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Gregory J. Riely, MD, PhD
Gregory J. Riely, MD, PhD
Posted: Wednesday, November 30, 2022
According to Peter M. Manders, BSc, MB, BS, PhD, FRACP, of Griffith University, Gold Coast, Australia, and colleagues, there were significant differences in carboplatin dosing depending on whether the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), or standard-of-care Cockcroft Gault (CG) equation was used to estimate the glomerular filtration rate in a population of patients with lung cancer. A retrospective study, which was published in BMC Cancer, suggested the CKD-EPI equation provides the most clinically appropriate carboplatin dosing.
“Carboplatin, like many cytotoxic agents, is almost exclusively eliminated renally and has a narrow therapeutic index, causing potentially major adverse reactions with subtle dose changes,” the investigators commented. “Overestimation of renal function may lead to supratherapeutic dosing and toxicity, while underestimation may lead to underdosing and therapeutic failure.”
Carboplatin dosing data from 96 patients were analyzed to compare the equations and identify patient profiles associated with significant carboplatin dose variation. When the investigators used the glomerular filtration rates estimated by the MDRD, CKD-EPI 2009, and CKD-EPI 2021 equations, hypothetical doses were calculated and compared with actual prescribed CG equation–based doses.
Although the MDRD and CKD-EPI equations predicted comparable doses, the CG equation resulted in up to 17% of the patients receiving a dose that was at least 20% higher than a non-CG equation would have predicted and 20% receiving a dose that was at least 20% lower than a non-CG equation would have predicted. The CG equation seemed to overestimate kidney function in patients with a higher body weight and surface area and underestimate it in those with a lower body weight and surface area. Of note, the CKD-EPI equation predicted lower doses for patients who later received a reduction of the prescribed CG equation–derived dose.
Disclosure: The study authors reported no conflicts of interest.
