Insulin-like growth factor Ⅱ mRNA binding protein 3 expression in the non-muscle invasive bladder cancer and its relationships with the prognosis / 中华泌尿外科杂志

ABSTRACT

Objective To investigate the expression of insulin-like growth factor Ⅱ mRNA binding protein 3 (IMP3) in non-muscle invasive bladder cancer and its relationship with the tumor recurrence and progression.Methods IMP3 protein expression was detected by immunohistochemistry in 130 cases of nonmuscle invasive bladder cancer specimens who underwent transurethral resection the first time at Beijing Chao-Yang hospital,from October 2010 to October 2013.Besides,we analyzed 20 cases of muscle-invasive samples and 20 benign tissues adjacent to cancer as control.The 130 patients were followed up by telephone and other methods.According to the UICC-TNM standard.Survival analysis was calculated by using the Kaplan-Meier method,and the difference in survival curves was analyzed by using the log-rank test.For multiple analyses,The Cox proportional hazards regression model was used.Results The positive expression rate of IMP3 in 130 patients with non-muscle invasive bladder cancer was 59.2％ (77/130),of which 30.0％ (39/130) was weak expression,29.2％ (38/130) was strong.However there was 80.0％ (16/20) in muscle-invasive specimens,of which 20.0％ (4/20) was weak,60.0％ (12/20) was strong (P =0.011).IMP3 was not detected in all benign tissues adjacent to cancer (P ＜0.001).All the 130 patients were followed-up for 5 to 69 mnonths,45 cases experienced disease recurrence,20 patients had progressed and 12 cases died.IMP3 expression was significantly related to higher tumor stage (P ＜ 0.001),high tumor grade (P =0.014),and tumor recurrence (P =0.003).Kaplan-Meier plots and log-rank tests showed that patients with IMP3-positive tumors had a lower disease-free survival (P =0.002) and progression-free survival rate (P =0.010) than those with IMP3-negative tumors.In the multivariable Cox analysis,we found that IMP3 protein was an independent predictor of disease-free survival (P =0.010) in non-muscle invasive urothelial carcinoma of bladder.Conclusions IMP3 was not expressed in benign tissue adjacent to cancer,whereas highly expressed in bladder cancer,and high IMP3 expression is an independent prognostic factor in NMIBC that can identify the patients with a high potential to relapse.