How to determine kidney function in cancer patients?

Challenges of Renal Function Assessment in Breast Cancer Patients Treated With Abemaciclib: A Case Report

Abemaciclib, a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor used for hormone-receptor-positive and human epidermal growth factor receptor 2 (HER-2)-negative breast cancer, can lead to elevated serum creatinine without implications on the true renal function. Although clinical trials have shown no increase in other kidney function biomarkers, this may still represent a challenge in cancer patients. We report a case of a 74-year-old female who presented with creatinine and cystatin-C elevation during treatment with abemaciclib without an equivalent decrease in measured glomerular filtration rate (GFR) with renal scintigraphy. The confirmation of adequate kidney function allowed for the maintenance of treatments that would otherwise be limited by renal impairment. Healthcare providers should be aware of abemaciclib's effect on serum creatinine but should not eliminate the possibility of actual kidney injury. Alternative biomarkers for GFR assessment are recommended, although the usefulness of cystatin-C in patients receiving abemaciclib should be investigated in greater depth.

Assessment of GFR in Patients with Cancer: A Statement from the American Society of Onco-Nephrology

Accurate assessment of GFR is crucial to guiding drug eligibility, dosing of systemic therapy, and minimizing the risks of both undertreatment and toxicity in patients with cancer. Up to 32% of patients with cancer have baseline CKD, and both malignancy and treatment may cause kidney injury and subsequent CKD. To date, there has been lack of guidance to standardize approaches to GFR estimation in the cancer population. In this two-part statement from the American Society of Onco-Nephrology, we present key messages for estimation of GFR in patients with cancer, including the choice of GFR estimating equation, use of race and body surface area adjustment, and anticancer drug dose-adjustment in the setting of CKD. These key messages are based on a systematic review of studies assessing GFR estimating equations using serum creatinine and cystatin C in patients with cancer, against a measured GFR comparator. The preponderance of current data involving validated GFR estimating equations involves the CKD Epidemiology Collaboration (CKD-EPI) equations, with 2508 patients in whom CKD-EPI using serum creatinine and cystatin C was assessed (eight studies) and 15,349 in whom CKD-EPI with serum creatinine was assessed (22 studies). The former may have improved performance metrics and be less susceptible to shortfalls of eGFR using serum creatinine alone. Since included studies were moderate quality or lower, the American Society of Onco-Nephrology Position Committee rated the certainty of evidence as low. Additional studies are needed to assess the accuracy of other validated eGFR equations in patients with cancer. Given the importance of accurate and timely eGFR assessment, we advocate for the use of validated GFR estimating equations incorporating both serum creatinine and cystatin C in patients with cancer. Measurement of GFR via exogenous filtration markers should be considered in patients with cancer for whom eGFR results in borderline eligibility for therapies or clinical trials.

Measurement of Glomerular Filtration Rate in Patients Undergoing Renal Surgery for Cancer: Estimated Glomerular Filtration Rate versus Measured Glomerular Filtration Rate in the Era of Precision Medicine

BACKGROUND

In the era of precision medicine, determining reliable renal function assessment remains a critical and debatable issue, especially in nephrology and oncology.

SUMMARY

This paper delves into the significance of accurately measured glomerular filtration rate (mGFR) in clinical practice, highlighting its essential role in guiding medical decisions and managing kidney health, particularly in the context of renal cancer (RC) patients undergoing nephrotoxic anti-cancer drugs. The limitations and advantages of traditional glomerular filtration rate (GFR) estimation methods, primarily using serum biomarkers like creatinine and cystatin C, are discussed, emphasizing their possible inadequacy in cancer patients. Specifically, newer formulae designed for GFR estimation in cancer patients may not perform at best in RC patients. The paper explores various methods for direct GFR measurement, including the gold standard inulin clearance and alternatives like iohexol plasma clearance.

KEY MESSAGE

Despite the logistical challenges of these methods, their implementation is crucial for accurate renal function assessment. The paper concludes by emphasizing the need for continued research and innovation in GFR measurement methodologies to improve patient outcomes, particularly in populations with complex medical needs.

