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

Cervical cancer screening efficacy using SurePath, ThinPrep and conventional cytology: A large data set analysis from the Japan Cancer Society

OBJECTIVE

Over the past decade, liquid-based cytology has replaced conventional cytology for cervical cancer screening in many countries, including Japan. We aimed to evaluate the efficacy of liquid-based cytology using a large database and compare two major liquid-based cytology platforms, SurePath and ThinPrep, to conventional cytology.

METHODS

Cervical cancer screening data were collected from the Japan Cancer Society between 2015 and 2019. The efficacy of liquid-based and conventional cytology in detecting cervical intraepithelial neoplasia (CIN) was evaluated. Detection rates and positive predictive values were compared using a Poisson regression model.

RESULTS

We collected data of 3,918,149 participants, including 2,248,202 conventional cytology, 874,807 SurePath and 795,140 ThinPrep smears. The detection rate of CIN2 or more was 1.14 times higher using SurePath than that using conventional cytology (95% confidence interval [CI], 1.09-1.20; p < 0.001). Contrastingly, the detection rate of CIN2 or more was 0.91 times lower using ThinPrep (95% CI, 0.86-0.96; p < 0.001). The detection rates of CIN3 or more did not differ significantly between SurePath and conventional cytology (detection rate ratio, 1.04; 95% CI, 0.97-1.12; p = 0.224). The positive predictive value ratios of CIN2 or more were 0.80 using SurePath (95% CI, 0.76-0.84; p < 0.001) and 0.83 using ThinPrep (95% CI, 0.79-0.87; p < 0.001) compared with conventional cytology.

CONCLUSIONS

Liquid-based cytology, particularly SurePath, was useful for detecting CIN2 or higher in population-based cervical cancer screening. Further widespread use of liquid-based cytology methods would lead to efficient detection of cervical precancerous lesions.

Sexually Transmitted Human Papillomavirus: Update in Epidemiology, Prevention, and Management

This review presents the epidemiology, pathophysiology, prevention, and management of sexually transmitted human papillomavirus (HPV) and its associated diseases. HPV is the most common sexually transmitted infection worldwide. Prevalence varies regionally. Low-risk strains cause anogenital warts, which can be managed with patient- or provider-applied therapies. High-risk strains cause lower anogenital cancers. Primary and secondary prevention strategies include vaccination and screening for precancerous lesions, respectively. Management of abnormal screening results vary by test result, anatomic site, and individual cancer risk. Approaches include close rescreening, high-resolution visualization with biopsy, and-when biopsy-proven precancer is identified-removal or destruction of the lesion.

Comparison of primary cytology, primary HPV testing and co-testing as cervical cancer screening for Chinese women: a population-based screening cohort

OBJECTIVES

We compared clinical performance of three strategies of primary human papillomavirus (HPV) testing, primary cytology and co-testing for cervical cancer screening.

DESIGN

A population-based prospective cohort study of clinical performance of screening strategy.

SETTING

Patients recruited from community in Changzhi County, Shanxi Province, China.

PATIENT

3209 women aged 30-64 years without gynaecological issues.

PRIMARY AND SECONDARY OUTCOME MEASURES

The performance of different screening strategies for detecting cervical intraepithelial neoplasia grade 2 or more severe (CIN2+).

RESULTS

A total of 53 CIN2+ and 31 CIN3+ cases are detected. For CIN2+, sensitivity of primary HPV (95.9%) and co-testing (98.0%) are not statistically different, but significantly higher than primary cytology (48.0%). Specificity (86.8%), colposcopy referral rate (7.8%) and number of colposcopies required to detect one case (9.8) for primary HPV are better than co-testing (79.8%, 11.9%, 14.3%, respectively). For CIN3+, primary HPV, co-testing have 100% of sensitivity and specificity, which is significantly higher than primary cytology (56.7% and 90.2%). Number of colposcopies required to detect one case for primary HPV (15.9) is better than co-testing (23.8).

CONCLUSIONS

Compared with co-testing, HPV primary screening had comparable sensitivity and higher specificity for CIN2+ detection, and both of them showed better performance than cytology primary screening in cervical cancer screening.

Comparison of Breast Cancer and Cervical Cancer in Uzbekistan and Korea: The First Report of The Uzbekistan-Korea Oncology Consortium

In general, as a country's economy, education level, and life expectancy increase, the incidence of cancer increases. This is because the peak incidence of cancer occurs in individuals in their 70s and 80s, and the health proportion of non-communicable diseases increases with the development of the living environment. Changes in diet, lifestyle and enhanced methods of detection contribute to an increase in cancer incidence as well. Recently, Uzbekistan has grown rapidly, and its incidence of cancer is also increasing. In the health management of cancer, not only treatment but also the identification and prevention of causes and effective screening should be considered. South Korea has a common ethnicity with Uzbekistan and has successfully performed national screening for seven major cancers over the past 20 years. The 5-year survival rate after cancer diagnosis in Korea was only 42.9% 20 years ago, but recently it has improved to 70.7%. We formed an advisory consortium in which oncologists from Uzbekistan and Korea could cooperate for cancer management in Uzbekistan. This advisory consortium intends to present the necessary considerations and recommendations for cancer management in Uzbekistan by examining the literature and cancer statistics of Uzbekistan and South Korea. In addition to the overall analysis, we identified and reviewed the major cancers with high morbidity in three categories in Uzbekistan: gynecological cancer (breast and cervical cancer), cancer common in men (lung and liver cancer), and gastrointestinal cancer (stomach and colorectal cancer). This review covers the general cancer statistics of Uzbekistan and a detailed review of gynecological cancer between two countries, and relevant recommendations.

Liquid-Based Cytology in the Detection of Premalignant Lesions in Patients with "Atypia in Squamous Cells" in Conventional Cytology

Background

The management of patients with "Atypical Squamous Cells" (ASC) in conventional papanicolaou smears (CPS) is based on the risk of high-grade squamous intraepithelial lesion (HSIL). The efficacy of liquid-based cytology (LBC) to detect this premalignant lesion is variable, with little evidence of its performance in Colombian patients.

Aims

The aim of this study is to determine the performance of LBC in the detection of premalignant lesions, in patients with ASC in CPS.

Materials and Methods

Were obtained patients who attended colposcopy clinic due the result of ASC in CPS. An LBC was taken, which was interpreted by two pathologists without access to other results. The performance of LBC to detect HSIL, was determined, considering as a gold standard: histopathological study/negative-satisfactory colposcopy.

Results

Were included 114 patients, with a mean age of 38.4 years (SD ± 13.3). LBC had abnormal results in 40.36% (n = 46), with a slightly higher proportion of low-grade squamous intraepithelial lesion (LSIL) than HSIL. The total of abnormal diagnoses by colposcopy and/or biopsy was 51.75% (n = 59), with a predominance of LSIL (36.84%). The sensitivity of the liquid-based cytology to detect premalignant lesions was 76.5%, specificity: 66.0%, positive predictive value: 28.3% and negative predictive value: 94.1%; The Cohen's kappa index of LBC for detecting HSIL was 0.2492 for the total population and 0.2907 for ≥30 years.

Discussion

Although LBC decreases abnormal cytology and increases the detection of HSIL, which improves diagnostic accuracy; sensitivity and predictive values for detecting HSIL are not significantly different between CPS and LBC.

Computer-aided diagnosis of cervical dysplasia using colposcopic images

Background

computer-aided diagnosis of medical images is becoming more significant in intelligent medicine. Colposcopy-guided biopsy with pathological diagnosis is the gold standard in diagnosing CIN and invasive cervical cancer. However, it struggles with its low sensitivity in differentiating cancer/HSIL from LSIL/normal, particularly in areas with a lack of skilled colposcopists and access to adequate medical resources.

