[892] Prostate-Specific Antigen, Prostate-Specific Acid Phosphatase, and Hormone Receptor Expression in Male and Female Breast Carcinoma

TS Kraus, C Cohen, MT Siddiqui. Emory University, Atlanta, GA

Background: Prostate specific antigen (PSA) and prostate-specific acid phosphatase (PSAP) are expressed in benign and malignant prostatic tissue. Immunohistochemical staining for these markers can be used to confirm the prostatic origin of metastatic carcinoma. PSA expression has been reported in male and female breast carcinoma and in gynecomastia, raising concerns about the utility of PSA for differentiating prostate carcinoma metastasis to the male breast from primary breast carcinoma. This study examined the frequency of PSA, PSAP, and hormone receptor expression in male breast carcinoma (MBC), female breast carcinoma (FBC), and gynecomastia.
Design: Immunohistochemical staining for PSA, PSAP, AR, ER, and PR was performed on tissue microarrays representing six cases of gynecomastia, thirty MBC, and fifty-six FBC. PSA and PSAP were considered positive if any cytoplasmic staining was observed. Positive reactions for AR, ER, and PR were defined by nuclear staining observed in at least 10% of tumor cells.

MBCFBCGynecomastiaP-value (MBC vs FBC)
PSA1/30 (3.3%)2/54 (3.7%)0/5 (0%)1
PSAP0/29 (0%)0/54 (0%)0/5 (0%)1
AR20/27 (74.1%)38/56 (67.9%)4/5 (80%)0.62
ER23/37 (85.2%)37/54 (68.5%)6/6 (100%)0.18
PR14/27 (51.9%)27/57 (47.4%)5/5 (100%)0.82

PSA was positive in two of fifty-six FBC (3.7%), focally positive in one of thirty MBC (3.3%), and negative in the five examined cases of gynecomastia.
Conclusions: PSA and PSAP are useful markers to distinguish primary breast carcinoma from prostate carcinoma metastatic to the male breast. The incidence of PSA expression in our population was too low to draw significant conclusions about an association between PSA expression and hormone receptor status in breast lesions.
Category: Genitourinary (including renal tumors)

Wednesday, March 24, 2010 1:00 PM

Poster Session VI # 109, Wednesday Afternoon


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