Comparison of three equations for estimating glomerular filtration rate as predictors of cisplatin-related acute kidney injury in lung cancer patients with normal renal function

OBJECTIVE

Cisplatin-associated acute kidney injury is a common clinical event that causes increased morbidity and mortality in cancer patients even if they are categorized as having normal functioning kidneys. We aimed to determine predictive factors that can predict acute kidney injury associated with cisplatin therapy in patients with normal renal function by comparison of pre-chemotherapy estimated glomerular filtration rates calculated separately by Cockcroft and Gault (CG), the Modification of Diet in Renal Disease (MDRD), and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPİ) equations and accompanying patient-associated factors.

MATERIALS AND METHODS

A total of 200 patients diagnosed with lung cancer and determined to have normal functioning kidneys and considered cisplatin eligible by the attending physician before chemotherapy were included in this retrospective study. Acute kidney injury after cisplatin chemotherapy (c-AKI) was determined according to the National Cancer Institute's Common Terminology Criteria for Adverse Events v4.03. Pre-chemotherapy serum laboratory parameters and clinico-histopathological characteristics of patients were recorded from the hospital electronic system. The optimal cut-off for eGFR methods was determined by the area under the receiver operating characteristic curve (ROC-AUC) analysis. Predictive factor analysis for c-AKI was performed by regression analyses.

RESULTS

C-AKI developed in 39 (19.5%) patients. In the univariate analysis, a significant correlation was observed between c-AKI and high body mass index (BMI) before treatment, older age (>62.5), female gender, eGFR by MDRD (≤94.5 mL/min) and eGFR by CKD-EPI (≤91.5 mL/min). There was no relation between eGFR by CG and c-AKI. Two different multivariate models were established. Model 1 showed that female gender (odds ratio [OR] =4.90, 95% confidence interval [CI]: 1.52-15.79, P = 0.008) and eGFR by MDRD less than or equal to 94.5 mL/min (OR = 3.52, 95% CI: 1.68-7.38, P = 0.001) were predictive markers for c-AKI. In Multivariate Model 2, female gender (OR = 5.51, 95% CI: 1.70-17.83, P = 0.004) and eGFR by CKD-EPI less than or equal to 91.5 mL/min (OR = 3.52, 95% CI: 1.67-7.42, P = 0.001) were found to be predictive markers for c-AKI.

CONCLUSIONS

This study revealed that eGFR calculated based on MDRD (≤94.5 mL/min/m2) or CKD-EPI (≤91.5 mL/min/m2) before chemotherapy indicates a strong tendency for c-AKI. In addition, we detected a high risk of c-AKI for females compared to their counterparts. Although eGFR 60 mL/min is considered the threshold level to accept patients as cisplatin-eligible, we recommend close follow-up of high-risk patients for cisplatin nephrotoxicity we detected in our models.

Real-world survival after colorectal surgery for malignancy in Korean patients with chronic kidney disease: an analysis of Korean healthcare big data, 2002-2019

Purpose

Globally, chronic kidney disease (CKD) is common and has been associated with an increased risk of colorectal cancer (CRC). There is a dearth of literature on the real-world morbidity and mortality associated with CKD comorbid with CRC. This study was performed to evaluate real-world survival outcomes of colorectal malignancy in Korean CKD patients.

Methods

The National Health Insurance Service of Korea provided data on patients who underwent surgical resection among patients diagnosed with CRC from 2002 to 2019.

Results

A total of 219,550 patients were included: 6,181 patients with underlying CKD and 213,369 patients without it. Each morbidity was significantly higher in the CKD-CRC group, and the postoperative mortality rates for the 30-day (3.11% vs. 1.78%, P < 0.001), 60-day (5.95% vs. 3.83%, P < 0.001), and 90-day mortality rate (8.12% vs. 5.32%, P < 0.001) were significantly higher in the CKD group. The median survival time (MST, year) was significantly lower in the CKD-CRC group (5.63; interquartile range [IQR], 5.26-5.91) than in the non-CKD-CRC group (8.71; IQR, 8.37-8.93). MST was significantly lower among CKD patients who received chemotherapy after adjustment by multivariate analysis (adjusted hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.37-1.49; P < 0.001]). Subgroup analysis showed that in the CKD-CRC group, MST was lower in patients who received dialysis than in those who did not, even after multivariate analysis (adjusted HR, 2.38; 95% CI, 2.20-2.58; P < 0.001).