Methods

the model used the auto-segmented colposcopic images to extract color and texture features using the T-test method. It then augmented minority data using the SMOTE method to balance the skewed class distribution. Finally, it used an RBF-SVM to generate a preliminary output. The results, integrating the TCT, HPV tests, and age, were combined into a naïve Bayes classifier for cervical lesion diagnosis.

Results

the multimodal machine learning model achieved physician-level performance (sensitivity: 51.2%, specificity: 86.9%, accuracy: 81.8%), and it could be interpreted by feature extraction and visualization. With the aid of the model, colposcopists improved the sensitivity from 53.7% to 70.7% with an acceptable specificity of 81.1% and accuracy of 79.6%.

Conclusion

using a computer-aided diagnosis system, physicians could identify cancer/HSIL with greater sensitivity, which guided biopsy to take timely treatment.

Cervical cell lift: A novel triage method for the spatial mapping and grading of precancerous cervical lesions

BACKGROUND

Primary HPV screening, due to its low specificity, requires an additional liquid-based cytology (LBC) triage test. However, even with LBC triage there has been a near doubling in the number of patients referred for colposcopy in recent years, the majority having low-grade disease.

METHODS

To counter this, a triage test that generates a spatial map of the cervical surface at a molecular level has been developed which removes the subjectivity associated with LBC by facilitating identification of lesions in their entirety. 50 patients attending colposcopy were recruited to participate in a pilot study to evaluate the test. For each patient, cells were lifted from the cervix onto a membrane (cervical cell lift, CCL) and immunostained with a biomarker of precancerous cells, generating molecular maps of the cervical surface. These maps were analysed to detect high-grade lesions, and the results compared to the final histological diagnosis.

FINDINGS

We demonstrated that spatial molecular mapping of the cervix has a sensitivity of 90% (95% CI 69-98) (positive predictive value 81% (95% CI 60-92)) for the detection of high-grade disease, and that AI-based analysis could aid disease detection through automated flagging of biomarker-positive cells.

INTERPRETATION

Spatial molecular mapping of the CCL improved the rate of detection of high-grade disease in comparison to LBC, suggesting that this method has the potential to decisively identify patients with clinically relevant disease that requires excisional treatment.

FUNDING

CRUK Early Detection Project award, Jordan-Singer BSCCP award, Addenbrooke's Charitable Trust, UK-MRC, Janssen Pharmaceuticals/Advanced Sterilisation Products, and NWO.

A retrospective analysis of serous effusions based on the newly proposed international system for reporting serous fluid cytopathology: a report of 3633 cases in an oncological center

Background

The International System for Reporting Serous Fluid Cytopathology (TIS) was recently proposed. We retrospectively applied TIS recommendations for reporting the cytological diagnosis of serous effusions and reported our experience.

Methods

All the serous effusions from January 2018 to September 2021 were retrieved from the database. Recategorization was performed using the TIS classification, the risk of malignancy (ROM) was calculated for each TIS category. In addition, on the basis of the original TIS classification, we further subdivided the TIS category IV (suspicious for malignancy, SFM) into 2 groups (IVa and IVb) according to cytological characteristics (quality and quantity) to explore the necessity of SFM subclassification. The performance evaluation was carried out using different samples (pleural, peritoneal and pericardial effusions) and preparation methods (conventional smears, liquid-based preparations and cell blocks).

Results

A total of 3633 cases were studied: 17 (0.5%) were diagnosed as ‘nondiagnostic’ (I, ND), 1100 (30.3%) as ‘negative for malignancy’ (II, NFM), 101 (2.8%) as ‘atypia of undetermined significance’ (III, AUS), 677 (18.6%) as ‘suspicious for malignancy’ (IV, SFM), and 1738 (47.8%) as ‘malignant’ (V, MAL). The ROMs for the categories were 38.5%, 28.6%, 52.1%, 99.4% and 100%, respectively. The ROM for SFM was significantly higher than that for AUS (P < 0.001), while the difference between the ROMs for IVa and IVb was insignificant. The sensitivity, negative predictive value (NPV) and diagnostic accuracy of liquid-based preparations were all superior to those of conventional smears and cell blocks in detecting abnormalities. Using the three preparation methods simultaneously had the highest sensitivity, NPV and diagnostic accuracy.

Conclusion

Serous effusion cytology has a high specificity and positive predictive value (PPV), and TIS is a user-friendly reporting system. Liquid-based preparations could improve the sensitivity of diagnosis, and it is best to use three different preparation methods simultaneously for serous effusion cytologic examination.

Efficacy of careHPV™ human papillomavirus screening versus conventional cytology tests for the detection of precancerous and cancerous cervical lesions among women living with HIV-1 in Lao People's Democratic Republic

BACKGROUND

In the Lao People's Democratic Republic (Lao PDR), cervical cancer is the third leading cause of women cancer.

AIMS

The objective of this cross-sectional study was to compare the efficacy of careHPV™ test versus conventional Pap smear or Siriraj liquid-based cytology in the detection of cervical cancer in women living with human immunodeficiency virus type 1 (HIV-1).

MATERIALS & METHODS

Overall, 631 women consented to participate. Four cervical specimens were taken for the purpose of conventional Pap smear, Siriraj liquid-based cytology, careHPV™ test, and HPV-16 genotyping. The exact McNemar test was used to compare the efficacy and diagnostic performance of the tests.

RESULTS

Of the 631 women with follow-up, 331 were human papillomavirus (HPV) negative. High-grade squamous intraepithelial lesions were found in 37 women, biopsy-proven high-grade cervical intraepithelial neoplasia in 50 women, and invasive carcinoma in seven women. The proportion of women with high-grade cervical lesion or carcinoma detected after abnormal careHPV™ test was higher (6.02%; 95% confidence interval [CI]: 4.4-8.1) than that detected by conventional Pap smear (4.59%; 95% CI: 3.2-6.5). careHPV™ and HPV-16 genotyping had, respectively, the highest sensitivity (80.8%; 95% CI: 67.4-89.5) and specificity (92.2%; 95% CI: 89.8-94.2). HPV-16 was the most frequently detected genotype.

CONCLUSIONS

careHPV™ test represents a screening option in Lao PDR, particularly in women living with HIV-1 because of higher prevalence of chronic HPV in this population.

Diagnostic accuracy for alternative cervical cancer screening strategies: A systematic review and meta-analysis

We performed a systematic review and meta-analysis to evaluate the accuracy of screening cervical cancer tests as alternative standalone methods. The combined estimates of sensitivity of visual inspection with acetic acid, visual inspection with lugol's iodine, conventional pap smear, liquid-based cytology, High risk HPV testing by clinician, High risk HPV testing by self- sampling, cervicography were 64%, 80%, 55%, 70%, 70% and 67% respectively; the combine values of specificity of these screening strategies were 88%, 88%, 96%, 59%, 94%, and 95% respectively. Our findings draw attention to an attractive opinion to facilitate the collection of specimens for DNA HPV by patients in settings where they don't have access to a regular screening programs.

New Trends in the Detection of Gynecological Precancerous Lesions and Early-Stage Cancers

The prevention and early diagnostics of precancerous stages are key aspects of contemporary oncology. In cervical cancer, well-organized screening and vaccination programs, especially in developed countries, are responsible for the dramatic decline of invasive cancer incidence and mortality. Cytological screening has a long and successful history, and the ongoing implementation of HPV triage with increased sensitivity can further decrease mortality. On the other hand, endometrial and ovarian cancers are characterized by a poor accessibility to specimen collection, which represents a major complication for early diagnostics. Therefore, despite relatively promising data from evaluating the combined effects of genetic variants, population screening does not exist, and the implementation of new biomarkers is, thus, necessary. The introduction of various circulating biomarkers is of potential interest due to the considerable heterogeneity of cancer, as highlighted in this review, which focuses exclusively on the most common tumors of the genital tract, namely, cervical, endometrial, and ovarian cancers. However, it is clearly shown that these malignancies represent different entities that evolve in different ways, and it is therefore necessary to use different methods for their diagnosis and treatment.

