Yaoguang Zhang

MiR-139-5p is Increased in the Peripheral Blood of Patients with Prostate Cancer

Background: Emerging evidence suggested that microRNAs (miRNAs) play a causal role in cancer tumorigenesis. Aberrant expression of miRNA (miR)-139-5p has been observed in various types of cancers. The present study evaluated the relationship between miR-139-5p expression levels and prostate cancer (PCa), to assess the feasibility of using peripheral blood miR-139-5p as a potential non-invasive biomarker for PCa. Methods: Total RNA was extracted from peripheral whole blood samples from 45 PCa patients, 45 benign prostatic hyperplasia (BPH) patients and 50 healthy controls (HC). The expression of miR-139-5p was assessed by reverse transcription quantitative polymerase chain reaction. Results: MiR-139-5p in peripheral blood was significantly higher in PCa patients than in patients with BPH and HC individuals (P<0.001). Higher miR-139-5p expression was observed to be associated with certain clinicopathological parameters, including PSA>20ng/ml (P<0.05), pathological tumor stage 3/4 (P<0.05) and Gleason score >7 (P<0.01). A receiver operating characteristic (ROC) curve analysis revealed that miR-139-5p distinguished PCa patients from BPH patients [area under the curve (AUC), 0.936; 95% CI, 0.878-0.993; P<0.001]. Conclusions: Peripheral blood miR-139-5p may be utilized as a potential novel non-invasive biomarker for PCa screening.

Association of Six Susceptibility Loci with Prostate Cancer in Northern Chinese Men

BACKGROUND/AIM Six prostate cancer (PCa) susceptibility loci were identified in a genome-wide association study (GWAS) in populations of European decent. However, the associations of these 6 single-nucleotide polymorphisms (SNPs) with PCa has remained tobe clarified in men in Northern China. This study aimed to explore the loci associated with PCa risk in a Northern Chinese population. METHODS Blood samples and clinical information of 289 PCa patients and 288 controls from Beijing and Tianjin were collected. All risk SNPs were genotyped using polymerase chain reaction (PCR)-high resolution melting curve technology and gene sequencing. Associations between PCa and clinical covariates (age at diagnosis, prostate-specific antigen [PSA], Gleason score, tumor stage, and level of aggressiveness) and frequencies of alleles and genotypes of these SNPs were analyzed using genetic statistics. RESULTS Among the candidate SNPs, 11p15 (rs7127900, A) was associated with PCa risk (P = 0.02, odds ratio [OR] = 1.64, 95% confidence interval [CI] = 1.09-2.46). Genotypes showed differences between cases and controls on 11p15 (rs7127900, A), 11q13 (rs7931342, T), and HNF1B (rs4430796, A) (P = 0.03, P = 0.01, and P = 0.04, respectively). The genotype TG on 11q13 (rs7931342, T) was positively associated with an increased Gleason score (P = 0.04, OR = 2.15, 95% CI = 1.02-4.55). Patients carrying TG on 17q24 (rs1859962, G) were negatively associated with an increased body mass index (BMI) (P = 0.03, OR = 0.44, 95% CI = 0.21-0.92) while those with AG on HNF1B (rs4430796, A) were more likely to have PSA increase (P = 0.002). CONCLUSION Our study suggests that 11p15 (rs7127900, A) could be a susceptibility locus associated with PCa in Northern Chinese. Genotype TG on 11q13 (rs7931342, T) could be related to an increased Gleason score, AG on HNF1B (rs4430796, A) could be associated with PSA increase, and TG on 17q24 (rs1859962, G) could be negatively associated with an increased BMI in Chinese men with PCa.

