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

Abstract

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.