Pharmacology of Tyrosine Kinase Inhibitors: Implications for Patients with Kidney Diseases

Tyrosine kinase inhibitors (TKI) have introduced a significant advancement in cancer management. These compounds are administered orally, and their absorption holds a pivotal role in determining their variable efficacy. They exhibit extensive distribution within the body, binding strongly to both plasma and tissue proteins. Often reliant on efflux and influx transporters, TKI undergo primary metabolism by intestinal and hepatic cytochrome P450 enzymes, with nonkidney clearance being predominant. Owing to their limited therapeutic window, many TKI display considerable intraindividual and interindividual variability. This review offers a comprehensive analysis of the clinical pharmacokinetics of TKI, detailing their interactions with drug transporters and metabolic enzymes, while discussing potential clinical implications. The prevalence of kidney conditions, such as AKI and CKD, among patients with cancer is explored in their effect on TKI pharmacokinetics. Finally, the potential nephrotoxicity associated with TKI is also examined.

Afatinib-Induced Tumor Lysis Syndrome in Pulmonary Adenocarcinoma: A Case Report and Literature Review

Tumor lysis syndrome (TLS) is a potentially fatal oncological emergency that typically develops during the treatment of rapidly proliferating malignancies. It is infrequently reported in solid tumors, such as pulmonary adenocarcinoma. A 59-year-old male patient with shortness of breath presented with a 3.3 cm × 3.0 cm mass in the right upper lobe, along with massive right-sided pleural effusion. A percutaneous needle biopsy was performed, and a diagnosis of pulmonary adenocarcinoma with an epidermal growth factor receptor (EGFR) mutation was made. The patient was treated with afatinib because of the malignant pleural effusion and multiple metastases to the intrathoracic lymph nodes, left scapula, and brain. After 4 days of afatinib treatment, he developed oliguric acute kidney injury and progressively worsening dyspnea. Based on the clinical and laboratory findings, the patient was diagnosed with afatinib-induced TLS. To the best of our knowledge, this is the first reported case of afatinib-induced TLS in pulmonary adenocarcinoma.

Effectiveness of leukapheresis on early survival in acute myeloid leukemia: An observational propensity score matching cohort study

BACKGROUND

The association between leukapheresis (LK) as a treatment option for hyperleukocytosis (HL) in patients with acute myeloid leukemia (AML) remains controversial.

METHODS

Data were extracted from the electronic medical record for 2801 patients with AML between April 2009 and December 2019. LK was performed when the leukocyte count was ≥100 × 109 /L at the time initial bone marrow examination.

RESULTS

A comparison between the patients with HL in the non-LK (n = 1579) and LK (n = 208) groups revealed survival probabilities (%) of 93.2% and 90.4% (P = .130) for day 30 (D30), 85.4% and 84.2% (P = .196) for D60, and 83.6% and 80.8% (P = .258) for D90, respectively. After propensity score matching, a comparison between the patients with HL in the non-LK (n = 192) and LK (n = 192) groups revealed survival probabilities (%) of 83.9% and 91.2% (P = .030) for D30, 75.0% and 84.9% (P = .015) for day 60 (D60), and 62.4% and 81.3% (P = .034) for day 90 (D90), respectively. After D150, the observed effect of LK appeared to be mitigated without a survival benefit.

DISCUSSION

LK was associated with improved early survival outcomes at D30, D60, and D90 among patients with AML exhibiting HL. Thus, it may be considered a treatment option for reducing cell mass in such patients.

Rasburicase in treating tumor lysis syndrome: An umbrella review

Tumor lysis syndrome (TLS) remains a debilitating cause of hospitalization and death in patients with cancer and is a significant challenge for healthcare providers despite advancements in its management. This umbrella review analyzed the results of meta-analyses on the use of rasburicase in the treatment of patients with cancer. A literature search was performed of five databases (PubMed, Google Scholar, Cochrane Library, Scopus, Global Index Medicus, and ScienceDirect) for articles with full texts available online. A measurement tool to assess systematic reviews 2 (AMSTAR 2) was used to assess the quality of the included studies, and Review Manager software was used to conduct all statistical analyses. The systematic search identified eight relevant meta-analyses, with primary analyses including outcome data that analyzed mortality, renal failure, and comparisons with allopurinol. The pooled data showed that rasburicase effectively reduced TLS development and serum uric acid levels in children and adults with malignancies. Most outcomes did not differ significantly compared with those of allopurinol. Future trials should focus on the cost-effectiveness of rasburicase compared to that of allopurinol while including high-, intermediate-, and low-risk patients. Rasburicase is safe and effective for managing patients with TLS. However, recent large-scale meta-analyses have reported conflicting results. Most meta-analyses were graded as low to critically low as per AMSTAR 2. The analysis revealed that the benefit of rasburicase did not differ significantly from that of allopurinol, which has higher cost-effectiveness and fewer side effects.

Rescue Therapies for AKI in Onconephrology: Rasburicase and Glucarpidase

Tumor lysis syndrome (TLS) and high-dose methotrexate (HD MTX) toxicity can present with potentially severe complications, including acute kidney injury, in patients with malignancy. Guidelines for using rasburicase and glucarpidase as rescue therapies for TLS and HD MTX toxicity, respectively, are widely used by clinicians intending to mitigate organ toxicity and decrease morbidity and mortality as a consequence of cancer therapy. This review discusses the pathogenesis of TLS and HD MTX-associated toxicity, to understand the mechanism of action of these therapeutic agents and to review the currently available evidence supporting their use.

Massive hyperphosphatemia in clinical tumor lysis syndrome during prophylactic rasburicase use: risk factors and treatment options

We report the case of a 76-year-old female with diffuse large B cell lymphoma who developed tumor lysis syndrome (TLS) and subsequent acute kidney injury (AKI) due to massive hyperphosphatemia during the prophylactic use of rasburicase. Our case showed no hyperphosphatemia before chemotherapy but had elevated uric acid and creatinine levels and unilateral hydronephrosis due to paraaortic lymphadenopathy. TLS risk was classified as high risk because of bulky mass, LDH elevation, and renal disturbance. With rasburicase use, uric acid was completely controlled but massive hyperphosphatemia and, subsequently, AKI developed. Immediate kidney replacement therapy led to improvement of hyperphosphatemia and AKI. In the rasburicase era, hyperphosphatemia has been a key target for preventing and treating TLS. Renal replacement therapy is the only effective option for lowering hyperphosphatemia and treating AKI.

[Glomerulopathy in kidney neoplasms: frequency of occurrence, structure of morbidity]

BACKGROUND

Malignant neoplasms of the kidneys are among the 10 most common oncological diseases in Russia, in which various kidney lesions can occur, including glomerulopathy. Glomerular pathology can be an independent nosology, a manifestation of paraneoplastic syndrome or metabolic disturbances.

OBJECTIVE

Evaluation of the incidence and structure of glomerulopathies in patients with kidney neoplasms.

