[234] A New Approach to Breast Carcinoma Detection: NYBR-1 Teamed up with Mammaglobin and Gross Cystic Disease Fluid Proteins

H Liu, S Muralitharan. Thermo Fisher Scientific (Anatomical Pathology Division), Fremont, CA

Background: NY-BR-1 is a novel differentiation marker with mRNA expression restricted to breast, testis, prostate and breast cancer. It has been shown by Immunohistochemistry (IHC) that NY-BR-1 was present solely in ductal epithelium of normal breast tissue. Invasive carcinoma of the breast and carcinoma in situ were positive for NY-BR-1, whereas most other tumors and normal tissues are negative. The exceptions are that one-third of sweat gland carcinomas and two percent of prostate carcinoma are positive for NY-BR-1. In a study by Varga et al (2006) forty-nine percent of lymph node metastasis were shown to be positive. Mammaglobin and GCDFP-15 are known metastatic breast carcinoma markers.
Design: IHC was performed using NY-BR-1, Mammaglobin and GCDFP-15 antibodies on different tissue arrays. NY-BR-1 was initially evaluated by IHC on arrays containing breast cancer, other cancers and normal tisssues. All three markers were further evaluated on metastatic multi-tumor arrays and metastatic breast carcinoma to node arrays. The arrays were scored based the staining intensity and percentage of positive tumor cells: tissue cores which showed 1 (weak) in 5% of tumor cells and tissue cores which showed 2 (moderate to strong) or above in 1% tumor cells were counted as positive.
Results: Analysis of results in breast cancer with clinicopathologic variables in 68 cases found that NY-BR-1 positive rate is lower in groups with larger tumor size, higher histology grade and auxiliary node metastasis. In addition, (2/12) prostate cancers showed moderate staining, while all other non-breast carcinoma tumors were negative for NY-BR-1. In human breast cancer arrays containing 209 cores, 60.3%are NY-BR-1 positive, 35.7% are Mammaglobin positive and 36.2% are GCDFP-15 positive. The combined positive rate is higher (77.3%) than that of the individual markers. All three markers were negative on forty metastatic non-breast carcinomas. Twenty seven cases of metastatic breast carcinoma of the lymph node, lung and liver demonstrate that the combined positive rate of the three markers is 74%.
Conclusions: NYBR-1 in itself is a specific breast cancer marker demonstrating a higher rate of positivity compared to both GCDFP-15 and Mammaglobin. The combined positive rate of the three breast markers is higher than each individual marker in both primary breast carcinoma and metastatic breast carcinomas. The use of the three markers has the potential to be a valuable diagnostic tool for metastatic breast carcinomas.
Category: Breast

Tuesday, March 10, 2009 1:00 PM

Poster Session IV # 1, Tuesday Afternoon