NY-BR-1 and PAX8 Immunoreactivity in Breast, Gynecologic Tract, and Other CK7+ Carcinomas

Abstract

The distinction between breast and müllerian carcinomas from each other and from tumors with a similar cytokeratin profile can be difficult. We tested the usefulness of 2 new markers, NY-BR-1 and PAX8, by staining a variety of breast and gynecologic carcinomas, along with tumors of pancreas, bile ducts, stomach, and gastroesophageal junction. NY-BR-1 expression (ie, H score >10) was seen in 58.4% of breast carcinomas (111/190), 5.6% of müllerian carcinomas (8/142), 7% of pancreatic tumors (1/15), 0% of cholangiocarcinomas (0/22), 0% of gastric tumors (0/36), and 0% of gastroesophageal carcinomas (0/25). All 188 breast carcinomas were negative for PAX8. PAX8 expression was seen in 72.4% of müllerian tumors (105/145). All pancreatic tumors (n = 15), cholangiocarcinomas (n = 23), and gastric (n = 35) and gastroesophageal junction (n = 25) carcinomas were negative for PAX8. Addition of NY-BR-1 and PAX8 in a panel would be useful in distinguishing breast cancer, gynecologic tumors, and tumors of the upper gastrointestinal tract.

Immunohistochemistry in Undifferentiated Neoplasm/Tumor of Uncertain Origin

“…Its expression in breast carcinomas was reported as 58.4% by Woodard et al 86 and 46.6% by Balafoutas et al 87 However, NY-BR-1 expression is strongly associated with ER expression in both studies. In ER À breast carcinomas, NY-BR-1 expression was reported to be as low as 18% and 28.4%, respectively.…”

Application of Immunohistochemistry in Breast Pathology: A Review and Update

“…141 In other tumors studied, NY-BR-1 expression was noted in 27% (3 of 11) of sweat gland carcinomas, 138 75% (18 of 24) of mammary Paget disease, 81% (21 of 26) of extramammary Paget disease, 140 5.6% (8 of 142) of müllerian carcinomas, and 7% (1 of 15) of pancreatic tumors. 141 The current data in the literature suggest the potential diagnostic utility of NY-BR-1 as a breast-specific immunomarker; however, a larger series of studies is necessary to validate those findings.…”

“…[135][136][137][138]141,142 In ER À breast CAs, its expression was reported as much lower, 18% by Woodard et al 141 and 28.4% by Balafoutas et al 142 In normal tissues, NY-BR-1 expression was noted exclusively in mammary gland epithelia [135][136][137][138]141,142 ; reactivities in skin adnexal structures 140 as well as focal, weak staining in Barrett esophagus and benign mucosal glands of the stomach were also noted. 141 In other tumors studied, NY-BR-1 expression was noted in 27% (3 of 11) of sweat gland carcinomas, 138 75% (18 of 24) of mammary Paget disease, 81% (21 of 26) of extramammary Paget disease, 140 5.6% (8 of 142) of müllerian carcinomas, and 7% (1 of 15) of pancreatic tumors. 141 The current data in the literature suggest the potential diagnostic utility of NY-BR-1 as a breast-specific immunomarker; however, a larger series of studies is necessary to validate those findings.…”

“…Since then, studies were undertaken to explore NY-BR-1 protein expression in normal and tumor tissues. [135][136][137][138][139][140][141][142] The immunostaining pattern was described as mainly cytoplasmic with focal nuclear staining. In invasive breast CAs, NY-BR-1 expression was reported in 46.6% to …”

Immunohistochemical Profile of Breast Cancer With Respect to Estrogen Receptor and HER2 Status

“…1,2 Although only 5% of breast cancers are diagnosed as stage IV (ie, metastatic at presentation), it is estimated that approximately 40% of breast cancer patients will develop distant metastasis during their disease course. [4][5][6][7][8] Often, the first step in immunohistochemical assessment of an adenocarcinoma of an unknown primary site is examination of its differential cytokeratin 7 (CK)7 and CK20 profile. [4][5][6][7][8] Often, the first step in immunohistochemical assessment of an adenocarcinoma of an unknown primary site is examination of its differential cytokeratin 7 (CK)7 and CK20 profile.…”