Computerassistierte Diagnostik in der Zervixzytologie

Two Years of Cytology and HPV Co-Testing in Germany: Initial Experience

Introduction On 1 January 2020 the screening programme for the prevention of cervical cancer in women from the age of 35 years of the Statutory Health Insurance (GKV) in Germany changed from an annual cytology examination to cytological and HPV co-testing carried out every three years. A large standard diagnostics laboratory has been using liquid-based cytology (LBC) with computer-assisted screening (CAS) since 1 January 2020 to assess the samples.

Patients and Methods The cytological and HPV results for all cases examined with co-testing from 01.01.2020 to 31.12.2021 (n = 395759) are reported and the cytology results obtained using co-testing are compared with the results obtained using only conventional primary cytology screening from the two previous years (n = 588192). Cytology tests were carried out using LBC and computer-assisted screening. A DNA PCR test which can identify 14 types of HPV was used for HPV testing. The cytology results are reported using the Munich Nomenclature III, which is mandatory in Germany, and converted to The Bethesda System (TBS). Problems occurring during the implementation phase are described here.

Results A total of 983951 cases who had primary screening between 01.01.2018 and 31.12.2021 were analysed. The HR HPV-positive rate with co-testing for all age groups was 6.41%. Of this group, 16.31% were positive for HPV-16, 4.43% for HPV-18, and 71.40% had one or more of the other 12 HR HPV types. Several different HPV types were identified in 7.86% of cases. The HPV-positive rate for cases with unremarkable cytological findings was 4.03%. 0.46% of tests were technically invalid. The results of primary cytology screening for 2020/21 (LBC) were: Pap 0 (TBS: unsatisfactory) 0.09%, Pap I and Pap II-a (NILM) 96.82%, Pap II-p/g (~ASC-US/AGC) 1.23%, Pap III-p/g (~ASC-H/AGC) 0.19%, Pap III D1 (LSIL) 1.08%, Pap III D2 (HSIL) 0.31%, Pap IVa/b-p/g (HSIL/AIS) 0.18%, and Pap V-p/g (carcinoma) 0.01%. The rates for 2018/19 (conventional cytology without routine testing for HPV) were significantly higher for Pap II-p/g (1.64%) and significantly lower for Pap III-p/g (0.13%), Pap III D1 (0.45%), Pap III D2 (0.10%) and Pap IVa/b-p/g (0.05%).

Conclusion Evaluation of the data for the two first years of cytology and HPV co-testing from a standard diagnostics laboratory found low HR HPV-positive rates. As regards the cytology tests, the Pap II-p/g rate was significantly lower and the ≥ Pap III rate was significantly higher compared to the two previous years. This points to a probable higher sensitivity and specificity of the new method.

Characterizing the Effect of Processing Technique and Solution Type on Cytomorphology Using Liquid-Based Cytology

INTRODUCTION

Liquid-based cytology (LBC) is increasingly used for nongynecologic applications. However, the cytological preparation of LBC specimens is influenced by the processing technique and the preservative used. In this study, the influence of the processing techniques and preservatives on cell morphology was examined mathematically and statistically.

METHODS

Cytological specimens were prepared using the ThinPrep (TP), SurePath (SP), and AutoSmear methods, with 5 different preservative solutions. The cytoplasmic and nuclear areas of Papanicolaou-stained specimens were measured for all samples.

RESULTS

The cytoplasmic and nuclear areas were smaller in cells prepared using the 2 LBC methods, compared to that prepared using the AutoSmear method, irrespective of the preservative used. The cytoplasmic and nuclear areas of cells prepared using the SP method were smaller than those of cells prepared using the TP method, irrespective of the preservative used. There were fewer differences among the cytoplasmic areas of cells prepared with different preservative solutions using the TP method; however, the cytoplasmic areas of cells prepared using the SP method changed with the preservative solution used.

CONCLUSIONS

The most significant difference affecting the cytoplasmic and nuclear areas was the processing technique. The TP method increased the cytoplasmic and nuclear areas, while the methanol-based PreservCyt solution enabled the highest enlargement of the cell. LBC is a superior preparation technique for standardization of the specimens. Our results offer a better understanding of methods suitable for specimen preparation for developing precision AI-based diagnosis in cytology.

