Zhibing Xu

Enhancer of zeste homolog 2 (EZH2) promotes tumour cell migration and invasion via epigenetic repression of E‐cadherin in renal cell carcinoma

To investigate the molecular mechanism and clinical significance for an oncogenic role of enhancer of zeste homolog 2 (EZH2) in renal cell carcinoma (RCC).

Experience of Mini-Percutaneous Nephrolithotomy in the Treatment of Large Impacted Proximal Ureteral Stones

Objectives: To evaluate the efficacy and safety of mini- percutaneous nephrolithotomy (PCNL) in the treatment of large impacted proximal ureteral stones. Methods: We retrospectively reviewed the outcomes of 163 patients who underwent mini-PCNL between January 2006 and August 2010. Mean age was 48.6 years and mean stone size was 18.4 mm. Hydronephrosis and/or hydroureterosis appeared in all patients. In the prone position, percutaneous access (16-Fr sheath) was established by placement of an access needle into the intended calyx under fluoroscopic guidance or combined with ultrasound guidance for complete obstruction by stones while the contrast agent cannot transit. Pneumatic or ultrasonic probes were used throughout ureterorenoscopy for lithotripsy. The ureteral stents and nephrostomy tube were placed at the end of the procedure. Mean drop in hemoglobin, operative time, success rate, hospital stay, and complications were assessed. Results: Mini-PCNL operations were performed successfully in all patients. Mean operation time was 37 min. Mean postoperative hospital stay was 3.6 days. All cases were followed up for 6-20 months. No major complications like hemorrhage, perforation or organic injury were noted during the operation or postoperatively. The stone-free rate in all patients was 95.7%. Calculus had no recurrence during the follow-up period. Hydronephrosis and hydroureterosis disappeared or were relieved. Conclusions: Mini-PCNL is a safe and effective therapy for large impacted proximal ureteral stones.

Prognostic Value of EZH2 Expression and Activity in Renal Cell Carcinoma: A Prospective Study

Increased expression of EZH2 correlates with aggressive clinical behavior in various malignancies. In this study, we aim to investigate the clinical and prognostic values of EZH2 expression and activity in tumor tissues and improve the risk stratification in patients with renal cell carcinoma after surgery. We analyzed EZH2 expression and its activity as indicated by H3K27me3 levels comprising 373 patients with renal cell carcinoma in our institute. Outcome was assessed as overall survival and disease free survival using Kaplan-Meier analysis. Prognostic values of EZH2 and H3K27me3 expression for clinical outcomes were evaluated by Cox regression analysis. We used receiver operating characteristic to calculate diagnostic accuracy. High EZH2 expression correlates with poor overall survival in all patients, especially in advanced RCC, which is an independent prognostic factor in disease free survival and overall survival. Compared with EZH2, H3K27me3 expression is not an independent prognostic factor. The expressions of H3K27me3 and EZH2 are not completely consistent, which might be due to complicated interaction of Polycomb Repressor Complex 2. A combination of EZH2 expression and TNM stage could have better prognostic value than do TNM stage or EZH2 expression alone in both sets for disease free survival and overall survival. These results imply that evaluating intratumoral EZH2 density might improve prognostic value to the TNM staging system and inform treatment decisions for patients with late-stage renal cell carcinoma.

Should Bone Scan be Performed in Chinese Prostate Cancer Patients at the Time of Diagnosis

Background: Prostate cancer (PCa) is increasingly being diagnosed in China. Early detection of bone metastases (BM) is critical in the management of patients with high-risk PCa. The aim of this study is to establish a screening model to determine if bone scan should be performed for BM in Chinese patients at the time when PCa is diagnosed. Materials and Methods: The study included 488 patients who were diagnosed with PCa between 2009 and 2011 at a single center. All patients received bone scans using technetium 99mTc methylene diphosphonate at the initial staging. If the bone scan finding was equivocal, computed tomography or magnetic resonance imaging was performed to confirm the diagnosis. Age, prostate-specific antigen (PSA) at diagnosis, clinical stage assigned according to the TNM 2002 staging system and biopsy Gleason score were collected in all patients. Multivariate logistic regression analysis was performed to identify statistically significant covariates and then receiver operating characteristic (ROC) curves were generated to identify optimal cut-off values. Using these cut-off values, a formula was devised to calculate an index value for BM screening at diagnosis. The model was cross-validated using the leave-one-out method. Results: Of the 488 patients, 65 patients (13.3%) had BM. The area under the ROC curve was 0.87 (95% confidence interval 0.83-0.94). The sensitivity of the cut-off point was 87.7% and the specificity was 73.1%. Bone scan is needed for all cT4 PCa patients, however, it is also advisable for cT1-T3 PCa patients who have a biopsy Gleason score ≤3 + 4 and a PSA >132.1, and for cT1-T3 patients having a Gleason score of ≥4 + 3 and PSA >44.5. Conclusions: The regression model may help determine if bone scan is needed to detect BM from PCa at the time of diagnosis. The model was generated upon a single center experience. Further validation is needed in future studies.

Is it safe to omit baseline bone scan for newly diagnosed prostate cancer patients

Objectives: The aim of this study is to modify and validate a novel screening tool to determine the necessity of bone scans in Chinese PCa patients at the time of diagnosis. Methods: Five-hundred-and-one patients diagnosed with PCa between 2010 and 2013 at Zhongshan Hospital, Fudan University, were included in the study. All received bone scans using technetium 99m methylene diphosphonate (99mTc-MDP) at the initial staging. Age, prostate-specific antigen (PSA) and alkaline phosphatase (ALP) at diagnosis, disease stage, and biopsy Gleason score were collected from all patients. Multivariate logistic regression analysis and discrimination analysis were performed. A validation analysis of this screening tool was performed by Shanghai Cancer Center, Fudan University. Results: Among the 501 patients, 84 (16.7%) of them had BM. The area under the ROC curve was 0.9006 (95% CI, 0.87-0.93). The sensitivity of the cut-off point was 94.1%, and the specificity was 58.3%. The validation analysis demonstrated an area under the ROC curve of 0.846 (95% CI, 0.805-0.887). Conclusions: Study results demonstrated that a baseline bone scan can be safely omitted for cT1-T3 PCa patients who have a PSA ≤39 ng/ml and an ALP ≤88 IU/l. This novel screening tool may help determine the necessity of including a bone scan at the time of initial diagnosis of PCa.