Abstract 525: Higher mutation rate is associated with more frequent expression of cancer/testis antigens in human tumors

Tumors with high mutation rate such as those of melanoma and non-small cell lung cancers (NSCLC) have shown greatest response to the emerging immune therapies. These tumors harbor a large number of somatic mutations, some of which could be translated into neoantigens, potentially evoking host immune response. To what degree self antigens, many of which are cancer testis (CT) antigens, contribute to enhanced immune response in these tumors has never been systematically studied. Here we show that cancers with higher mutation rate frequently express a larger number of CT antigens than cancers with fewer mutations. In NSCLC, tumors with more than 300 non-synonymous mutations (75th percentile, n = 158) express more than 3 times as many CT antigens as those tumors with fewer than 100 mutations (25th percentile, n = 162), with a P-value of 1.6e-13. In head and neck cancers, tumors with more than 140 non-synonymous mutations (75th percentile, n = 79) express nearly twice as many CT antigens as those tumors with fewer than 60 mutations (25th percentile, n = 80), with a P-value of 0.004. Additionally, in NSCLC, tumors with high mutation rate are associated with higher expression of CD8B and granzyme B, markers representing cytotoxic lymphocytes. Tumors with more expressed CT antigens are also associated with higher expression of these markers. These data suggest that CT antigens, along with neoantigens, may contribute to a stronger host immune response in these hypermutative tumors. Citation Format: Junping Jing, Patrick Mayes, Yan Degenhardt, James R. Brown, Philippe Sanseau. Higher mutation rate is associated with more frequent expression of cancer/testis antigens in human tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 525.