Apoptosis occurs more frequently in intraductal carcinoma than in infiltrating duct carcinoma of human breast cancer and correlates with altered p53 expression: Detected by terminal-deoxynucleotidyl-transferase- mediated dUTP-FITC nick end labelling (TUNEL)

Aims: We examined the relationship between apoptosis and three different major stages of human breast carcinoma: intraductal carcinoma (DCIS), infiltrating duct carcinoma (IDC) and metastatic carcinoma in lymph nodes. We also determined the correlation between apoptosis and oestrogen receptor (ER), progesterone receptor (PR) and p53. Methods and results: The study investigates the extent of apoptosis in 63 breast carcinomas by in-situ endlabelling, in formalin-fixed, paraffin-processed tissue sections. The 63 breast carcinomas, included 22 DCISs, 26 IDCs, three infiltrating lobular carcinomas (ILC) and 12 metastatic lymph nodes. The apoptotic labelling index was higher in DCIS than IDC and metastatic carcinoma (P<0.001, P<0.007, respectively). By immunohistochemistry, we also analysed p53, ER and PR. Apoptosis correlated significantly with p53 (r= 0.748, P=0.0004) in IDC. Also, ER correlated significantly with PR (r=0.629, P=0.00001). No apparent correlation was found between the apoptosis and ER or PR. Conclusion: Our data suggest that not only does apoptosis differ between intraductal carcinoma and infiltrating carcinoma but also it might be regulated by altered p53 expression.