Synergistic effect between Juzen-taiho-to, a Japanese traditional herbal medicine, and gemcitabine single-agent chemotherapy for advanced biliary tract cancer.

This is the first report of the successful treatment of advanced biliary tract cancer with gemcitabine single-agent chemotherapy in combination with Juzen-taiho-to (JTT), a Japanese traditional herbal medicine. An 84-year-old woman was referred to our hospital with general fatigue and appetite loss; she was diagnosed with advanced biliary tract cancer and accompanying colonic invasion and hepatic metastasis. The patient's response to combination chemotherapy was extremely good, and her tumors disappeared. Recent studies have confirmed the occurrence of spontaneous and induced antitumor immune responses, carried out by tumor-infiltrating lymphocytes in the tumor microenvironment. The availability, antigen presentation, and proliferation of these immune cells are increased by cytokines such as granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-2. Recently, JTT has gained recognition as a biological response modifier that has stimulatory effects on systemic immune responses such as enhancement of cytokine expression (GM-CSF, IL-2, etc.). In addition, some chemotherapy agents, such as anthracyclines and gemcitabine, are effective boosters of the immune response through tumor-specific antigen overexpression after apoptotic tumor cell destruction. These findings suggest that JTT enhances the antitumor effects of gemcitabine, in particular its tumor-specific effects on immune response, and these drugs are a good combination for advanced biliary tract cancer therapy.