Performance and reproducibility of gynecologic cytology interpretation using the FocalPoint system: results of the RODEO Study Team

Digital cytology part 2: artificial intelligence in cytology: a concept paper with review and recommendations from the American Society of Cytopathology Digital Cytology Task Force

Digital cytology and artificial intelligence (AI) are gaining greater adoption in the cytology laboratory. However, peer-reviewed real-world data and literature are lacking in regard to the current clinical landscape. The American Society of Cytopathology in conjunction with the International Academy of Cytology and the Digital Pathology Association established a special task force comprising 20 members with expertise and/or interest in digital cytology. The aim of the group was to investigate the feasibility of incorporating digital cytology, specifically cytology whole slide scanning and AI applications, into the workflow of the laboratory. In turn, the impact on cytopathologists, cytologists (cytotechnologists), and cytology departments were also assessed. The task force reviewed existing literature on digital cytology, conducted a worldwide survey, and held a virtual roundtable discussion on digital cytology and AI with multiple industry corporate representatives. This white paper, presented in 2 parts, summarizes the current state of digital cytology and AI practice in global cytology practice. Part 1 of the white paper is presented as a separate paper which details a review and best practice recommendations for incorporating digital cytology into practice. Part 2 of the white paper presented here provides a comprehensive review of AI in cytology practice along with best practice recommendations and legal considerations. Additionally, the cytology global survey results highlighting current AI practices by various laboratories, as well as current attitudes, are reported.

Cervical cancer: Automation of Pap test screening

BACKGROUND

Cervical cancer progresses slowly, increasing the chance of early detection of pre-neoplastic lesions via Pap exam test and subsequently preventing deaths. However, the exam presents both false-negatives and false-positives results. Therefore, automatic methods (AMs) of reading the Pap test have been used to improve the quality control of the exam. We performed a literature review to evaluate the feasibility of implementing AMs in laboratories.

METHODS

This work reviewed scientific publications regarding automated cytology from the last 15 years. The terms used were "Papanicolaou test" and "Automated cytology screening" in Portuguese, English, and Spanish, in the three scientific databases (SCIELO, PUBMED, MEDLINE).

RESULTS

Of the resulting 787 articles, 34 were selected for a complete review, including three AMs: ThinPrep Imaging System, FocalPoint GS Imaging System and CytoProcessor. In total, 1 317 148 cytopathological slides were evaluated automatically, with 1 308 028 (99.3%) liquid-based cytology slides and 9120 (0.7%) conventional cytology smears. The AM diagnostic performances were statistically equal to or better than those of the manual method. AM use increased the detection of cellular abnormalities and reduced false-negatives. The average sample rejection rate was ≤3.5%.

CONCLUSION

AMs are relevant in quality control during the analytical phase of cervical cancer screening. This technology eliminates slide-handling steps and reduces the sample space, allowing professionals to focus on diagnostic interpretation while maintaining high-level care, which can reduce false-negatives. Further studies with conventional cytology are needed. The use of AM is still not so widespread in cytopathology laboratories.

Evidence based appropriate triage strategies for implementing high risk HPV as primary technology in cervical cancer screening

Primary cervical cancer screening by HPV testing for high risk human papillomavirus (hrHPV) is expected to replace cytology-based programs in many parts of the world. Its high sensitivity and negative predictive value permit longer screening intervals up to beyond five years. However, low positive predictive value can lead to unnecessary referrals and overtreatment since most hrHPV infections are transient and will not develop disease. Therefore risk stratification is needed to effectively triage and identify women among the hrHPV positives, who are at an increased risk of cervical (pre)cancer who need further diagnostic evaluation to decide on further management. Several triage strategies like HPV16/18 genotyping, p16/Ki67 dual staining and DNA methylation markers (CADM1, MAL and miR-124-2) have been evaluated to determine suitable triage options. Triage with p16/Ki-67 dual-stain provided better long-term risk stratification than cytology with significant reduction in cumulative 5 years CIN3+ risk in p16/Ki-67 negative women. DNA methylation assays have shown higher specificity than cytology and higher sensitivity than HPV16/18 genotyping with added advantages of reproducibility and application on self-collected samples. Based on current evidence, Pap cytology with or without additional HPV16/18 genotyping remains the most recommended triage strategies for primary HPV screening. Other strategies will need more longitudinal studies to provide evidence of risk reduction in test negative results. WHO recommends Visual Inspection with Acetic Acid (VIA) for triaging HPV-positive women in LMIC settings. An optimal triage strategy that can be integrated with primary HPV screening should be able to segregate and reassure the large majority of women who are at very low risk of cervical cancer.

