Association between cervical lesion grade and micronucleus frequency in the Papanicolaou test

The role of micronucleus scoring in cervical papanicolaou smears: A 1-year study

Aims and Objectives

To compare the micronucleus (MN) score in all the major diagnostic categories as per "The Bethesda System for Reporting Cervical Cytology" 2014 including negative for intraepithelial lesions and malignancy (NILM), inflammatory, abnormal squamous cells of undetermined significance (ASC-US), abnormal squamous cells cannot exclude high-grade squamous intraepithelial lesion (HSIL) (ASC-H), low-grade squamous intraepithelial lesion (LSIL), HSIL, and invasive carcinoma (IC) and to assess the role of MN scoring as a biomarker for predicting risk of carcinoma.

Materials and Methods

A total of 1000 conventional cervical smears stained with Papanicolaou (Pap) stain, comprising unsatisfactory for evaluation (86), NILM (140), inflammatory (696), ASC-US (23), ASC-H (16), LSIL (18), HSIL (15), and IC (6) were studied independently by two pathologists, and the number of MN cells per 1000 epithelial cells in high-power (×400) and oil immersion (×1000) was counted and expressed as MN score per 1000 cells.

Results

The mean MN score ± standard deviation was found to be 0.99 ± 0.744 in NILM cases, 0.67 ± 0.782 in inflammatory cases, 1.57 ± 0.507 in ASC-US cases, 1.63 ± 0.50 in ASC-H cases, 1.56 ± 0.511 in LSIL cases, 2.47 ± 0.516 in HSIL cases, and 3.0 ± 0.00 in IC cases. A step-wise increase was observed in MN score from inflammatory to IC categories.

Conclusions

MN score is a reliable and easy test that can be used in conjunction with routine cervical PAP to assess the risk of malignant transformation in the uterine cervix as a biomarker for predicting the risk of carcinoma.

Genomic instability in peripheral blood lymphocytes of patients diagnosed with high-grade squamous intraepithelial lesions: CIN 2 versus CIN 3

Cancer is a genomic disease associated with accumulation of genetic damage. Cancer-initiating events, such as chromosome breakage, loss and rearrangement, can be used as biomarkers to evaluate individual cancer risk. Cytokinesis-block micronucleus cytome (CBMN - Cyt) assay parameters in peripheral blood lymphocytes (PBL) of thirty four patients diagnosed with high-grade squamous intraepithelial lesions (HSIL) and fifteen healthy women were measured. The genomic instability of patients diagnosed with HSIL were investigated in order to compare differences between the two subgroups of HSIL (CIN 2 and CIN 3). The micronucleus (MN) frequencies in PBL, as well as the frequencies of nucleoplasmic bridges (NPB) and nuclear buds (NBUD) were higher in patients than in controls (Mann- Whitney test, p < 0.05). These results provide evidence that CBMN cytome assay in peripheral blood lymphocytes may be used to identify individuals who are at high risk of developing cervical cancer. Since the extent of DNA damage varies between CIN 2 and CIN 3, these findings support the CIN grading system.

Micronuclei and Their Association with Infertility, Pregnancy Complications, Developmental Defects, Anaemias, Inflammation, Diabetes, Chronic Kidney Disease, Obesity, Cardiovascular Disease, Neurodegenerative Diseases and Cancer

Micronuclei (MN) are a strong cytogenetic indicator of a catastrophic change in the genetic structure and stability of a cell because they originate from either chromosome breaks or whole chromosomes that have been lost from the main nucleus during cell division. The resulting genetic abnormalities can to lead to cellular malfunction, altered gene expression and impaired regenerative capacity. Furthermore, MN are increased as a consequence of genetic defects in DNA repair, deficiency in micronutrients required for DNA replication and repair and exposure to genotoxic chemicals and ultraviolet or ionising radiation. For all of these reasons, the measurement of MN has become one of the best-established methods to measure DNA damage in humans at the cytogenetic level. This chapter is a narrative review of the current evidence for the association of increased MN frequency with developmental and degenerative diseases. In addition, important knowledge gaps are identified, and recommendations for future studies required to consolidate the evidence are provided. The great majority of published studies show a significant association of increased MN in lymphocytes and/or buccal cells with infertility, pregnancy complications, developmental defects, anaemias, inflammation, diabetes, cardiovascular disease, kidney disease, neurodegenerative diseases and cancer. However, the strongest evidence is from prospective studies showing that MN frequency in lymphocytes predicts cancer risk and cardiovascular disease mortality.

