Positive correlation between the frequency of micronucleated cells and dysplasia in Papanicolaou smears

Abstract

Most cancers arise in epithelial tissues and these tissues are typically the targets of the carcinogens responsible for the tumors. Exfoliated epithelial cells have traditionally been used for cancer screening by cytopathologists and these cells also can be used for biomonitoring of genotoxic effects in humans. Cervical cancer results from the progression of preinvasive precursor lesions, called low-grade squamous intraepithelial lesions (LGSILs), to high-grade squamous intraepithelial lesions (HGSILs). The gradient from low to high-grade lesions is characterized by increasing nuclear atypia and the failure of cellular differentiation in progressively more superficial levels of the epithelium. These phenotypic changes are hypothesized to be accompanied by increased genetic instability that can be documented using the micronucleus (MN) assay in exfoliated cervical cells. A retrospective study was performed to investigate the frequency of micronucleated cells in cervical smears from women at high risk for developing cervical cancer. Papanicolaou (Pap) smears from 275 women previously studied at a cancer clinic were coded and analyzed for the frequency of micronucleated cells. LGSIL, HGSIL, and invasive carcinoma smears had significantly higher frequencies than normal and ASCUS (abnormal squamous cells of undetermined origin) smears. HGSIL or severely dysplastic smears had the highest frequency of micronucleated cells (although not significantly higher than LGSIL smears), an observation that that could be useful in confirming these types of lesions. The results indicate that the MN frequency in exfoliated cervical cells may be an additional criterion for establishing cervical cancer risk.

Effects of dietary boron on cervical cytopathology and on micronucleus frequency in exfoliated buccal cells

“…Therefore, the frequency of micronuclei in epithelial cells is viewed as an indicator of a potential tissue-specific cancer risk (Sarto et al, 1987;Tolbert et al, 1992). In this study, the purpose was not to examine MN frequencies in patients with cervical malignancies, as has been done previously (Leal-Garza et al, 2002;Guzman et al, 2003). MN frequencies in exfoliated buccal cells are affected by race, environment, life style, and diet (Adhvaryu et al, 1991;Karahalil et al, 1999;Gomez-Arroyo et al, 2000).…”

How virus persistence can initiate the tumorigenesis process

“…In this setting the measurement of chromosomal abnormalities in peripheral blood lymphocytes should result particularly fruitful, if one considers that circulating cells are exposed to infectious agents even in localized infections during tissue perfusion [23,58,59] . Precious information would be generated through the analysis of pre-tumoral and tumoral banked samples, where the observation of abnormal mitosis and genetic abnormalities can be associated with the identification of virus related antigens or nucleic acids [60] , while prospective studies could include virus isolation. As an example, hepatic biopsies from non-responders to anti-HCV treatment could be analyzed for the presence of genetic abnormalities and the findings would be compared to responders in relation to incidence of hepatocarcinoma development over time.…”

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

“…A correlation between MN frequency and grade of cervical lesion, and a posi tive linear trend between the MN frequency and increased cervical cancer risk was also shown [9]. Moreover, a retrospective study was performed to investigate the frequency of cells with MN in Pap smears from patients, and a strong correlation was observed between these two parameters -MN fre quency and grade of cervical lesions [10]. Appli cation of molecular cytogenetic technique (FISH) supports this observation in 143 women [11].…”

“…It is of extremely importance that in urothelial cells of women suffering from cancer of cervix significantly increased number of MN was also observed [16]. Based on the mentioned data, some investigators [9,10,[14][15][16] proposed that MN test in exfoliated cervix and urothelial cells should be applied in mass screening pro grams in developing countries based on high corre lation between the results in MN assay in exfoliat ed cervix cells and Pap test on one the hand, and a correlation between cancer and increased MN level in urothelial and cervix cells on the other.…”

“…In the study in India the increment of cells with MN in the first stage of cancer was 7 fold and at higher stages 11-14 fold higher compared with the level observed in healthy females [16]. It has been shown that MN level increased from the control level with the progression of premalignant changes in the cervix (2.4-3.2 fold [9] and 2.7-4.2 fold increase [10]) to cancer (4.7 fold [9] and 5.6-7.7 fold [10] increase compared with appropriate control levels). These data strongly support a positive correlation between the MN incidence and cancer progress (changes from premalignant stage to cancer).…”