Cancer-testis antigens are predominantly expressed in uterine leiomyosarcoma compared with non-uterine leiomyosarcoma

Leiomyosarcomas account for ~24% of all adult sarcomas, and develop predominantly either in the uterus [uterine leiomyosarcoma (ULMS)] or in deep soft tissue or the retroperitoneum [non-uterine leiomyosarcoma (NULMS)]. Leiomyosarcomas are relatively chemoresistant tumors, and the prognosis of patients with leiomyosarcomas is poor. Cancer-testis (CT) antigens are considered promising immunotherapeutic targets because of their restricted expression in normal tissue, except in the testis. Little is known about the expression of CT antigens in leiomyosarcomas. In the present study, the protein expression of the CT antigens MAGE family member A (MAGEA)1, MAGEA3, MAGEA4, G antigen 7 (GAGE7) and cancer/testis antigen 1 (NY-ESO-1) in ULMS and NULMS were investigated using immunohistochemistry (IHC), and their expression profiles compared. In ULMS and NULMS, positive expression was observed in 11/32 (31%) and 1/31 (3%; MAGEA1), 15/32 (47%) and 5/31 (16%; MAGEA3), 11/32 (34%) and 3/31 (10%; MAGEA4), 23/32 (72%) and 11/31 (35%; GAGE7) and 3/32 (9%) and 0/31 (0%; NY-ESO-1), respectively. The ULMSs demonstrated significantly higher positive expression of MAGEA1 (P=0.0034), MAGEA3 (P=0.0141), MAGEA4 (P=0.0319) and GAGE7 (P=0.0054) compared with the NULMSs. The ULMSs also had significantly higher IHC scores for MAGEA1 (P=0.0023), MAGEA3 (P=0.0474), MAGEA4 (P=0.011), GAGE7 (P=0.0319) and NY-ESO-1 (P=0.0437). The results of the present study support the potential utility of MAGEA1, MAGEA3, MAGEA4 and GAGE7 in ULMS and GAGE7 in NULMS as immunotherapeutic targets.