MATERIAL AND METHODS

We analyzed 141 samples with a tumor obtained during nephrectomy. To diagnose glomerular pathology, a fragment of the kidney parenchyma was examined at a distance of at least 4 cm from the tumor border. Histological slides were stained with hematoxylin and eosin, methenamine silver, trichrome Masson, Congo red, PAS reaction was performed. Immunofluorescent microscopy was performed with antibodies to IgA, IgG, IgM, C3c, C1q, Kappa light chain and Lambda light chain. Samples for electron microscopy were contrasted with a solution of 0.1% lead citrate.

RESULTS

Malignant neoplasms were diagnosed in 130 (92.2%) patients, benign ones - in 11 (7.8%) patients. In 59 patients with kidney tumors, glomerulopathies were detected, which amounted to 41.8%. All cases of glomerulopathies were diagnosed in combination with carcinomas of the kidneys and renal pelvis. Among 59 cases of glomerulopathy, diabetic nephropathy was diagnosed in 44 (74.6%) cases, IgA nephropathy - in 7 (11.9%) cases, membranous nephropathy - in 1 (1.6%), minimal change disease - in 2 (3.4%), focal segmental glomerulosclerosis - in 5 (8.5%).

CONCLUSION

The study demonstrates a high incidence of glomerulopathies in patients with malignant kidney tumors. The performed work emphasizes the importance of an in-depth morphological study of the kidneys in the presence of a tumor with an integrated approach to the treatment of patients.

Tumor Lysis Syndrome: An Endless Challenge in Onco-Nephrology

Tumor lysis syndrome (TLS) is a common cause of acute kidney injury in patients with malignancies, and it is a frequent condition for which the nephrologist is consulted in the case of the hospitalized oncological patient. Recognizing the patients at risk of developing TLS is essential, and so is the prophylactic treatment. The initiation of treatment for TLS is a medical emergency that must be addressed in a multidisciplinary team (oncologist, nephrologist, critical care physician) in order to reduce the risk of death and that of chronic renal impairment. TLS can occur spontaneously in the case of high tumor burden or may be caused by the initiation of highly efficient anti-tumor therapies, such as chemotherapy, radiation therapy, dexamethasone, monoclonal antibodies, CAR-T therapy, or hematopoietic stem cell transplantation. It is caused by lysis of tumor cells and the release of cellular components in the circulation, resulting in electrolytes and metabolic disturbances that can lead to organ dysfunction and even death. The aim of this paper is to review the scientific data on the updated definition of TLS, epidemiology, pathogenesis, and recognition of patients at risk of developing TLS, as well as to point out the recent advances in TLS treatment.

Metabolic Profiling of Thymic Epithelial Tumors Hints to a Strong Warburg Effect, Glutaminolysis and Precarious Redox Homeostasis as Potential Therapeutic Targets

Simple Summary

Thymomas and thymic carcinomas (TCs) are malignant thymic epithelial tumors (TETs) with poor outcome, if non-resectable. Metabolic signatures of TETs have not yet been studied and may offer new therapeutic options. This is the first metabolomics investigation on thymic epithelial tumors employing nuclear magnetic resonance spectroscopy of tissue samples. We could detect and quantify up to 37 metabolites in the major tumor subtypes, including acetylcholine that was not previously detected in other non-endocrine cancers. A metabolite-based cluster analysis distinguished three clinically relevant tumor subgroups, namely indolent and aggressive thymomas, as well as TCs. A metabolite-based metabolic pathway analysis also gave hints to activated metabolic pathways shared between aggressive thymomas and TCs. This finding was largely backed by enrichment of these pathways at the transcriptomic level in a large, publicly available, independent TET dataset. Due to the differential expression of metabolites in thymic epithelial tumors versus normal thymus, pathways related to proline, cysteine, glutathione, lactate and glutamine appear as promising therapeutic targets. From these findings, inhibitors of glutaminolysis and of the downstream TCA cycle are anticipated to be rational therapeutic strategies. If our results can be confirmed in future, sufficiently powered studies, metabolic signatures may contribute to the identification of new therapeutic options for aggressive thymomas and TCs.

Abstract

Thymomas and thymic carcinomas (TC) are malignant thymic epithelial tumors (TETs) with poor outcome, if non-resectable. Metabolic signatures of TETs have not yet been studied and may offer new therapeutic options. Metabolic profiles of snap-frozen thymomas (WHO types A, AB, B1, B2, B3, n = 12) and TCs (n = 3) were determined by high resolution magic angle spinning 1H nuclear magnetic resonance (HRMAS 1H-NMR) spectroscopy. Metabolite-based prediction of active KEGG metabolic pathways was achieved with MetPA. In relation to metabolite-based metabolic pathways, gene expression signatures of TETs (n = 115) were investigated in the public “The Cancer Genome Atlas” (TCGA) dataset using gene set enrichment analysis. Overall, thirty-seven metabolites were quantified in TETs, including acetylcholine that was not previously detected in other non-endocrine cancers. Metabolite-based cluster analysis distinguished clinically indolent (A, AB, B1) and aggressive TETs (B2, B3, TCs). Using MetPA, six KEGG metabolic pathways were predicted to be activated, including proline/arginine, glycolysis and glutathione pathways. The activated pathways as predicted by metabolite-profiling were generally enriched transcriptionally in the independent TCGA dataset. Shared high lactic acid and glutamine levels, together with associated gene expression signatures suggested a strong “Warburg effect”, glutaminolysis and redox homeostasis as potential vulnerabilities that need validation in a large, independent cohort of aggressive TETs. If confirmed, targeting metabolic pathways may eventually prove as adjunct therapeutic options in TETs, since the metabolic features identified here are known to confer resistance to cisplatin-based chemotherapy, kinase inhibitors and immune checkpoint blockers, i.e., currently used therapies for non-resectable TETs.

Hematological Malignancies and the Kidney

The incidence of hematologic malignancies is on the rise worldwide. Kidney disease is ubiquitous in patients with hematologic malignancies, encompassing a wide spectrum of disorders involving each kidney compartment, including the vasculature, tubules, interstitium, and glomerulus, and there is significant overlap of kidney involvement with each hematologic malignancy. Vascular disorders include both microvascular and macrovascular damage, via thrombotic microangiopathy, hyperleukocytosis, hyperviscosity, and cryoglobulinemia. The tubulointerstitial compartment may be affected by prerenal azotemia and acute tubular injury, but malignant infiltration, tumor lysis syndrome, extramedullary hematopoiesis, cast nephropathy, granulomatous interstitial nephritis, and lysozymuria should be considered in certain populations. Obstructive uropathy may occur due to nephrolithiasis or retroperitoneal fibrosis. Glomerular disorders, including membranoproliferative, membranous, minimal change, and focal segmental glomerulosclerosis, can rarely occur. By understanding how each compartment may be affected, care can best be optimized for these patients. In this review, we summarize the widely varied etiologies of kidney diseases stratified by kidney compartment and hematologic malignancy, focusing on demographics, pathology, pathophysiology, mechanism, and outcomes. We conclude with common electrolyte abnormalities associated with hematologic malignancies.