Conclusion

Prevention of CKD-to-end-stage renal disease progression should be adopted as a strategy to increase postoperative survival, along with active surveillance and cancer treatment.

Glomerular Filtration Rate Measurement and Chemotherapy Dosing

Many chemotherapeutic drugs used to treat malignancies undergo renal clearance. Thus, accurate knowledge of kidney function is critical to ensure proper dosing, maximize efficacy, and minimize toxicity of drugs that often have a narrow therapeutic index. Making this issue more salient is the fact that impaired kidney function, as assessed by glomerular filtration rate (GFR), is encountered commonly in patients with cancer. Recent data and expert guidelines recommend the use of the Chronic Kidney Disease-Epidemiology Collaboration equation to guide the assessment of kidney function, except when directly measured GFR is clinically necessary. Controversies regarding the measurement of kidney function include the use of race in this equation, indexing to body surface area, and dosing of medications based on stages of chronic kidney disease versus more discrete values of estimated GFR. The development of accurate, real-time GFR measures may hold great promise in allowing for more accurate dosing of these important drugs.

The Onco-Nephrology Field: The Role of Personalized Chemotherapy to Prevent Kidney Damage

In recent years, the onco-nephrology field has acquired a relevant role in internal medicine due to the growing number of cases of renal dysfunction that have been observed in cancer patients. This clinical complication can be induced by the tumor itself (for example, due to obstructive phenomena affecting the excretory tract or by neoplastic dissemination) or by chemotherapy, as it is potentially nephrotoxic. Kidney damage can manifest as acute kidney injury or represent a worsening of pre-existing chronic kidney disease. In cancer patients, physicians should try to set preventive strategies to safeguard the renal function, avoiding the concomitant use of nephrotoxic drugs, personalizing the dose of chemotherapy according to the glomerular filtration rate (GFR) and using an appropriate hydration therapy in combination with nephroprotective compounds. To prevent renal dysfunction, a new possible tool useful in the field of onco-nephrology would be the development of a personalized algorithm for the patient based on body composition parameters, gender, nutritional status, GFR and genetic polymorphisms.

Pseudo-AKI associated with targeted anti-cancer agents-the truth is in the eye of the filtration marker

Besides true acute kidney injury (AKI), the occurrence of pseudo-AKI has been associated with several targeted agents. To improve the management of cancer patients treated with targeted agents, we need to be aware of this and use diagnostic approaches to differentiate between pseudo-AKI and AKI. In an article by Wijtvliet et al. in this issue of CKJ, tepotinib is added to the list of targeted agents associated with pseudo-AKI. In this editorial we discuss the current literature regarding pseudo-AKI and true AKI associated with targeted agents, and subsequently propose a management strategy to monitor kidney function in patients treated with targeted agents.

Long-Term Response of Pembrolizumab in a Patient with Metastatic Squamous Non-Small Cell Lung Cancer on Hemodialysis: Case Report and Review of the Literature

In patients with renal failure and hemodialysis, there are difficulties in drug selection and dose adjustment for cancer treatment. The use of immune checkpoint inhibitors (ICIs), including pembrolizumab, approved by the U.S. Food and Drug Administration (FDA) for patients with metastatic non-small cell lung cancer (NSCLC) in 2015, has become an important option for the treatment of metastatic NSCLC. However, data regarding the dosage and schedule for long-term use of ICIs, especially pembrolizumab, in hemodialysis patients are limited. We present the case of a patient with metastatic squamous NSCLC who demonstrated a long-term partial response to pembrolizumab monotherapy for 45 months during hemodialysis and showed no immune-related adverse events (irAEs). To our knowledge, this is the longest remission to be reported without irAEs after discontinuation of pembrolizumab in a NSCLC patient undergoing HD. In addition, we reviewed previously reported lung cancer patients who used ICI during dialysis, comparing them with our case in clinical aspect. We believe that this report will provide clinical insights into the long-term efficacy and safety of pembrolizumab in lung cancer patients undergoing hemodialysis.

