Nephrotic Syndrome and Acute Renal Failure Apparently Induced by Sunitinib

A Case of Acute Kidney Injury, Proteinuria, and Thrombotic Microangiopathy Associated With Sunitinib Therapy in Metastatic Pancreatic Neuroendocrine Tumor

There have been rare reports of patients developing nephrotic syndrome and thrombotic microangiopathy (TMA) with tyrosine kinase inhibitors (TKIs). We present the case of a patient with a history of metastatic pancreatic neuroendocrine tumor (pNET), treated with sunitinib, who rapidly developed TMA and acute kidney injury. The patient was successfully treated with cessation of sunitinib and administration of steroids. This case report contributes to the growing body of literature surrounding the rare side effects of TKIs and our experience with the management of these adverse events.

Nephrotic Syndrome Due to Sunitinib: A Rare Complication of Treatment of Renal Cell Carcinoma

This case report details a 62-year-old male with a history of right renal cell carcinoma (RCC) who developed sunitinib-induced nephrotic syndrome during treatment. The patient had a complex medical history, including a right nephrectomy in 2009, brain metastasis excisions in 2011 and 2012, and prolonged sunitinib therapy. Hypothyroidism, hypertension, and various surgeries further complicated his clinical picture. In April 2022, the patient presented with bilateral pedal edema, acute kidney injury superimposed on chronic kidney disease, and proteinuria. Upon examination, the decision was made to discontinue sunitinib, leading to the resolution of nephrotic syndrome. Adjustments in thyroxine dosage were made, and pharmacological interventions were employed to manage proteinuria and renal dysfunction. A multidisciplinary approach involving oncologists, nephrologists, and endocrinologists was essential in achieving a favorable outcome. The case highlights the intricate balance required in managing patients undergoing targeted cancer therapies, emphasizing the importance of vigilant monitoring, prompt intervention, and a collaborative approach for optimal patient care.

Chronic thrombotic microangiopathy presenting as acute nephrotic syndrome in a patient with renal cancer receiving tyrosine kinase inhibitor therapy

Thrombotic microangiopathy (TMA) is a rare but serious side effect of tyrosine kinase inhibitor (TKI) therapy. Previous case reports of renal TMA have usually occurred in the first few months of TKI initiation with only very few cases occurring within 2-3 years. We report a case of a patient who was referred to the Nephrology service for nephrotic syndrome and worsening renal function after 8 years of sunitinib therapy for metastatic clear cell carcinoma of the kidney. Renal biopsy showed chronic TMA without another secondary aetiology identified. With discontinuation of sunitinib and pharmacological optimisation of his hypertension, his renal function and proteinuria both significantly improved. No relapse or recurrence of disease activity was noted after a year of follow-up. This case highlights the importance of remaining vigilant for the development of renal TMA even after an extended duration of TKI therapy.

Onconephrology: Update in Anticancer Drug-Related Nephrotoxicity

The relation that connects cancer and renal damage is bidirectional and this renal damage worsens quality of life and increases morbidity in high-complexity patients such as patients with cancer and kidney injury. Strikingly, in the last decade, the treatment of advanced cancer has clearly advanced in terms of new therapeutic strategies with the ability to transform the advanced metastatic cancer in a chronic condition. In this new era of cancer therapies, cancer treatment including conventional chemotherapy, targeted cancer agents and immunotherapies among others are significantly associated with kidney injury. Renal toxicity that is currently seen in onconephrology departments is in part related to the new therapies such as immunotherapy, and to the prolonged survival achieved at the expense of increasing therapy lines, and a combination of different drugs. In this review, we will discuss in a practical way, nephrotoxicity caused by the main oncospecific treatments such as classical chemotherapy agents, targeted therapies, and immunotherapy. In addition, strategies for prevention and management recommendations in patients with malignancies and kidney disease will also be addressed.

Sunitinib-related high-grade proteinuria and allograft dysfunction in a kidney recipient: a rare case report

Background

Sunitinib-induced high-grade proteinuria and irreversible renal allograft dysfunction are rare conditions. Here, we present a patient who had received renal allograft and later developed metastatic clear cell renal cell carcinoma(cc-mRCC), for which he was prescribed sunitinib. High-grade proteinuria, hypoalbuminemia, peripheral edema and renal allograft dysfunction (manifesting as an increase in the serum creatinine concentration) occurred 5 months after sunitinib prescription.

