The advent of Onco-nephrology – a novel subspecialty

*Corresponding author: Mohammed Mahdi Althaf MD, MRCP (UK), Department of Medicine, Section of Nephrology, King Faisal Specialist Hospital and Research Center, P.O.Box 3354, Riyadh 11211, Kingdom of Saudi Arabia, Email: [email protected] The term onco-nephrology has been coined in an attempt to highlight the evolution of an increasingly complex and important sub-specialty in the practice of renal medicine. Given the improved survival and aging population, the prevalence of comorbidities is ever expanding and chronic kidney disease (CKD) is a major constituent. Between 2005 and 2009 >75% of cancer diagnoses occurred in individuals aged ≥65 years (1). When the words ‘Kidney’ and ‘Cancer’ are read in the same sentence several links between the two prop up in the mind of a nephrologist. It is important to note in cancer patients that the prevalence, cause and rate of progression of acute kidney injury (AKI) as well as CKD are different when compared to the general population. The one-year risk of AKI (defined as a >50% rise in serum creatinine) in patients with cancer was 17.5%, with a 27% risk over 5 years (2). Nephrologists are involved in several levels of care for patients with cancer. In end-stage renal disease (ESRD) patients on hemodialysis or peritoneal dialysis we screen patients for certain common malignancies in addition to age appropriate screening. Dialysis patients are more prone to develop bladder cancer, renal cell carcinoma, hepatocellular carcinoma, thyroid cancers, tongue cancers, cancer of the cervix, multiple myeloma and non-Hodgkin lymphoma. However, the incidence of other solid tumors are not more common than the general population (3,4). We have previously described a system that we employed where patients in a dialysis unit are screened for malignancies as well as other chronic ailments in a setting where a general practitioner is not involved (5). During pre-transplant recipient work-up we screen for malignancies and also decide on when a patient is fit for transplantation after a period of remission from a cancer. With renal transplant recipients we balance immunosuppression and allograft function whilst monitoring them vigilantly for malignancy. In patents with active malignancy who undergo several contrast enhanced imaging studies; we deal with contrast nephropathy risk assessment as well as management if AKI does occur. Furthermore, we deal with complex scenarios of electrolyte and fluid disturbances that are often encountered with an oncology patient. The most common paraneoplastic syndrome being AKI resulting from volume depletion related to malignancy treatmentassociated malnutrition (6). Other settings include management of tumor lysis syndrome, thrombotic microangiopathy, obstructive uropathy, cancer associated hypercalcemia, lymphomatous infiltration of the kidney, kidney disease in hematopoietic cell transplantation, hepatic veno-occlusive disease and hypertension induced by anti-angiogenic therapies. Interestingly there are renal manifestations of several malignancies, namelyImplication for health policy/practice/research/medical education: The term onco-nephrology has been coined in an attempt to highlight the evolution of an increasingly complex and important sub-specialty in the practice of renal medicine. A R T I C L E I N F O