Expression of cancer/testis (CT) antigens in squamous cell carcinoma of the head and neck: evaluation as markers of squamous dysplasia.

Cancer/testis (CT) antigens, normally only expressed in germ cells of adult testis, can be activated in malignancy as tumor-specific antigens. The potential value of CT antigens as biomarkers in the evaluation of mucosal squamous precursor lesions of the head and neck has not been investigated. The expression of 8 CT antigens (MAGE-A, GAGE, NY-ESO-1, CT7, CT10, SAGE1, CT45 and NXF2) in 76 cases of invasive head and neck squamous cell carcinoma (SCC) was evaluated immunohistochemically. 65 mucosal biopsies of squamous dysplasia and 55 squamous papillomas with dysplasia were analyzed for 6 CT antigens, using an antibody cocktail. Of invasive SCC, 66% (50/76) expressed at least one CT antigen, most commonly MAGE-A (47%). Among the biopsies, only 1 of 55 squamous papillomas was CT-positive, whereas 8 of 65 (12%) squamous dysplasia lesions were CT-positive. These 8 CT-positive biopsies were from 6 patients, 3 of which had concurrent or subsequent SCC. CT antigens are frequently expressed in head and neck SCC; however, there was no difference in the clinicopathological characteristics or behavior of CT-positive tumors compared to CT-negative tumors. The usefulness of CT antigens as positive predictors for SCC in squamous dysplasia biopsies remains to be determined by long-term follow-up in larger cohorts.