Estimation of cefepime, piperacillin, and tazobactam clearance with iohexol-based glomerular filtration rate in paediatric patients

PURPOSE

Estimated glomerular filtration rate (eGFR) equations reflect kidney function imprecisely. We aimed to describe whether iohexol-based GFR or eGFRs predict clearance of cefepime, piperacillin, and tazobactam in pharmacokinetic (PK) models in this population and its clinical significance.

METHODS

Hospitalized patients (0.5-25 years) with haemato-oncological disease and infection receiving cefepime or piperacillin/tazobactam were included. PK samples were collected at a steady state concomitantly with samples for iohexol-based GFR. PK models were developed in NONMEM. Weight, postmenstrual age, iohexol-based GFR, different eGFR equations (Schwartz updated, Lund-Malmö revised, CKD-EPI, Bouvet, Schwartz cystatin C-based) were tested as covariates. Probabilities of neurotoxic/therapeutic concentrations were assessed by simulations.

RESULTS

Fifteen patients receiving cefepime and 17 piperacillin/tazobactam were included (median (range) age 16.2 (1.9-26.0) and 10.5 (0.8-25.6) years, iohexol-based GFR 102 (68-140) and 116 (74-137) mL/min/1.73 m², respectively). Two-compartment model provided the best fit for all drugs. Weight was covariate for central and peripheral compartment, clearance and intercompartmental clearance (only tazobactam), and postmenstrual age for clearance (excluding cefepime). Iohexol-based GFR was the best predictor of clearance. The model of cefepime without vs with iohexol-based GFR underestimated the probability of neurotoxic concentrations (28.3-28.6% vs 52.1-69.3%) and overestimated the probability of therapeutic concentrations (> 90% vs 81.9-87.1%) in the case of iohexol-based GFR 70-80 and 130-140 mL/min/1.73 m², respectively.

CONCLUSION

Iohexol-based GFR can predict better than eGFRs the clearance of cefepime, piperacillin, and tazobactam in children and young adults with haemato-oncological disease and infection, warranting further investigation as an indicator of renal function to improve targeting of therapeutic window.

TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION

EudraCT 2015-000,631-32, EudraCT 2016-003,374-40 (24.10.2016).

A prospective cross-sectional study estimated glomerular filtration rate from creatinine and cystatin C in adults with solid tumors

Current guidelines recommend estimating glomerular filtration rate (eGFR) using creatinine (eGFRcr) with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation as the first test for GFR evaluation, but the Cockcroft-Gault (CG) equation is still commonly used in oncology practice and clinical trials despite increasing evidence of its inaccuracy compared to measured GFR (mGFR). Guidelines recommend eGFR using cystatin C (eGFRcys) or both markers (eGFRcr-cys) as a confirmatory test, but neither was carefully evaluated in cancer patients. Therefore, we compared performance of the CKD-EPI equations and others to the CG equation in adults with a variety of solid tumors. The mGFR was determined by plasma clearance of ⁵¹Cr-EDTA. Bias was defined as the median of the differences between mGFR and eGFR while accuracy was defined as the percentage of estimates that differed by more than 30% from the measured GFR (1-P30). We prospectively recruited 1,200 patients between April 2015 and September 2017 with a mean age and mGFR of 58.8 years and 78.4 ml/min/1.73m², respectively. Bias among eGFRcr equations varied from -8.1 to +6.1 ml/min/1.73 m². CG was the least accurate, 1-P30 (95% confidence interval) was 24.9 (22.4- 27.3)%; CKD-EPI had 1-P30 of 19.1 (16.8-21.2)% while eGFRcr-cys had the best performance: bias -2.0 (-2.6 to -1.1) ml/min/1.73m² and 1-P30 7.8 (6.3-9.4)%. Thus, the CG equation should not be preferred over CKD-EPI equation, and eGFRcr-cys can be used as a confirmatory test in adults with solid tumors. Hence, a major policy implication would be to adopt general practice guideline-recommended methods for GFR evaluation in oncology practice and clinical trials.