Lower accuracy of cytological screening for high-grade squamous intraepithelial neoplasia in women over 50 years of age in Japan

Background

As the population ages in developed countries, the number of Pap smears for cervical cancer screening of older women is increasing. There is concern that cervical atrophy may cause misinterpretation of results for this segment of the population. The present study evaluated the accuracy of screening for high-grade intraepithelial lesions (HSILs) in women younger or older than 50 years, to determine whether aging affects cytological interpretation.

Methods

Patients with HSIL cytology (N = 1565) were dichotomized into those aged 20–49 years or aged ≥ 50 years. Association between histology results and age was examined. Pearson’s chi-squared test and Cochran-Armitage trend test were used for statistical analysis.

Results

The positive predictive value (PPV) for cervical intraepithelial neoplasia (CIN)2 and worse was 65.2% (62/95) in older women but 87.3% (482/552) in younger women (p < 0.001). Older patients had a significantly lower PPV (p = 1.69 × 10^–8). Separately analyzing chronic cervicitis, CIN1 and overt cancer grouped together, compared with another group composed of CIN2 and CIN3, we found that the PPV for CIN2 and CIN3 was lower in older than in younger women [44.2% (42/95)-vs-82.4% (455/552), p < 0.001], respectively.

Conclusions

HSILs are associated with a wide range of disease categories as age increases, and the accuracy of HSIL interpretation is lower in older women.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10147-021-02065-w.

Cytohistological Correlation in Pleural Effusions Based on the International System for Reporting Serous Fluid Cytopathology

The International System for Reporting Serous Fluid Cytology (TIS) was recently developed. Given its novelty, most studies looking into the risk of malignancy (ROM) of serous effusion diagnostic categories were published before the development of TIS. We searched the database of our department for pleural effusions diagnosed in the last five years, excluding those without a corresponding pleural biopsy. Cases were reviewed and reclassified according to the TIS. A cytohistological correlation was performed. In total, 350 pleural effusion specimens with one or more corresponding pleural biopsies were included. After reclassification, 5 (1.43%) were nondiagnostic (ND), 253 (72.29%) were negative for malignancy (NFM), 7 (2.00%) had atypia of unknown significance (AUS), 14 (4.00%) were suspicious for malignancy (SFM), and 71 (20.57%) were malignant (MAL). Calculated ROM was 40% for ND, 20.16% for NFM, 42.86% for AUS, 78.57% for SFM, and 100% for MAL. Effusion cytology sensitivity and specificity were 60.29% and 98.56%, respectively. This is the first publication looking into the cytohistological correlation of a retrospective cohort of pleural effusions based on the TIS. We add to the body of data regarding the ROM for TIS categories, highlighting areas of potential future research.

Aneuploidy detection for diagnostic and prognostic use in premalignant and malignant lesions of the uterine cervix: A systematic review

OBJECTIVE

To systematically review the role of aneuploidy detection alone or in combination with other methods in cervical cancer screening and to evaluate the value of aneuploidy to predict the behavior of premalignant cervical lesions.

METHOD

We conducted a systematic review based on an electronic search for articles published between 2001 and 2020 across databases including MEDLINE/PubMed, Scopus, and Web of Science. Studies were subjected to data extraction, risk of bias, and narrative synthesis.

RESULTS

A total of 15 articles were included in the review. Eight out of 15 studies (53.3%) were judged to be at a high or unclear risk of bias. From the 15 included studies, the index test to detect aneuploidy was DNA image cytometry (DNA-ICM) in 12 studies and DNA flow cytometry (DNA-FCM) in three studies. Nine studies also evaluated the performance of cytology and/or human papillomavirus (HPV) tests. For DNA-ICM, sensitivity to detect cervical intraepithelial neoplasia or worse (CIN2+) varied between 59.0% and 95.9% and specificity varied between 54.1% and 100%. For DNA-FCM, sensitivity varied between 27.3% to 96.8% and specificity was 100%. For cytological evaluation, sensitivity varied between 25.0% and 70.4% and specificity varied between 70.6% and 99.9%. For HPV detection, sensitivity varied between 39.4% and 100% and specificity varied between 23.3% and 84.3%.

CONCLUSION

DNA ploidy along with atypical cells findings in cytology and/or HPV detection revealed great value to detect CIN2+ lesions and to predict which lesions are more likely to progress to cervical cancer.

Cervical Cancer Screening: Comparison of Conventional Pap Smear Test, Liquid-Based Cytology, and Human Papillomavirus Testing as Stand-alone or Cotesting Strategies

BACKGROUND

Some countries have implemented stand-alone human papillomavirus (HPV) testing while others consider cotesting for cervical cancer screening. We compared both strategies within a population-based study.

METHODS

The MARZY cohort study was conducted in Germany. Randomly selected women from population registries aged ≥30 years (n = 5,275) were invited to screening with Pap smear, liquid-based cytology (LBC, ThinPrep), and HPV testing (Hybrid Capture2, HC2). Screen-positive participants [ASC-US+ or high-risk HC2 (hrHC2)] and a random 5% sample of screen-negatives were referred to colposcopy. Post hoc HPV genotyping was conducted by GP5+/6+ PCR-EIA with reverse line blotting. Sensitivity, specificity (adjusted for verification bias), and potential harms, including number of colposcopies needed to detect 1 precancerous lesion (NNC), were calculated.

RESULTS

In 2,627 screened women, cytological sensitivities (Pap, LBC: 47%) were lower than HC2 (95%) and PCR (79%) for CIN2+. Cotesting demonstrated higher sensitivities (HC2 cotesting: 99%; PCR cotesting: 84%), but at the cost of lower specificities (92%-95%) compared with HPV stand-alone (HC2: 95%; PCR: 94%) and cytology (97% or 99%). Cotesting versus HPV stand-alone showed equivalent relative sensitivity [HC2: 1.06, 95% confidence interval (CI), 1.00-1.21; PCR: 1.07, 95% CI, 1.00-1.27]. Relative specificity of Pap cotesting with either HPV test was inferior to stand-alone HPV. LBC cotesting demonstrated equivalent specificity (both tests: 0.99, 95% CI, 0.99-1.00). NNC was highest for Pap cotesting.

CONCLUSIONS

Cotesting offers no benefit in detection over stand-alone HPV testing, resulting in more false positive results and colposcopy referrals.

IMPACT

HPV stand-alone screening offers a better balance of benefits and harms than cotesting.See related commentary by Wentzensen and Clarke, p. 432.

Method for preservation of DNA stability of liquid-based cytology specimens from a lung adenocarcinoma cell line

Liquid-based cytology (LBC) specimens of lung adenocarcinoma have the potential to be widely used for genetic analysis. However, formaldehyde contained in some LBC preservation solutions can cause DNA fragmentation during specimen storage, rendering the samples unsuitable for molecular analysis. To investigate a novel preservation technique for improved DNA stability, which was evaluated by mutation analysis of epidermal growth factor receptor (EGFR) gene in human lung adenocarcinoma cell lines. Cells were fixed in CytoRich Red preservation solution. After 30 min of fixation, cells were either stored using the conventional method (suspended in preservation solution) or washed in phosphate-buffered saline and stored as a cell pellet (newly proposed method). The effect of storage was evaluated after 5, 7, and 9 days of storage at ambient temperature. The cell pellet group was also tested after 14 and 28 days. Specifically, we evaluated the DNA stability, DNA yield, and sample suitability for polymerase chain reaction (PCR), and EGFR mutation detection. The DNA yields and degree of stability from the cell pellet group were higher than those from the suspension group at every time point examined. PCR amplification from the cell pellet group was successful up to day 28. Mutation detection using the Cycleave PCR method indicated that the Ct values of the cell pellet group were significantly lower than those of the suspension group. Storing LBC specimens as a cell pellet post-fixation can maintain the DNA quality for a longer period than the conventional method, making it a promising strategy for molecular analysis.

