RESUMO
Objective: To investigate the role of indoleamine 2, 3-dioxygenase in the development of uterine cervical squamous carcinoma. Methods: From January 2008 to December 2008, 116 uterine cervical carcinoma specimens and 18 metastatic lymph node specimens from patients with CIN Ⅰ-Ⅲ and uterine cervical squamous carcinoma were evaluated for iDO expression by immunohistochemistry. Twenty normal cervical specimens and 20 normal lymph node specimens were used as the controls. Results: The expression of IDO was not found in normal cervix and CIN Ⅰ. In CIN Ⅱ, IDO expres-sion was weakly positive in 2 cases (2/10, 20%) and negative in 8 cases (8/10, 80%). In CIN Ⅲ, IDO expression was weak-ly positive in 8 cases (8/13, 61.5%), positive in 1 case (1/13, 7.7%) and negative in 4 cases (4/13, 30.8%). The positive ex-pression rate of IDO in cervical cancer stage Ⅰ -Ⅳ was 100% (83/83). In cervical cancer stage Ⅰ A and Ⅰ B, the positive ex-pression rate of IDO was significantly higher than that in CIN Ⅱ and CIN Ⅲ (P<0.01). The positive expression rate of IDO in cervical cancer stage Ⅱ A-Ⅳ B was significantly higher than that in Ⅰ A and Ⅰ B. IDO expression was associated with cervi-cal cancer progression (OR=0.807, P<0.01). IDO expression in primary lesions with lymph node metastasis was significant-ly higher than that in those without lymph node metastasis. IDO expression rate was 100% in metastatic lymph nodes. The IDO expression was not associated with cervical squamous carcinoma differentiation degree (OR=-0.139,P>0.05). Conclu-sion: In CIN Ⅱ, escape mechanisms that stimulate cervical squamous carcinoma progression is gradually developed. IDO expression in metastatic lymph nodes is possibly associated with immune tolerance. IDO expression is not associated with differentiation degree of cervical squamous carcinoma. IDO may be a prognostic factor for uterine cervical squamous carci-noma and a therapeutic target for treatment.