Fluid overload and acute kidney injury in children with tumor lysis syndrome

AIM

Tumor lysis syndrome (TLS) is a common oncologic emergency among patients with pediatric hematologic malignancies. The mainstay of TLS management is aggressive intravenous hydration. However, the epidemiology of fluid overload (FO) and acute kidney injury (AKI) in this population is understudied. In this study, we aimed to describe the incidence, severity, and complications of FO and AKI among pediatric patients with TLS.

METHODS

We completed a single-center retrospective cohort study of pediatric patients with a new diagnosis of hematologic malignancy over a 10-year period. Patients with TLS were analyzed in two groups based on the severity of AKI and FO. Charts were reviewed for complications associated with AKI and FO including hypoxemia, mechanical ventilation, hyponatremia, pulmonary edema, pediatric intensive care (PICU) admission, and need for renal replacement therapy (RRT).

RESULTS

We analyzed 56 patients with TLS for FO and AKI. We found severe FO (≥10%) occurred in 35.7% (n = 20). PICU admission occurred in 35% of patients with severe FO compared to 8.3% in those with mild/moderate FO <10% (p = .013). Complications of hypoxemia (30% vs. 5.6%, p = .012) and pulmonary edema (25% vs. 2.8%, p = .010) were more common among those with severe FO. AKI occurred in 37.5% (n = 21) patients and resulted in a significant increase in PICU admission and requirement for RRT (p = .001 and <.001, respectively).

CONCLUSION

Our results show FO and AKI are common, and often unrecognized complications of TLS associated with increased morbidity. Prospective, multicenter studies are needed to further dissect the burden of FO and AKI within this vulnerable population.

Therapeutics for paediatric oncological emergencies

Background

With advancements in the field of oncology, cancer survival rates have improved dramatically but modern cancer treatments also come with an increasing number of disease and treatment-associated complications. This article provides an updated narrative review on the pathophysiology, clinical presentations and latest management strategies for common paediatric oncological emergencies.

Methods

An extensive PubMed^® search of all human studies in the English literature was performed in Clinical Queries for different oncology syndromes and conditions using the following Medical Subject Headings: “tumour lysis syndrome”, “hyperleukocytosis”, “disseminated intravascular coagulation”, “superior mediastinal syndrome”, “superior vena cava syndrome”, “sepsis”, “severe inflammatory response syndrome”, “acute respiratory distress syndrome”, “posterior reversible encephalopathy syndrome” and “reversible posterior leukoencephalopathy syndrome”. Categories were limited to clinical trials and reviews for ages from birth to 18 years.

Results

The general description, presentation and management of these oncologic emergencies are systematically described. Early recognition along with prompt and proactive treatment can reduce the chances of potential complications and improve the clinical outcomes, thereby improving not only survival rates in oncology patients but also their clinical outcomes and quality of life.

Conclusions

Oncologic emergencies are associated with significant mortality and morbidity. Healthcare professionals involved with the care of oncology patients must be vigilant of these emergencies.

Spontaneous tumour lysis syndrome in multiple myeloma with loss of 17p13.1, t(4;14) and monosomy 13

Tumour lysis syndrome (TLS) is a constellation of metabolic derangements caused by lysis of tumour cells. It is an oncological emergency that is considered a rare occurrence in multiple myeloma (MM) and usually occurs after patients have been treated with chemotherapy. We describe a very rare case of TLS occurring before the official diagnosis or treatment of MM. We report infrequent karyotype abnormalities, including loss of 17p13.1 (TP53 mutation), t(4;14) (FGFR3/IGH fusion) and monosomy 13, that have not been explicitly described in association with spontaneous tumour lysis syndrome (STLS) in MM. This case adds to the sparse literature available on STLS in MM, which is a life-threatening situation requiring urgent medical intervention.

Onconephrology: The intersections between the kidney and cancer

Onconephrology is a new subspecialty of nephrology that recognizes the important intersections of kidney disease with cancer. This intersection takes many forms and includes drug-induced nephrotoxicity, electrolyte disorders, paraneoplastic glomerulonephritis, and the interactions of chronic kidney disease with cancer. Data clearly demonstrate that, when patients with cancer develop acute or chronic kidney disease, outcomes are inferior, and the promise of curative therapeutic regimens is lessened. This highlights the imperative for collaborative care between oncologists and nephrologists in recognizing and treating kidney disease in patients with cancer. In response to this need, specific training programs in onconephrology as well as dedicated onconephrology clinics have appeared. This comprehensive review covers many of the critical topics in onconephrology, with a focus on acute kidney injury, chronic kidney disease, drug-induced nephrotoxicity, kidney disease in stem cell transplantation, and electrolyte disorders in patients with cancer.

COVID-19-Associated Acute Kidney Injury and Quantified Protein Catabolic Rate: A Likely Effect of Cytokine Storm on Muscle Protein Breakdown

Rationale & Objectives

Previously we reported a cohort of patients with coronavirus disease 2019 (COVID-19)–associated acute kidney injury (AKI) with striking biochemical evidence of tissue breakdown in the absence of apparent rhabdomyolysis. We sought to quantify the extent of tissue catabolism in similar patients.

Study Design

During acute peritoneal dialysis (PD) in patients with COVID-19–associated AKI, we measured urea Kt/V adequacy and calculated the daily urea nitrogen generation rate while quantifying daily protein intake.

Setting & Population

We did calculations in 8 patients with COVID-9–associated AKI undergoing acute PD at Mount Sinai Hospital in New York City. As a comparator, we obtained urea kinetic parameters from our database of ambulatory patients receiving maintenance PD.

Exposure or Predictors

8 patients with COVID-19–associated AKI undergoing acute PD.

Outcomes

Urea nitrogen generation rate in relation to daily protein intake.

Analytical Approach

Urea nitrogen generation rate from urea kinetics was related to measured daily dietary protein intake in these patients and we compared it with this relationship in ambulatory maintenance PD patients for whom both parameters were calculated from urea kinetics.

Results

Urea nitrogen generation rate in patients with AKI was 10.2 ± 5 g/d, which is more than 2-fold higher than for stable outpatients receiving maintenance PD (4.7 ± 3 g/d) despite similar dietary protein intake (74.8 ± 11 vs 67.2 ± 29 g/d, respectively). This strongly suggests endogenous protein breakdown, probably from muscle. Urea nitrogen generation rate in these patients with AKI corresponds to 315 g/d of ongoing muscle breakdown and cumulative 2.5 kg of muscle breakdown during the early course of AKI.

Limitations

Small number of participants and assumptions in comparing urea nitrogen generation rate with protein intake.

Conclusions

In highly catabolic patients, an endogenous source of urea generation such as muscle protein breakdown seems to be the most likely explainable cause for our findings. This is the first study that we are aware of to quantify the degree of endogenous protein breakdown induced by COVID-19–related cytokine storm.

