Assessment of the Validity and Reproducibility of the Pap Smear in Mexico: Necessity of a Paradigm Shift

Human Papillomavirus: Challenges and Opportunities for the Control of Cervical Cancer

Viruses are the most abundant and genetically diverse entities on the planet, infect all life forms and have evolved with their hosts. To date, 263 viral species have been identified that infect humans, of which only seven are considered type I oncogenic. Human papillomavirus (HPV) is the main virus associated with cancer and is responsible for practically all cases of cervical carcinoma. Screening tests for early detection have been available since the 1960s. Undoubtedly, the entailment between knowledge of HPV biology and the natural history of cervical cancer has contributed to the significant advances that have been made for its prevention since the 21^st century, with the development of prophylactic vaccines and improved screening strategies. Therefore, it is possible to eradicate invasive cervical cancer as a worldwide public health problem, as proposed by the WHO with the 90-70-90 initiative based on vaccination coverage, screening, and treatment, respectively. In addition, the emerging knowledge of viral biology generates opportunities that will contribute to strengthening prevention and treatment strategies in HPV-associated neoplasms.

Serum Levels of Galectin-9 are Increased in Cervical Cancer Patients and are Higher in Advanced Clinical Stages

Purpose

Cervical cancer (CC) is the second most frequent cancer in undeveloped countries. Serum biomarkers could be useful for evaluation of the treatment response and as a complementary means to improve diagnosis. The expression of galectin-9 is altered in cancer tissue, and higher concentrations are found in the serum of cancer patients. The objectives of this study were (a) to determine the serum galectin-9 concentration in patients with intraepithelial lesions and CC, (b) to determine if the concentration was related to the clinicopathological characteristics and (c) to determine if the galectin-9 concentration was related to its expression level in tumour tissue.

Patients and Methods

In all, 222 serum samples from women with different diagnoses, including premalignant lesions and CC, as well as samples from women with normal cytology were included in the study. The serum galectin-9 concentration was determined by ELISA. To evaluate the expression level of galectin-9 in CC tissue, immunohistochemistry was performed in 34 CC biopsy specimens.

Results

The galectin-9 concentration in the serum of CC patients (8.171 ng/mL) was increased compared with serum from women with normal epithelia (4.654 ng/mL) and those with low-grade (4.806 ng/mL) and high-grade (5.354 ng/mL) intraepithelial lesions (p value < 0.0001). The area under the ROC curve considering the CC group and the control group was 0.882. The optimal cut-off value was ≥6.88 ng/mL, the specificity obtained was 100%, and the sensitivity was 68.2%. In the CC group, the analysis of the clinical stage showed an increase of galectin-9 in the advanced stage IV group. Serum galectin-9 was not related to the level of galectin-9 expression in tissue, which suggests that galectin-9 is not secreted by tumour cells.

Conclusion

The serum galectin-9 concentration is related to cancer progression, as the level of this protein is higher in patients with advanced-stage disease.

A Hierarchical Feature-Based Methodology to Perform Cervical Cancer Classification

Prevention of cervical cancer could be performed using Pap smear image analysis. This test screens pre-neoplastic changes in the cervical epithelial cells; accurate screening can reduce deaths caused by the disease. Pap smear test analysis is exhaustive and repetitive work performed visually by a cytopathologist. This article proposes a workload-reducing algorithm for cervical cancer detection based on analysis of cell nuclei features within Pap smear images. We investigate eight traditional machine learning methods to perform a hierarchical classification. We propose a hierarchical classification methodology for computer-aided screening of cell lesions, which can recommend fields of view from the microscopy image based on the nuclei detection of cervical cells. We evaluate the performance of several algorithms against the Herlev and CRIC databases, using a varying number of classes during image classification. Results indicate that the hierarchical classification performed best when using Random Forest as the key classifier, particularly when compared with decision trees, k-NN, and the Ridge methods.

Evaluation of Serum Levels and Expression of Galectin-4 in Cervical Cancer

Galectin-4 has been reported to be altered in different cancer types. Its expression changes have been associated with early recurrence and metastasis. In cervical cancer (CC), galectin-4 has not been studied. The aim of the study was to determine the expression level and subcellular localization of galectin-4 in CC tissue and the concentration in the serum of patients with CC. For the analysis of serum levels of galectin-4, an ELISA assay was performed. To assess the expression in cervical tissue, immunohistochemical staining was performed. The results showed that the concentration of galectin-4 in the serum of patients with CC was higher (647.9 pg/ml) than that in the serum of women with normal cytology (382.1 pg/ml). The immunohistochemical analysis of CC samples showed a higher expression in keratinizing tumor than nonkeratinizing tumors and a trend of increased expression in tumors from patients with advanced clinical stage. In normal cervical tissue, galectin-4 was detected in the cytoplasm, and in tumor cells, the presence of galectin-4 was also detected in the nucleus, in both adenocarcinoma and squamous cervical cancer. The increase in serum concentration and different localization in the tumor cells suggest a possible role of galectin-4 in CC development.

Benefit of double-reading cytology smears as a triage strategy among high-risk human papillomavirus-positive women in Mexico

BACKGROUND

The goal of this study was to determine whether the detection of histologically confirmed cases of cervical high-grade squamous intraepithelial lesions or worse (HSIL+) can be increased by having each liquid-based cytology (LBC) slide read by 2 cytotechnologists as part of routine screening.

