The association between the expression and activity of indoleamine 2,3-dioxygenase and the efficacy of neoadjuvant chemotherapy in patients with breast cancer / 中国肿瘤临床

ABSTRACT

Objective:To investigate the association between indoleamine 2,3-dioxygenase(IDO)expression in tumor tissue,its periph-eral blood activity, and the efficacy of neoadjuvant chemotherapyin patients with breast cancer. Methods: Immunohistochemistry (IHC)and high-performance liquid chromatography(HPLC)were used to measure IDO protein expression in tumor tissue,and kynuren-ine(Kyn),tryptophan(Trp),and IDO activity(Kyn/Trp)in peripheral blood before neoadjuvant chemotherapy in 53 patients with breast cancer from Tianjin Medical University Cancer Institute and Hospital between September 2015 and December 2016.The correlations between the expression and activity of IDO and the efficacy of chemotherapy were analyzed.Results:In tumor tissue,IDO expression-before neoadjuvant chemotherapy was related to clinical tumor stages(P=0.006),node stages(P=0.020),clinical stages(P=0.045),and estrogen receptor(ER)status(P=0.014).High IDO activity before neoadjuvant chemotherapy in peripheral blood was associated with high IDO expression in tumor tissue(P=0.004),and was also correlated with clinical tumor stages(P=0.019)and node stages(P=0.047). Univariate analysis showed that the clinical efficacy of neoadjuvant chemotherapy was associated with pre-chemotherapeutic clinical tumor stages(P=0.049),ER status(P=0.025),and molecular subtype(P=0.014),while pathologic complete response(pCR)was related to pre-chemotherapeutic clinical tumor stages(P=0.014).Importantly,the clinical efficacy of neoadjuvant chemotherapy and pCR were both related to IDO expression and activity before chemotherapy(all P<0.05).Multivariate analysis showed that pre-chemotherapeu-tic IDO activity in peripheral blood was the only independent factor that affected pCR(P=0.032).Conclusions:Tumor tissue IDO expres-sion and peripheral blood IDO activity before chemotherapy were associated with chemotherapy efficacy,and could provide promising information for the clinical prediction of chemotherapy sensitivity.