Comparative study between liquid-based cytology & conventional Pap smear for cytological follow up of treated patients of cancer cervix

Screening Methods for Cervical Cancer

Cervical cancer seriously affects the health of women worldwide. Persistent infection of high-risk HPV (Human Papilloma Virus) can lead to cervical cancer. There is a great need for timely and efficient screening methods for cervical cancer. The current screening methods for cervical cancer are mainly based on cervical cytology and HPV testing. Cervical cytology is made of Pap smear and liquid-based cytology, while HPV testing is based on immunological and nucleic acid level detection methods. This review introduces cervical cancer screening methods based on cytology and human papillomavirus testing in detail. The advantages and limitations of the screening methods are also summarized and compared.

Comparison of liquid-based cytology and cell blocks prepared from cell remnants for diagnosis of cervical pathology

BACKGROUND

Cervical cancer is a global public health problem with high mortality. Advances in screening programs for cervical cancer are considered key to eliminate cervical cancer. We aimed to examine the contribution of cell block analysis to the detection of epithelial cell abnormalities in cervical smear samples.

METHODS

A total of 559 patients with suspected cervical pathology were examined, and their samples were analyzed by both liquid-based cytology (LBC) and cell blocks. The biopsy results of 149 out of the 559 patients were obtained.

RESULTS

Of the 50 patients who were identified as HSIL by biopsy, only 12 were diagnosed as HSIL by the LBC method, 22 as LSIL, 12 as ASCUS, and 4 as ASC-H (p < 0.001). With the cell block analysis, results for these patients were: 20 HSIL, 17 LSIL, 7 NILM, 4 'unsatisfactory', and 2 ASC cases (p < 0.001). LBC detected only 1 of the 10 patients with biopsy-diagnosed tumors, while 7 of these were defined as HSIL, 1 as ASCUS and 1 as AGC. The results of cell block analysis in patients with biopsy-diagnosed tumors were as follows: 7 HSIL, 1 tumor, 1 ASC and 1 LSIL.

CONCLUSIONS

Cell block analysis might be superior to LBC in terms of diagnostic accuracy in cervical pathologies, particularly in the detection of HSIL. However, both methods were similarly poor in diagnosing tumors. Cell blocks may improve diagnostic accuracy and can be a complementary method to LBC, while having the advantage of revealing histological architecture.

Analysis of the Differences between Bethesda Groups according to Conventional Smear and Liquid-Based Cytology Methods in Cervicovaginal Cytology: A Single-Center Experience with 165,915 Cases

INTRODUCTION

Liquid-based cytology (LBC) has replaced conventional smear (CS) in the world. In this study, through a series with a large number of cases, we aimed to make a comparison and general evaluation in all groups, primarily epithelial abnormalities, according to LBC and CS methods. This study was carried out in a private pathology laboratory located in a metropolitan city, where cytological materials sent from many clinics were examined.

MATERIAL AND METHODS

There were 165,915 cases whose smears were examined between 2012 and 2020, most of them conventional (131,224 CS, 34,691 LBC). Cases were evaluated on the basis of the Bethesda 2014 classification and divided into sub-diagnostic categories after they were divided into two main groups as "with epithelial abnormalities" and "without." χ2 and Fischer's precision statistical tests were conducted using SPSS 23.0 package. In the CS process, cervical samples were obtained using an endocervical brush and a spatula. Cells were directly spread onto the slides and promptly fixed in 95% ethanol, followed by staining with the standard Papanicolaou stain. For LBC ThinPrep, cervical specimens were gathered using a cervix brush. The brush was washed in a vial and discarded. Finally, cells were isolated through vacuum filtration and transferred to the slide using air pressure.

RESULTS

Squamous cell abnormalities (atypical squamous cells of undetermined significance [ASC-US], atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion [ASC-H], low-grade squamous intraepithelial lesion [LSIL], high-grade squamous intraepithelial lesion [HSIL], squamous cell carcinoma, atypical glandular cells of undetermined significance) were reported in 5,696 (3.43%) cases. ASC (ASC-US + ASC-H)/SIL ratio (1.36/2.04) was found to be 0.67 (recommended Bethesda ratio is <3). ASC-US (p < 0.001), ASC-H (p < 0.001), and HSIL(p < 0.001) detection rate of LBC was found to be significantly higher than CS. ASC-US (1.8/1.2), ASC-H (0.08/0.008), and HSIL (0.6/0.3) case ratios of LBC/CS were found to be significantly higher in LBC. LSIL (1.72/1.66) rate was similar.