Artificial intelligence-assisted cytology for detection of cervical intraepithelial neoplasia or invasive cancer: A multicenter, clinical-based, observational study

OBJECTIVE

Artificial intelligence (AI) could automatedly detect abnormalities in digital cytological images, however, the effect in cervical cancer screening is inconclusive. We aim to evaluate the performance of AI-assisted cytology for the detection of histologically cervical intraepithelial lesions (CIN) or cancer.

METHODS

We trained a supervised deep learning algorithm based on 188,542 digital cytological images. Between Mar 13, 2017, and Oct 20, 2018, 2145 referral women from organized screening were enrolled in a multicenter, clinical-based, observational study. Cervical specimen was sampled to generate two liquid-based slides: one random slide was allocated to AI-assisted reading, and the other to manual reading conducted by skilled cytologists from senior hospital and cytology doctors from primary hospitals. HPV testing and colposcopy-directed biopsy was performed, and histological result was regarded as reference. We calculated the relative sensitivity and relative specificity of AI-assisted reading compared to manual reading for CIN2+. This trial was registered, number ChiCTR2000034131.

RESULTS

In the referral population, AI-assisted reading detected 92.6% of CIN 2 and 96.1% of CIN 3+, significantly higher than or similar to manual reading. AI-assisted reading had equivalent sensitivity (relative sensitivity 1.01, 95%CI, 0.97-1.05) and higher specificity (relative specificity 1.26, 1.20-1.32) compared to skilled cytologists; whereas higher sensitivity (1.12, 1.05-1.20) and specificity (1.36, 1.25-1.48) compared to cytology doctors. In HPV-positive women, AI-assisted reading improved specificity for CIN1 or less at no expense of reduction of sensitivity compared to manual reading.

CONCLUSIONS

AI-assisted cytology may contribute to the primary cytology screening or triage. Further studies are needed in general population.

The artificial intelligence-assisted cytology diagnostic system in large-scale cervical cancer screening: A population-based cohort study of 0.7 million women

Background

Adequate cytology is limited by insufficient cytologists in a large‐scale cervical cancer screening. We aimed to develop an artificial intelligence (AI)‐assisted cytology system in cervical cancer screening program.

Methods

We conducted a perspective cohort study within a population‐based cervical cancer screening program for 0.7 million women, using a validated AI‐assisted cytology system. For comparison, cytologists examined all slides classified by AI as abnormal and a randomly selected 10% of normal slides. Each woman with slides classified as abnormal by either AI‐assisted or manual reading was diagnosed by colposcopy and biopsy. The outcomes were histologically confirmed cervical intraepithelial neoplasia grade 2 or worse (CIN2+).

Results

Finally, we recruited 703 103 women, of whom 98 549 were independently screened by AI and manual reading. The overall agreement rate between AI and manual reading was 94.7% (95% confidential interval [CI], 94.5%‐94.8%), and kappa was 0.92 (0.91‐0.92). The detection rates of CIN2+ increased with the severity of cytology abnormality performed by both AI and manual reading (P_trend < 0.001). General estimated equations showed that detection of CIN2+ among women with ASC‐H or HSIL by AI were significantly higher than corresponding groups classified by cytologists (for ASC‐H: odds ratio [OR] = 1.22, 95%CI 1.11‐1.34, P < .001; for HSIL: OR = 1.41, 1.28‐1.55, P < .001). AI‐assisted cytology was 5.8% (3.0%‐8.6%) more sensitive for detection of CIN2+ than manual reading with a slight reduction in specificity.

Conclusions

AI‐assisted cytology system could exclude most of normal cytology, and improve sensitivity with clinically equivalent specificity for detection of CIN2+ compared with manual cytology reading. Overall, the results support AI‐based cytology system for the primary cervical cancer screening in large‐scale population.

Cytohistological correlation in serous effusions using the newly proposed International System for Reporting Serous Fluid Cytopathology: Experience of an oncological center

BACKGROUND

Cytological analysis is part of the initial etiological evaluation of serous effusions. The newly proposed International System for Reporting Serous Fluid Cytopathology (ISRSFC) aims to standardize reporting.

METHODS

All pleural and peritoneal effusion samples admitted for cytological analysis at our institution between 2012 and 2016, and pericardial effusion samples admitted between 2008 and 2018, were reviewed and reclassified according to the ISRSFC. Risk of malignancy (ROM) and performance parameters were calculated.

RESULTS

1496 pleural effusion samples were reclassified: 12(0.8%) non-diagnostic (ND), 944(63.1%) negative for malignancy (NFM), 9(0.6%) atypia of undetermined significance (AUS), 54(3.6%) suspicious of malignancy (SFM) and 477(31.9%) malignant (M). 64 pericardial effusion samples were reclassified: 23(35.9%) NFM, 1(1.6%) AUS, 4(6.3%) SFM and 36(56.2%) M. 763 peritoneal effusion samples were reclassified: 5(0.7%) ND, 457(59.9%) NFM, 12(1.6%) AUS, 37(4.8%) SFM and 252(33%) M. The ROM was, respectively, for each of the aforementioned categories, 57.1%, 23.9%, 50%, 76.2%, 100% in pleural effusions, 100%, 26.3%, 62.5%, 91.7%, 100% in peritoneal effusions and 0% for NFM, 0% for AUS and 100% for M in pericardial effusions. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were, respectively, 61.6%, 100%, 100%, 73.3%, 81.3% for pleural, 100%, 100%, 100%, 100%, 100% for pericardial and 61.2%, 100%, 100%, 70%, 79.7% for peritoneal effusion samples.

CONCLUSION

Serous effusion cytology has a high specificity and positive predictive value and a modest sensitivity and negative predictive value, supporting its role in confirming the diagnosis of malignancy. The ISRSFC will increase standardization and reproducibility in reporting, leading to improved clinical decision-making.

A comparison of liquid-based and conventional cytology using data for cervical cancer screening from the Japan Cancer Society

OBJECTIVE

Liquid-based cytology has replaced conventional cytology in cervical cancer screening in many countries. However, a detailed comparison of liquid-based cytology with conventional cytology has not been reported in Japan. Therefore, the aim of the study is to evaluate efficacy of liquid-based cytology in Japan.

METHODS

We first evaluated the prevalence of use of liquid-based cytology and then examined the efficacy of liquid-based cytology and conventional cytology for detecting CIN and the rate of unsatisfactory specimens using data from cancer screening collected by the Japanese Cancer Society from FY2011 to FY2014. A Poisson regression model with random effects analyses was used to classify histological outcomes and unsatisfactory specimens using liquid-based cytology compared to conventional cytology.

RESULTS

A total of 3 815 131 women were analyzed in the study. The rate of liquid-based cytology increased from approximately 8% in FY2011 to 37% in FY2014. Compared to conventional cytology, the detection rates with liquid-based cytology were significantly higher (1.42 times) for CIN1+ [detection rate ratio (DRR) = 1.42, 95% confidence interval (CI) 1.35-1.48, P < 0.001] and CIN2+ (DRR = 1.16, 95% CI 1.08-1.25, P < 0.001). Positive predictive value ratios of CIN1+ and CIN2+ were also significantly higher for liquid-based cytology than for conventional cytology. However, there was no significant difference between liquid-based cytology and conventional cytology for detection rates and positive predictive values of CIN3+ and cancer. The rate of unsatisfactory specimens was significantly lower with liquid-based cytology compared to conventional cytology (DRR = 0.07, 95% CI 0.05-0.09, P < 0.001).

CONCLUSIONS

In order to avoid the unsatisfactory specimens in cervical cancer screening, the results of this study did indicate that liquid-based cytology was more useful than conventional cytology in practical standpoints.

