Expression of Cancer-testis Antigens in Adenoid Cystic Carcinoma of the Salivary Glands Correlates with Clinical Outcomes

Abstract

This study aimed to explore the expression and clinicopathological significance of CTAs MAGE-1, NY-ESO-1, MAGE-C2 and SCP-1 in adenoid cystic carcinoma (ACC). Immunohistochemistry was used to detect their expressions in 70 cases of ACC, and in 6 healthy tumor-adjacent salivary glands. The correlation between the expressions of the four CTAs, clinical and pathological features, and patients' overall survival (OS) were analyzed. Of the 70 ACC cases, strong staining was observed in 43 (61.4%) for MAGE-1, 14 (20%) for NY-ESO-1, 9 (12.9%) for SCP-1, and 6 (8.6%) for MAGE-C2. We also found some significant correlations between the CTAs expression and clinicopathological parameters, for example, MAGE-1 and tumor size, NY-ESO-1 and distant metastasis, MAGE-C2 and tumor site, SCP-1 and age, SCP-1 and histopathological types (P < 0.05). Patients with any single CTAs positive staining showed a similar OS compared to those with negative staining, however patients with strong expression (score 6-7) of MAGE-C2 showed a significantly reduced OS compared to those scored 0-5 (P < 0.05). There was no OS difference between patients expressing simultaneously any 2 of the 4 CTAs and those with negative expression or those expressing only one of the 2 CTAs. Similar results were found in patients expressing at least 3 CTAs compared with patients expressing less than 3 CTAs. However, patients with the four CTAs co-expression had a substantially reduced mean survival time of 131.8 months compared with 176.5 months in patients with at least one CTA negative (P < 0.05). In conclusion, a significant fraction of patients with ACC showed expression of MAGE-1, NY-ESO-1, MAGE-C2 and SCP-1, indicating these CTAs might represent potential antigens for cancer vaccines. In addition, MAGE-C2 may be an important prognostic marker of ACC.