Low-level Ki-67 expression as an independent predictor of bladder tumour recurrence in patients with primary upper tract urothelial carcinoma after radical nephroureterectomy

OBJECTIVE To evaluate the association of molecular markers and conventional clinicopathological factors with bladder tumour recurrence in patients with primary upper tract urothelial carcinoma after radical nephroureterectomy. METHODS The expressions of Ki-67 and P53 were measured by immunohistochemical staining prospectively in 115 consecutive patients with primary upper tract urothelial carcinoma from March 2004 to February 2014. The Cox proportional hazards regression model was used to identify independent predictors. The association between Ki-67 expression and clinicopathological variables was assessed by the χ(2) test. RESULTS Intravesical recurrence occurred in 13 out of 115 (11.3%) patients with a mean follow-up of 54.2 months (range: 7-130). Low-level Ki-67 expression (P = 0.010), older age (>65, P = 0.040) and lower ureter tumour (P = 0.001) were independent predictors of bladder tumour recurrence in Cox regression analysis. Ki-67 expression was elevated with the progression of tumour grade (P = 0.004) but not with stage (P = 0.186). Ki-67 overexpression was also significantly higher in aggressive pathological types (P = 0.008), but only shows an inclination towards poor oncologic outcomes in the cancer-specific survival rate (P = 0.107) and the overall survival rate (P = 0.063). CONCLUSIONS Low-level Ki-67 expression was an independent predictor for bladder tumour recurrence, while Ki-67 overexpression was associated with adverse clinicopathological parameters and poor prognosis in patients with primary upper tract urothelial carcinoma after radical nephroureterectomy.

Susceptibility Loci Associations with Prostate Cancer Risk in Northern Chinese Men

BACKGROUND KLK3 gene products, like human prostate-specific antigen (PSA), are important biomarkers in the clinical diagnosis of prostate cancer (PCa). G protein-coupled receptor RFX6, C2orf43 and FOXP4 signaling plays important roles in the development of PCa. However, associations of these genes with PCa in northern Chinese men remain to be detailed. This study aimed to investigate their impact on occurrence and level of malignancy. METHODS All subjects were from Beijing and Tianjin, including 266 cases with prostate cancer and 288 normal individuals as controls. We evaluated associations between clinical covariates (age at diagnosis, prostate specific antigen, Gleason score, tumor stage and aggressive) and 6 candidate PCa risk loci, genotyped by PCR- high resolution melting curve and sequencing methods. RESULTS Case-control analysis of allelic frequency of PCa associated with PCa showed that one of the 6 candidate risk loci, rs339331 in the RFX6 gene, was associated with reduced risk of prostate cancer (odds ratio (OR) = 0.73, 95% confidence interval (CI) =0.57-0.94, P = 0.013) in northern Chinese men. In addition, subjects with CX (CC+TC) genotypes had a decreased risk for prostrate cancer compared to those carrying the TT homozygote (OR =0.64, 95% CI = 0.45- 0.90, P = 0.008). The TT genotype of 13q22 (rs9600079, T) was associated with tumor stage (P=0.044, OR=2.34, 95% CI=0.94-5.87). Other SNPs were not significantly associated with clinical covariates in prostate cancer (P > 0.05). CONCLUSIONS. rs339331 in the RFX6 gene may be associated with prostate cancer as a susceptibility locus in northern Chinese men.

Systematic meta-analyses of gene-specific genetic association studies in prostate cancer

In the past twenty-five years, over 700 case-control association studies on the risk of prostate cancer have been published worldwide, but their results were largely inconsistent. To facilitate following and explaining these findings, we performed a systematic meta-analysis using allelic contrasts for gene-specific SNVs from at least three independent population-based case-control studies, which were published in the field of prostate cancer between August 1, 1990 and August 1, 2015. Across 66 meta-analyses, a total of 20 genetic variants involving 584,100 subjects in 19 different genes (KLK3, IGFBP3, ESR1, SOD2, CAT, CYP1B1, VDR, RFX6, HNF1B, SRD5A2, FGFR4, LEP, HOXB13, FAS, FOXP4, SLC22A3, LMTK2, EHBP1 and MSMB) exhibited significant association with prostate cancer. The average summary OR was 1.33 (ranging from: 1.016–3.788) for risk alleles and 0.838 (ranging from: 0.757–0.896) for protective alleles. Of these positive variants, FOXP4 rs1983891, LMTK2 rs6465657 and RFX6 rs339331 had not been previously meta-analyzed. Further analyses with sufficient power design and investigations of the potential biological roles of these genetic variants in prostate cancer should be conducted.