Comparative evaluation of conventional cytology and a low-cost liquid-based cytology technique, EziPREP™, for cervicovaginal smear reporting: A split sample study

Background:

Liquid-based cytology (LBC) for cervical cancer screening offers several advantages over conventional cytology. However, the extremely high cost of the current approved devices precludes widespread application of LBC technique in resource-constrained countries. This study aimed to evaluate the performance of an indigenous low-cost LBC technique, EziPREP™ (EP), against conventional preparations (CPs) for cervical cancer screening.

Materials and Methods:

A cross-sectional split-sample study with consecutive cervical sampling was conducted on 515 women attending the clinic at our institute. CP smears were prepared as per the standard technique using spatula and endocervical brush followed by detaching the head of brush into the fixative vial of EP. The EP samples were processed as per the manufacturer's protocol. Both CP and EP smears were stained using standard Papanicolaou stain protocol. Both sets of smears were evaluated for staining quality, morphologic details, and cytologic diagnoses. Cytologic diagnoses were correlated with cervical biopsy findings, wherever available. Performance characteristics of the two techniques were calculated.

Results:

The unsatisfactory rate for CP was 1.0%, while on EP, 1.3% smears had inadequate cellular material. The staining quality and morphological details were comparable in both sets of smears. The detection of infections and epithelial cell abnormality was more, though not statistically significant in EP smears. There was a 98% concordance in cytologic diagnosis between CP and EP smears. Cytohistologic concordance was observed in 96% of cases for both CP and EP smears. Although the time taken for processing and staining of smears was higher for EP (2.5 min for EP per smear and 1.6 min for CP per smear), the screening time reduced from 6.5 min per smear for CP to 2.2 min in EP smears.

Conclusion:

EP provides monolayered cervical smears with vivid morphological details, leading to reduced screening time and relatively higher pick-up of infections and low-grade cervical lesions as compared to conventional smears. The availability of such low-cost devices may enable wider application of cytology-based cervical cancer screening in low-resource countries.

Are we ready to develop a tiered scheme for the effusion cytology? A comprehensive review and analysis of the literature

BACKGROUND

Cytology is widely utilized in the initial evaluation of fluid accumulation in the body cavities. The aim of this study was to determine the accuracy of cytology in distinguishing between benign and malignant (MAL) effusions.

METHODS

A comprehensive and systematic review of the literature was conducted to evaluate the accuracy of serous effusion cytology (SEC) against tissue biopsy/resection histology, imaging, or clinical follow-up as the reference test. Risk of publication bias and level of heterogeneity in the included studies was assessed. Meta-regression was performed to assess the effect of various variables on the accuracy of SEC.

RESULTS

Eighty studies met the inclusion criteria for meta-analysis comprising of 34 941 samples; of which 52 (0.2%), 22 202 (72.7%), 194 (0.6%), 711 (2.3%), and 6507 (21.3%) could be reclassified as nondiagnostic (ND), negative for malignancy (NFM), atypical (atypia of uncertain significance-AUS), suspicious for malignancy (SFM), and malignant (MAL), respectively. On follow-up, the mean risk of malignancy for ND, NFM, AUS, SFM, MAL was 17.4%, 20.7%, 65.9%, 81.8%, and 98.9%, respectively. A total of 73 studies were included in estimating the diagnostic accuracy of SEC. The bivariate mixed-effect model estimated the SEC sensitivity, specificity, diagnostic odds ratio, positive likelihood ratio, and negative likelihood ratio as 73.1%, 99.9%, 7850.6%, 2112.2%, and 0.27%, respectively.

CONCLUSION

Serous effusion cytology shows high specificity and moderate sensitivity in the evaluation of serous effusions. A tiered classification scheme can improve the consistency of terminology for reporting SEC results, thus improving communication between the pathologists and clinical team, and quality of patient care.

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.

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.

Atypical Squamous Cells of Undetermined Significance Cervical Cytology Report Rate and Histologic Follow-up Findings From the Largest College of American Pathologists-Certified Laboratory in China

CONTEXT.—

Reports for atypical squamous cells of undetermined significance (ASC-US) and histologic findings are rare in China.

OBJECTIVE.—

To analyze the correlation findings of ASC-US cytology with high-risk human papillomavirus (hrHPV) test and histopathologic follow-ups.

DESIGN.—

ASC-US cases with hrHPV test and histologic follow-ups between 2011 and 2015 were analyzed at a College of American Pathologists-certified laboratory.

RESULTS.—

A total of 2 206 588 Papanicolaou (Pap) tests were performed, including 1 513 265 liquid-based cytology preparations (68.58%), and 693 323 conventional Pap tests (31.42%). The overall ASC-US reporting rate was 3.77% (83 199 of 2 206 588), with the highest in women aged 40 to 49 years. Of 18 574 women with ASC-US Pap and HPV testing, the hrHPV positivity rate was 34.98% (6498 of 18 574) with the highest in women younger than 30 years. A total of 6012 women with ASC-US Pap test findings had histologic follow-ups within 6 months; the overall cervical intraepithelial neoplasia 2 and above (CIN2+) detection rate was 7.87% (473 of 6012). One thousand nine hundred nine women with ASC-US Pap and HPV testing had histologic results. CIN2+ lesion was found in 13.98% (124 of 887) of women with ASC-US Pap/HPV-positive test results, significantly higher than 2.84% (29 of 1022) for women with ASC-US Pap/HPV-negative test results. Cervical squamous cell carcinoma was found in 3.95% (35 of 887) of women with ASC-US/HPV-positive test results.

CONCLUSIONS.—

This is one of the largest studies to investigate HPV and histologic follow-up findings in women with ASC-US in China. The ASC-US reporting rate, HPV positivity rate, and CIN2+ detection rate were all within the currently recognized benchmark ranges. These findings may contribute to establishing a baseline for better understanding of the status of cervical screening in China.

Comparison of conventional Pap smear and liquid-based cytology: A study of cervical cancer screening at a tertiary care center in Bihar

Background

Cervical cancer is the fourth leading cause of cancer in women in the world and it is the second most common cancer in women 15-44 years of age. Strict implementation of screening programs has led to a large decrease in cervical cancer incidence and mortality in the developed countries. In contrast, cervical cancer remains largely uncontrolled in high-risk developing countries because of ineffective or no screening programs. Conventional Pap smear method has been the mainstay of most of the screening programs for many decades. However, this technique is not without limitations, and the sensitivity and specificity of cervical cytology are relatively low. To overcome the limitations of conventional Pap smear (CPS), liquid-based cytology (LBC) was introduced in 1990s as a better tool for processing cervical samples.

Objectives

This study was undertaken to compare CPS with liquid-based methods, to assess the effectiveness and feasibility of LBC over CPS in our setting, and also to evaluate the prevalence of human papillomavirus (HPV) in our population.

Materials and Methods

This study was conducted in Gynecological Oncology Unit of Regional Cancer Center at Indira Gandhi Institute of Medical Sciences, Patna, Bihar. About 310 women were enrolled in this study and the sample was taken for both conventional cytology and LBC. The smears were studied in detail and were interpreted as per the Bethesda system of reporting Pap smears. The results were compared and analyzed statistically.

Results

Unsatisfactory smears were more commonly reported by conventional method (7.1%) than with liquid-based method (1.61%), and this difference is statistically significant. There was no difference in the detection of epithelial cell abnormalities using both the methods. HPV DNA for high-risk oncogenic strains (16 and 18) was detected in 6.45% of women in this study.

Conclusion

LBC has been found to be more superior to conventional smears only with respect to lesser number of unsatisfactory smears, but considering the economic implications of LBC, conventional Pap is more feasible in our setting.

Reducing DNA damage by formaldehyde in liquid-based cytology preservation solutions to enable the molecular testing of lung cancer specimens

BACKGROUND

Liquid-based cytology (LBC) is a useful cytopathological method, and LBC lung adenocarcinoma specimens may be used for genetic analysis in the near future. In the current study, the authors determined whether LBC specimens can be used for epidermal growth factor receptor (EGFR) mutation analysis in human lung adenocarcinoma cell lines.

