[20] Although different end-points were used (disease progression and the development of brain metastasis), results of these two studies and our study suggest that breast cancer has unique characteristics in young patients. Anders et al. described different gene expression profiles in tumors from younger women. [21] They found lower expression of ER alpha and beta mRNA, with higher expression of HER-2 and epidermal growth factor receptor (EGFR) compared to older patients. [21] Moreover, elevated EGFR expression was associated with brain metastasis [22], [23]. The gene discussed is ESR1; the disease is breast cancer.