Prevention of Cervical Cancer: Guideline of the DGGG and the DKG (S3 Level, AWMF Register Number 015/027OL, December 2017) - Part 1 with Introduction, Screening and the Pathology of Cervical Dysplasia

Aims Annual opportunistic screening for cervical carcinoma has been carried out in Germany since 1971. The creation of this S3 guideline meets an important need, outlined in the National Cancer Plan, with regard to screening for cervical cancer, as the guideline aims to provide important information and support for planned organized screening for cervical cancer in Germany. Methods With the financial support of German Cancer Aid, 21 professional societies developed evidence-based statements and recommendations (classified using the GRADE system) for the screening, management and treatment of precancerous conditions of the cervix. Two independent scientific institutes compiled systematic reviews for this guideline. Recommendations The first part of this short summary presents the pathological basis and considers various questions related to screening for cervical cancer. As also reported in earlier reviews, the meta-analysis by Kleijnen Systematic Reviews showed that HPV-based screening offers better protection against invasive cervical cancer compared to cytology-based screening. The authors of this guideline therefore recommend - in accordance with the guideline of the Joint National Committee of Germany (Gemeinsamer Bundesauschuss, G-BA) - that women aged 35 and above should be examined at regular intervals (at least every 3 years) and undergo HPV-based screening. Co-testing can also be carried out. Women between the ages of 20 and 35 should have cytological screening every 2 years.

Study of the Pre-Analytical Phase of an ISO 15189: 2012-Certified Cytopathology Laboratory: A 5-Year Institutional Experience

OBJECTIVE

Total quality management, which basically involves pre-analytical, analytical, and postanalytical phases, is relatively more difficult in cytopathology due to descriptive reports and subjective variability. The pre-analytical phase of total quality management constitutes a major burden of errors in the laboratory and it has not been widely studied in cytopathology except in cervical Pap smears. The present study was therefore conducted to study the pre-analytical phase over 5 years from April 2013 until May 2018 at an ISO 15189: 2012-certified cytopathology laboratory, in a resource-limited setting. It was also intended to study the level of satisfaction of the patients and the training of the professionals provided in the cytology lab so as to improve and maintain high quality standards.

METHODS

The study included all the documents relating to the quality program used in the last 5 years in a medical institute situated in the north sub-Himalayan region of India. All the data were recorded and analysed for pre-analytical analysis of the total quality management system.

RESULTS

In total, 20,130 samples were received for cytological investigation. The total number of errors which were detected in the cytopathology lab were 1,430, constituting 7.1% of the total investigations done. The pre-analytical phase errors comprised 57% of the total errors (815/1,430), analytical errors constituted 11% (157/1,430), while postanalytical errors represented 32% (458/1,430). Incompletely filled requisition forms constituted the most common pre-analytical error (38%). There was a gradual decrease in the errors with time, but with a sudden increase between January to June 2015 due to new technicians joining during that period.

CONCLUSION

Pre-analytical quality management is an essential component for maintaining the quality and reducing the errors in the cytopathology lab. Documentation, continuous training, and maintenance of internal and external quality control with quality charts are the key for successful quality management. The identification of non-conformance with root-cause analysis and provision of scope for continuous improvement is vital for quality improvement in the lab. Patient satisfaction is an important aspect of quality in the lab, which should be combined with the satisfaction of the personnel working in the lab.

Pelvic radiotherapy for cervical cancer affects importantly the reproducibility of cytological alterations evaluation

Background

to evaluate the intraobserver and interobserver reproducibility of cervical cytopathology according to previous knowledge of whether patients received radiotherapy (RT) treatment or not.

Methods

The study analyzed a sample of 95 cervix cytological slides; 24 with cytological abnormalities (CA) and presence of RT; 21 without CA and presence of RT; 25 without CA and without previous RT; 25 with CA and without previous RT. Two cytopathology (CP) evaluations of the slides were carried out. For the first CP re-evaluation, the cytotechnologist was blinded for the information of previous RT. For the second CP re-evaluation, the cytotechnologist was informed about previous RT. The results were analyzed through inter and intraobserver agreement using the unweighted and weighted kappa.