Characterizing the Effect of Automated Cell Sorting Solutions on Cytomorphological Changes

INTRODUCTION

Liquid-based cytology has become a widely adopted, automated screening system for gynecologic and nongynecologic cytology. Automated screening systems function by distinguishing atypical cells based on their cytoplasmic and nuclear areas, densitometric measurement, and so on. However, the morphological influence of the washing solution has not been fully considered. Here, we examined the morphological effect and temporal change resulting from saving the cytologic samples in various solutions.

METHODS

Cytologic specimens were obtained from the ascites (AS) of patients with peritoneal cancer. Various solutions of a physiological saline, a Ringer's solution, a low-molecular dextran L injection, VOLUVEN 6% solution, MIXID L injection (ML), RPMI-1640 medium, and horse serum (HS) were added to aliquot sediments. All samples were refrigerated at 4°C, and aliquots were subsequently processed at specific time points (0, 1, 2, 4, 7, and 14 days). For all samples, cytoplasmic and nuclear size of the Papanicolaou-stained specimens were measured.

RESULTS

In terms of cytoplasmic and nuclear areas, samples stored in ML and HS showed no significant difference compared to the AS sample; in contrast, the other samples were significantly larger in both cytoplasmic and nuclear areas than the AS sample. In examining the temporal change among the solutions, we found that the cytoplasms and nuclei became small over the time course for all of the tested solutions.

CONCLUSION

We showed that cells swell in the solution after 1 h of storage and contract as time progresses. Together, our findings have important implications for how mathematical analysis is applied during the automated screening process.

Introducing a new scoring system for pap smear in the detection of high-grade squamous intraepithelial lesions in pregnancy (The Luebeck Score)

PURPOSE

To construct a scoring system for pap smears to objectify cytological appraisal and to enhance the accuracy and comparability of pap smear interpretation in pregnancy.

MATERIALS AND METHODS

For development of a scoring system for cell appraisal of pap smears the style of the Modified Masood's Scoring Index for appraisal of cells from fine needle aspirations of breast lesions was used. Cohort analysis of n = 54 dysplastic pap smears for polymorphology of cells, anisonucleosis, structure of the nucleus, signs of tissue destruction, nucleus/plasma relation and signs of tumordiathesis. Each criteria was classified into three stages: The first with little evidence for dysplasia (one point), second stage with sporadic evidence (two points) or third stage with frequent evidence (three points). To further evaluate if pregnancy associated cells changes interfere with this scoring system we compared the results of pregnant and non-pregnant women. Histological result was used as an indicator of correctness of the score.

RESULTS

Statistical analysis showed a good correlation of the scoring system with histological results. Especially in pregnancy statistical analysis shows promising results (sensitivity 86.67 %, Specificity 100 %, receiver operating characteristic analysis p ≤ 0.05).

CONCLUSION

The Luebeck Score seems to be a useful approach for appraisal of pap smears in pregnancy. Further studies containing high numbers of cases are needed for further evaluation of potential benefits of the scoring system compared to conventional evaluation of pap smears.

Comparative analysis of cervical cytology screening methods and staining protocols for detection rate and accurate interpretation of ASC-H: Data from a high-volume laboratory in Turkey

BACKGROUND

This study evaluated the effectiveness of the ThinPrep(®) Imaging System (TIS) and ThinPrep(®) Pap Stain (TPPS). A comparative analysis was conducted to determine the detection rates of atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H), the ASC:squamous intraepithelial lesion (SIL) ratio, biopsy follow-up for ASC-H in terms of the screening method used (manual screening [MS] vs. TIS screening [TISS]) and the staining protocol (regular Pap stain [RPS] vs. TPPS).

METHODS

This study was performed over two periods. The RPS period included manually screened slides, whereas the TPPS period included TIS + manually screened slides. All data from the study periods were compared using statistical analysis.

RESULTS

The detection rate of ASC-H was significantly higher during the TPPS period than during the RPS period (0.49% vs. 0.23%); this finding is in contrast to the insignificant difference between the screening method periods. The positive predictive value (PPV) of ASC-H cytodiagnosis for cervical intraepithelial neoplasia of grade 2 or more severe histologies was significantly different between manually screened and TIS slides (22.10% vs. 38.55%), in contrast to an insignificant difference between RPS and TPPS periods (37.14% vs. 29.77%).

CONCLUSION

Implementation of the TIS did not change the ASC-H detection rates appreciably. However, the new technology improved PPV for ASC-H cytodiagnosis and enabled the detection of true disease. Our laboratory statistics indicate that the TPPS is not a superior staining protocol and did not increase our diagnostic accuracy for ASC-H compared with RPS.