Repeatability of glomerular filtration rate studies performed using 99mTc-DTPA in a population including cancer patients

OBJECTIVE

Glomerular filtration rate (GFR) measurement remains an integral investigation in clinical practice and is particularly important in the prediction and follow-up of renal side-effects of nephrotoxic chemotherapy in cancer patients. Knowing the coefficient of variation (CV) of a test is vital for the correct interpretation of serial studies. Recent difficulties with 51Cr-EDTA availability have renewed interest in 99mTc-DTPA, but there is a paucity of data on the test-retest variability of this radiopharmaceutical. Furthermore, the authors are unaware of published repeatability data in cancer patients. The aim of this study was to determine the CV of repeat 99mTc-DTPA GFR measurements in a clinical patient population that included cancer patients.

METHODS

Patients who had undergone ≥2 GFR studies at our department between January 2009 and December 2019 were retrospectively identified. Patients with chronic kidney disease and those who had received chemotherapy, radiotherapy or surgery between measurements were excluded. The CV for each patient was calculated and the mean CVs of cancer and prospective renal donor groups were calculated and compared.

RESULTS

Fifty-four patients were included in the final analysis. The mean CV in the cancer group (38 patients) was 8.5% [95% confidence interval (CI) 6.9-10.2%] and in the renal donor group (16 patients) 7.1% (95% CI 4.2-10.1%). These figures did not differ significantly (P = 0.37). The groups were combined to calculate the final overall mean CV of 8.1% (95% CI 6.7-9.6%).

CONCLUSION

In both non-cancer and cancer patients the CV of GFR studies performed with 99mTc-DTPA was comparable with mostly 51Cr-EDTA figures presented in literature.

Monographic consultation of onconephrology. Rationale and implementation

The increase in demand for medical care for renal complications associated with neoplastic diseases is a reality in most nephrology departments. In response to this overall situation, the creation of healthcare models such as monographic consultations and develop training programs in Onconephrology could improve the care of these patients. Through an exploratory and descriptive study, we identified current situation of kidney involvement in cancer patients. The objective of the present study is to establish the criteria for specific assistance in the field of Onconephrology. For this, we have reviewed key aspects and analyzed the current situation in our country, through a survey addressed to all nephrologists through the Spanish Society of Nephrology., together with the experience of two Spanish centers. From this information, we have established some requirements and recommendations for the start-up of these consultations.

Drug dosing in cancer patients with decreased kidney function: A practical approach

Correct drug dosing of anticancer agents is essential to obtain optimal outcomes. Overdosing will result in increased toxicity, treatment interruption and possible cessation of anticancer treatment. Underdosing may result in suboptimal anti-cancer effects and may increase the risk of cancer-related mortality. As it is practical nor feasible to perform therapeutic drug monitoring for all anti-cancer drugs, kidney function is used to guide drug dosing for those drugs whose primary mode of excretion is through the kidney. However, it is not well-established what method should be utilized to measure or estimate kidney function and the choice of method does influence treatment decisions regarding eligibility for anti-cancer drugs and their dose. In this review, we will provide an overview regarding the importance of drug dosing, the preferred method to determine kidney function and a practical approach to drug dosing of anticancer drugs.

Nephrotoxicity Associated with Novel Anticancer Agents (Aflibercept, Dasatinib, Nivolumab): Case Series and Nephrological Considerations

Cancer patients have an incidence of about 60% kidney disease development and are at elevated risk of acute renal damage. Kidney disease in these patients is frequently associated with nephrotoxicity from the ongoing oncological treatment. New anticancer therapeutic strategies, such as targeted therapies and immunotherapies, offer substantial benefits in the treatment of many neoplasms. However, their use is associated with significant nephrotoxicity, which qualitatively differs from that seen with traditional cytotoxic chemotherapy, while the underlying mechanisms are complex and still to be clearly defined. Nephrologists need to be knowledgeable about the array of such renal toxicities for effective collaboration with the oncologist in the prevention and management of kidney involvement. Renal adverse effects may range from asymptomatic proteinuria to renal failure, and their prompt identification and timely treatment is essential for optimal and safe care of the patient. In this article, after presenting clinical cases we discuss the differing renal toxicity of three novel anticancer agents (aflibercept, dasatinib, and nivolumab) and possible measures to counter it.