Background: In the past years, morphological indexes and kinetic parameters have been introduced to characterize breast cancer in order to select breast cancer patients for adjuvant therapy. The alterations of the proliferative activity of neoplastic cells and DNA ploidy may provide important information about the aggressiveness of the lesion and may be used as powerful prognostic factors. In fact, prognostic information based on the classic clinico-pathologic parameters such as histotype, stage and grade are no longer sufficient to select patients for long term follow-up. The aim of this study was to evaluate the malignant potential of neoplastic cells through the determination of modifications of the proliferative index and the evaluation of DNA ploidy.
Methods: Forty-five breast cancer patients, 32 to 80 years of age, were studied. Proliferative indexes and DNA ploidy, besides the other clinical-pathologic parameters have been evaluated. The proliferative index was assessed with the immunocytochemical determination of Ki67 and quantified with the CAS 200: 31 cases had a high proliferative index, 12 medium and 2 low. DNA ploidy was analyzed on cytologic preparations with static cytometry utilizing an image analyzer CAS 200: 13 cases were diploid, 32 non-diploid.
Results: A close relationship was found between Ki67 expression and DNA ploidy. In fact, lesions with a high proliferative index were all non-diploid, whereas, those with a low proliferative index were all diploid. Lesions with a medium proliferative index were 2 diploid and 1 non-diploid. Among the 45 cases, studied in a follow-up period of 36 months, 12 showed disease recurrence; 3 showed a medium Ki67 expression and were diploid, 9 a high Ki67 expression and were all non-diploid.
Conclusions: In conclusion, proliferative indexes and DNA ploidy may be considered additional prognostic parameters which may potentially influence the clinical behaviour of breast cancer and may be utilized besides all the other clinico-pathologic data to assess these lesions.