A Survey of NY-BR-1 Immunohistochemistry in Breast, Ovarian, Endometrial and Lung Cancers: A Correlation Study with Estrogen and Progesterone Receptors.
Authors: Liu H. , Muralitharan S. 
Published: December 2010

Abstract
Background: Estrogen and progesterone hormone receptors are expressed in a majority of breast cancers. Therefore they are commonly included to the work-up of metastatic breast tumors in addition to the mammary markers, mammaglobin and GCDFP-15. The sensitivity and specificity of various markers for detecting breast cancer is of some concern. Some breast cancer metastases are negative to ER and PR, while tumors of ovarian or endometrial origin are often positive to ER and PR. Our previous study showed that NY-BR-1 is a better mammary marker demonstrating higher positive rate than GCDFP and mammaglobin, in both primary and metastases breast cancers. The aims of the present study are to further investigate the characteristics of NY-BR-1 in various cancerous tissues: 1) whether NY-BR-1 is positive in ER and PR negative breast cancers, 2) whether NY-BR-1 is negative in ER or PR positive ovarian and endometrial cancers, 3) comparison of the expression profile of NY-BR-1 to ER and PR in lung cancers.Materials and Methods: IHC was performed using NY-BR-1, ER and PR antibodies on tissue arrays including three breast cancer arrays (total 207 cases), an endometrial cancer array (70 cases), an ovarian cancer array (70 cases) and a lung cancer array (70 cases). The arrays were scored as following: 1) NY-BR-1 was scored based on the staining intensity and percentage of positive tumor cells: tissue cores which scored 1 (weak) in 5% of tumor cells or scored 2 or above (moderate to strong) in 1% tumor cells were counted as positive; 2) ER and PR were scored as positive if ≥5% showed immunoreactivity.Results: In a total of 207 breast cancer cases, 38.2% (79 cases) of the cases are negative to ER and 46.9% (97 cases) are negative to PR. Among the total 67 cases of double ER and PR negative breast cancers, 46.3% (31 cases) are NY-BR-1 positive.In the 70 ovarian tumor cases, 25.7% (18 cases) of the cases`express ER, 45.7% (32 cases) express PR and all but one are negative to NY-BR-1. Among ER or PR positive ovarian tumors (37 cases), 97.3% are NY-BR-1 negative.In the 70 cases of endometrial cancers, 27.1% of the cases (19 cases) are positive to ER, 60% (42 cases) are positive to PR and only 3 cases are positive to NY-BR-1. Among those that are either ER or PR positive tumors, 97.8% were NY-BR-1 negative.Out of a total of 70 lung cancer cases none are ER or PR positive. However, 12.9% are NY-BR-1 positive.Discussion: 1) The present study demonstrated that NY-BR-1 is often positive in both ER and PR negative breast cancers; therefore NY-BR-1 could be complementary to ER and PR in the work-up of breast metastases 2) Among the ovarian and endomethrial cancers tested, more than a quarter are positive to ER and about half are positive to PR, while rarely expressing NY-BR-1. Thus, it might be appropriate to use NY-BR-1 and avoid using ER and PR in the detection of breast metastases in the ovary and endometrium. 3) NY-BR-1 expresses in approximately 13% of primary lung cancers while ER and PR are totally negative suggesting that these markers are more specific to mammary origin in lung, whereas, NY-BR-1 should be used with caution.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6018.