840 Kidney cancer, treatment with nephrectomy and survival in chronic kidney disease (CKD)

Abstract Background and Aims People with chronic kidney disease (CKD) have increased incidence of kidney cancer and poorer survival post-diagnosis compared to people without CKD. Nephrectomy, either partial or radical is the primary treatment for many kidney cancers and can be curative even in cases with locally advanced disease or single metastasis. We hypothesised that nephrectomy may be less frequently undertaken in people with kidney cancer and pre-existing CKD and that this might contribute to poorer survival in this group. Method Using data from the prospective research cohort UK Biobank (n = 502,536) linked to cancer registry, participants with available biochemistry and a new diagnosis of kidney cancer during follow-up were identified. Occurrence of nephrectomy was extracted from linked hospital data and all-cause mortality data from death certification records. Estimated glomerular filtration rate (eGFRCr) was calculated by CKD-EPI 2009 formula with race coefficient, as this was the formula recommended for use in the UK at the time of recruitment to UK Biobank. Cox proportional hazards models tested associations between eGFRCr and i) undergoing nephrectomy and ii) all-cause mortality by 10 ml/min/1.73 m2 decline from a reference value of 90 ml/min/1.73 m2. We additionally conducted subgroup analyses for nephrectomy and all-cause mortality within eGFRCr categories >105, 90-105, 75-90 (reference), 60-75, 45-60, 30-45 and