METHODS

Genomic DNA was extracted from 3 lung adenocarcinoma cell lines that were fixed in LBC preservation solution using 2 protocols (one for cultured cells and one for tissues) of a DNA extraction kit. Different fixation times were tested for each protocol: 30 minutes, 1 hour, and 1 to 9 days. As controls, cells also were fixed in 10% formalin or 95% ethanol. The authors investigated the effect of fixation time on DNA fragmentation, polymerase chain reaction (PCR) amplification, and EGFR mutation detection.

RESULTS

The DNA yield of LBC specimens tended to decrease depending on fixation time. When using the DNA extraction protocol for tissues, PCR amplification was successful after 9 days of fixation, although extracted genomic DNA that was fixed for >1 hour demonstrated fragmentation. Mutation analyses using the Cycleave PCR method were successful after 7 days of fixation. The DNA extraction protocol for tissues was appropriate for lung adenocarcinoma cell lines that were stored for >1 day in a preservative solution. The results of the current study demonstrated that EGFR mutations can be detected on day 7 using lung adenocarcinoma cell lines fixed in CytoRich Red preservative.

CONCLUSIONS

When LBC specimens are used for targeted molecular genetic testing, the appropriate preservative solution and extraction protocol first should be determined.

Enhanced Detection of Cervical Cancer and Precancer Through Use of Imaged Liquid-Based Cytology in Routine Cytology and HPV Cotesting

OBJECTIVES

Cervical screening strives to prevent cervical cancer (CxCa), minimizing morbidity and mortality. Most large US reports on cytology and human papillomavirus (HPV) cotesting of women aged 30 years and older are from one laboratory, which used conventional Papanicolaou (Pap) smears from 2003 to 2009.

METHODS

We quantified detection of CxCa and precancer (cervical intraepithelial neoplasia 3/adenocarcinoma in situ [CIN3/AIS]) in 300,800 cotests at Magee Womens Hospital since 2005. Screening histories preceding CxCa and CIN3/AIS diagnoses were examined to assess the contribution of cytology and HPV testing. Cotesting utilized Food and Drug Administration-approved imaged liquid-based cytology (LBC) and from-the-vial HPV tests.

RESULTS

LBC identified more women subsequently diagnosed with CxCa and CIN3/AIS than HPV testing. HPV-negative/cytology-positive results preceded 13.1% of CxCa and 7.2% of CIN3/AIS diagnoses.

CONCLUSIONS

LBC enhanced cotesting detection of CxCa and CIN3/AIS to a greater extent than previously reported with conventional Pap smear and HPV cotesting.

Updates in Cervical Cytology: The 90-Year-Long Journey from Battle Creek to Today

Ninety years ago, at the Battle Creek conference, Papanicolaou introduced cervical exfoliative cytology. Since then, the "Pap test" has come a long way. The discovery of a causal relationship between cervical carcinoma and HPV infection opened the door for molecular testing and immunomarkers for HPV. The Clinical Laboratory Improvement Amendments, 1988, established quality assurance and quality control programs to monitor performance of cytology laboratories. The Bethesda System for reporting cervical cytology laid the foundations for cervical cytology education, implementation of management guidelines, and further research on cervical carcinogenesis. HPV vaccine penetration in both genders remains 62% or less.

Frequency of unsatisfactory cervical cytology smears in cancer screening of Japanese women: A systematic review and meta-analysis

The Bethesda system (TBS) has been used for cervical cytological diagnosis in Japan since 2008. Evaluation of specimen adequacy is the most important aspect of quality assurance and for precise diagnosis in TBS. A systematic review and meta‐analysis were carried out to assess the unsatisfactory specimen rate in the primary cervical cancer screening setting in Japan. Ovid Medline and Ichushi‐Web databases were searched from inception through to May 2017. Prospective and retrospective studies that reported the proportion of unsatisfactory specimens in healthy asymptomatic Japanese women in a cervical cancer screening program were eligible for inclusion; 17 studies were included in the meta‐analysis. The random‐effects model meta‐analysis calculated summary estimates of the unsatisfactory rate of 0.60% (95% confidence interval [CI], 0.18‐1.96%; I² = 99%) for conventional cytology and 0.04% (95% CI, 0.00‐0.35%; I² = 99%) for liquid‐based cytology (LBC). However, comparative results between conventional and liquid‐based cytology, based on four direct and nine comparative studies, showed no significant difference (summary odds ratio = 3.5 × 10⁻² favoring LBC [95% CI, 6.9 × 10⁻⁴‐1.7]; I² = 98%). In the subgroup analyses and meta‐regressions, use of non‐cotton devices for conventional cytology and use of a particular platform for LBC were associated with lower unsatisfactory rates. Meta‐regression also suggested chronological improvement in unsatisfactory rates for both tests. In Japanese cervical cancer screening programs, conventional cytology remains prevalent. Future research needs to focus on evaluating the impact of screening programs using LBC by comparing the accuracy, performance, and cost‐effectiveness with conventional cytology in the Japanese population.

Performance indicators in a newly established organized cervical screening programme: registry-based analysis in the Czech Republic

In 2008, the organized Czech National Cervical Cancer Screening Programme (CNCCSP) was initiated by transformation of the existing opportunistic efforts. The aim of our study was to examine recent cervical cancer burden trends and to assess the quality of the Czech National Cervical Cancer Screening Programme using a set of standard performance indicators. Our study utilized data from the national Cervical Cancer Screening Registry and the Czech National Cancer Registry. We computed internationally accepted indicators and assessed time trends and variability among screening centres. Between 1995 and 2011, the incidence of age-standardized cervical cancer decreased by 21% (1023 cases in 2011), and the mortality decreased by 35% (399 deaths in 2011). The annual coverage of the target population by cervical screening increased to 56% in 2013 (as compared with 35% in 2001). If we consider a 2-year interval (2012-2013), the estimated coverage was 77%. Over two million women underwent screening in 2013; 96% of them had a negative result. About 0.2% of smears showed cytological signs of a high-grade intraepithelial lesion or a malignancy, and the estimated positive predictive value for advanced intraepithelial neoplasia (cervical intraepithelial neoplasia grade 2+) was 79.6%. However, performance indicators show considerable heterogeneity between screening centres. The reported values of performance indicators are in line with the results of programmes that have previously been shown to be successful in terms of decreasing the cervical cancer burden, and are promising with respect to an even more pronounced decrease in cervical cancer mortality in the near future, provided that continuous quality improvement can be maintained. Linkage studies between screening, cancer and cause-of-death registers can provide further information on screening effectiveness and validity issues.

Adequacy of voided urine specimens prepared by ThinPrep and evaluated using The Paris System for Reporting Urinary Cytology

INTRODUCTION

The Paris System for Reporting Urinary Cytology (TPS) currently includes a volume recommendation for voided urine specimens of 30 mL based on observations of performance with BD SurePath preparation system. Given that many labs use the Hologic ThinPrep methods for voided urines, an analysis of data acquired with this system is undertaken in this study.

MATERIALS AND METHODS

We identified a total of 744 voided urine specimens. All specimens were processed fresh by ThinPrep at a large academic center that had incorporated a tiered urine cytology reporting template prior to TPS. To determine the optimum binary cutoff thresholds for voided urine volume, the fraction of high-risk cytologic diagnoses-suspicious for high-grade urothelial carcinoma (SHGUC) or worse-was compared below and above various volumes cutpoints.

RESULTS

The cytology diagnosis was inadequate in 1.5%, negative for high-grade urothelial carcinoma in 64%, atypical urothelial cells in 14.2% SHGUC in 6.6%, high-grade urothelial carcinoma (HGUC) in 11.3%, low-grade urothelial neoplasm in 1.9%, and other malignancies in 0.5%. High-risk cytology was diagnosed in 19.1% of specimens ≥25 mL and in 13.5% of specimens <25 mL (P = 0.090). Volume of ≥25 mL was associated with the optimum cutoff for diagnosing SHGUC or HGUC.

