[Indoleamine 2,3-dioxygenase activity in breast cancer patients with local recurrence or distant metastases].

ABSTRACT

We evaluated the significance of indoleamine 2,3-dioxygenase(IDO)activity in breast cancer patients with local recurrence or distant metastases. IDO activity can be determined using the tryptophan/kynurenine(Trp/Kyn)ratio. Trp and Kyn were measured by high-performance liquid chromatography(HPLC). The survival rate after recurrence was higher in the local recurrence group(n=11)than in the distant metastases group(n=26). The mean Trp/Kyn ratio was lower in the distant metastases group than in the local recurrence group. The mean Trp/Kyn ratio was also lower in patients who had multiple metastases than in patients who had a single metastatic lesion. The Trp/Kyn ratio decreased during chemotherapy in all patients who received chemotherapy.