5304

PIP

prolactin-induced protein;PIP;prolactin-induced protein

SABP|gross cystic disease fluid protein 15|prolactin-inducible protein|secretory actin-binding protein

7q34

protein-coding

Morphologic differentiation of breast carcinoma from nonmammary malignancies in fluid specimens can be a diagnostic challenge. Immunocytochemistry is often employed in the differential diagnosis. In this study, we evaluated the expression of mammoglobin (MGB1) in body-cavity fluid specimens and compared its efficacy as a marker for metastatic breast carcinomas with that of gross cystic disease fluid protein-15 (GCDFP-15). Cell blocks from 40 fluid specimens were immunostained with monoclonal antibodies against MGB1 and GCDFP-15. They included 15 breast carcinomas and 25 nonmammary carcinomas (10 lungs, 10 ovaries, 3 gastrointestinal tracts, 1 kidney, and 1 urinary bladder). Positivity was defined as the presence of cytoplasmic staining in 10% or more carcinoma cells. Thirteen (87%) and seven (47%) breast carcinomas showed positive staining with MGB1 and GCDFP-15, respectively. Three (12%) nonmammary carcinomas (2 ovarian and 1 colonic) showed positive MGB1 staining; one (3%) nonmammary carcinoma demonstrated positive GCDFP-15 staining. The differences of MGB1 and GCDFP-15 staining between breast and nonmammary carcinomas were statistically significant (P < 0.05). Both MGB1 and GCDFP-15 are specific markers for metastatic breast carcinomas in cell block fluid specimens (88 vs. 96%). However, MGB1 is more sensitive than GCDFP-15 as a marker for metastatic breast carcinoma (87 vs. 46%).

OBJECTIVE: Triple-negative-breast-cancer that accounts for 10-20% of all breast carcinomas is defined by the lack of estrogen receptor, progesterone receptor, HER2 expression, and agressive clinical behavior. Triple-negative-breast-cancer is categorized into basal like and other types. The basal-like subtype is characterized by the expression of myoepithelial/basal markers. MATERIAL AND METHOD: We studied 41 immunohistochemically triplenegative- breast-cancer patients to determine EGFR, Cytokeratine 5/6, p53, Ki67, GCDFP-15 expression profiles, HER2 and Chromosome 17 centromere gene status by fluorescence-in-situ-hybridization method. RESULTS: Histological type was invasive ductal carcinoma in 90.2% of the tumors. p53, Ki67, GCDFP-15 mean positivity rates were 55.6%, 51.7%, and 3.2%, respectively. GCDFP-15 positivity was noted in 8 cases of which 6 were Cytokeratine 5/6 negative. The cut-off value for Cytokeratine 5/6 positivity was 5%. EGFR immunoreactivity was grouped into 0, 1+ as negative; 2+, 3+ as positive categories. Cytokeratine 5/6 was positive in 56,1%, EGFR was positive in 51.2% of the patients. The relation between Cytokeratine 5/6 and EGFR expression was statistically significant (p < 0.01). None of the cases showed HER2 amplification by fluorescence-in-situ-hybridization method. CONCLUSION: GCDFP-15 alone is not a useful marker to detect the metastasis of basaloid type breast cancers. Cytokeratine 5/6 and EGFR expressions showed correlation so these markers are reliable to diagnose basaloid type tumors with a 5% cut-off value.

OBJECTIVE: There are small studies on expression of mammaglobin and GCDFP-15 for detection of basal-like triple negative breast cancer. This type of cancer has shorter survival and higher mortality rate. There must be reliable markers for detecting this type of tumor especially in metastatic cases with unknown origin. MATERIAL AND METHOD: In this study we assessed 66 paraffin blocks of breast cancers previously diagnosed as triple negative subtype in Mehr hospital (Tehran, Iran) by tissue microarray and immunohistochemistry technique for expression of mammaglobin and GCDFP-15. RESULTS: GCDFP-15 was positive in 12 cases (18.2%) and the other 54 (81.8%) cases remained negative. Mammaglobin was positive only in 6 cases (9.1%) and the remaining 60 (90.9%) cases were negative. CONCLUSION: According to recent studies and our findings, there is no useful immunohistochemical marker for detection of breast source in cases of metastatic triple negative breast cancer with unknown origin and we must try hard to discover more accurate immunohistochemical markers for these highly metastatic breast cancers.