METHODS

Over 36,212 women aged 30 to 64 years participated in the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage (FRIDA) Study in Mexico between 2013 and 2016. For each participant, 2 cervical samples were collected at the same clinic visit, one to test for high-risk human papillomavirus (hrHPV) and the other for LBC, which was used to triage those with a hrHPV positive result. LBC slides were evaluated by 7 cytotechnologists, with each slide read independently by 2 blinded cytotechnologists. All women with atypical cells of undetermined significance or a worse result were referred to colposcopy for further evaluation and diagnosis. Three pathologists evaluated the biopsy specimens to confirm the final HSIL+ diagnosis. The HSIL+ detection rates for the single versus double reading were estimated and compared.

RESULTS

A total of 3,914 women with a positive hrHPV result were triaged with LBC. The first and second cytology readings resulted in 43 HSIL+ cases detected; the double-reading strategy detected 9 additional HSIL+ cases, resulting in a total of 52 HSIL+ cases. The HSIL+ detection rate increased from 10.99/1000 with a single reading to 13.29/1000 with the double-reading strategy (P = .004).

CONCLUSION

A 20.9% increase in HSIL+ cases detected was achieved with a double reading of the LBC slides in this sample of hrHPV-positive women.

Diagnostic Role of Papanicolaou Smear, Hemoglobin, Blood Group, and Other Clinical Symptoms in Detecting Endometrial Carcinoma: A Clinicopathological Study of 175 Iranian Women with Endometrial Carcinoma

Objectives:

Endometrial carcinoma (EC) is a common gynecologic malignancy in the female genital tract, especially in postmenopausal women. The current study aimed to analyze Papanicolaou (Pap) smear in patients with EC to assess the relationship between EC and abnormal cells in Pap smear, ABO blood group, and hemoglobin anemia.

Materials and Methods:

A retrospective study was conducted on 175 patients with EC in Imam Hossein Hospital, Tehran, Iran, during the period from 2013 to 2019. The histology information of cases was extracted from the hospital database, and Pap smear slides were taken from pathological archives. The acquired information and slides were then reviewed by an expert pathologist in the hospital. The data were analyzed in SPSS (version 18) by the Chi-square test, Fisher's exact test, and independent-samples t-test. P < 0.05 was assigned as significant.

Results:

The mean age of patients was 54.47 ± 11.34, ranging from 32 to 85 years, and 31.4% of the patients were premenopausal women. Grade III, invasion ≥ 50% of myometrial, and advanced stage (III and IV) were diagnosed in 30%, 7.4%, and 22.86% of the patients, respectively. The most common histological types of EC were endometrioid (66.9%), papillary (10.3%), and malignant mixed Mullerian tumor (5.7%). The abnormal Pap smear was achieved only in 37 EC patients (21.1%). Endometrial cells, atypical squamous cells of undetermined significance, and atypical glandular cells were observed in 56.8%, 29.7%, and 13.5% of the patients > 40 years of age with abnormal Pap smears, respectively. In patients with normal Pap smears, the most common results were inflammation in 75.1% and atrophy in 14.6% of the patients. Abnormal uterine bleeding was the most important problem observed in patients with EC.

Conclusion:

The efficacy of Pap smear in detecting EC is limited. Therefore, women with EC, >40 years of age, with heavy bleeding, anemia, O blood group, inflammation, and atrophy in Pap smear in the past 3 years need to be precisely checked up for EC. These items can be added as new criteria for EC screening procedures.

Performance of rapid prescreening and 100% rapid review as internal quality control methods for cervical cytopathology

BACKGROUND

An objective of quality control for cervical cytopathology is reducing high rates of false-negative results of laboratory tests. Therefore, methods to review smears such as rapid prescreening and 100% rapid review, which have shown better performance detecting false-negative results, have been widely used. The performance of rapid prescreening and the performance of 100% rapid review as internal quality control methods for cervical cytology examinations were evaluated.

METHODS

For 24 months, 9318 conventional cervical cytology smears underwent rapid prescreening and routine screening. The 100% rapid review method was performed for 8244 smears classified as negative during routine screening. Any discordant results underwent detailed review to define the final diagnosis. This was considered the gold standard for evaluating the performance of rapid prescreening and 100% rapid review.

RESULTS

Routine screening showed increases of 13.3% and 11.5% in the detection of abnormal smears with rapid prescreening and 100% rapid review, respectively. The relative percentage variation showed a 38.1% increase in the diagnosis of atypical squamous cells of undetermined significance with routine screening and rapid prescreening and a 12.5% increase in the diagnosis of atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion with both rapid prescreening and 100% rapid review. Sensitivity rates of rapid prescreening and routine screening were 48.2% and 83.2%, respectively. Sensitivity rates of rapid prescreening and 100% rapid review were 65.7% and 57.8%, respectively, for detecting false-negative results.

CONCLUSIONS

Inclusion of rapid prescreening and/or 100% rapid review improved the diagnostic sensitivity of the cervical cytology examination and reduced false-negative results of routine screening and can provide good quality control.