Lung Cancer Cell-Derived Secretome Mediates Paraneoplastic Inflammation and Fibrosis in Kidney in Mice

Simple Summary

Paraneoplastic nephrotic syndrome is a complication arising in lung cancer patients. In the present study, we established an LLC1 cell orthotopic xenograft C57BL/6 mice model to translation paraneoplastic nephrotic syndrome (PNS). The pathological aspects of PNS were characterized in TGF-β signaling-engaged renal fibrosis, and renal inflammation with IL-6 expression in kidney. To reveal how the lung cancer cells remotely drive pathogenic progression, secretome derived from LLC1 cells and A549 cells were proteomically profiled. Additionally, the secretome profiling was subjected to diseases and biofunctions assessment by Ingenuity Pathway analysis (IPA). As matter of secretome profiling and IPA prediction, the Fibronectin, C1r, and C1s are potential of nephrotoxicity linked to paraneoplastic effects on glomerular pathogenesis in these lung cancer mice.

Abstract

Kidney failure is a possible but rare complication in lung cancer patients that may be caused by massive tumor lysis or a paraneoplastic effect. Clinical case reports have documented pathological characteristics of paraneoplastic syndrome in glomeruli, but are short of molecular details. When Lewis lung carcinoma 1 (LLC1) cells were implanted in mice lungs to establish lung cancer, renal failure was frequently observed two weeks post orthotopic xenograft. The high urinary albumin-to-creatinine ratio (ACR) was diagnosed as paraneoplastic nephrotic syndrome in those lung cancer mice. Profiling the secretome of the lung cancer cells revealed that the secretory proteins were potentially nephrotoxic. The nephrotoxicity of lung cancer-derived secretory proteins was tested by examining the pathogenic effects of 1 × 10⁶, 2 × 10⁶, and 5 × 10⁶ LLC1 cell xenografts on the pathogenic progression in kidneys. Severe albuminuria was present in the mice that received 5 × 10⁶ LLC1 cells implantation, whereas 10⁶ cell and 2 × 10⁶ cell-implanted mice have slightly increased albuminuria. Pathological examinations revealed that the glomeruli had capillary loop collapse, tumor antigen deposition in glomeruli, and renal intratubular casts. Since IL-6 and MCP-1 are pathologic markers of glomerulopathy, their distributions were examined in the kidneys of the lung cancer mice. Moderate to severe inflammation in the kidneys was correlated with increases in the number of cells implanted in the mice, which was reflected by renal IL-6 and MCP-1 levels, and urine ACR. TGF-β signaling-engaged renal fibrosis was validated in the lung cancer mice. These results indicated that lung cancer cells could provoke inflammation and activate renal fibrosis.

Preventive strategies for acute kidney injury in cancer patients

Acute kidney injury (AKI) is a common complication of cancer that occurs in up to 50% of neoplastic patients during the natural history of their disease; furthermore, it has a huge impact on key outcomes such as overall prognosis, length of hospitalization and costs. AKI in cancer patients has different causes, either patient-, tumour- or treatment-related. Patient-related risk factors for AKI are the same as in the general population, whereas tumour-related risk factors are represented by compression, obstruction, direct kidney infiltration from the tumour as well by precipitation, aggregation, crystallization or misfolding of paraprotein (as in the case of multiple myeloma). Finally, treatment-related risk factors are the most common observed in clinical practice and may present also with the feature of tumour lysis syndrome or thrombotic microangiopathies. In the absence of validated biomarkers, a multidisciplinary clinical approach that incorporates adequate assessment, use of appropriate preventive measures and early intervention is essential to reduce the incidence of this life-threatening condition in cancer patients.

Bortezomib administration is a risk factor associated with the development of tumor lysis syndrome in male patients with multiple myeloma: a retrospective study

BACKGROUND

Novel agents such as proteasome inhibitors have been developed for several years to treat multiple myeloma. Although multiple myeloma is a low-risk disease for developing tumor lysis syndrome (TLS), treatment with these novel therapies might increase TLS risk. Previous studies, mostly case reports or case series, have reported bortezomib-induced TLS in patients with multiple myeloma. This study aimed to investigate risk factors associated with TLS development in multiple myeloma patients.

METHODS

We retrospectively investigated incidences of laboratory and clinical TLS (LTLS and CTLS, respectively) in patients who received primary therapy for treatment-naive, symptomatic multiple myeloma between May 2007 and January 2018. We used multivariate logistic regression analyses to evaluate the associations between TLS and several parameters previously reported to be associated with increased risk.

RESULTS

This study included 210 patients with multiple myeloma, of which ten (4.8%) had LTLS and seven (3.3%) had CTLS. The characteristics of the administered anticancer or prophylactic antihyperuricemic agents were similar between patients with and without TLS. Multivariate analyses revealed that TLS was most strongly associated with bortezomib-containing therapy (odds ratio = 3.40, P = 0.069), followed by male sex (odds ratio = 2.29, P = 0.153). In a subgroup analysis focused on men, treatment with bortezomib-containing therapy was significantly associated with increased risk of TLS (odds ratio = 8.51, P = 0.046).

CONCLUSION

In the present study, we investigated the risk factors associated with TLS development in 210 multiple myeloma patients, which, to the best of our knowledge, is the largest number of patients reported to date. Furthermore, this study is the first to evaluate TLS risk factors in MM by adjusting for the effects of potential confounding factors in patients' backgrounds. Consequently, we found that bortezomib-containing therapy increases the risk of TLS in male patients with multiple myeloma. TLS risk should be evaluated further in low-risk diseases such as multiple myeloma, since a significant number of novel therapies can achieve high antitumor responses.

A Rare Case of T-Cell Lymphoma Presenting With Bilateral Nephrolithiasis and Acute Renal Failure

We present the rare case of a young boy who was found to have T-cell lymphoma after presenting with flank pain and bilateral nephrolithiasis. He initially underwent bilateral ureteral stent placement but returned with oliguria and acute renal failure. His subsequent workup revealed lymphoma involving both kidneys. He was started on chemotherapy for his lymphoma and dialysis for his renal failure. His stones ultimately dissolved with aggressive hydration and correction of serum uric acid levels. In this report, we discuss the identification and management of this rare condition.

Rasburicase in hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli: a report of nine cases

BACKGROUND

Hyperuricemia might induce additional renal damage in children with hemolytic uremic syndrome related to Shiga toxin-producing Escherichia coli (STEC-HUS). A few case reports have shown rasburicase to be effective in decreasing serum uric acid (UA) and improving renal function. However, there is only one report on the use of rasburicase in a child with STEC-HUS, which shows satisfactory results. We describe here the safety and efficacy of rasburicase in nine additional cases.

CASE-DIAGNOSIS/TREATMENT

Data from 9 children (5 females, median age 2 years) who received rasburicase were reviewed. At admission, 6 were dehydrated and 3 euvolemic. Dehydrated patients received saline solution and afterwards, as well as for those initially euvolemic, we aimed to keep a neutral fluid balance. Despite this, urine output did not increase. Baseline creatinine was 3.35 mg/dL (1.47-9.1) and UA 11.4 mg/dL (8.3-19.2). A single dose of rasburicase (0.2 mg/kg) was given 6-8 h after admission, which reduced UA levels to 1.8 mg/dL (0.3-5, p = 0.009) on the next day. However, renal parameters worsen and dialysis had to be initiated. Then, while still on dialysis, a UA rebound occurred in all cases reaching a peak of 8.9 mg/dL (4.5-13.8). Just after a steady increase in urine output, a sustained decline in UA levels concomitantly occurred with an improvement in renal function. At discharge, all patients reached normal UA levels. No side effects were recorded.