CONCLUSION

LBC is superior to CS in detecting epithelial lesions. In addition to being used as a screening method, it is clear that it makes a great contribution to reducing cervical carcinomas due to HPV typing. Definitive comments regarding comparison of methods on reactive changes and microorganism detection are challenging. Preanalytical factors might account for these situations.

The Role of p16/Ki67 Dual Staining in Cervical Cancer Screening

Cervical cancer screening has enabled a decrease in the incidence and mortality of cervical cancer. Various screening modalities have been studied to date. In many countries, screening is still based on cervical cytology, where cervical cells obtained either on glass or in a liquid medium are examined under a microscope. However, the fact that the vast majority of cervical cancers are a result of persistent infection with high-risk human papillomaviruses (hr-HPV) has led to the implementation of primary HPV screening in many countries. Taking into consideration the fact that the majority of HPV infections are transient and do not cause cervical precancer, effective triage methods are needed to prevent an increase in colposcopy referrals. Among these, the most extensively investigated are HPV genotyping, HPV methylation, and p16/Ki67 dual staining. In this manuscript, we briefly summarize the current knowledge regarding different screening strategies for the prevention of cervical cancer, with a focus on p16/Ki67 dual staining. In addition, we provide an explanation regarding the rationale for the use of various screening modalities based on the molecular biology of cervical cancer and cervical precancerous lesions.

The comparative evaluation of CK17 expression in histologic and cytological sections of oral squamous-cell carcinoma using immunohistochemistry

BACKGROUD

Squamous-cell carcinoma of the mouth accounts for 90% of all oral cancers and despite advances in treatment methods, its 5-year survival rate is reported to be about 68%. This is due to the late diagnosis of the disease and its resistance to radiotherapy and chemotherapy treatments. One of the methods for diagnosing oral lesions is exfoliative cytology, which is a noninvasive method and can be easily carried out in a dental office.

AIM

The purpose of this study is to find a method that in addition to being fast, accurate and less aggressive has high value and a good degree of accuracy for diagnosis of oral squamous-cell carcinoma.

MATERIALS AND METHODS

In this descriptive-analytical study, 14 patients who were diagnosed with oral squamous-cell carcinoma and 14 specimens from exfoliative cytology of the same tissue before surgery were examined. Immunohistochemically stained specimens were examined by two pathologists simultaneously. Next, five nonoverlapping sections with magnification (×400) and the number of cells stained with the cytokeratin marker 17 are counted and the average percentage of each slide is determined. One-sample t-test is used to analyze the data and significance level in tests is considered 0.05.

RESULTS

In examining the diagnostic value of cytology, we concluded that out of 280 affected cells, 211 cells were stained. Therefore, the sensitivity of cytology in the diagnosis of squamous-cell carcinoma of the mouth is 75.4%. In other words, cytology correctly identifies 75.4% of affected cells as affected. Also, the positive predictive value of cytology was 100%.

High-Risk Human Papillomavirus Detection via Cobas® 4800 and REBA HPV-ID® Assays

Persistent infection with high-risk human papillomaviruses (HR-HPVs), particularly HPV16 and 18, has long been known to induce cervical cancer progression. However, given that a minority of HPV-infected women develop cancer, analysis of HR-HPV-infected women could help to predict who is at risk of acquiring cervical cancer. Therefore, to improve HR-HPVs detection, we used the FDA-approved cobas^® 4800 HPV and REBA HPV-ID^® HPV assays to detect HR-HPVs in colposcopy-derived cervical cells from 303 patients, detecting 72.28% (219) and 71.62% (217) of HR-HPVs positive cases, with HPV16 detection rates of 35.64% (108) and 30.69% (93), respectively. Of the HPV16-positive cases, cobas^® 4800 and REBA HPV-ID^® identified 28.81% (51) and 25.42% (45) of the CIN1 cases, and 55% (33) and 50% (30) of the 60 CIN2/3 cases, respectively. HPV-diagnostic concordance was 82.17% overall (kappa = 0.488), 87.45% for HR-HPVs (kappa = 0.689), and 88.33% for CIN2/3 (kappa = 0.51). The HR-HPVs detection rates of these assays were comparable. Our findings reveal that the FDA-approved HR-HPVs detection assay is appropriate for screening women with HR-HPVs infection, and for predicting increased risk of cervical cancer progression. REBA HPV-ID^® can be used to detect low risk-HPV types in high-grade cervical lesions that are HR-HPV negative as well as in the distribution of HPV types.

