Silver-stained nucleolar organizer regions in normal and dysplastic cervical lesions: correlation with DNA ploidy and S-phase fraction by flow cytometry

Abstract

Objectives: To investigate the prognostic significance of DNA ploidy and silver-stained nucleolar organizer regions (AgNOR), their relation to the cytological grades of cervical dysplasia and correlation of cells in the S-phase of the cell cycle and DNA ploidy with AgNOR count.

Methods: Multiparametric DNA flow-cytometric analysis and AgNOR count were performed on cervical smear samples, cytologically diagnosed as normal (n = 196), atypical squamous cells of unknown significance (ASCUS, n = 98) and various grades of cervical dysplasia (n = 127).

Results: Among the cytological grade, aneuploid cases from low-grade squamous intraepithelial lesion (mild) and high-grade squamous intraepithelial lesion (moderate and severe) groups were showing high AgNOR counts (ranges 4.33-5.86 and 5.91-7.42, respectively). Aneuploid cases from the ASCUS group also presented high AgNOR (range 3.72-4.93). The high percentage of cells in the S-phase (>12%) correlated with these 2 parameters in the ASCUS and dysplasia groups. After grouping the cases into those with high (>4.0) and low (<4.0) AgNOR counts, significant correlations in the group with high AgNOR count with DNA ploidy, S-phase and cytological grade were recorded (p < 0.001). Results obtained from follow-up study revealed that cases with aneuploidy, high AgNOR count and S-phase fraction presented with a progressive trend of disease.

Conclusions: Thus, the study shows that high AgNOR count, S-phase fraction and aneuploid DNA have prognostic significance in the early detection of cervical cancer.