CONCLUSIONS

Administration of rasburicase in children with STEC-HUS was safe but failed to provide any significant benefit despite fall in serum UA levels.

Pembrolizumab-axitinib-induced tumor lysis syndrome in a patient with metastatic renal cancer

Tumor lysis syndrome is uncommon in solid tumors but with the use of immunotherapy (checkpoint inhibitors) their incidence is increasing. Physicians need to take adequate precautions while treating patients with immunotherapy. The findings of our case report will help improve our current understanding of tumor lysis syndrome specially in solid tumors and will help in developing multidisciplinary treatment and prophylaxis strategies for this uncommon, but potentially fatal complication.

A rare cause of tumour lysis syndrome and acute kidney injury

Tumour lysis syndrome is rare in solid malignancies. Here, we report a case of tumour lysis syndrome and acute kidney injury in a 23-year-old female with gestational trophoblastic neoplasia. Hydration and early dialysis therapy were started with good recovery. On follow up she progressed to chronic kidney disease. After 6 years of follow up, the patient conceived and delivered successfully.

Tumor lysis syndrome in childhood malignancies

Background

Tumor lysis syndrome (TLS) is the most common life-threatening oncological emergency encountered by physicians treating children with lymphoproliferative malignancies. Healthcare providers should be aware of the condition in order to prevent occurrence and prompt timely management to avoid severe consequences.

Objective

To provide an update on the current understanding, evaluation, and management of tumor lysis syndrome in childhood malignancies.

Methods

A PubMed search was performed in Clinical Queries using the keywords ‘tumor lysis syndrome’ and ‘malignancies’ with Category limited to clinical trials and reviews for ages from birth to 18 years.

Results

There were 22 clinical trials and 37 reviews under the search criteria. TLS is characterized by acute electrolyte and metabolic disturbances resulting from massive and abrupt release of cellular contents into the circulation due to breakdown of tumor cells. If left untreated, it can lead to multiorgan compromise and eventually death. Apart from close monitoring and medical therapies, early recognition of risk factors for development of TLS is also necessary for successful management.

Conclusions

Prophylactic measures to patients at risk of TLS include aggressive fluid management and judicious use of diuretics and hypouricemic agents. Both allopurinol and urate oxidase are effective in reducing serum uric acid. Allopurinol should be used as prophylaxis in low-risk cases while urate oxidase should be used as treatment in intermediate to high-risk cases. There is no evidence on better drug of choice among different urate oxidases. The routine use of diuretics and urine alkalinization are not recommended. Correction of electrolytes and use of renal replacement therapy may also be required during treatment of TLS.

A diagnostician's field guide to crystalline nephropathies

The kidney's role in filtration of blood and production of urine occurs via a combination of size and charge filtration at the glomerular basement membrane and resorption and excretion of molecules through a complex tubular system embedded within an ion gradient. This delicate system provides the kidney with a unique propensity for substrate saturation and crystal nucleation within the nephron. While crystalline nephropathies may seem exotic to the uninitiated, they are comprised of easily recognizable morphologies and generally lack complicated classification schemas. Additionally, unlike many intrinsic kidney diseases, crystalline nephropathies are often associated with systemic conditions that, upon further investigation, may elucidate critically important information. This review focuses on practical, diagnostically relevant and high yield information that can be utilized by diagnosticians. Our hope is to equip the reader who reviews renal tissue with a practical toolkit that they feel empowered to use when faced with crystal formation in a kidney biopsy, pre-implantation biopsy, or nephrectomy specimen. Short Abstract The kidney's role in filtration of blood and production of urine provides a unique propensity for substrate saturation and crystal nucleation within the nephron. While crystalline nephropathies may seem exotic to the uninitiated, they are comprised of easily recognizable morphologies and generally lack complicated classification. Additionally, crystalline nephropathies are often associated with systemic conditions that, upon further investigation, may elucidate critically important information.

Acute Liver Failure as the Leading Manifestation of Spontaneous Tumour Lysis Syndrome in a Patient with NonHodgkin Lymphoma: Do Current Diagnostic Criteria of Tumour Lysis Syndrome Need Re-Evaluation?

Tumour lysis syndrome (TLS) is a group of pathophysiological processes caused by rapid degradation of tumour cells with subsequent release of intracellular contents into the extracellular space. It is characterized by the development of systemic metabolic disturbances with or without clinical manifestations. The process usually occurs in highly proliferative, large tumours after induction of cytotoxic therapy. Rarely, however, spontaneous TLS can develop, as well as signs of multiorgan failure triggered by an excessive metabolic load and sterile inflammation. The combination of the aforementioned is thus quite unique. Here, we present a 63-year-old male in which spontaneous TLS was accompanied with acute liver failure and delineated underlying nonHodgkin lymphoma. Initial laboratory findings included hyperkalaemia, hyperphosphataemia, hypocalcaemia, uraemia, and increased creatinine levels indicating the onset of TLS with acute kidney injury. Moreover, the patient showed signs of jaundice, coagulopathy, and hepatic encephalopathy. Development of TLS with multiorgan failure prompted rapid initiation of critical care management, including vigorous intravenous fluid therapy, allopurinol treatment, high flow continuous venovenous haemodiafiltration, and commencement of chemotherapy. The case highlights the possibility of TLS as a differential diagnosis in patients presenting with multiorgan failure and the importance of early detection of this potentially challenging and fatal diagnosis.

Current understanding of tumor lysis syndrome

Tumor lysis syndrome (TLS) is an oncologic emergency from the intracellular release of material in lysing malignant cells. The earlier it is treated, the less likely it is to be harmful to an individual and spread through the body. Common complications of TLS include arrhythmias, which are caused by hypocalcemia or hyperkalemia, renal failures due to hyperuricemia or hyperphosphatemia, and seizures. Furthermore, the risk to develop TLS varies widely based on several factors including factors that are related to disease, the patient, and the treatment of the patient. Laboratory data can be used to gauge the severity of TLS based on patient serum levels for specific markers. On the contrary, evidence of TLS via radiological imaging and electrocardiogram findings has been a limited way to evaluate TLS, indicating the need for further research in this area. Common trends of treatment have also been seen in the past several years, evident by case studies seen in the following literature review.

Evaluation of Rasburicase Use in the Fraser Health Authority: A Retrospective Review

BACKGROUND

Rasburicase, a recombinant urate oxidase, is restricted in the Fraser Health Authority (FHA) to the "treatment of acute or at high risk of tumour lysis syndrome [TLS], when other therapeutic options are not suitable". The manufacturer's recommended dosage is 0.2 mg/kg daily for up to 7 days. Given the high cost of this drug, several studies have investigated other strategies and found that a single dose, repeated as needed, is effective in reducing serum uric acid. However, there are currently no guidelines in FHA for the use of rasburicase, which may result in different prescribing practices within the health authority.