Case presentation

The patient was a 58-year-old male who had end-stage renal disease with regular hemodialysis through arteriovenous fistula for 17 years since 1998 and received a renal allograft from a deceased kidney donor in 2015. Unfortunately, in 2019, the patient developed cc-mRCC originating from the left native kidney. We suggested a needle biopsy on left native kidney or radical left nephrectomy, but the patient refused. Sunitinib was prescribed. Follow-up urine analysis showed proteinuria (500 mg/dL) 2 weeks after sunitinib prescription. He was hospitalized 5 months later because of body weight gain, decreased urine output, pitting edema of both lower extremities, and shortness of breath. The image studies showed progression in his cc-mRCC. His serum creatinine level and spot urine protein at admission increased to 4.26 mg/dL and 300 mg/dL, respectively. He agreed on a biopsy for the renal allograft and the pathology studies showed focal segmental glomerulosclerosis, acute interstitial nephritis, and acute tubular injury. Based on the time sequence of clinical presentations with the laboratory and pathological findings, sunitinib-induced renal allograft dysfunction secondary to high-grade proteinuria was most likely. Despite of discontinuation of sunitinib and increased dose of everolimus, renal impairment progressed. Thus, he had to receive hemodialysis starting 2 week after hospitalization. Unfortunately, the patient died of advanced metastasis despite of aggressive medical treatments 3 weeks after admission.

Conclusion

This case report is a reminder that renal allograft dysfunction can happen secondary to proteinuria after taking sunitinib. Hence, clinicians must regularly check renal function and urine protein for renal allograft recipients. Monitoring and modifying drug prescription, especially sunitinib, is necessary if persistent proteinuria accompanied by deteriorating serum creatinine level occurs. Renal biopsy may be considered if more evidence is required to make a differential diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02789-5.

Worsening membranous nephropathy in a patient with GIST treated with sunitinib

Tyrosine kinase inhibitors (TKI) are anticancer agents widely used for a variety of malignancies including gastrointestinal stromal tumours (GIST). Although generally well-tolerated, TKIs have been associated with a number of adverse events including hypertension, proteinuria and nephrotic syndrome. We present the case of a 70-year-old patient with metastatic GIST on long-standing sunitinib who developed hypertension, oedema and hypoalbuminemia with a rising serum creatinine and was found to have nephrotic syndrome. Workup revealed elevated antiphospholipase A2 receptor (PLA2R) antibody IgG titres and a kidney biopsy confirmed PLA2R-positive membranous nephropathy without findings of thrombotic microangiopathy. Cessation of sunitinib led to reduction in anti-PLA2R antibody IgG titres while resumption, due to concern for cancer progression, led to worsening symptoms. Treatment with rituximab led to undetectable anti-PLA2R IgG titres. We highlight the importance of maintaining a systematic approach for evaluating nephrotic syndrome and provide a case showing that TKIs can exacerbate underlying nephrotic syndrome.

Role of rivaroxaban in sunitinib-induced renal injuries via inhibition of oxidative stress-induced apoptosis and inflammation through the tissue nacrosis factor-α induced nuclear factor-κappa B signaling pathway in rats

Rivaroxaban (RIVA) inhibits factor Xa and exhibits antithrombotic and anti-inflammatory activities by inhibiting several cellular signaling molecules. Sunitinib (SUN) is FDA approved first-line drug for metastatic renal cancers and advanced cancerous states of gastrointestinal tract. Present hypothesis was aimed to examine the nephroprotective potential of RIVA in SUN-induced nephrotoxicity, mediated through the inhibition of oxidative stress-induced apoptosis and inflammation, via the TNF-α/NFk-B signaling pathways. Wistar rats 200-250 g were selected and divided randomely in 5 groups (n = 6): Group 1 kept as normal control; Group 2 as disease control and exposed to SUN 50 mg/kg thrice-weekly upto 21 days; Groups 3 and 4, were treatment groups and administered SUN 50 mg/kg thrice-weekly as of group 2 and treated with RIVA 5 and 10 mg/kg/daily for 21 days, respectively; and Group 5 fed with RIVA alone (10 mg/kg/daily for 21 days). Serum was separated from blood to estimate serum biochemical parameters and kidney tissues were collected to estimate antioxidant enzyme, mRNA and protein expression. SUN exposure significantly elevated levels of creatinine, urea, uric acid, blood urea nitrogen, albumin, and bilirubin, and decreased serum magnesium and iron levels. Malondialdehyde and catalase levels were significantly increased and glutathione and glutathione reductase levels were significantly decreased. Intracellular levels of caspase-3 and TNF-α were significantly increased; RIVA treatment restored the altered levels. In SUN-exposed animals, western blotting revealed significantly elevated NFk-B, IL-17, and MCP-1 expression, and IKBα levels were significantly downregulated; RIVA restored these levels to normal values.RIVA treatment significantly restored the apoptotic and inflammatory parameters in SUN-damaged renal tissues.