CONCLUSIONS

A specimen volume of ≥25 mL is associated with higher rates of diagnosis of HGUC or SHGUC in voided urine specimens processed by ThinPrep. This is similar to the 30 mL cutoff determined for SurePath preparation that was incorporated into TPS and may provide helpful information for ThinPrep labs that are in the process of adopting TPS.

Cervical Cancer Screening in Resource-Constrained Countries: Current Status and Future Directions

Cervical cancer continues to be a major public health problem affecting large numbers of women in many developing countries. Limitations of various screening modalities and the lack of ready availability of a cost-effective point-of-care screening tool have hindered the efficient implementation of population-based screening programs in these settings. It has not proved possible for many countries to adopt cytology as a screening modality due to inadequate infrastructure and trained manpower. However, recent developments, notably design and testing of a low-cost HPV test kit and initiatives by countries like India in developing and putting into operation a framework for large-scale screening of women, have raised hopes that cervical cancer control may be possible even in resource-constrained locations. With the advent of HPV vaccination, primary prevention of cervical cancer also seems a distinct possibility. However, wide availability and acceptability of vaccination is still an unresolved issue for developing countries. The possible future effects of vaccination on test characteristics of various screening strategies also need to be evaluated. This review gathers information on the current status of cervical cancer screening with a special focus on low resource settings. It revisits the strengths and limitations of the available screening modalities for cervical cancer viz. cytology, visual methods and HPV testing, in the context of their applicability in developing countries. In addition, the role of newer HPV-detection methods, for instance DNA, RNA and protein-based techniques, in triage of screen-positive women is discussed. The contemporary issue of impact of HPV vaccination on cervical cancer screening is also addressed briefly. The main highlight of the review is the reference to ‘operational framework guidelines’ for population-based cervical cancer screening, which have recently been formulated and are in the process of being implemented in India. The guidelines may serve as a model for other similar low-resource settings where implementation of cancer screening is desired.

Comparison of Unsatisfactory Samples from Conventional Smear versus Liquid-Based Cytology in Uterine Cervical Cancer Screening Test

BACKGROUND

Cervical cytology for uterine cervical cancer screening has transitioned from conventional smear (CS) to liquid-based cytology (LBC), which has many advantages. The aim of this study was to compare the proportion of unsatisfactory specimens from CS versus LBC at multiple institutions including general hospitals and commercial laboratories.

METHODS

Each participating institution provided a minimum of 500 Papanicolaou (Pap) test results for analysis. Pap tests were classified according to the participating institution (commercial laboratory or general hospital) and the processing method (CS, ThinPrep, SurePath, or CellPrep). The causes of unsatisfactory results were classified as technical problems, scant cellularity, or complete obscuring factors.

RESULTS

A total of 38,956 Pap test results from eight general hospitals and three commercial laboratories were analyzed. The mean unsatisfactory rate of LBC was significantly lower than that of CS (1.26% and 3.31%, p = .018). In the LBC method, samples from general hospitals had lower unsatisfactory rates than those from commercial laboratories (0.65% vs 2.89%, p = .006). The reasons for unsatisfactory results were heterogeneous in CS. On the other hand, 66.2% of unsatisfactory results in LBC were due to the scant cellularity.

CONCLUSIONS

Unsatisfactory rate of cervical cancer screening test results varies according to the institution and the processing method. LBC has a significantly lower unsatisfactory rate than CS.

Conventional Pap smear cervical cancer screening in 11 rural counties in Hainan Province, China: analysis of Bethesda system reporting rates for 218,195 women (predominantly ages 35-64 years) screened in China's National Cervical Cancer Screening Program in Rural Areas (NCCSPRA)

OBJECTIVE

Recently the Chinese government has introduced support for cervical screening in rural areas. The College of American Pathologists (CAP)-certified Guangzhou Kingmed Diagnostics laboratory supported rural screening program in Hainan Providence utilizing low-cost conventional Papanicolaou smears (CPS).

STUDY DESIGN

This was a retrospective study of CPS screening results from 2011 to 2014 in 11 rural counties in Hainan Province. Women, most previously unscreened, volunteered to attend free CPS screening. The targeted population was women aged 35-65 years.

RESULTS

Among total 218,195 conventional Papanicolaou smears, the reported abnormal rate was 4.4% of all smears, with 0.5% for high-grade squamous intraepithelial lesion (HSIL), 0.9% for low-grade squamous intraepithelial lesion (LSIL), 2.6% for atypical squamous cells of undetermined significance, and 0.3% for atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion. Reporting rates for different TBS categories were generally within CAP benchmark ranges, except for low reporting rates for unsatisfactory smears and for atypical glandular cells. Abnormal cytology rates varied among counties. Comparing different age groups, the LSIL rate was significantly higher in women <50 years than in women ≥50 years (1.04% versus 0.64%). The HSIL rate was significantly higher in women ≥40 years than in women <40 years (5.3% versus 0.38%). A total of 2286 women with abnormal Papanicolaou smears had documented colposcopic and histopathologic follow-up. Cervical cancer was diagnosed in 23 of 2286 (1.01%) of screened and biopsied patients. Histopathologic HSIL results were confirmed in 80% of biopsied women with HSIL Papanicolaou tests.

CONCLUSIONS

CPS offered a low cost method to introduce cervical screening in rural China. The international College of American Pathologists Laboratory Accreditation Program provided laboratory quality control standards not otherwise readily available. Educational training programs have been instituted to address areas identified for quality improvement.

Introduction of molecular HPV testing as the primary technology in cervical cancer screening: Acting on evidence to change the current paradigm

Since being introduced in the 1940s, cervical cytology - despite its limitations - has had unequivocal success in reducing cervical cancer burden in many countries. However, we now know that infection with human papillomavirus (HPV) is a necessary cause of cervical cancer and there is overwhelming evidence from large-scale clinical trials, feasibility studies and real-world experience that supports the introduction of molecular testing for HPV as the primary technology in cervical cancer screening (i.e., "HPV primary screening"). While questions remain about the most appropriate age groups for screening, screening interval and triage approach, these should not be considered barriers to implementation. Many countries are in various stages of adopting HPV primary screening, whereas others have not taken any major steps towards introduction of this approach. As a group of clinical experts and researchers in cervical cancer prevention from across Canada, we have jointly authored this comprehensive examination of the evidence to implement HPV primary screening. Our intention is to create a common understanding among policy makers, agencies, clinicians, researchers and other stakeholders about the evidence concerning HPV primary screening to catalyze the adoption of this improved approach to cervical cancer prevention. With the first cohort of vaccinated girls now turning 21, the age when routine screening typically begins, there is increased urgency to introduce HPV primary screening, whose performance may be less adversely affected compared with cervical cytology as a consequence of reduced lesion prevalence post-vaccination.

Comparison of Unsatisfactory Samples from Conventional Smear versus Liquid-Based Cytology in Uterine Cervical Cancer Screening Test

BACKGROUND

Cervical cytology for uterine cervical cancer screening has transitioned from conventional smear (CS) to liquid-based cytology (LBC), which has many advantages. The aim of this study was to compare the proportion of unsatisfactory specimens from CS versus LBC at multiple institutions including general hospitals and commercial laboratories.

METHODS

Each participating institution provided a minimum of 500 Papanicolaou (Pap) test results for analysis. Pap tests were classified according to the participating institution (commercial laboratory or general hospital) and the processing method (CS, ThinPrep, SurePath, or CellPrep). The causes of unsatisfactory results were classified as technical problems, scant cellularity, or complete obscuring factors.