OBJECTIVES

To describe the prescribing of rasburicase in FHA, including indications and doses, and to report the uric acid-lowering effects of rasburicase and any clinical outcomes, such as dialysis or death.

METHODS

This retrospective descriptive chart review included adult patients receiving care in FHA for whom rasburicase was prescribed between June 1, 2010, and November 30, 2016. Descriptive statistics were used to summarize patient characteristics and results.

RESULTS

The prescribing practices for rasburicase in this health authority were largely inconsistent, but the most common dose administered was 3 mg (8/12 [67%] among those receiving rasburicase for prophylaxis and 9/32 [28%] among those receiving rasburicase for treatment; combined total 17/44 or 39%). Regardless of dose, rasburicase reduced serum uric acid levels to less than 476 μmol/L and decreased the risk of TLS.

CONCLUSIONS

Having a uniform approach-involving a single dose that can be repeated as needed-for prevention and treatment of elevated serum uric acid levels could result in sufficient reduction of uric acid levels with fewer doses and lower cost. The results of this study support the need for a resource in FHA to guide and standardize the use of rasburicase.

Acute kidney injury as initial presentation of renal lymphoma: Diagnostic and therapeutic challenges in a resource-limited setting

Non-Hodgkin’s lymphoma is reportedly common in Africa; however, there is limited data on renal involvement. Acute kidney injury only at presentation is rare for lymphoproliferative malignancies. A 7-year old presented to our facility with a 2-week history of progressive abdominal distension and pain, examination revealed anasarca and hypertension. On further evaluation, there were bilateral nephromegaly, acute kidney injury (AKI) and cytomorphological findings suggestive of lymphoma. Patient management was mostly supportive, and evolution was unfavourable leading to his demise. We discuss diagnostic and therapeutic challenges due to unavailability of state-of-the-art facilities in resource-constrained settings.

Tumor lysis syndrome following cabazitaxel administration for metastatic castration-resistant prostate cancer: A case report

Introduction

Tumor lysis syndrome is a rare and potentially fatal complication of oncological treatment. It is characterized by biochemical changes associated with the rapid lysis of malignant cells, usually after chemotherapy. Tumor lysis syndrome is typically noted in patients with hematological malignancies, and it rarely occurs in patients with solid tumors.

Case presentation

We report a case of tumor lysis syndrome after cabazitaxel administration for metastatic castration‐resistant prostate cancer. To our knowledge, tumor lysis syndrome after cabazitaxel therapy has not been reported previously. The patient was a 77‐year‐old man who developed clinical tumor lysis syndrome after a single dose of cabazitaxel for metastatic castration‐resistant prostate cancer. He was treated with hydration and the recombinant uricolytic agent rasburicase, and his condition improved.

Conclusion

It is extremely important to assess the risk factors for tumor lysis syndrome and to perform active prevention procedures in order to avoid fatal outcomes. It may be beneficial to use rasburicase in patients with established tumor lysis syndrome.

Stability studies of two compounded solutions potentially used in tumor lysis syndrome

OBJECTIVE

The aim of the study was to determine the stability of two non-commercially produced solutions: 1.68% sodium bicarbonate in 5% glucose (BIC solution) and 1.6% calcium chloride in 0.9% sodium chloride (CAL solution), which can be used to treat tumor lysis syndrome. One of the ways to treat the tumor lysis syndrome is to irrigate patients, alkalinize the urine through the supply of BIC solution or continuous hemodialysis with regional citrate anticoagulation, using a CAL solution.

METHOD

The study took place in two independent hospital pharmacies. Fifty samples of each solution were prepared under aseptic conditions, then the concentration of sodium and calcium ions was determined and microbiological purity tests were carried out. The tests were performed on the day of sample preparation and after seven days of storage at 4 ± 1℃.

RESULTS

The obtained results showed that applied preparation method was precise and accuracy. The average concentration of sodium ions in BIC solutions ranged from 187.7 to 185.26 mmol/L on 1st and 7th day, respectively. The average concentration of calcium ions in CAL solution ranged from 68.92 to 68.80 mmol/L on 1st and 7th day, respectively. None of the samples were microbiologically contaminated.

CONCLUSION

Studied solutions for infusion were characterized by good chemical and microbiological stability when prepared in a clean room and stored at 4 ± 1℃.

Elevated admission serum calcium phosphate product as an independent risk factor for acute kidney injury in hospitalized patients

BACKGROUND

Increased serum calcium-phosphate product (CaP) can result in acute kidney injury (AKI) due to tubular and interstitial calcium phosphate deposits. CaP of > 55 mg²/dL² is also associated with systemic calcification. However, the risk of AKI development among hospitalized patients with different admission calcium-phosphate product levels remains unclear.

METHODS

All adult hospitalized patients who had both admission serum calcium and phosphate levels available from 2009 through 2013 were enrolled. Admission CaP was categorized based on its distribution into six groups (<22, 22- < 27, 27- < 32, 32- < 37, 37- < 42 and ≥42 mg²/dL²). The odds ratio (OR) of in-hospital mortality by admission CaP, using the CaP category of < 22 mg²/dL² as the reference group, was obtained by logistic regression analysis.

RESULTS

After excluding patients with end-stage renal disease, without serum creatinine measurement, and those who presented with AKI at the time of admission, a total of 9,864 patients were studied. In-hospital AKI occurred in 1,478 patients (15.0%). The incidence of AKI among patients with admission CaP < 22, 22 to < 27, 27 to < 32, 32 to < 37, 37 to < 42, and ≥42 mg²/dL² was 11.1%, 12.4%, 14.9%, 15.2%, 17.5%, and 19.9%, respectively. After adjusting for potential confounders, a CaP ≥37 mg²/dL² was associated with an increased risk of developing AKI with OR of 1.53 (CI 1.19-1.96) and 1.63 (CI 1.25-2.14) in patients with admission CaP 37- < 42 and ≥42, respectively. Subgroup analysis based on eGFR consistently demonstrated that CaP ≥37 mg²/dL² was associated with an increased risk of developing AKI in both chronic kidney disease (CKD) and non-CKD patients.

CONCLUSION

Elevated admission CaP was independently associated with an increased risk for in-hospital AKI.

Tumour lysis syndrome

Tumour lysis syndrome (TLS) is a life-threatening emergency characterised by a massive cytolysis with the release of intracellular electrolytes, nucleic acids, and metabolites into the circulation. TLS comprises laboratory derangements (hyperuricaemia, hyperkalaemia, hyperphosphataemia, and hypocalcaemia) responsible for acute kidney injury. In patients with hematologic malignancies after cytotoxic therapy or spontaneously and also in advanced solid tumours. Assessment of disease specific risk level for TLS in patients receiving anti-tumoural therapy is essential for early diagnosis. Prophylaxis is the mainstay of management of TLS. It is important to routinely initiate a risk-adapted prophylactic strategy to correct metabolic alterations and preserve renal function. High and intermediate risk patients and patients with established TLS should be managed with multidisciplinary medical care in a hospital unit to receive monitoring and medical care. Renal replacement therapy should be considered in patients with refractory TLS.

