How many times were you consulted on or followed up on a child with cancer with one of the following issues: hypertension, acute kidney injury, proteinuria, hematuria, fluid and electrolyte imbalances, tumor lysis syndrome, kidney and urinary tract infections, kidney tumor, on nephrotoxic medications, stem cell or bone marrow transplant, thrombotic microangiopathy, or chronic kidney disease (CKD)? All the time, right? With advances in cancer therapies and development of novel treatments like CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy and vascular endothelial growth factor (VEGF)-targeted therapy, challenges have only increased. Since the first onco-nephrology forum at ASN Kidney Week in 2012, there have been several publications and conferences on this topic, leading to the emergence of onco-nephrology as a medical subspecialty, but the idea of pediatric onco-nephrology is still fledgling.
The survival of children and adolescents with cancer has improved significantly over the past 50 years, with 5-year survival rates of 83%-85% in 2008-2014, compared to 58%-68% in the mid-1970s. This begs the question, what will the long-term kidney function be in these young adult populations who were exposed to a variety of therapies that are potentially nephrotoxic?
The survival of children and adolescents with cancer has improved significantly over the past 50 years.
To answer this question, Green et al. (1) conducted a prospective study on a patient population from St. Jude Children's Research Hospital, aiming to define the prevalence of and risk factors for impaired kidney function. Based on the St. Jude Lifetime Cohort Study (SJLIFE) eligibility criteria (Figure 1), 2753 patients, who were followed for a median of 23.2 years, were selected for this study. Investigators quantified kidney function by measuring serum creatinine, urine protein (qualitative), estimated glomerular filtration rate, and quantified exposure to a variety of cancer treatments such as chemotherapy, radiation therapy, and surgery. In this cohort, the prevalence of CKD stages 3-5 was 2% (~0.4% in a 30- to 39-year-old population in Tennessee), and proteinuria was 6%. At an older age at evaluation, hypertension, cumulative doses of alkylating or platinating agents, usage of calcineurin inhibitors (CNIs), an increase in volume or dose of radiation, or nephrectomy increased the odds for CKD in this population. Similarly, Knijnenburg, et al. (2) showed that in a European childhood cancer survivor cohort, the prevalence of CKD stage 2 or above, proteinuria, and hypertension was 5%, 15%, and 15%, respectively.
Kidney injury is not uncommon in childhood cancer survivors, and development of new protocols and screening guidelines aids in early diagnosis and treatment of CKD in this population. This highlights the importance of pediatric onco-nephrology and drives the attitude from “why” to “now.”
Green MG, et al. Kidney function after treatment for childhood cancer: A report from the St. Jude Lifetime Cohort Study. J Am Soc Nephrol 2021; 32:983–993. doi: 10.1681/ASN.2020060849
Knijnenburg SL, et al. Renal dysfunction and elevated blood pressure in long-term childhood cancer survivors. Clin J Am Soc Nephrol 2012; 7:1416–1427. doi: 10.2215/CJN.09620911