GFR Measurement and Chemotherapy Dosing in Patients with Kidney Disease and Cancer

Older age, CNS leukaemic involvement and induction tumour lysis increases the risk of methotrexate (MTX)-induced neurotoxicity in childhood acute lymphoblastic leukaemia/lymphoma: Experience from a tertiary care centre in South India

Methotrexate (MTX), although an indispensable part of contemporary treatment protocols for childhood acute lymphoblastic leukaemia (ALL)/lymphomas (LBL) in improving outcomes, can lead to serious neurotoxicity with long-term consequences. The aetiopathogenesis, predisposing factors and treatment for MTX-induced neurotoxicity are not yet well defined. The aim of our study was to detect the incidence, risk factors and to assess the overall outcomes of MTX-induced neurotoxicity among large cohort of paediatric ALL/LBL patients treated on a uniform protocol. We conducted retrospective audit of medical records of 622 consecutive children (≤14 years) diagnosed with ALL and LBL between January 2018 and December 2022 and treated on modified BFM-95 protocol at the Department of Pediatric Oncology, Regional Cancer Centre, Thiruvananthapuram. Risk factors predisposing to MTX-induced neurotoxicity were identified using binary logistic regression analysis. Forty-three children were diagnosed with MTX-induced neurotoxicity with an incidence rate of 6.9%. More than two-thirds of them had high-grade MTX-induced neurotoxicity CTCAE v5.0 with a median age of 9 years (range: 9 months to 14 years). Almost half of them developed MTX neurotoxicity during Protocol M followed by Phase-Ib consolidation (15%). Majority of these patients (84%, 36/43) were challenged again with MTX, with 11% (4/36) developing recurrence. Fifteen per cent had persistent neurological deficits at last follow-up. Univariate analysis found older age (age > 5 years) (p < 0.001), T-cell phenotype (p = 0.040), tumour lysis syndrome during induction (p < 0.001), baseline renal problems prior to MTX exposure (p < 0.001) and CNS leukaemic involvement (p < 0.003) to be significantly associated with MTX neurotoxicity. On multivariate analysis, older age (>5 years), tumour lysis during induction and CNS leukaemia retained statistical significance (p < 0.05). Methotrexate-induced neurotoxicity during paediatric acute lymphoblastic leukaemia/lymphoma therapy is a transient phenomenon in majority and re-challenge with MTX is generally safe. Older age children who develop tumour lysis during induction and CNS leukaemic involvement are at increased risk for MTX-induced neurotoxicity during ALL/LBL treatment.

Prevalence of renal insufficiency and factors associated among selected cancer patients on chemotherapy at Ocean Road Cancer Institute in Tanzania: a cross-sectional study

BACKGROUND

Cancer is among the leading cause of death worldwide. Chemotherapy is commonly used in cancer management and among the challenges in managing cancer patients is renal insufficiency (RI), which can be due to cancer or anticancer treatment and can be potentiated by different factors. Data regarding the prevalence of RI and associated factors in Tanzania is scanty. This study aims to assess the prevalence of RI and associated factors among selected cancer patients on chemotherapy.

METHODS

This analytical cross-sectional study was conducted at Ocean Road Cancer Institute (ORCI) in Dar es Salaam, Tanzania, from March to May 2023. The study included cancer patients on chemotherapy. Data was collected using semi-structured questionnaires whereby socio-demographics, clinical and laboratory data were recorded. Data was analyzed by using STATA version 15. Categorical data was presented as frequencies and percentages, and continuous data was summarized using means. A modified Poisson regression model was used to assess factors associated with RI. The p-values ≤ 0.05 was considered statistically significant.

RESULTS

Out of 354 patients, the majority (76.6%) were female. The enrolled patients' mean age was 53 ± 13.19 years. The proportion of cancer patients with RI was 62.2% with most (60%) having stage 2 and stage 3 (37.7%). Age, hypertension (HTN), human immunodeficiency virus (HIV), diabetes mellitus (DM) and non-steroidal anti-inflammatory drugs (NSAIDs) use were significantly associated with increased risk of RI (p ≤ 0.05).

CONCLUSION

This study showed that RI is common among cancer patients on chemotherapy. Age, HTN, DM, HIV and NSAIDS use were associated with RI. Close monitoring of kidney function is necessary for cancer patients with other factors associated with RI. Use of creatinine clearance (CrCl) rather than serum creatinine in estimating kidney function is important.

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.