8q24 rs4242382 polymorphism is a risk factor for prostate cancer among multi-ethnic populations: evidence from clinical detection in China and a meta-analysis.

BACKGROUND Evidence supporting an association between the 8q24 rs4242382-A polymorphism and prostate cancer (PCa) risk has been reported in North American and Europe populations, though data from Asian populations remain limited. We therefore investigated this association by clinical detection in China, and meta-analysis in Asian, Caucasian and African-American populations. MATERIALS AND METHODS Blood samples and clinical information were collected from ethnically Chinese men from Northern China with histologically- confirmed PCa (n=335) and from age-matched normal controls (n=347). The 8q24 (rs4242382) gene polymorphism was genotyped by polymerase chain reaction-high-resolution melting analysis. We initially analyzed the associations between the risk allele and PCa and clinical covariates. A meta-analysis was then performed using genotyping data from a total of 1,793 PCa cases and 1,864 controls from our study and previously published studies in American and European populations, to determine the association between PCa and risk genotype. RESULTS The incidence of the risk allele was higher in PCa cases than controls (0.222 vs 0.140, P=7.3?10-5), suggesting that the 8q24 rs4242382-A polymorphism was associated with PCa risk in Chinese men. The genotypes in subjects were in accordance with a dominant genetic model (ORadj=2.03, 95%CI: 1.42-2.91, Padj=1.1?10-4). Presence of the risk allele rs4242382-A at 8q24 was also associated with clinical covariates including age at diagnosis ≥65 years, prostate specific antigen >10 ng/ml, Gleason score <8, tumor stage and aggressive PCa, compared with the non-risk genotype (P=4.6?10-5-3.0?10-2). Meta-analysis confirmed the association between 8q24 rs4242382-A polymorphism and PCa risk (OR=1.62, 95%CI: 1.39-1.88, P=1.0?10-5) across Asian, Caucasian and African American populations. CONCLUSIONS The replicated data suggest that the 8q24 rs4242382-A variation might be associated with increased PCa susceptibility in Asian, Caucasian and African American populations. These results imply that this polymorphism may be a useful risk biomarker for PCa in multi-ethnic populations.

The Cumulative Effect of Gene-Gene and Gene-Environment Interactions on the Risk of Prostate Cancer in Chinese Men

Prostate cancer (PCa) is a multifactorial disease involving complex genetic and environmental factors interactions. Gene-gene and gene-environment interactions associated with PCa in Chinese men are less studied. We explored the association between 36 SNPs and PCa in 574 subjects from northern China. Body mass index (BMI), smoking, and alcohol consumption were determined through self-administered questionnaires in 134 PCa patients. Then gene-gene and gene-environment interactions among the PCa-associated SNPs were analyzed using the generalized multifactor dimensionality reduction (GMDR) and logistic regression methods. Allelic and genotypic association analyses showed that six variants were associated with PCa and the cumulative effect suggested men who carried any combination of 1, 2, or ≥3 risk genotypes had a gradually increased PCa risk (odds ratios (ORs) = 1.79–4.41). GMDR analysis identified the best gene-gene interaction model with scores of 10 for both the cross-validation consistency and sign tests. For gene-environment interactions, rs6983561 CC and rs16901966 GG in individuals with a BMI ≥ 28 had ORs of 7.66 (p = 0.032) and 5.33 (p = 0.046), respectively. rs7679673 CC + CA and rs12653946 TT in individuals that smoked had ORs of 2.77 (p = 0.007) and 3.11 (p = 0.024), respectively. rs7679673 CC in individuals that consumed alcohol had an OR of 4.37 (p = 0.041). These results suggest that polymorphisms, either individually or by interacting with other genes or environmental factors, contribute to an increased risk of PCa.

Photoselective Vaporesection of the Prostate via an End-firing Lithium Triborate Crystal Laser

The occurrence of lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) is a common problem with a high incidence in the aging male population. Although it is not a life-threatening disease, BPH causes problems that seriously impact the quality of life. Here, we introduce a new technique called photoselective vaporesection of the prostate (PVRP) in treating BPH, which can be seen as a variation of photoselective vaporization of the prostate (PVP). This procedure presents several advantages compared to the PVP technique including less laser energy loss, less intraoperative complications as well as more tissue resection rate.

