Possible role of the micronucleus assay in diagnostics and secondary prevention of cervix cancer: A minireview

Abstract

Recent literature data are presented concerning micronu clei (MN) frequency in exfoliated cells of cervix cancer patients. These data strongly support a positive correlation between the MN level and malignization (changes from pre malignant stage to cancerCervical cancer is the second most common cancer in women worldwide and the leading cause of cancer mortality in women in developing coun tries [1]. In the United States, over $6 billion is spent annually in the evaluation and treatment of low grade cervical lesions, many of which do not deve lope into full blown cancer. In developing coun tries cervical cancer goes undetected because of the cost of testing and the lack of resources and trained personnel to screen and diagnose the dis ease [1]. The goal of one of the programs of the National Cancer Institute is to assess the emerging technologies of fluorescence and reflectance spec troscopy and quantitative cytology and histopathol ogy for the diagnosis of cervical cancer. All of these technologies should decrease mortality, morbidity, and the cost of treating cervical cancer.Recently Leyden et al.[2] examined factors associated with the diagnosis of cervical cancer among women enrolled in health plans and con cluded that to reduce the incidence of invasive cer vical cancer, the Papanicolaou (Pap) cervical cytology screening (which helps to reduce cervical cancer rates through the detection of premalignant lesions) should be improved. This test is of extremely importance in cancer prevention. Recent publication has shown that during first 18 months after the last negative screening Pap test in women with > or = 3 prior negative tests, cancer incidence increases to an estimated 4-5 per 100,000 woman years in each of the subsequent 2 years [3].It is well known that some specific human papil loma viruses (HPV) are associated with cancer and dysplasia of cervix, penis, anus, vagina, and vulva [4,5]. These viruses selectively infect the epitheli um of skin and mucous membranes and it results in numerical and structural chromosome aberra tions, chromosomal instability, increased aneu ploidy, and these events initiate cervical carcinogen esis. The micronucleus [fragment of chromosomes and/or whole chromosome lagged in the mytosis] assay (MN) can register both numerical and struc tural chromosomal aberrations, and MN can be easily detected in exfoliated human cells [6,7]. Since HPV infection induces cytogenetic instabil ity in cervix cells, it can be evaluated by means of MN assay. Indeed, it has been shown that in exfo liated cervical cells of patients with moderate and severe dysplasia a significantly higher frequency of MN level was observed compared with healthy women [8]. The same effect was shown by a group 64ISSN 0564-3783. Цитология и генетика.

Micronuclei as biomarkers for evaluating the risk of malignant transformation in the uterine cervix

“…Several studies have indicated that there is an association between micronucleus occurrence and progression of precursor lesions of cervical cancer (Cerqueira et al, 1998;Leal-Garza et al, 2002;Guzman et al, 2003). According to Nersesyan (2007), "evaluation of the frequency of micronuclei in exfoliated cervical cells may be an additional criterion for establishing cervical cancer risk and the study of micronuclei in Pap smears will increase the sensitivity and specificity of cervical cytology which could impact in diagnostics and secondary prevention of cervical cancer".…”

“…The study was approved by the Ethics Committee of Feira de Santana State University (Protocol No. 034;2007).…”

“…This virus induces structural chromosomal alterations and aneuploidy in the cervical epithelium that are associated with the initiation of the malignant process (Nersesyan, 2007).…”

Significance of Micronucleus in Cervical Smears

“…The Papanicolaou test (Pap smear) is the main measure for the prevention of this type of cancer and is capable of detecting pre-invasive lesions in the slow progression of the tumor [5]. Another test is the micronucleus (MN) test on exfoliated cells and it has been successfully used to screen population groups at risk for cancers of oral cavity, urinary bladder, cervix and esophagus [6].…”

A Current Method in Gynecological Cancer Prediction: 'Micronucleus': Review

“…9 Generally, MN of exfoliated epithelial cells assay can be used to investigate genotoxicity in hair follicle cells, oral cavity, corneal epithelial, lung, esophagus, spleen,vagina, urinary bladder, cervix and testis. [9][10][11][12][13] When the target tissue is epithelial tissue, the exfoliated cell MN assay has advantages over the more widely used MN assay in lymphocytes. The target tissue can be studied directly without stimulation, whereas lymphocytes must first be stimulated.…”