Tryptophan catabolism increases in breast cancer patients compared to healthy controls without affecting the cancer outcome or response to chemotherapy

Indoleamine 2,3-dioxygenase catalyzes the conversion of tryptophan to kynurenine, an immunosuppressive metabolite involved in T regulatory cell differentiation. Indoleamine 2,3-dioxygenase is expressed in many cancer types, including breast cancer. Here, we analyze kynurenine and tryptophan and their ratio in breast cancer patients and healthy controls.Breast cancer patients and healthy controls were prospectively enrolled in our study. All...