Risk-based management strategy and outcomes of tumor lysis syndrome in children with leukemia/lymphoma: Analysis from a resource-limited setting

BACKGROUND

Data from low- and middle-income countries on tumor lysis syndrome (TLS) in the pediatric population are limited. This study aims to analyze the clinical and biochemical characteristics and treatment outcomes of TLS in children with leukemia/lymphomas in a resource-limited setting.

PROCEDURE

Children with intermediate risk (IRD) and high risk (HRD) for developing TLS were retrospectively studied at a tertiary cancer center in India.

RESULTS

Over a three-year period, 224 children with acute leukemia/lymphoma having IRD (21.8%, n = 49) and HRD (78.1%, n = 175) were identified. TLS developed in 53.6% (n = 120) cases, of which 75% (n = 90) had laboratory TLS alone. Thirteen children had clinical TLS (C-TLS) at presentation while 17 patients progressed to develop C-TLS. TLS developed in 51% (n = 25) and 54.5% (n = 95) of children with IRD and HRD, respectively. Rasburicase was used in 8.5% (n = 19) cases and five children required hemodialysis. Two children (0.8%) expired during the course of TLS management. Multivariate analysis identified the presence of hyperuricemia as the single significant risk factor for developing TLS. When children in whom a 25% change in biochemical values from the baseline that falls within the normal range were excluded, 21.4% (48/224) cases were identified to have clinically relevant TLS (8% in IRD and 25% in HRD).

CONCLUSION

With hydration, supportive care and judicious use of rasburicase, it is feasible to manage TLS efficiently in resource-limited settings. A modification of the TLS definition criteria would help to identify clinically relevant TLS.

Impact of daytime continuous veno-venous haemofiltration on treatment of paediatric tumour lysis syndrome

Objective

Continuous renal replacement therapy (CRRT) is well suited for treating metabolic abnormalities and renal insufficiency associated with tumour lysis syndrome (TLS). However, there is controversy regarding the choice of time for CRRT, the selection of CRRT models, and methods of decreasing complications of CRRT. This study aimed to evaluate the efficacy and outcomes of daytime continuous veno-venous haemofiltration (CVVH) for treating paediatric TLS.

Methods

The clinical features, technique-related complications, and prognosis were prospectively analysed in eight paediatric patients with TLS who were supported by daytime CVVH in West China Second University Hospital, Sichuan University from January 2007 to July 2016.

Results

Seven patients were boys and one was a girl. All of the patients had hyperphosphataemia, and there were four cases of hyperkalaemia, four cases of hyperuricaemia, and two cases of hypocalcaemia. All of the patients received one to 10 CVVH treatments. Urine output, renal function, serum uric acid levels, and potassium, phosphate, and calcium levels returned to normal in all of the patients, but recovery of renal function was relatively slow. No significant adverse reactions were observed. All of the patients recovered and were discharged.

Conclusion

Daytime CVVH is a safe and effective treatment for paediatric TLS.

Individualized treatment strategies for hyperuricemia informed by a semi-mechanistic exposure-response model of uric acid dynamics

To provide insight into pharmacological treatment of hyperuricemia we developed a semi-mechanistic, dynamical model of uric acid (UA) disposition in human. Our model represents the hyperuricemic state in terms of production of UA (rate, PUA), its renal filtration (glomerular filtration rate, GFR) and proximal tubular reabsorption (fractional excretion coefficient, FE). Model parameters were estimated using data from 9 Phase I studies of xanthine oxidase inhibitors (XOI) allopurinol and febuxostat and a novel uricosuric, the selective UA reabsorption inhibitor lesinurad, approved for use in combination with a XOI. The model was qualified for prediction of the effect of patients' GFR and FE on concentration of UA in serum (sUA) and UA excretion in urine and their response to drug treatment, using data from 2 Phase I and 4 Phase III studies of lesinurad. Percent reduction in sUA from baseline by a XOI is predicted to be independent of GFR, FE or PUA. Uricosurics are more effective in underexcreters of UA or patients with normal GFR. Co-administration of a XOI and an uricosuric agent should be considered for patients with high sUA first in the treatment algorithm of gout before uptitration of XOI. The XOI dose in combination with a uricosuric can be reduced compared to XOI alone for the same target sUA to the degree dependent on patient's GFR and FE. This exposure-response model of UA can be used to rationally select the best drug treatment option to lower elevated sUA in gout patients under differing pathophysiological situations.

Tumor Lysis Syndrome in Patients with Hematological Malignancies

Tumor lysis syndrome is a metabolic complication that may follow the initiation of cancer therapy. It commonly occurs in hematological malignant patients particularly non-Hodgkin's lymphoma and acute leukemia due to chemotherapy or spontaneously. It is characterized by a biochemical abnormality such as hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia and its clinical outcome is directly related to these biochemical abnormalities. Prevention and treatment of tumor lysis syndrome depend on immediate recognition of patients at risk. Therefore, identifying patients at risk and prophylactic measures are important to minimize the clinical consequences of tumor lysis syndrome. Patients with low risk should receive hydration and allopurinol. On the other hand patients with high risk should receive hydration and rasburicase in an inpatient setting. It is important to start therapy immediately, to correct all parameters before cancer treatment, to assess risk level of patients for TLS, and to select treatment options based on the risk level. In this review a comprehensive search of literatures was performed using MEDLINE/PubMed, Hinari, the Cochrane library, and Google Scholar to summarize diagnostic criteria, incidence, predicting factors, prevention, and treatment options for tumor lysis syndrome in patients with hematological malignancies.

Tumor Lysis Syndrome in Chronic Lymphocytic Leukemia with Novel Targeted Agents

Tumor lysis syndrome (TLS) is an uncommon but potentially life-threatening complication associated with the treatment of some cancers. If left untreated, TLS may result in acute renal failure, cardiac dysrhythmia, neurologic complications, seizures, or death. Tumor lysis syndrome is most commonly observed in patients with hematologic malignancies with a high proliferation rate undergoing treatment with very effective therapies. In chronic lymphocytic leukemia (CLL), historically, TLS has been observed less often, owing to a low proliferation rate and slow response to chemotherapy. New targeted therapies have recently been approved in the treatment of CLL, including the oral kinase inhibitors, idelalisib and ibrutinib, and the B-cell lymphoma-2 protein inhibitor, venetoclax. Several others are also under development, and combination strategies of these agents are being explored. This review examines the diagnosis, prevention, and management of TLS and summarizes the TLS experience in CLL clinical trials with newer targeted agents. Overall, the risk of TLS is small, but the consequences may be fatal; therefore, patients should be monitored carefully. Therapies capable of eliciting rapid response and combination regimens are increasingly being evaluated for treatment of CLL, which may pose a higher risk of TLS. For optimal management, patients at risk for TLS require prophylaxis and close monitoring with appropriate tests and appropriate management to correct laboratory abnormalities, which allows for safe and effective disease control.

