Introduction : Immune-based therapies that enhance the ability of cytotoxic T cell to target tumor cells showed a moderate promise to several solid tumors. However, the neoplastic cells in pancreatic cancers are refractory to all immune-based therapies or the combination of immune-based therapies with chemotherapies including PD-L, IDO target therapies. Multiple mechanisms cause the insensitivity of neoplastic cells to immune-based therapies including low immunogenicity of pancreatic cancer neoplastic cells.

Methods : The recent study in Japan has revealed the tumor-infiltrating CD4+ and CD8+ T-cells as independent prognosticators useful for evaluating the immune microenvironment of PDC. Using immunohistochemistry, the examination and analysis of tumor-infiltrating cells pan-macrophages, M1, CD163+ or CD204+ M2 macrophages (M2), CD66b+ neutrophils, CD4+ T cells, CD8+T cells, regulatory T cells in 212 cases of PDC, it is anticipated that tumor-infiltrating immune/inflammatory cells would be useful hallmarks for evaluating and monitoring the characteristics of a tumor immune microenvironment.

Results : Several studies showed that immunocheck point agents showed a promising therapeutic effect to inhibit murine pancreatic cancer development by enhancing the immonogenicity of pancreatic tumor cells. Recongnizing the neoplastic cells by cytotoxic T cells is the first step in exerting cytotoxic effects of tumor killing T cells.

Conclusions : Collectively, the precise strategy of PDA treatment remained unclear but based on recent studies and trials, the most promising target to suppress cancer cells is immunotherapy. The dual mechanism of both increasing CD4+ and CD8+ T-cells along with deactivating the tumor microenvironment, as well as drug combination therapy might significantly improve the response to chemotherapy and overall survival.