Cisplatin is a preferred treatment for a wide range of cancers, including breast, head and neck, lung, ovary, and more. However, its side effects — particularly nephrotoxicity — can be severe. Kidney injury on cisplatin is associated with higher mortality and can jeopardize a patient’s eligibility for other therapies.
Now, in a large study using data from six US cancer centers, researchers have developed a risk algorithm to predict acute kidney injury (AKI) after cisplatin administration.
A risk prediction calculator based on the algorithm is available online for patients and providers to determine an individual patient›s risk for kidney injury from cisplatin using readily available clinical data.
Other risk scores and risk prediction models have been developed to help clinicians assess in advance whether a patient might develop AKI after receiving cisplatin, so that more careful monitoring, dose adjustments, or an alternative treatment, if available, might be considered.
However, previous models were limited by factors such as small sample sizes, lack of external validation, older data, and liberal definitions of AKI, said Shruti Gupta, MD, MPH, director of onco-nephrology at Brigham and Women’s Hospital (BWH) and Dana-Farber Cancer Institute, and David E. Leaf, MD, MMSc, director of clinical and translational research in AKI, Division of Renal Medicine, BWH, Boston.
Dr. Gupta and Dr. Leaf believe their risk score for predicting severe AKI after intravenous (IV) cisplatin, published online in The BMJ, is “more accurate and generalizable than prior models for several reasons,” they told this news organization in a joint email.
“First, we externally validated our findings across cancer centers other than the one where it was developed,” they said. “Second, we focused on moderate to severe kidney injury, the most clinically relevant form of kidney damage, whereas prior models examined more mild forms of kidney injury. Third, we collected data on nearly 25,000 patients receiving their first dose of IV cisplatin, which is larger than all previous studies combined.”
‘Herculean Effort’
“We conceived of this study back in 2018, contacted collaborators at each participating cancer center, and had numerous meetings to try to gather granular data on patients treated with their first dose of intravenous (IV) cisplatin,” Dr. Gupta and Dr. Leaf explained. They also incorporated patient feedback from focus groups and surveys.
“This was truly a Herculean effort that involved physicians, programmers, research coordinators, and patients,” they said.
The multicenter study included 24,717 patients — 11,766 in the derivation cohort and 12,951 in the validation cohort. Overall, the median age was about 60 years, about 58% were men, and about 78% were White.
The primary outcome was cisplatin-induced AKI (CP-AKI), defined as a twofold or greater increase in serum creatinine or kidney replacement therapy within 14 days of a first dose of IV cisplatin.
Their simple risk score consisting of nine covariates — age, hypertension, type 2 diabetes, hemoglobin level, white blood cell count, platelet count, serum albumin level, serum magnesium level, and cisplatin dose — predicted a higher risk for CP-AKI in both cohorts.
Notably, adding serum creatinine to the model did not change the area under the curve, and therefore, serum creatinine, though also an independent risk factor for CP-AKI, was not included in the score.
Patients in the highest risk category had 24-fold higher odds of CP-AKI in the derivation cohort and close to 18-fold higher odds in the validation cohort than those in the lowest risk category.
The primary model had a C statistic of 0.75 (95% CI, 0.73-0.76) and showed better discrimination for CP-AKI than previously published models, for which the C statistics ranged from 0.60 to 0.68. The first author of a paper on an earlier model, Shveta Motwani, MD, MMSc, of BWH and Dana-Farber Cancer Institute in Boston, is also a coauthor of the new study.
Greater severity of CP-AKI was associated with shorter 90-day survival (adjusted hazard ratio, 4.63; 95% CI, 3.56-6.02) for stage III CP-AKI vs no CP-AKI.