Terminal uridine nick end labelling and mitosis in breast carcinoma. Correlation with tumor grade and p53...

To study the relationship of cell death and proliferation to histologic grade and p53 expression in invasive carcinoma of the breast.

A total of 31 cases of infiltrating duct carcinoma of the breast were randomly selected. The terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling (TUNEL) reaction and p53 immunostaining were performed on representative paraffin-embedded tissue sections. Mitotic and apoptotic indices (MI and AI) were also measured on hematoxylin-eosin-stained sections. Histologic grade of infiltrating duct carcinoma was performed with the help of the Nottingham modification of the Bloom-Richardson system. Tumor grade and p53 overexpression were correlated with MI, AI and AI detected by TUNEL.

There were a total of 31 infiltrating duct carcinomas of the breast, of which 13 cases were grade 1 and nine cases each were grade 2 and 3. Cells with positive TUNEL showed a strong brown nuclear positivity. TUNEL showed positivity from the periphery of the nuclear margin to the central portion. AI detected by TUNEL did not correlate with tumor grade (ANOVA, P > .05). MI was significant only in grade 1 versus grade 3 and 2 versus grade 3 carcinomas (ANOVA, P < .01). The morphologic apoptotic index was significant only in grade 1 versus grade 3 carcinomas. Nine cases showed p53 overexpression, and the rest of the cases were negative for p53 immunostaining. MI, AI and TUNEL were not significantly different in p53-negative and -positive groups. Pearson's correlation coefficient showed that AI and MI were significantly related, but there was no significant relation between AI detected by TUNEL and MI.

MI is still more useful than AI or AI detected by TUNEL in differentiating various grades of carcinoma of the breast.