Short summary

This study will investigate the outcome in renal function and overall survival after nephrectomy in patients with renal cell carcinoma (RCC) and diabetes mellitus (DM). These patients will be compared to a general population without DM receiving nephrectomy for RCC.

Rationale

With improved life-expectancy in western populations, also the incidence of chronic kidney disease (CKD) has been increasing in developed countries, with associated increased risk of death, in particular from cardiovascular causes.

Causes of CKD are in fact often secondary to aging and other - often age-related - conditions, like hypertension or diabetes, that exert their effect in course of time. Age itself is also known to determine a physiological decrease in the number of functioning nephronic units, with an overall reduction of the glomerular filtration rate (eGFR), even though its role in the determinism of CKD in the otherwise healthy population, has recently been questioned, while age-associated comorbidities are likely to be more important determinants.

In particular, diabetes mellitus (DM) affects over 170 million worldwide (WHO statistics). The effects of the diabetic condition with chronic protein glycosylation involve all bodily organ systems and the kidneys represent one of the most frequently involved organs in this process.

In this setting, the role and type of surgery for the treatment of renal cell carcinoma (RCC) - whose peak incidence is also in the older population - becomes an argument of debate.

Description of the cohort

We will collect data on Danish patients operated with radical nephrectomy for renal cell carcinoma from 2000 to 2010. Patients will be grouped according to the presence of pre-operative diagnosis of diabetes mellitus (DM). Patients not pre-operatively diagnosed with DM will be excluded using an algorithm on the dates patients were registered with radical nephrectomy versus DM.

Data and biological material

The following characteristics will be recorded on included individuals:

• Patient Identification Number (PIN)
• Sex
• Date patient was recorded, as relevant, with:
• Diabetes mellitus
• Renal cell carcinoma
• Radical nephrectomy,
• Receiving first treatment for end-stage renal disease (ESRD) i.e. dialysis or transplantation
• Dead
• Recurrence of kidney cancer
• Patient's age when nephrectomy was performed
• TNM staging of renal tumour
• Histopathology of kidney tumour
• Type (clear cell, papillary, chromophobe etc.)
• Grade 

Data can be retrieved from the following registries:

• The Danish National Patient Register (DNPR)
• The National Diabetes Register (NDR)
• The Danish Cancer Registry (CAR)
• The Danish Pathology Register (DPR)
• The Danish Civil Registration System (DCRS)

Collaborating researchers and departments

Department of Urology, Odense University Hospital

• Urologist Alessandro Conti, MD
• Sune Moeller Jeppesen, BSc.med
• Consultant and Urologist Mikhael Diatchikhine, MD
• Professor and Urologisk Lars Lund, DMSc

OPEN Odense Patient data Explorative Network, Odense University Hospital

• Professor and Consultant Clinical Epidemiologist Anders Green, MD, DMSc, PhD