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

Abstract

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 ¼ 80) was immunohistochemically scored as four groups (IDOÀ, 1 þ , 2 þ , and 3 þ ). The high IDO expression (IDO2 þ or 3 þ ) 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 ¼ 0.002 and P ¼ 0.001, respectively) compared to patients with no or weak expression of IDO (IDOÀ or 1 þ ). The 5-year PFS for IDOÀ/1 þ , 2 þ , and 3 þ 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 ¼ 64), the PFS for IDO2 þ /3 þ was significantly poor (P ¼ 0.001) compared to that for IDOÀ/1 þ . On multivariate analysis, IDO expression was an independent prognostic factor for PFS (P ¼ 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.

Indoleamine 2,3-dioxygenase (IDO) expression in lung cancer

“…These factors could also account for the wide variation of IDO expression values detected in all of our samples as well as in other tumor types. 5,11,12,20 In tumor types other than lung cancer, several investigators have reported correlations of IDO expression with clinicopathological parameters, sometimes with prognostic significance. 7,11,12,20 Our inability to uncover such correlations can be partially attributed to the small size of our sample.…”

“…5,11,12,20 In tumor types other than lung cancer, several investigators have reported correlations of IDO expression with clinicopathological parameters, sometimes with prognostic significance. 7,11,12,20 Our inability to uncover such correlations can be partially attributed to the small size of our sample. However, this might not be unreasonable since the isolation of one and only parameter with clinical significance amongst the numerous ones contributing to the complicating process of tumor immune escape parallels the difficulty in exploring a dark room using a laser pointer.…”

Status of cellular immunity lacks prognostic significance in vulvar squamous carcinoma

“…1A and B) [9,10]. IDO expression was assessed according to a semi-quantitative scale which is based on the extent and intensity of the staining [29]. Intensity of the cytoplasmic staining was scored as 0 for absent, 1 for weak, 2 for positive or 3 for strong positive expression.…”

High INDO (indoleamine 2,3-dioxygenase) mRNA level in blasts of acute myeloid leukemic patients predicts poor clinical outcome

“…However, negative influence of high indoleamine 2,3-dioxygenase expression on overall survival of patients has only been demonstrated for endometrial and colorectal cancer. 8,9 In the present study we investigated whether the expression of INDO (the gene encoding for indoleamine 2,3-dioxygenase) correlates to clinical outcome of patients with acute myeloid leukemia. We determined INDO expression in myeloid leukemic blasts of 285 patients by gene-expression analyses and in 71 patients by real-time quantitative polymerase chain reaction (qPCR) and correlated these data to relevant known prognostic factors and survival.…”

“…6 Second, the effector phase of an anti-tumor immune response is hampered because many human solid tumors themselves express indoleamine 2,3-dioxygenase. [7][8][9] In acute myeloid leukemia, acquired mutations of the hematopoietic stem cells block differentiation. The result is accumulation of immature cells in the bone marrow and peripheral blood, often accompanied by suppression of the normal blood cells.…”