Aim: Apoptosis in breast cancer has been correlated with histopathological and clinical prognostic parameters and its significance in biology and behavior of breast cancer is being intensely studied. Our aim was to point out any relations of the apoptotic and mitotic index in infiltrating ductal breast carcinomas to the survival and recurrence rates of the patients.

Materials and methods: One hundred-seven patients (mean age 54 years, range 29-80) with infiltrating ductal breast carcinoma, NOS, were followed, up to 36 months. Ninety-two patients (86%) (group A) showed no evidence of disease, whereas in 15 patients (14%) (group B) local reccurence (n=5), metastases (n=5) or death because of the disease occured (n=5). Apoptotic (AI) and mitotic indices (MI) were calculated on paraffin sections stained with H&E and were expressed as the number of cells undergoing apoptosis and mitosis, respectively, per 20 HPF (X400). The two groups were compared for AI, MI and their ratio (AI/MI), the size and the grade of the tumor, the presence of lymph node metastases and the hormone receptor status.

Results: In patients with recurrent disease (group B) the AI and MI were higher (mean 4 and 2.1 respectively), compared with the patients with no evidence of disease (group A, mean 2.3 and 1.6 respectively), although the difference was not statistically significant. The ratio AI/MI did not differ between the two groups (2 for group A and 2.5 for group B). The correlation of the two groups with the other parameters showed no significant differences, except for the size of the tumor, which was larger in group B (P<0.05).

Conclusions: Our findings, in this relatively short period of follow up, suggest that although the apoptotic index might influence tumor growth, it cannot yet be considered as an independent prognostic indicator, since it seems to be strongly related to the proliferative activity of breast cancer, as expressed by the mitotic index.

Key words: Breast cancer, apoptosis, prognosis.

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