MAGE-A is more highly expressed than NY-ESO-1 in a systematic immunohistochemical analysis of 3668 cases

Two cancer testis antigens, the New York esophageal squamous cell carcinoma-1 (NY-ESO-1) and the melanoma-antigen family A (MAGE-A), represent promising immunotherapy targets due to the low expression of these antigens in nonmalignant tissue. To assess overexpression patterns in various cancers, we performed a systematic immunohistochemical analysis for NYESO- 1 and MAGE-A on tissue array samples of 3668 common epithelial carcinomas (CA) and germ cell tumors of high prevalence and mortality. Here, we find significantly higher expression of MAGE-A (> 50% on tumor cells) compared with NY-ESO-1 in several CAs including cutaneous squamous cell carcinomas (SCC) (52.8%/2.8%), esophageal SCC (50%/0%), head and neck SCC (41.1%/> 1%), bladder urothelial CA (40.4%/8.3%), cervical/anal SCC (37.5%/0%), lung SCC (34%/3.8%), lung adenocarcinomas (27.6%/3.9%), ovarian CA (26.4%/3.6%), endometrial CA (26.3%/1.3%), lung small cell CA (24.4%/2.4%), gastric adenocarcinomas (20%/4%), breast mucinous CA (19.3%/0%), hepatocellular CA (18.8%/1.2%), breast infiltrating ductal CA (16.4%/1.8%), colorectal adenocarcinomas (10.7%/< 1%), cholangiocarcinomas (9.8%/0%), thymic CA (9%/4.5%), and mesotheliomas (7.9%/< 1%). Furthermore, high expression of MAGEA, but not NY-ESO-1, was seen in whole slide evaluations of an independent cohort of metastatic SCC (45.5%/3.6%) and metastatic CA (13.5%/0%) of various primaries with significantly higher expression of MAGE-A in metastatic SCC compared with other metastatic CA. MAGE-A is also more highly expressed in germ cell tumors, seminomas (69%/3.5%) and nonseminomas (40.1%/4.7%). In summary, MAGE-A is more highly expressed than NY-ESO-1 in a majority of human malignancies, and targeting MAGE-A may benefit a large number of patients.