Background: Cervical cancer is the second most common malignancy in women
worldwide. Chemoprevention of cervical cancer is highly desirable to reduce incidence
and prevalence of cervical cancer. Biomarkers for chemoprevention are essential to
develop successful chemoprevention trials.
Purpose: to better understand the field cancerization and multistep tumorigenesis
process in cervical intraepithelial neoplasia and invasive cancer of the cervix, we
examined chromosome 9 polysomy in tissues that changed from histologically normal
epithelium through cervical intraepithelial neoplasia to invasive cancer of the cervix.
Methods: 37 specimens from the same number of patients were studied. These
specimens show transition from normal to CIN-3 - invasive cancer. Hybridization with
DNA probes specific for the centromeric region of chromosome 9 was performed. A
pathologist marked each pathological area. At least 200 nuclei were scored for each
defined histological area for number of chromosomes. A chromosome index was
obtained dividing the total number of signal spots by the number of nuclei analyzed.
Differences for each specific pathological entity means were analyzed.
Results: An increase in the normalized chromosome index was present as the tissue
progressed from normal to cervical intraepithelial neoplasia to invasive carcinoma. The
frequency of cells with polysomy increased as the tissues progressed. Genotypic
abnormalities adjacent to the tumor were present.
Conclusions: The determination of the degree of accumulated genetic abnormalities
in cervical tissue may be useful for identifying individuals with high risk of progression
to cervical cancer. This parameter may be a biomarker as an intermediate end-point
in chemoprevention trials.

Keywords: Cervical cancer, Biomarkers, Genetic instability, Tumorigenesis, Chemopreventio