The expression of prostate-specific antigen in invasive breast carcinoma and its relationship with routine clinicopathologic parameters

Background: Invasive breast carcinoma is one of the most common cancers of women. Parameters such as lymph node status, tumor grade, and the status of hormone receptors are among the main prognostic determinants of this cancer. Immunohistochemical detection of prostate-specific antigen (PSA) is widely used to identify metastatic prostatic adenocarcinoma. However, its immunoreactivity has been found in some non-prostatic tissues. This study was conducted to assess PSA expression in invasive breast carcinoma and its relationship with routine clinicopathologic parameters. Materials and Methods: 100 formalin-fixed and paraffin-embedded invasive breast carcinoma tissue specimens from the pathology archive of Alzahra hospital (Isfahan, Iran) were studied for the expression of estrogen receptor (ER), progesterone receptor (PR), HER2/neu, and PSA by immunohistochemistry. Stained sections were classified according to the intensity of staining and the percentage of cells showing PSA staining. The relationship between PSA expression and other markers, age, lymph node status, tumor subtype, and tumor grade was then studied. Results: No association was found between PSA expression on one hand and PR, Her2/neu, age, lymph node status, tumor grade, and tumor subtype on the other. PSA score was reversely correlated with ER expression (P = 0.015). Conclusion: Despite the reverse relationship between PSA expression and the immunoreactivity of ER, PSA expression was not correlated with other prognostic factors. Therefore, the detection of PSA by immunohistochemistry does not seem to be a significant prognostic parameter in patients with invasive breast carcinoma