Clinicopathologic significance of molecular classification of breast cancer: relation to nottingham prognosis index.

PURPOSE The aim of this work is to determine the possible relationship between the different profiles of molecular expression of hormone receptors and Her-2÷neu receptors to clinical and histopathological known prognostic variables for breast cancer. MATERIALS AND METHODS A total of 110 breast carcinoma tumor samples were included. In this study 4 groups or immunohistochemical profiles were defined, based on expression of hormone receptors (estrogen and÷or progesterone) and÷or Her2÷neu (Luminal A, Luminal B, HER2 overexpressing profile, and triple-negative profile). We studied whether there were differences between them regarding clinical and histopathological variables with a known prognostic significance in addition to Nottingham Prognosis Index (NPI). RESULTS In this series, 65 cases corresponded to Luminal A (59.1%), 18 cases (16.4%) were Luminal B, in 14 cases (12.7%) HER2 was over-expressed, while 13 cases (11.8%) were of the triple negative subtype. It is worth noting the relationship between the triple negative and HER2 over-expressing immunophenotypes and the high NPI (>3.4) in comparison with the Luminal A and Luminal B immunophenotypes (p=.029). The association of the former two types with higher tumor grade was also observed, but such association did not reach statistical significance. CONCLUSION The subgroups without hormone receptor expression, with Her2÷neu overexpression or without (triple-negative group), have characteristics associated with variables of a poorer prognosis. KEY WORDS Breast cancer- Hormone receptors- Her2neu- Classification- Nottingham prognosis index.