Results

Post radiotherapy effects were identified in 44.4% of cases that undergone previous pelvic RT. The agreement for RT status was 66.32% (unweighted K = 0.31, 95%CI: 0.13; 0.49, moderate agreement). The intraobserver agreement, regarding the cytological diagnoses, regardless of radiotherapy status, was 80.32% (weighted K = 0.52, 95%CI: 0.34; 0.68). In no RT group, the intraobserver agreement was 70% (weighted K = 0.47, 95%CI: 0.27;0.65) and in patients that received RT, the intraobserver agreement was 84.09% (unweighted K = 0.37, 95%CI: 0.01;0.74). The interobserver agreement between cytopathology result (abnormal or normal) in the group with RT, considering normal and abnormal CP diagnosis was 14.0% and 12.5%, respectively. There was no association between the cytological alterations and the median time between the end of RT and the cytological diagnosis.

Conclusion

This study showed that RT has an important impact in CP diagnosis because the agreement, also in interobserver and intraobserver analysis, had high discrepancy in patients that received RT. Also, demonstrated that it is difficult to recognize the presence of RT in cytological slides when this information is not provided.

Recommendations on Quality Control and Quality Assurance in Cervical Cytology

OBJECTIVE

We aimed to critically evaluate the importance of quality control (QC) and quality assurance (QA) strategies in the routine work of uterine cervix cytology.

STUDY DESIGN

We revised all the main principles of QC and QA that are already being implemented worldwide and then discussed the positive aspects and limitations of these as well as proposing alternatives when pertinent.

RESULTS

A literature review was introduced after highlighting the main historical revisions, and then a critical evaluation of the principal innovations in screening programmes was conducted, with recommendations being postulated.

CONCLUSIONS

Based on the analysed data, QC and QA are two essential arms that support the quality of a screening programme.

Critical Analyses of the Introduction of Liquid-Based Cytology in a Public Health Service of the State of São Paulo, Brazil

OBJECTIVE

The aim of this study was to compare the performance of the current conventional Pap smear with liquid-based cytology (LBC) preparations.

STUDY DESIGN

Women routinely undergoing their cytopathological and histopathological examinations at Fundação Oncocentro de São Paulo (FOSP) were recruited for LBC. Conventional smears were analyzed from women from other areas of the State of São Paulo with similar sociodemographic characteristics.

RESULTS

A total of 218,594 cases were analyzed, consisting of 206,999 conventional smears and 11,595 LBC. Among the conventional smears, 3.0% were of unsatisfactory preparation; conversely, unsatisfactory LBC preparations accounted for 0.3%. The ASC-H (atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion) frequency did not demonstrate any differences between the two methods. In contrast, the incidence of ASC-US (atypical squamous cells of undetermined significance) was almost twice as frequent between LBC and conventional smears, at 2.9 versus 1.6%, respectively. An equal percentage of high-grade squamous intraepithelial lesions were observed for the two methods, but not for low-grade squamous intraepithelial lesions, which were more significantly observed in LBC preparations than in conventional smears (2.2 vs. 0.7%). The index of positivity was importantly enhanced from 3.0% (conventional smears) to 5.7% (LBC).

CONCLUSIONS

LBC performed better than conventional smears, and we are truly confident that LBC can improve public health strategies aimed at reducing cervical lesions through prevention programs.

Cervicovaginal cytology in patients undergoing pelvic radiotherapy using the Focalpoint system: results from the RODEO study

BACKGROUND

Evaluate the performance of the Focalpoint system in identifying and classifying cervical cytology alterations from samples collected from patients treated with Radiotherapy (RT).

METHODS

The reproducibility of manual and automated screening by cytotechnologists using the BD Focalpoint GS Imaging System was examined. Samples were collected from May 2010 to August 2011.

RESULTS

A total of 378 treated with RT and 8,967 cytology samples from patients without previous RT, were evaluated. The kappa values for cytological diagnoses read manually and automated in cases without previous RT were as follows: < ASC-H vs. ≥ ASC-H = 0.71; < LSIL vs. ≥ LSIL = 0.66; and < HSIL vs. ≥ HSIL = 0.67. The kappa for cytological diagnoses in post-RT women have showed: < ASC-H vs. ≥ ASC-H = 0.71; < LSIL vs. ≥ LSIL = 0.65; < HSIL vs. ≥ HSIL = 0.57.

CONCLUSIONS

There was no significant difference among the kappa values we found. Post-RT cytology showed small diagnostic agreement between manual and automated examination.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_231.