Expression of NY-ESO-1 in Triple-Negative Breast Cancer Is Associated with Tumor-Infiltrating Lymphocytes and a Good Prognosis

Objectives: Accumulating evidence suggests that immunotherapy has great potential for treating triple-negative breast cancer (TNBC). We analyzed the expression of NY-ESO-1, which is a potent immunogenic cancer testis antigen, and its association with clinicopathological factors in large cohorts of breast cancer patients. Methods: A total of 623 consecutive breast cancer patients who underwent surgery between 1993 and 1998 and 612 TNBC patients who underwent surgery between 2004 and 2010 at Asan Medical Center were included. Immunohistochemical staining for NY-ESO-1 was performed using tissue microarrays. Results: NY-ESO-1 was expressed in 2.6% of consecutive breast cancers, all of which were TNBC (p < 0.001). NY-ESO-1 expression was identified in 9.7% of the TNBC cohort and was significantly correlated with a higher level of tumor-infiltrating lymphocytes (TIL; p = 0.026). In survival analyses, a lower level of TIL (all, p < 0.001) and the absence of NY-ESO-1 expression (p = 0.024) were significantly associated with poor disease-free survival. Additionally, positive NY-ESO-1 expression was an independent favorable prognostic factor in TNBC patients (p = 0.046). Conclusions: NY-ESO-1 is specifically expressed in TNBC, and NY-ESO-1 expression is an independent good prognostic factor in TNBC. Evaluation of NY-ESO-1 expression in TNBC might be useful for selecting patients who may benefit from vaccination therapy and also has a prognostic significance in TNBC. (C) 2015 S. Karger AG, Basel