Analysis of differential gene expression caused by cervical intraepithelial neoplasia based on GEO database

The aim of the present study was to identify the differentially expressed genes between cervical intraepithelial neoplasias (CIN) and adjacent normal tissue, and to construct a protein-protein interaction (PPI) network. A CIN dataset was obtained from Gene Expression Omnibus, and data of gene expression in CIN and adjacent normal tissue were extracted from GSE64217. The differentially expressed genes were selected using software package and heat map was drawn using the ‘pheatmap’ package. The selected differentially expressed genes were subjected to PPI, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis using Cytoscape, Database for Annotation, Visualization and Integrated Discovery, STRING and KOBAS. In the present study, 287 genes were differentially expressed between CIN and adjacent normal tissue, of which 170 were significantly upregulated and 118 genes were significantly downregulated (P<0.00001, fold-change >6). A differential gene expression network map was constructed to show the interactions of 30 protein products encoded by differentially expressed genes using STRING software. In particular, the key gene, EGR1, was identified using Cytoscape software. The KEGG pathway analysis revealed that the differential genes were mainly involved in several pathways, including ‘glutathione metabolism’, ‘arachidonic acid metabolism’, and ‘pentose phosphate pathway’. Results of the GO analysis showed that differential genes were enriched in different subsets. Specifically, small proline-rich protein 2E and 3, distal-less homeobox 5, epithelial membrane protein 1, cornifelin, periplakin, homeobox protein Hox-A13, estrogen receptor α, transglutaminase 1, small proline-rich protein 2A, Rh C glycoprotein, tumor protein p63, TGM3, homeobox B5 and small proline-rich protein 2D were enriched in ‘epithelial cell differentiation’, which affected the differentiation of epithelial cells. In conclusion, 287 differentially expressed genes were identified successfully. The key gene was identified based on the results of PPI, GO and KEGG analyses, and functional annotation and pathway analysis were also performed. Our study provides the basis for further studies on the interaction among differentially expressed genes.

The association between micronucleus, nucleoplasmic bridges, and nuclear buds frequency and the degree of uterine cervical lesions

BACKGROUND AND AIM

The loss of genomic stability plays an important role in carcinogenesis. Therefore, it is imperative to use certain biomarkers of DNA damage due to genomic instability in order to predict cancer risk. The aim of this study was the evaluation of genomic instability in patients with cervical lesions.

MATERIALS AND METHODS

We investigated the genetic damages in 80 subjects: 40 patients with high-grade squamous intraepithelial lesions (HSIL), 20 patients with invasive squamous cervical cancer (SCC) and 20 healthy women with a biomarker in two different tissues; the micronucleus (MN) test in peripheral blood lymphocytes (PBL), and in buccal exfoliated cells (BEC). This study also examined the frequency of other nuclear anomalies such as nucleoplasmic bridges (NPBs) and nuclear bunds (NBUDs) in PBL.

RESULTS

The frequency of MN in BEC, MN in PBL, NPB in PBL and NBUD in PBL were significantly higher (p < 0.001), in patients compared to controls. The DNA damages in BEC and PBL were correlated positively with histological grade of cervical lesions.

CONCLUSION

Although larger studies are needed, our data support the predictive value of MN, NPB and NBUD as biomarkers of genomic instability for evaluation of risk level of cancer diseases.

Micronucleus Assay in Urothelial Cells in Cancer Cervix

INTRODUCTION

Cancer ranks third among the ten leading global causes of death. To evaluate the genotoxic risks, observed as DNA damages, can be assessed by Micronucleus (MN) test.

AIM

To identify the occurrence of MN in normal and cancer cervix and find the correlation between MN and stage of cancer.