Chapter 1: Evaluation of kidney function in patients undergoing anticancer drug therapy, from clinical practice guidelines for the management of kidney injury during anticancer drug therapy 2022

The prevalence of CKD may be higher in patients with cancer than in those without due to the addition of cancer-specific risk factors to those already present for CKD. In this review, we describe the evaluation of kidney function in patients undergoing anticancer drug therapy. When anticancer drug therapy is administered, kidney function is evaluated to (1) set the dose of renally excretable drugs, (2) detect kidney disease associated with the cancer and its treatment, and (3) obtain baseline values for long-term monitoring. Owing to some requirements for use in clinical practice, a GFR estimation method such as the Cockcroft-Gault, MDRD, CKD-EPI, and the Japanese Society of Nephrology's GFR estimation formula has been developed that is simple, inexpensive, and provides rapid results. However, an important clinical question is whether they can be used as a method of GFR evaluation in patients with cancer. When designing a drug dosing regimen in consideration of kidney function, it is important to make a comprehensive judgment, recognizing that there are limitations regardless of which estimation formula is used or if GFR is directly measured. Although CTCAEs are commonly used as criteria for evaluating kidney disease-related adverse events that occur during anticancer drug therapy, a specialized approach using KDIGO criteria or other criteria is required when nephrologists intervene in treatment. Each drug is associated with the different disorders related to the kidney. And various risk factors for kidney disease associated with each anticancer drug therapy.

Simultaneous magnetic resonance imaging of pH, perfusion and renal filtration using hyperpolarized 13C-labelled Z-OMPD

pH alterations are a hallmark of many pathologies including cancer and kidney disease. Here, we introduce [1,5-13C2]Z-OMPD as a hyperpolarized extracellular pH and perfusion sensor for MRI which allows to generate a multiparametric fingerprint of renal disease status and to detect local tumor acidification. Exceptional long T1 of two minutes at 1 T, high pH sensitivity of up to 1.9 ppm per pH unit and suitability of using the C1-label as internal frequency reference enables pH imaging in vivo of three pH compartments in healthy rat kidneys. Spectrally selective targeting of both 13C-resonances enables simultaneous imaging of perfusion and filtration in 3D and pH in 2D within one minute to quantify renal blood flow, glomerular filtration rates and renal pH in healthy and hydronephrotic kidneys with superior sensitivity compared to clinical routine methods. Imaging multiple biomarkers within a single session renders [1,5-13C2]Z-OMPD a promising new hyperpolarized agent for oncology and nephrology.

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.

The Nephrotoxicity of Drugs Used in Causal Oncological Therapies

In recent years, a dynamic development of oncology has been observed, resulting from the increasingly frequent occurrence of neoplasms and therefore, increasing population of patients. The most effective form of therapy for cancer patients is complex multidisciplinary specialized disease management, including nephro-oncology care. Different forms of renal function impairment are frequently diagnosed in cancer patients. They are caused by different co-morbidities existing before starting the oncologic treatment as well as the direct undesirable effects of this therapy which may cause temporary or irreversible damage of the urinary system-especially kidneys. According to different therapeutic programs, in such cases the degree of renal damage is often crucial for the possibility of further anti-cancer treatment. Medical personnel responsible for delivering care to oncology patients should be properly educated on current methods of prevention and treatment of renal complications resulting from anti-cancer therapy. The development of oncologic medicines design, including especially immuno-oncological agents, obliges us to learn new patomechanisms determining potential adverse effects, including renal complications. This publication is focused on the most important undesirable nephrotoxic effects of the frequently used anti-cancer drugs.

Cancer Drug Dosing in Chronic Kidney Disease and Dialysis

Patients with malignancies have a high prevalence of kidney disease and are often treated with antineoplastic agents that undergo kidney metabolism or excretion or clearance via renal replacement therapies. Thus, the dosing of these agents, including classic chemotherapeutic drugs, targeted therapies, and immunotherapy, must take into account patients' kidney function. In this review, we will discuss the pitfalls of accurate measurement of kidney function and how kidney disease affects both pharmacodynamic and pharmacokinetic properties of drugs. Lastly, we will discuss specific agents and summarize current dosing strategies for use in patients with chronic kidney disease and end-stage kidney disease.

