[Long-term follow-up study: indolemamine 2,3-dioxygenase activity during chemotherapy or hormone therapy in patients with breast cancer].

We evaluated a significance of indoleamine 2,3-dioxygenase( IDO) in breast cancer patients during chemotherapy or hormone therapy every three months after the therapy. IDO activity can be measured by kynurenine( Kyn)/tryptophan (Trp) ratio. Trp and Kyn were measured by high performance liquid chromatography (HPLC). The correlations about Kyn/ Trp ratio between chemotherapy group and hormone therapy group in pre-chemotherapies or post-chemotherapies were studied. The Kyn/Trp ratio of chemotherapy group in post-FEC chemotherapy phase and in post-wPTX chemotherapy phase was higher than in pre-chemotherapy phase. And the Kyn/Trp ratio of chemotherapy group is significantly higher than hormone therapy in post-FEC chemotherapy phase and in post-wPTX chemotherapy phase. There were no significant changes for the Trp/Kyn ratio of hormone therapy group in each phase. After the chemotherapy, there was no correlation between both groups. These results suggest that the hormone therapy may be less invasive for breast cancer patients than the chemotherapy.