Cervical Cancer Prophylaxis—State-of-the-Art and Perspectives

Background: Each year 604,127 new cases of cervical cancer (CC) are diagnosed, and 341,831 individuals die from the disease. It is the fourth most common cancer among women and the fourth most common cause of death from female cancers worldwide. The pathogenesis of CC is associated with human papillomavirus (HPV) infections and consists of several steps involving cell proliferation outside the human body’s control mechanisms. Strategies to prevent CC are based on screening and vaccination. Scope of the Review: The aim of this paper was to collect and analyze the available literature on the issue of CC prevention and the impact of the COVID-19 pandemic on its implementation. For this purpose, PubMed and Google Scholar databases were searched using keywords, such as “cervical cancer”; “HPV”; “prevention”; “prophylaxis”; “vaccination”; “screening” and “COVID-19” in different variations. Only articles published since 2018 were included in the study. Conclusions: Selected European countries have different CC prevention programs funded by national budgets. This translates into observed differences in the risk of death from CC (age-standardized rate Malta = 1.1, Poland = 5.9). COVID-19 pandemic due to disruption of CC screening may exacerbate these differences in the future. To improve the situation, new screening methods, such as p16/Ki67, HPV self-testing, and the use of artificial intelligence in colposcopic assessment, should be disseminated, as well as free HPV vaccination programs implemented in all countries. The search for new solutions is not without significance and entails ultra-sensitive screening tests for risk groups (mRNA E6/E7, SOX1/SOX14), HPV vaccines with shorter dosing schedules, and new therapeutic pathways using nanotheranostics.

Cervical cytology: Radiation and other therapy effects

The different treatment options for carcinoma cervix include radiation, chemotherapy, and surgical treatments. Cytological analysis of smears is crucial for patient follow-up to determine response to therapy and to diagnose the persistence or recurrence of malignancy. Anatomical alterations and changes in cell morphology following radiation or chemotherapy make collecting and interpreting cervical cytology samples difficult. These issues can be mitigated by liquid-based cytology. Ionizing radiation is used in radiotherapy (RT) to kill cells. It is important that cytologists are aware of alterations in morphology of the cells. Radiation can cause cytoplasmic and nuclear changes. Cellular enlargement, vacuolation, granularity loss, and other changes linked with cell death are examples of cytoplasmic alterations. Nuclear enlargement and multinucleation are the most frequent nuclear alterations. These changes are determined by the amount of time that has passed since radiation. It should be emphasized that no one characteristic is pathognomonic. Post-irradiation dysplasia is a condition described as abnormal cellular changes in non-neoplastic epithelial cells after RT. Chemotherapy causes comparable alterations as radiation but impacts fewer cells. Busulfan and other chemotherapeutic treatments may produce morphological alterations, which cytologists must be aware of and able to identify. Immunosuppressive treatments, hormonal therapy, and tamoxifen are some of the other drugs that might cause changes in cervical morphology. Surgical methods used in the detection and treatment of cervical cancer may potentially cause alterations as a result of thermal damage and healing. For the treatment of cervical lesions, electrocautery and the loop electrosurgical excisional procedure are available. These procedures employ electric current ablation leading to ischemic changes in the cervical smear. Cytological analysis of smears following treatment with these modalities necessitates a comprehensive history, kind of therapy, and duration of treatment.

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.

Cervical screening: A complete and patient centred approach

Cervical screening is an important intervention in the detection and management of early cancer. The global situation regarding cervical cancer is briefly discussed and a family physician’s approach to the procedure and the response to laboratory findings is documented.

Cric searchable image database as a public platform for conventional pap smear cytology data

Amidst the current health crisis and social distancing, telemedicine has become an important part of mainstream of healthcare, and building and deploying computational tools to support screening more efficiently is an increasing medical priority. The early identification of cervical cancer precursor lesions by Pap smear test can identify candidates for subsequent treatment. However, one of the main challenges is the accuracy of the conventional method, often subject to high rates of false negative. While machine learning has been highlighted to reduce the limitations of the test, the absence of high-quality curated datasets has prevented strategies development to improve cervical cancer screening. The Center for Recognition and Inspection of Cells (CRIC) platform enables the creation of CRIC Cervix collection, currently with 400 images (1,376 × 1,020 pixels) curated from conventional Pap smears, with manual classification of 11,534 cells. This collection has the potential to advance current efforts in training and testing machine learning algorithms for the automation of tasks as part of the cytopathological analysis in the routine work of laboratories.