Association of metformin intake with bladder cancer risk and oncologic outcomes in type 2 diabetes mellitus patients: A systematic review and meta-analysis.

BACKGROUND: Recent clinical trials indicated that metformin intake might play a protective role in the incidence and oncologic outcomes of various cancers. However, its protective effect on bladder cancer remains uncertain. METHODS: We performed a meta-analysis to investigate the association between metformin intake and bladder cancer risk as well as oncologic outcomes in diabetes mellitus (DM) patients. A comprehensive literature search was performed using PubMed, Embase, and the Cochrane Central Search Library in December 2017. Hazard ratio (HR) with 95% confidence interval (CI) was pooled. RESULTS: A total of 9 retrospective cohort studies with 1,270,179 patients were included. A meta-analysis revealed that metformin intake was associated with an increased recurrence-free survival (HR = 0.55, 95% confidence interval [CI] = 0.35-0.88; P = .01; I = 64%), improved progression-free survival (HR = 0.70, 95% CI = 0.51-0.96; P = .03; I = 33%), and prolonged cancer-specific survival (HR = 0.57, 95% CI = 0.40-0.81; P = .002; I = 0%). However, results demonstrated that metformin intake was not associated with a decreased incidence of bladder cancer (HR = 0.82, 95% CI = 0.61-1.09; P = .17; I = 85%) or an increased overall survival in bladder cancer patients (HR = 0.83, 95% CI = 0.47-1.44; P = .50; I = 64%). CONCLUSION: The present meta-analysis indicated that metformin intake could improve the prognosis of bladder cancer patients. Further prospective cohort studies and mechanistic studies are still required to determine the precise role of metformin in the initiation and progression of bladder cancer.

Association Between 12 Polymorphisms of VEGF/Hypoxia/Angiogenesis Pathway Genes and Risk of Urogenital Carcinomas: A Meta-Analysis Based on Case-Control Studies.

Objective: Previous studies indicated potential associations between polymorphisms in genes of VEGF/hypoxia/angiogenesis pathway and risk of urogenital carcinomas However, the results were controversial and inconclusive. Here, we conducted an in-depth meta-analysis to investigate the precise associations between polymorphisms in VEGF/hypoxia/angiogenesis related genes and risk of urogenital carcinomas. Methods: We searched PubMed, Web of Science, EMBASE, and Cochrane Library to identify all eligible publications. Pooled odds ratios (ORs) corresponding with the 95% confidence intervals (CIs) were calculated to evaluate their associations. Subgroup analysis was conducted to further ascertain such relationship and investigate sources of heterogeneity. Results: In the end, a total of 96 case-control studies fulfilled the inclusion criteria were enrolled for 12 polymorphisms in 4 VEGF/hypoxia/angiogenesis related genes. The pooled results showed eNOS-rs2070744 polymorphism conferred a significantly increased overall risk of urogenital carcinomas in allele, homozygote, and recessive models, respectively. In addition, eNOS-Intron 4a/b VNTR polymorphism was identified related to an increased risk of urogenital carcinomas in recessive model. And VEGF-rs699947 polymorphism was also identified an increased risk of renal cell carcinoma (RCC) in allelic, heterozygote, dominant, homozygote, and recessive models. Conclusion: To conclude, eNOS-rs2070744 and eNOS-Intron 4a/b VNTR polymorphisms are risk factors for urogenital carcinomas. VEGF-rs699947 polymorphism was also identified as an increased risk factor for renal carcinoma.

High Expression of Long Noncoding RNA MALAT1 Indicates a Poor Prognosis and Promotes Clinical Progression and Metastasis in Bladder Cancer.

BACKGROUND: Recent studies have demonstrated that the expression of long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) promotes cancer cell proliferation, invasion, and metastasis in many tumor types, but the association between bladder cancer and MALAT1 remains unknown. MATERIALS: The expression of MALAT1 was tested by in situ hybridization (ISH) in 120 bladder cancer specimens. The association between MALAT1 expression and clinicopathological features and prognosis of the patients with bladder cancer was analyzed. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to verify the relationship between the expression of MALAT1 and progression and metastasis of bladder cancer. RESULTS: ISH showed that high MALAT1 expression was associated with advanced histological grade, high tumor stage, and positive lymph nodes. Kaplan-Meier survival analysis and Cox regression analysis indicated that high tumor stage, positive lymph nodes, and high MALAT1 expression were independent prognostic indicators for overall survival (OS) of patients with bladder cancer. qRT-PCR showed that the expression of MALAT1 in bladder cancer tissues was 2.85 times higher than those measured in adjacent normal tissues (P < .001). The expression of MALAT1 was 2.673 ± 0.254 in non-muscle-invasive bladder cancer and 2.987 ± 0.381 in muscle-invasive bladder cancer (P = .018). In bladder cancer specimens with positive lymph nodes, MALAT1 expression was 3.167 ± 0.297 versus 2.896 ± 0.329 in bladder cancer specimens with negative lymph nodes (P = .020). CONCLUSION: High MALAT1 expression could serve as an independent prognostic factor for OS of patients with bladder cancer and could be considered as a potential therapeutic target of bladder cancer.