Objective: To detect the expression of pan-neuronal marker protein gene product (PGP)9.5 and its clinicopathologic significance in breast cancer.
Methods: The expression of PGP9.5 was examined by immunohistochemistry EnVision method in 196 cases during 2007 to 2011, including 20 normal tissues, 14 cases of fibroadenoma, 18 cases of ductal carcinoma in situ (DCIS) and 144 cases of invasive ductal carcinoma (IDC) of the breast. The relationship between PGP9.5 expression and clinicopathologic characteristics of IDC was assessed.
Results: PGP9.5 expression was localized in the stroma of all normal breast tissues, but there was no expression observed in all fibroadenomas and DCIS. Overall, the expression rate of PGP9.5 in IDC was 61.8% (89/144). PGP9.5 expression increased from grade 1 tumors (29.4%, 10/34) to grade 2-3 tumors (71.8%, 79/110; P = 0.000). In addition, patients with less than 3 years disease-free survival tended to show higher PGP9.5 expression (64.8%, 35/54), compared to patients with equal to and/or more than 3 years disease-free survival (46.7%, 42/90; P = 0.035). However, there was no correlation between PGP9.5 expression and tumor size, tumor stage, lymph metastasis, hormone receptor expression.
Conclusion: PGP9.5 expression is correlated with tumor grade and prognosis in IDC of the breast.