title: [Indoleamine 2,3-dioxygenase activity during toremifene therapy for aromatase inhibitor-resistant metastatic breast cancer].
abstract: We evaluated the clinical significance of indoleamine 2,3-dioxygenase(IDO)activity during toremifene(TOR)therapy for aromatase inhibitor(AI) / -resistant metastatic breast cancer. IDO activity can be measured using the tryptophan/kynurenine (Trp/Kyn)ratio. Trp and Kyn were measured using high performance liquid chromatography(HPLC). The response rate of TOR therapy for AI-resistant metastatic breast cancer patients was 21.9%, and the clinical benefit rate was 62.5%. The serum Trp/Kyn ratio was significantly lower in AI-resistant metastatic breast cancer patients with distant metastases than in patients who had local recurrence. During TOR therapy, IDO activity was significantly decreased in the TOR responder group compared to the TOR non-responder group. IDO activity correlated with the number of metastatic lesions treated during TOR therapy. These results suggest that the Trp/Kyn ratio is a useful measurement in evaluating the immunological metastatic status during endocrine therapy.
authors.affiliation: Division of Breast and Endocrine Surgery, Dept. of Surgery, Nihon University School of Medicine.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sakurai
authors.forename: Shigeru
authors.initials: S
authors.lastname: Fujisaki
authors.forename: Saki
authors.initials: S
authors.lastname: Nagashima
authors.forename: Tetsuyo
authors.initials: T
authors.lastname: Maeda
authors.forename: Ryouichi
authors.initials: R
authors.lastname: Tomita
authors.forename: Shuhei
authors.initials: S
authors.lastname: Suzuki
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Hara
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Hirano
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Enomoto
authors.forename: Sadao
authors.initials: S
authors.lastname: Amano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000378:metabolism*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D017312:Toremifene / Q000627:therapeutic use*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D017312:Toremifene