Genetic and epigenetic changes in the von Hippel-Lindau (VHL) tumor suppressor gene are common in sporadic conventional renal cell carcinoma (cRCC). Further insight into the clinical significance of these changes may lead to increased biological understanding and identification of subgroups of patients differing prognostically or who may benefit from specific targeted treatments. We have comprehensively examined the VHL status in tissue samples from 115 patients undergoing nephrectomy, including 96 with sporadic cRCC. In patients with cRCC, loss of heterozygosity was found in 78.4%, mutation in 71%, and promoter methylation in 20.4% of samples. Multiplex ligation-dependent probe amplification identified intragenic copy number changes in several samples including two which were otherwise thought to be VHLnoninvolved. Overall, evidence of biallelic inactivation was found in 74.2% of patients with cRCC. Many of the mutations were novel and approximately two-thirds were potentially truncating. Examination of these and other published findings confirmed mutation hotspots affecting codons 117 and 164, and revealed a common region of mutation in codons 60 to 78. Gender-specific differences in methylation and mutation were seen, although not quite achieving statistical significance (P = 0.068 and 0.11), and a possible association between methylation and polymorphism was identified. No significant differences were seen between VHL subgroups with regard to clinicopathologic features including stage, grade, tumor size, cancer-free and overall survival, with the exception of a significant association between loss of heterozygosity and grade, although a possible trend for survival differences based on mutation location was apparent.
Background
There is a global pandemic of type 2 diabetes mellitus (T2DM), especially in Asia. Singapore has a prevalence of T2DM at 10.5%, which is higher than the world average of 8.8%. Multiple studies have shown that multidisciplinary, team-based, coordinated care has been associated with improved measures of quality care and reduced healthcare utilization. Patients with poor glycemic control and nephropathy are at the highest risk of developing cardiovascular complications and renal failure. In this study, we aimed to investigate the impact of intensive multidisciplinary diabetes mellitus care with patient empowerment versus routine clinical care on the rate of progression of micro and macrovascular complications and peripheral atherosclerotic burden, as measured by changes in femoral intima-media thickness (IMT) in patients with persistently elevated HbA1c and nephropathy.
Methods
The study is a single-center randomized controlled trial (RCT) with two study arms - intensive diabetes mellitus care versus routine clinical care. Patients in the intensive arm will receive care from a multidisciplinary team consisting of an endocrinologist, diabetes nurse educator, dietitian, renal pharmacist and medical social worker for counselling. In addition, patients will be provided with tools for self-care empowerment such as glucometers, blood pressure monitors and android tablets to facilitate care, monitoring and education. Patients in the routine clinical care arm will receive standard clinical care. Follow up (FU) will be for 3 years. Primary outcomes include cardiovascular events, rate of progression of nephropathy and development of end-stage renal disease. Secondary endpoints include the proportions of patients with documented improved control of cardiovascular risk factors (HbA1c, blood pressure, low density lipoprotein-C (LDL-C), reduction in body weight), frequency of hypoglycemia, hospitalization days and changes in femoral IMT. We will also examine the prevalence of peripheral atherosclerosis and the predictive value and usability of lower extremity arterial ultrasound to predict cardio-cerebrovascular events, amputation and peripheral intervention.
Discussion
Diabetes mellitus carries significant healthcare costs. Patients with poor glycemic control and nephropathy are at highest risk of developing cardiovascular complications and renal failure. Intensive diabetes mellitus care with patient empowerment may lead to sustained glycemic control, reduction of clinical complications and progression of nephropathy, and incidence of cardiovascular complications.
Trial registration
ClinicalTrials.gov,
NCT03413215
. Registered on 29 January 2019.
Electronic supplementary material
The online version of this article (10.1186/s13063-019-3601-3) contains supplementary material, which is available to authorized users.
Flow-independent relaxation-based non-contrast MR angiography techniques yield good signal-to-noise ratio and high blood-tissue contrast, complementing non-contrast flow-dependent and contrast-enhanced MR angiography techniques in the assessment of vascular disorders. However, these techniques often suffer from imaging artifacts at high magnetic field strengths or across large fields-of-view. Relaxation-Enhanced Angiography without Contrast and Triggering (REACT) is a recently introduced flow-independent non-gated non-contrast three-dimensional MR angiography technique that has been developed to mitigate some of these issues. We present our initial experience with the clinical applications of REACT in imaging disorders of the central and peripheral vascular systems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.