Indoleamine 2,3-dioxygenase is a novel prognostic indicator for endometrial cancer

K. Ino, N. Yoshida, H. Kajiyama, K. Shibata, E. Yamamoto, K. Kidokoro, N. Takahashi, M. Terauchi, A. Nawa, S. Nomura, T. Nagasaka, O. Takikawa, F. Kikkawa

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229 Citations (Scopus)


Indoleamine 2,3-dioxygenase (IDO) is a tryptophan-catabolising enzyme inducing immune tolerance. The present study aimed to investigate IDO expression and its prognostic significance in endometrial cancer. Indoleamine 2,3-dioxygenase expression in endometrial cancer tissues (n=80) was immunohistochemically scored as four groups (IDO-, 1+, 2+, and 3+). The high IDO expression (IDO2+ or 3+) in tumour cells was found in 37 (46.3%) of the 80 cases, and was positively correlated with surgical stage, myometrial invasion, lymph-vascular space involvement, and lymph node metastasis, but not with the histological grade. Patients with high IDO expression had significantly impaired overall survival and progression-free survival (PFS) (P=0.002 and P=0.001, respectively) compared to patients with no or weak expression of IDO (IDO- or 1+). The 5-year PFS for IDO-/1+, 2+, and 3+ were 97.7, 72.9, and 36.4%, respectively. Even in patients with early-stage disease (International Federation of Gynecology and Obstetrics I/II, n=64), the PFS for IDO2+/3+ was significantly poor (P=0.001) compared to that for IDO-/1+. On multivariate analysis, IDO expression was an independent prognostic factor for PFS (P=0.020). These results indicated that the high IDO expression was involved in the progression of endometrial cancer and correlated with the impaired clinical outcome, suggesting that IDO is a novel and reliable prognostic indicator for endometrial cancer.

Original languageEnglish
Pages (from-to)1555-1561
Number of pages7
JournalBritish Journal of Cancer
Issue number11
Publication statusPublished - 04-12-2006
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Oncology
  • Cancer Research


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