Expression of the intestinal marker Cdx2 in secondary adenocarcinomas of the colorectum.
BACKGROUND
Secondary adenocarcinomas of the large bowel can closely mimic primary tumors. The differentiation of secondary from primary adenocarcinomas of the colorectum, however, is important because their clinical management and prognosis are different. Immunostaining with the nuclear transcription factor Cdx2, expressed in normal intestinal epithelia and colorectal adenocarcinomas, could be of potential diagnostic use.


OBJECTIVE
To investigate the diagnostic value of Cdx2 immunoexpression in distinguishing primary from common forms of secondary colorectal adenocarcinomas.


METHODS
Cdx2 immunoexpression was analyzed in 20 primary colorectal adenocarcinomas and in 34 secondary colorectal adenocarcinomas and their corresponding primary tumors. All secondary tumors were diagnosed through endoscopic biopsies and included 8 cases of ovarian (4 serous, 2 mucinous, and 2 endometrioid), 6 of mammary (4 lobular and 2 ductal), 4 of gastric (2 intestinal and 2 diffuse), 4 of pulmonary, 4 of pancreatic (ductal), 3 of prostatic, 3 of colorectal, and 2 of endometrial origin.


RESULTS
Cdx2 was expressed in normal colorectal epithelium, in primary colorectal adenocarcinomas (20/20 cases), in secondary adenocarcinomas of colorectal (3/3) and gastric (3/4) origin, and in metastatic ovarian mucinous adenocarcinomas (2/2). In contrast, no Cdx2 immunoreactivity was observed in secondary colorectal tumors of ovarian (serous and endometrioid), mammary, pancreatic, pulmonary, prostatic, and endometrial origin.


CONCLUSIONS
Cdx2 immunostaining may be useful in discriminating primary colorectal carcinomas from frequent types of secondary colorectal adenocarcinomas of nongastrointestinal origin. We suggest including Cdx2 in any antibody panel put together to distinguish between primary and secondary epithelial colorectal malignancies.
Department of Pathology, Hillel Yaffe Medical Center, Hadera, Israel. groisman@hillel-yaffe.health.gov.il
Gabriel M
GM
Groisman
Joelle
J
Bernheim
Marisa
M
Halpern
Eli
E
Brazowsky
Alona
A
Meir
D000230:Adenocarcinoma / Q000235:genetics* / Q000556:secondary*; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000473:pathology; D000071616:CDX2 Transcription Factor; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology / Q000556:secondary*; D016889:Endometrial Neoplasms / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology; D008297:Male; D010051:Ovarian Neoplasms / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000473:pathology; D011471:Prostatic Neoplasms / Q000473:pathology; D013274:Stomach Neoplasms / Q000473:pathology
D014408:Biomarkers, Tumor; D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins