Cancer/testis (CT) antigens are attractive tumor antigens for cancer immunotherapy. They comprise a group of proteins normally expressed in germ cells and aberrantly activated in a variety of human cancers. The protein expression of eight CT antigens [MAGEA, NY-ESO-1, GAGE, MAGEC1(CT7), MAGEC2(CT10), CT45, SAGE-1 and NXF2] was evaluated by immunohistochemistry in 61 esophageal carcinomas (40 adenocarcinoma, 21 squamous cell carcinoma), 50 gastric carcinomas (34 diffuse and 16 intestinal type) and 141 colorectal carcinomas. The highest frequency of expression was found in esophageal squamous cell carcinomas: positive staining for MAGEA, CT45, CT7, SAGE1, GAGE, NXF2, NY-ESO-1 and CT10 was observed in 57%, 38%, 33%, 33%, 29%, 29%, 19% and 14% of squamous cell carcinomas. Similar staining patterns were observed in squamous dysplasias. Expression frequencies of CT antigens was seen in 2-24% of gastroesophageal adenocarcinomas and were not significantly different between adenocarcinomas of the stomach versus the esophagus, or between diffuse and intestinal types of gastric adenocarcinomas. Colorectal cancers did not express NY-ESO-1, CT7, CT10 or GAGE, and only infrequently expressed SAGE1 (0.7%) MAGEA (1.4%), CT45 (3.5%) and NXF2 (8.5%). We conclude that CT antigens are frequently expressed in esophageal squamous neoplasms. Although CT antigens are generally considered to be expressed later in tumor progression, they are found in squamous dysplasias, suggesting a potential diagnostic role for CT antigens in the evaluation of pre-malignant squamous lesions.
- Received August 13, 2013.
- Revision received October 11, 2013.
- Accepted November 5, 2013.
- Copyright © 2013, American Association for Cancer Research.