MATERIALS AND METHODS

A total of 60 females were included in the study and visual examination of the cervix was done. Based on the examination two groups were formed: A- Normal cervix (n-23) and B- Presence of erosion or growth or ulcer etc., in cervix (n-37). Midstream urine sample was collected and centrifuged from the cases after getting the informed consent. Slides were prepared from the pellet, were fixed in methanol, glacial acetic acid fixative and stained with Giemsa and May Grunwald stain. Statistical analysis was done by student's t-test and chi-square test.

RESULTS

A linear association was noted between the mean MN count and cancer cervix stage. Almost 18.2% of the Group A cases had significant MN count. Sensitivity and specificity of MN count in Group A was 83.8% and 82.6% respectively. The efficiency was 83.3%.

CONCLUSION

A statistically significant MN count was seen in the different stages of cancer cervix. There are cases who had normal findings on visual inspection of cervix but with significant MN count are prone for malignant transformation. MN assay is an easy, non-invasive, cost-effective method and can be used as a screening test for a large population.

Comparison of Pap Smear and Colposcopy in Screening for Cervical Cancer in Patients with Secondary Immunodeficiency

Introduction

Cervical cancer is the second most common cancer among women worldwide. The sensitivity of conventional Pap smear in detecting cervical lesions before cervical cancer is 51%, which means the false negative value is 49%. The aim of this study was to compare two methods for screening for cervical cancer in patients with secondary immunodeficiency, i.e., the conventional Pap smear and colposcopy.

Methods

This cross-sectional study was conducted on 101 immunodeficient patients who were referred to the Gynecologic Clinic at Shahid Sadughi Hospital in Yazd from March 2011 to August 2012. All patients underwent the Pap test, a colposcopy, and a cervical biopsy, with the latter being considered as the gold-standard test.

Results

The most frequency of immunodeficiency was noted among patients with rheumatoid arthritis (53.3%), and this was followed by patients who were undergoing chemotherapy (30.7%), patients with lupus erythematosus (12.9%), and patients with AIDS (3%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the Pap smear were 18.2, 98.5, 85.5, 71.3, and 72.2%, respectively. The respective values for colposcopy were 66.7, 98.94, 80, 97.9, and 97%, respectively.

Conclusion

In this study the accuracy, sensitivity, specificity, and negative predictive values of colposcopy were higher than those for the Pap smear in detecting high-grade, cervical, pre-malignant lesions (cervical intraepithelial neoplasia: CIN ≥ 2). Therefore, an annual colposcopy is advised for secondary immunodeficient patients instead of a Pap smear.

Association between micronucleus frequency and cervical intraepithelial neoplasia grade in Thinprep cytological test and its significance

A micronucleus is an additional small nucleus formed due to chromosomes or chromosomal fragments fail to be incorporated into the nucleus during cell division. In this study, we assessed the utility of micronucleus counting as a screening tool in cervical precancerous lesions in Thinprep cytological test smears under oil immersion. High risk HPV was also detected by hybrid capture-2 in Thinprep cytological test smears. Our results showed that micronucleus counting was significantly higher in high-grade squamous intraepithelial lesion (HSIL) and invasive carcinoma cases compared to low-grade squamous intraepithelial lesion (LSIL) and non-neoplastic cases. Receiver operating characteristic (ROC) curve analysis revealed that micronucleus counting possessed a high degree of sensitivity and specificity for identifying HSIL and invasive carcinoma. Cut-off of 7.5 for MN counting gave a sensitivity of 89.6% and a specificity of 66.7% (P = 0.024 and AUC = 0.892) for detecting HSIL and invasive carcinoma lesions. Multiple linear regression analysis showed that only HSIL and invasive cancer lesions not age, duration of marital life and number of pregnancy are significantly associated with MN counting. The positive rate of high risk HPV was distinctly higher in LSIL, HSIL and invasive cancer than that in non-neoplstic categories. In conclusions, MN evaluation may be viewed as an effective biomarker for cervical cancer screening. The combination of MN count with HPV DNA detection and TCT may serve as an effective means to screen precancerous cervical lesions in most developing nations.