Assessment of kidney function: clinical indications for measured GFR

In the vast majority of cases, glomerular filtration rate (GFR) is estimated using serum creatinine, which is highly influenced by age, sex, muscle mass, body composition, severe chronic illness and many other factors. This often leads to misclassification of patients or potentially puts patients at risk for inappropriate clinical decisions. Possible solutions are the use of cystatin C as an alternative endogenous marker or performing direct measurement of GFR using an exogenous marker such as iohexol. The purpose of this review is to highlight clinical scenarios and conditions such as extreme body composition, Black race, disagreement between creatinine- and cystatin C-based estimated GFR (eGFR), drug dosing, liver cirrhosis, advanced chronic kidney disease and the transition to kidney replacement therapy, non-kidney solid organ transplant recipients and living kidney donors where creatinine-based GFR estimation may be invalid. In contrast to the majority of literature on measured GFR (mGFR), this review does not include aspects of mGFR for research or public health settings but aims to reach practicing clinicians and raise their understanding of the substantial limitations of creatinine. While including cystatin C as a renal biomarker in GFR estimating equations has been shown to increase the accuracy of the GFR estimate, there are also limitations to eGFR based on cystatin C alone or the combination of creatinine and cystatin C in the clinical scenarios described above that can be overcome by measuring GFR with an exogenous marker. We acknowledge that mGFR is not readily available in many centres but hope that this review will highlight and promote the expansion of kidney function diagnostics using standardized mGFR procedures as an important milestone towards more accurate and personalized medicine.

Comparison of Equations To Estimate Glomerular Filtration Rate and Their Impact on Frequency of Cisplatin-associated Acute Kidney Injury

Background

Accurate estimation of kidney function is essential for patient selection and drug dosing in patients with cancer. eGFR equations are necessary for decision making and monitoring. Our aim was to identify which of these equations-estimated creatinine clearance (eCrCl) by Cockcroft-Gault (CG), eGFR by Modification of Diet in Renal Disease (eGFRMDRD), CKD Epidemiology Collaboration (eGFRCKD-EPI) or the recently proposed Janowitz-Williams equation (eGFRJ-W)-would be most suitable for GFR estimation among patients with cancer receiving cisplatin.

Methods

We assembled a cohort of 5274 patients with cancer treated with cisplatin-based chemotherapy at two large cancer centers. We ascertained the frequency of cisplatin-associated AKI (C-AKI) defined as a ≥0.3 mg/dl rise in serum creatinine over baseline. We compared baseline eGFR and eCrCl using Bland-Altman (B-A) plots, coefficients of variation (CV), and concordance correlation coefficients. We calculated the positive predictive value (PPV), negative predictive value (PPV), accuracy, and area under the curve (AUC).

Results

Patients were predominantly middle aged (median 58 years, IQR 49-66 years), overweight (median BMI 26.2, IQR 23.1-29.8 kg/m2), and White (88%), with a median baseline creatinine of 0.8 mg/dl and median cisplatin dose of 99 mg. C-AKI developed in 12% of the cohort. eGFRCKD-EPI had the highest PPV and AUC. eGFRCKD-EPI and eGFRMDRD, along with their BSA-modified counterparts, had the closest agreement with the lowest CV (7.2, 95% CI, 7.0 to 7.3) and the highest concordance. C-AKI was lowest when using eGFRCKD-EPI to define eGFR ≥60 ml/min per 1.73 m2.

Conclusions

On the basis of its superior diagnostic performance, eGFRCKD-EPI should be used to estimate GFR in patients being considered for cisplatin-based chemotherapy.

Defining cisplatin eligibility in patients with muscle-invasive bladder cancer

The current treatment paradigm for muscle-invasive bladder cancer (MIBC) consists of cisplatin-based neoadjuvant chemotherapy followed by local definitive therapy, or local definitive therapy alone for cisplatin-ineligible patients. Given that MIBC has a high propensity for distant relapse and is a chemotherapy-sensitive disease, under-utilization of chemotherapy is associated with suboptimal cure rates. Cisplatin eligibility criteria are defined for patients with metastatic bladder cancer by the Galsky criteria, which include creatinine clearance ≥60 ml/min. However, consensus is still lacking regarding cisplatin eligibility criteria in the neoadjuvant, curative MIBC setting, which continues to represent a substantial barrier to the standardization of patient care and clinical trial design. Jiang and colleagues accordingly suggest an algorithm for assessing cisplatin eligibility in patients with MIBC. Instead of relying on an absolute renal function threshold, their algorithm emphasizes a multidisciplinary and patient-centred approach. They also propose mitigation strategies to minimize the risk of cisplatin-induced nephrotoxicity in selected patients with impaired renal function. This new framework is aimed at reducing the inappropriate exclusion of some patients from cisplatin-based neoadjuvant chemotherapy (which leads to under-treatment) and harmonizing clinical trial design, which could lead to improved overall outcomes in patients with MIBC.