanese women were prepared using the conventional and SurePath methods; the cytological and histological results from biopsy samples were compared. HPV typing using an HPV linear array assay was carried out on residual specimens using the SurePath method. The cytodiagnostic results showed a concordance rate of 85.3% (Κ= 0.46) between the two methods. The sensitivity of lesions histopathologically diagnosed as CIN1 or above was not significantly different between the two methods (P = 0.575-1.000). The receiver operating characteristic curve analysis of the detectability in CIN2 or above revealed no significant difference between the two methods (P = 0.096). Among the 44 patients who underwent HPV typing using a linear array assay, 33 samples were eligible for HPV testing and were stored at ambient temperature. In conclusion, the SurePath and conventional methods have equivalent abilities for detecting cervical lesions. After preparation for cytological diagnosis, use of the remaining cells from the SurePath specimens to perform HPV typing using the linear array method could be feasible.

Options for managing low grade cervical abnormalities detected at screening: cost effectiveness study

OBJECTIVE

To estimate the cost effectiveness of alternative methods of managing low grade cervical cytological abnormalities detected at routine screening. Design Cost analysis within multicentre individually randomised controlled trial.

SETTING

Grampian, Tayside, and Nottingham.

PARTICIPANTS

4201 women with low grade abnormalities.

INTERVENTIONS

Cytological surveillance or referral to colposcopy for biopsy and recall if necessary or referral to colposcopy with immediate treatment based on colposcopic appearance.

MAIN OUTCOME MEASURES

Data on resource use collected from participants throughout the duration of the trial (36 months), enabling the estimation of both the direct (health care) and indirect (time and travel) costs of management. Quality of life assessed at recruitment and at 12, 18, 24, and 30 months, using the EQ-5D instrument. Economic outcomes expressed as costs per case of cervical intraepithelial neoplasia (grade II or worse) detected, by trial arm, as confirmed at exit, and cost utility ratios (cost per quality adjusted life year (QALY) gained) for the three pairwise comparisons of trial arms.

RESULTS

The mean three year discounted costs of surveillance, immediate treatment, and biopsy and recall were pound150.20 (euro177, $249), pound240.30 (euro283, $415), and pound241.10 (euro284, $4000), respectively, viewed from the health service perspective. From the social perspective, mean discounted costs were pound204.40 (euro241, $339), pound339.90 (euro440, $563), and pound327.50 (euro386, $543), respectively. Estimated at the means, the incremental cost effectiveness ratios indicated that immediate treatment was dominated by the other two management methods, although it did offer the lowest cost per case of cervical intraepithelial neoplasia detected and treated. The pronounced skews in the distributions indicated that probabilistic uncertainty analysis would offer more meaningful estimates of cost effectiveness. The observed differences in the cost effectiveness ratios between trial arms were not significant.

CONCLUSION

Judged within the time frame of the TOMBOLA evaluation, there is no compelling economic reason to favour any one follow-up method over either of the others.

TRIAL REGISTRATION

ISRCTN 34841617.

Barriers to adoption of recent technology in cervical screening

The Pap smear is one of the modern success stories in the field of preventive medicine. Since its introduction as a screening test, there has been a dramatic reduction in the incidence of cervical cancer. However, the search for a better screening test continues. The new technologies, including liquid-based cytology (LBC), Human Papilloma Virus (HPV) testing and automated or machine-assisted screening have been introduced. However, there is continuous debate about whether society's limited resources are better spent on reaching the underserved rather than on these technologies. Another question is whether these technologies create yet another kind of disparity in delivering preventive care. For example, despite the wide use of LBC (99% of tests submitted to our laboratory are LBC), conventional Pap smears are still used to screen/follow up some women. It is not clear why some providers continue to prefer conventional smear over LBC and what are the barriers for adopting LBC in cervical cancer screening. We hypothesize the lower cost of conventional compared to LBC Pap testing, patient's lower socio-economic indices, a patient's medical history and provider's subspecialty/training all appear to play a role in the choice of using conventional Pap testing rather than LBC. Unintentionally, this choice results in repeat testing, delayed treatment and potentially higher costs than intended. The ultimate goal of this review article is to understand and explore possible barriers and disparities to adopting new technology in cancer screening.