Photoselective Vaporesection of the Prostate with an End-firing Lithium Triborate Crystal Laser

Background: Photoselective vaporization of the prostate is a technique that is widely used for the treatment of benign prostatic hyperplasia (BPH) and has pronounced advantages compared to the traditional transurethral resection of the prostate. Following the recent introduction of end-firing lithium triborate lasers, we have created a new technique called photoselective vaporesection of the prostate (PVRP). This study described our initial experience using the PVRP technique for the treatment of BPH. Methods: This prospective study included a total of 35 patients with BPH who underwent PVRP from August 2013 to July 2014. The chief clinical parameters were obtained and evaluated during the perioperative period and follow-up, including the International Prostate Symptom Score (IPSS), quality of life (QoL) score, maximum urinary flow rate, and prostate volume. All variables were evaluated for statistically significant differences compared to baseline values using the analysis of variance. Results: The mean subgroup IPSS and QoL scores significantly improved during follow-up; the respective decreases in IPSS storage score, IPSS voiding score, IPSS nocturia score, and QoL score were 75.3%, 83.6%, 51.4%, and 71.7%, respectively (all P < 0.001 compared with baseline). Three patients were diagnosed with prostate cancer based on postoperative pathological examinations. There were no serious perioperative complications. Conclusion: The PVRP technique demonstrates satisfactory short-term clinical outcomes and perioperative safety in the treatment of BPH.

MP62-09 LAPAROENDOSCOPIC SINGLE-SITE RADICAL PROSTATECTOMY VS CONVENTIONAL LAPAROSCOPIC RADICAL PROSTATECTOMY: A PROSPECTIVE RANDOMIZED CLINICAL TRIAL

INTRODUCTION AND OBJECTIVES: The primary objective was to evaluate the learning curve of Minimally Invasive Radical Prostatectomy (MIRP) in our institution and apply the cumulative summation (CUSUM) analytical technique to identify salient learning curve transition points in terms of oncological outcomes. METHODS: Clinical, pathologic, and oncological outcome data were collected from our prospectively collected MIRP database to estimate Positive Surgical margin (PSM) and Biochemical Recurrence (BCR) trends during a 15 year period from 1998 to 2013. All the RPs (laparoscopic (LRP) / Robotic Assisted [RARP]) were performed by 9 surgeons. PSM was defined as presence of cancer cells at inked margins. BCR was defined as serum Prostate Specific Antigen (PSA) >0.2 ng/ml and rising or start of secondary therapy. Surgical learning curve was assessed with the application of Kaplan-Meier curves, Cox regression model, CUSUM and logistic model in order to define the “transition point” of surgical improvement. RESULTS: We identified 5547 patients with localized prostate cancer treated with MIRP (3846 LRP and 1701 e RARP). Patient characteristics of LRP and RARP were similar. The overall risk of PSM in LRP was 25%, 20% and 17% for the first 50, 50 to 350 and >350 cases, respectively. For the same population, the 5-year BCR rate decreased from 21.5% to 16.7%. RARP started 3 years after the LRP program (after approximately 250 LRP). The PSM rate for RARP decreased from 21.8% to 20.4% and the corresponding 5-year BCR rate decreased from 17.6% to 7.9%. The CUSUM analysis showed significantly lower PSM and BCR at 2 years occurred at the transition point of 350 cases for LRP and 100 cases for RARP. (Figure 1) In multivariable analysis, predictors of BCR were PSA, Gleason score, extra prostatic disease, seminal vesicle invasion and number of operations (p < 0.05). Patients harboring PSM showed higher BCR risk (23% vs. 8%, p < 0.05) CONCLUSIONS: Learning curve trends in our large, single center experience shows correlation between surgical experience and oncological outcomes in MIRP. Significant reduction in PSM and BCR risk at 2 years is noted after the initial 350 cases and 100 cases of LRP and RARP, respectively.