IMPLICATIONS FOR PRACTICE

Tumor lysis syndrome (TLS) is a potentially fatal condition observed with hematologic malignancies, caused by release of cellular components in the bloodstream from rapidly dying tumor cells. The frequency and severity of TLS is partly dependent upon the biology of the disease and type of therapy administered. Novel targeted agents highly effective at inducing rapid cell death in chronic lymphocytic leukemia (CLL) may pose a risk for TLS in patients with tumors characterized by rapid growth, high tumor burden, and/or high sensitivity to treatment. In this review, prevention strategies and management of patients with CLL who develop TLS are described.

Cancer and the kidney: dangereoux liasons or price paid for the progress in medicine?

A long time ago, the links between renal disease and malignancy were observed, however, quite recently, their importance was recognized and 'new' subspecialty in nephrology, namely 'onconephrology' was established. In the XXI century, patients with malignancy make up the most growing number of the subjects seen for nephrology consult and/or critical care nephrology services. A plethora of renal problems may be found in patients with malignancy. They may influence not only their short-term outcomes but also the adequate therapy of the underlying oncological problem. Thus, all these kidney-related issues pose an important challenge for both specialities: oncology and nephrology. In the review a spectrum of acute and chronic renal injury caused by the malignancy is presented as well as the associations between renal disease and cancer. Assessment of kidney function and its importance in patients with malignancy is also discussed as medical oncologists should check the appropriate dose of chemotherapeutic drugs in relation to the actual renal function before prescribing them to the patients. Moreover, effects of kidney function on outcomes in oncology is presented. In addition, nephrology services should better understand both the biology of malignancy with its treatment to become a valuable part treating team to yield the best possible outcome. It is important for nephrology services to be acknowledged and to take an active participation in care of oncology patients.

Elevated baseline potassium level within reference range is associated with worse clinical outcomes in hospitalised patients

The clinical significance of elevated baseline serum potassium (K⁺) levels in hospitalised patients is rarely described. Hence, we performed a retrospective study assessing the significance of elevated K⁺ levels in a one-year admission cohort. Adult patients without hypokalaemia or end-stage renal disease were included. Adverse outcomes were all-cause mortality, hospital-acquired acute kidney injury, and events of arrhythmia. In total, 17,777 patients were included in the study cohort, and a significant difference (P < 0.001) was observed in mortality according to baseline serum K⁺ levels. The adjusted hazard ratios (HRs) and associated 95% confidence intervals (CIs) of all-cause mortality for K⁺ levels above the reference range of 3.6–4.0 mmol/L were as follows: 4.1–4.5 mmol/L, adjusted HR 1.075 (95% CI 0.981–1.180); 4.6–5.0 mmol/L, adjusted HR 1.261 (1.105–1.439); 5.1–5.5 mmol/L, adjusted HR 1.310 (1.009–1.700); >5.5 mmol/L, adjusted HR 2.119 (1.532–2.930). Moreover, the risks of in-hospital acute kidney injury and arrhythmia were higher in patients with serum K⁺ levels above 4.0 mmol/L and 5.5 mmol/L, respectively. In conclusion, increased serum K⁺ levels, including mild elevations may be related to worse prognosis. Close monitoring and prompt correction of underlying causes or hyperkalaemia itself is warranted for admitted patients.

Considering renal risk while managing cancer

Renal function is an important consideration in the management of patients with advanced cancer. There is a reciprocal relationship between cancer and the kidney: chronic kidney disease can increase the risk of developing cancer, and patients with cancer often experience renal impairment owing to age, disease-related factors and nephrotoxic treatments. As therapies for cancer continue to improve, patients are living longer with their disease, potentially extending the period over which they are susceptible to long-term complications. Furthermore, secondary symptoms, such as bone metastases or infections, may arise that will require treatment. Certain treatments, including chemotherapy, antibiotics and some bone-targeted agents, are nephrotoxic and may require dose modifications or interruptions to prevent renal injury. Nephrologists should play a key role in the identification and management of renal impairment in patients with cancer. Furthermore, they may be able to provide advice on protecting the kidneys in instances where nephrotoxic agents require dose reductions or interruptions, and when novel therapies or combinations are used. Collaboration between oncologists and nephrologists is important to optimal patient management. This article reviews the relationship between cancer and kidney disease and examines the treatments that may impact kidney function. Considerations for monitoring renal function are also discussed.

Effect of Vitamin D Supplementation on Delayed Hyperphosphatemia in Pediatric Acute Lymphoblastic Leukemia Patients During Induction Chemotherapy

OBJECTIVES

Vitamin D plays a role in maintaining bone health and calcium metabolism, but recent studies cast doubt on vitamin D supplementation's benefits in survivors of acute lymphoblastic leukemia (ALL). Vitamin D supplementation could increase serum phosphate through increased intestinal absorption of phosphate and suppression of parathyroid hormone, which would lead to decreased renal phosphate excretion. Because of the potential for renal injury during induction chemotherapy for ALL, Vitamin D supplementation's potential for increasing hyperphosphatemia could outweigh its suggested but unproven benefits.

METHODS

To measure the interaction between vitamin D supplementation and phosphate during chemotherapy induction, a retrospective study was done. Demographic data; clinical information about the diagnosis; laboratory data regarding calcium, phosphate, and vitamin D concentrations; and medication histories were reviewed.

RESULTS

A retrospective study of 41 children with ALL showed no statistically significant difference in the final phosphate concentrations that were obtained (4.41 mg/dL vs. 4.53 mg/dL, p = 0.635) with regard to their vitamin D supplementation status. Longitudinal effects with vitamin D and phosphate showed a trend toward increasing phosphate concentrations in patients who received supplemental vitamin D (0.035 vs. 0.010 mg/dL per day; p = 0.102).

CONCLUSIONS

Vitamin D potentially poses a risk of hyperphosphatemia in children undergoing induction chemotherapy for ALL.

Spontaneous tumor lysis syndrome in a patient with metastatic prostate cancer

Tumor lysis syndrome (TLS) is a life-threatening oncological emergency, with most cases occurring in hematological malignancies following the initiation of treatment. However, on rare occasions, TLS may occur in solid tumors as well. In the present case study, the case is reported of a 56-year-old African-American man who presented with a recent diagnosis of prostate cancer, abdominal pain, elevated transaminases, renal insufficiency, hyperkalemia, and hyperuricemia, consistent with spontaneous TLS in the setting of metastatic prostate cancer. A computed tomography scan of the patient's abdomen demonstrated diffuse metastatic tumor burden. Following treatment with allopurinol, rasburicase, and initiation of anti-androgen therapy for the prostate cancer, the patient's TLS laboratory results normalized, however, his renal functions continued to decline. TLS is rare in solid tumors, and particularly rare in prostate cancer, with only six other case reports of the syndrome occurring to the best of our knowledge. This case report highlights the need for early recognition of TLS, even in cases that are not typically associated with the syndrome, as prompt diagnosis will affect early management and may be able to prevent or minimize complications.