RESULTS

A total of 38,956 Pap test results from eight general hospitals and three commercial laboratories were analyzed. The mean unsatisfactory rate of LBC was significantly lower than that of CS (1.26% and 3.31%, p = .018). In the LBC method, samples from general hospitals had lower unsatisfactory rates than those from commercial laboratories (0.65% vs 2.89%, p = .006). The reasons for unsatisfactory results were heterogeneous in CS. On the other hand, 66.2% of unsatisfactory results in LBC were due to the scant cellularity.

CONCLUSIONS

Unsatisfactory rate of cervical cancer screening test results varies according to the institution and the processing method. LBC has a significantly lower unsatisfactory rate than CS.

Cervical cancer incidence after normal cytological sample in routine screening using SurePath, ThinPrep, and conventional cytology: population based study

Objective To compare the cumulative incidence of cervical cancer diagnosed within 72 months after a normal screening sample between conventional cytology and liquid based cytology tests SurePath and ThinPrep.Design Retrospective population based cohort study.Setting Nationwide network and registry of histo- and cytopathology in the Netherlands (PALGA), January 2000 to March 2013.Population Women with 5 924 474 normal screening samples (23 833 123 person years).Exposure Use of SurePath or ThinPrep versus conventional cytology as screening test.Main outcome measure 72 month cumulative incidence of invasive cervical cancer after a normal screening sample for each screening test. Cox regression analyses assessed the hazard ratios, adjusted for calendar time, age, screening history, and socioeconomic status and including laboratories as random effects.Results The 72 month cumulative cancer incidence was 58.5 (95% confidence interval 54.6 to 62.7) per 100 000 normal conventional cytology samples, compared with 66.8 (56.7 to 78.7) for ThinPrep and 44.6 (37.8 to 52.6) for SurePath. Compared with conventional cytology, the hazard of invasive cancer was 19% lower (hazard ratio 0.81, 95% confidence interval 0.66 to 0.99) for SurePath, mainly caused by a 27% lower hazard (0.73, 0.57 to 0.93) of a clinically detected cancer. For ThinPrep, the hazard was on average 15% higher (hazard ratio 1.15, 0.95 to 1.38), mainly caused by a 56% higher hazard of a screen detected cancer (1.56, 1.17 to 2.08).Conclusions These findings should provoke reconsideration of the assumed similarity in sensitivity to detect progressive cervical intraepithelial neoplasia between different types of liquid based cytology and conventional cytology.

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.

Current Technologies and Recent Developments for Screening of HPV-Associated Cervical and Oropharyngeal Cancers

Mucosal infection by the human papillomavirus (HPV) is responsible for a growing number of malignancies, predominantly represented by cervical cancer and oropharyngeal squamous cell carcinoma. Because of the prevalence of the virus, persistence of infection, and long latency period, novel and low-cost methods are needed for effective population level screening and monitoring. We review established methods for screening of cervical and oral cancer as well as commercially-available techniques for detection of HPV DNA. We then describe the ongoing development of microfluidic nucleic acid-based biosensors to evaluate circulating host microRNAs that are produced in response to an oncogenic HPV infection. The goal is to develop an ideal screening platform that is low-cost, portable, and easy to use, with appropriate signal stability, sensitivity and specificity. Advances in technologies for sample lysis, pre-treatment and concentration, and multiplexed nucleic acid detection are provided. Continued development of these devices provides opportunities for cancer screening in low resource settings, for point-of-care diagnostics and self-screening, and for monitoring response to vaccination or surgical treatment.

Pap Test Reporting Rates for Conventional Smear and Liquid-Based Cervical Cytology from the Largest Academic Women's Hospital in China: Analysis of 1,248,785 Pap Test Reports

OBJECTIVE

The Obstetrics and Gynecology Hospital of Fudan University (OGHFU) in Shanghai is the largest academic women's hospital in China. Between 2009 and 2014, the use of liquid-based cytology (LBC) significantly increased while gradually adopting the Bethesda System (TBS), and in 2012 local regulations mandated that pathologists replace technicians to sign out Pap tests.

DESIGN

A retrospective OGHFU database search documented all Pap test reports between 2009 and 2014 by specimen type, either LBC or conventional Pap smears (CPS), and final reporting category. A total of 1,224,785 Pap reports were analyzed to document variations in Pap test reporting during a period of major change in cervical screening in China.

RESULTS

LBC gradually replaced CPS, which declined from over 65% of Pap tests in 2010 to 6.4% in 2014. Of 514,811 Pap reports using the traditional class system, class I (negative) reports accounted for 98.3% of results. With the introduction of TBS reporting, pathologist reviews and substantial replacement of CPS by LBC, the laboratory abnormal Pap test rate increased significantly to almost 5%.

CONCLUSIONS

Changes in cervical cytology reporting between 2009 and 2014 in China's largest academic women's hospital reflected both increased use of LBC and the introduction of pathologist TBS reporting. Abnormality rates increased significantly and fell within CAP benchmark ranges.

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.

Increased cervical cancer risk associated with extended screening intervals after negative human papillomavirus test results: Bayesian risk estimates using the Pittsburgh Cervical Cancer Screening Model

INTRODUCTION

Questions have recently been raised about the acceptability of increased cervical cancer risk projected with the new guideline-recommended rescreening interval of 5 years after negative cytology and human papillomavirus (HPV) cotest results. Additional data sources capable of evaluating cervical cancer risk over time are being sought. We employed the continuously updated Bayesian Pittsburgh Cervical Cancer Screening Model (PCCSM) to estimate invasive cancer risks for patients screened at extended screening intervals after negative HPV test results.

MATERIALS AND METHODS

The analyzed database included cervical screening data collected over 10 years (2005-2014) at Magee Womens Hospital with 976,624 liquid-based cytology (LBC) results, 285,351 companion high-risk US Food and Drug Administration-approved HPV test results from LBC vials, and 112,435 follow-up histopathologic results from surgical procedures with cervical tissue sampling. Histopathologic cervical cancer risk estimates for patients with prior double negative results with cervical LBC and from-the-vial HPV cotesting were computed using the PCCSM for women rescreened at intervals ranging from 1 to 9 years. Similar risks were computed for women with any negative HPV test result, not considering cytology results.

RESULTS

Histopathologic invasive cervical cancer risk computed following LBC and HPV cotesting double negative results progressively increased with rescreening intervals of 1 to 9 years. Cervical cancer risks computed following any HPV-negative result, not considering cytology results, were consistently even higher at each comparable extended rescreening interval.

CONCLUSIONS

The PCCSM is a new data source that allows evaluation of cervical cancer risk over time. Cervical cancer risk is minimized with more frequent cytology and HPV cotesting.

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.

Cervical histology after routine ThinPrep or SurePath liquid-based cytology and computer-assisted reading in Denmark

Background:

We compared the sensitivity and specificity of liquid-based cytology (LBC) and computer-assisted reading for SurePath/FocalPoint and ThinPrep with those of manually read conventional cytology in routine cervical screening in four Danish laboratories.

Methods:

Using data from five nationwide registers, technological phases were identified by slide preparation, reading technique, and triage of borderline cytology. Trends in the detection of cervical intraepithelial neoplasia (CIN) were an indicator of the technology's relative sensitivity, and trends in false-positive tests an indicator of relative specificity.

Results:

At 23–29 years, SurePath/FocalPoint statistically significantly increased the detection of ⩾CIN3 by 85% compared with manually read conventional cytology. The 11% increase with ThinPrep was not significant. At 30–44 years, the increase with SurePath/FocalPoint was 58% the 16% increase with ThinPrep was not significant. At 45–59 years, both technologies led to nonsignificant decreases in the detection. SurePath/FocalPoint doubled the frequency of false-positive tests at any age. With ThinPrep, these proportions remained the same at 23–29 years, but decreased by two-thirds at 45–59 years. In a fourth laboratory with continuous use of manually read conventional cytology, no such trends were seen.

Conclusions:

The sensitivity and specificity of modern LBC and computer-assisted reading technologies may be brand- and age-dependent.