Prognostic value of flow-cytometric DNA analysis in breast cancer

Background. Prognosis of breast cancer is mostly dependent on the biological aggressiveness of the neoplasia. New parameters, including DNA content and cellular cycle of neoplastic cells, are now routinely used to assess malignancy. In this work we have studied the clinical value of flow-cytometric DNA ploidy analysis. Particular attention has been addressed towards establishing if these values give additional information to that of histological examination. Methods. Patients who underwent surgical treatment for primary breast cancer have been selected. At present, all of them are still living, no one has long-distance metastases and all are free of tumor relapses. Thin sections were tested, after staining, by a Coulter Epics Profile flow cytometer. DNA-index (DI) was assumed to be 1.0 if only a single G0/1 peak was evident. When a second peak was clearly identified (more than 10%), this was considered as an indicator of clonal abnormality of the DNA content. The slides were also examined to define the stage of the neoplasia. Grading was made by evaluation of tubular growth, nuclear polymorphy and number of mitosis. Cell cycles, DI and coefficent of variation G0-G1 peak were compared. Results. A significant relationship among histological stage, S-phase fraction (SPF) and ploidy was observed. In accord to the survival rate, nodule size and SPF determine 3 classes of infiltrating ductal carcinoma with negative axillary lymph nodes. Our twenty cases show a correlation between DNA ploidy and histological stage. In fact there are no aneuploid tumors in stage I group, all cases of stage III and most of stage II are aneuploid. We did not find a correlation with survival. Conclusions. The new screening methods and the improvement of the available methodologies have permitted an earlier diagnosis of breast cancer. Unfortunately, according to our data, flow-cytometric information does not seem to offer predictive elements about tumor clinical outcome.