Expression of MAGE-A and NY-ESO-1 in Primary and Metastatic Cancers.

Melanoma-associated antigen-A (MAGE-A) and New York esophageal squamous cell cancer-1 (NY-ESO-1) are 2 cancer testis antigens (CTA) demonstrating potential for use in targeted immunotherapy. Clinical trials in melanoma and synovial sarcomas targeting these antigens in immune-based therapies have demonstrated durable tumor regression. Although protein expression of NY-ESO-1 has been assessed in a variety of cancer types, the expression of MAGE-A has not been studied in depth. In this study we analyzed MAGE-A and NY-ESO-1 expression in 314 melanoma specimens from 301 melanoma patients, 38 patients with squamous cell cancers and 111 patients with adenocarcinomas. Our results demonstrated higher expression of MAGE-A compared with NY-ESO-1 in melanomas (32% vs. 13%) and squamous cell carcinomas (45% vs. 7.9%), and higher expression of both CTAs in metastatic versus primary tumors. CTA expression in adenocarcinomas was low (MAGE-A: 10%, NY-ESO-1: 0.9%). In addition, we looked at concordance of expression among metastatic melanoma lesions within the same patient and found concordant expression in 38 of 47 patients for MAGE-A and 43 of 47 patients for NY-ESO-1. Our study demonstrated that the MAGE-A family may be of greater utility than NY-ESO-1 for targeted immunotherapy in a variety of cancer histologies, in particular metastatic melanomas and squamous cell carcinomas.