en Pathology Pathology Original Research Original Research To investigate the patterns of DNA ploidy and proliferating activity in breast cancer and relate them to other prognostic factors, paraffin blocks of 53 cases of breast carcinoma were studied. Cancer cells obtained by mechanical tissue disaggregation were examined for DNA content, ploidy and S-phase fraction. DNA assay was done using a CAS interactive image analyzing system. All of the cases showed high degrees of proliferation. The rate of aneuploidy was 77% in invasive breast carcinomas. S-phase fractions were correlated with the grades of the tumors (p<O.05). There was no statistically significant correlation between S-phase fractions and other prognostic factors this was also true about the pattern of ploidy and other prognostic factors. Breast cancer, S-phase fraction, Image analysis. 207 209 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-307&slc_lang=en&sid=1 F SARI ASLANI 20031947532846004337 20031947532846004337 Yes From the Department of Pathology, Shiraz University of Medical Sciences, Shiraz, I.R. Iran. B SALIMI 20031947532846004338 20031947532846004338 No