Human mammaglobin: A specific marker for breast cancer prognosis.

PURPOSE In this study, we examined the expression of human mammaglobin (hMAM) mRNA and the protein levels in patients with breast cancer and their relationship with prognostic clinicopathological parameters. METHODS hMAM mRNA expression in leucocytes from peripheral blood samples from patients diagnosed with primary invasive breast cancer (IC), carcinoma in situ (CIS), or benign breast diseases was analyzed using RT-PCR. The hMAM protein levels and expression patterns in tissue from 3 patient groups were evaluated by immunohistochemical staining, and several non-breast neoplasms were selected as negative controls, undergoing the same examination. RESULTS The expression of hMAM mRNA was significantly higher in patients with IC or CIS compared to those with benign tumors (both<0.01). Immunohistochemical staining revealed similar results, where patients with IC or CIS had higher levels of hMAM protein (p<0.01 and p<0.01, respectively), while none of the negative controls expressed hMAM. Further analyses showed a strong correlation between hMAM protein/mRNA expression and clinicopathological factors, such as histological grade, clinical stage, and lymph node status, in patients with IC. CONCLUSION The hMAM mRNA and protein expression profiles validate the potential of hMAM as a specific marker for breast cancer diagnosis and target treatment delivery.