Study on the mechanism and intervention strategy of sunitinib induced nephrotoxicity

Sunitinib is an oral small molecular tyrosine kinase inhibitor that exhibits potent antiangiogenic and antitumor activity. Unfortunately, sunitinib kidney toxicity limits its clinical use. Renal injury caused by sunitinib treatment can not only lead to the failure of cancer treatment, but also jeopardizes the health and life of patients. Currently, there is no better intervention measure for renal injury caused by sunitinib therapy except reducing the dosage or stopping the medication. In this study, we learned from clinical case report that sunitinib can cause severe renal injury. Subsequently, we compiled the clinical trials data of sunitinib found that sunitinib can cause general renal damage. Based on this finding, we conducted a study on the mechanism of sunitinib-induced renal injury. The results showed that sunitinib can inhibit the survival of HK-2 cells (human tubule epithelial cells) in a dose- and time-dependent manner. The survival inhibition is mainly due to the activation apoptotic signaling pathway by sunitinib in HK-2 cells and induces apoptosis of HK-2 cells. Subsequently, we found that natural compound oxypeucedanin can significantly alleviate the apoptosis of HK-2 cells induced by sunitinib. Through clinical investigation and experimental study of sunitinib, we found that sunitinib can cause extensive renal damage by inducing apoptosis of renal tubular epithelial cells and natural compound oxypeucedanin is a potentially effective intervention for nephrotoxicity of sunitinib. Thus, our research will provide a theoretical basis for the future rational use of sunitinib and the search for appropriate interventions for sunitinib-induced kidney damage.

Focal segmental glomerulosclerosis lesion associated with inhibition of tyrosine kinases by lenvatinib: a case report

Background

Lenvatinib is a tyrosine kinase inhibitor with novel binding ability. It is considered the standard of care for metastatic thyroid cancer; moreover, whether it is indicated for other malignant tumors has been examined. Lenvatinib increases the risk of kidney injury in some patients. In comparison with sorafenib, which is a conventional tyrosine kinase inhibitor (TKI), lenvatinib results in more side effects, including hypertension and proteinuria. We describe a case of secondary focal segmental glomerulosclerosis (FSGS) that developed following treatment of metastatic thyroid cancer with lenvatinib and reviewed the mechanisms of renal impairment.

Case presentation

We describe a patient with metastatic thyroid cancer who developed hypertension, nephrotic syndrome, and acute kidney injury after 3 months of lenvatinib treatment. Renal biopsy results revealed that 7 of 16 glomeruli indicated complete hyalinization, and that the glomeruli with incomplete hyalinization showed FSGS due to a vascular endothelial disorder and podocyte damage, which seemed to have been induced by lenvatinib treatment. These findings were similar to those of renal impairment treated with conventional TKIs. Although lenvatinib treatment was discontinued, up to 15 months were required to achieve remission of proteinuria, thus leading to chronic kidney disease with hyalinized lesions.

Conclusions

To the best of our knowledge, this is the first reported case of secondary FSGS by lenvatinib treatment. Renal impairment treated with TKIs is commonly associated with minimal change nephrotic syndrome/FSGS findings, and it is suggested that renal involvement with TKI is different from that with the vascular endothelial growth factor ligand. Overexpression of c-mip due to TKI causes disorders such as podocyte dysregulation and promotion of apoptosis, which cause FSGS. Lenvatinib may result in FSGS by a similar mechanism with another TKI and could cause irreversible renal impairment; therefore caution must be used. It is essential to monitor blood pressure, urinary findings, and the renal function.

Effect of tyrosine kinase inhibitors on renal handling of creatinine by MATE1

Creatinine is actively secreted across tubular epithelial cells via organic cation transporter 2 (OCT2) and multidrug and toxin extrusion 1 (MATE1). We previously showed that the tyrosine kinase inhibitor (TKI) crizotinib inhibits OCT2-mediated transport of creatinine. In the present work, we examined the inhibitory potency of TKIs, including crizotinib, on MATE1-mediated transport of creatinine. Then, we used the kinetic parameters estimated in this and the previous work to predict the potential impact of TKIs on serum creatinine level (SCr) via reversible inhibition of creatinine transport. Crizotinib inhibited [¹⁴C]creatinine uptake by MATE1-overexpressing cells, and the inhibitory effect increased with incubation time, being greater in the case of pre-incubation or combined pre-incubation/co-incubation (pre/co-incubation) than in the case of co-incubation alone. The inhibition was non-competitive, with K _i values of 2.34 μM, 0.455 μM and 0.342 μM under co-, pre- or pre/co-incubation conditions, respectively. Similar values were obtained for inhibition of [³H]MPP⁺ uptake by MATE1-overexpressing cells. Gefitinib, imatinib, pazopanib, sorafenib, and sunitinib also inhibited MATE1-mediated creatinine uptake. Further, all these TKIs except pazopanib inhibited [¹⁴C]creatinine uptake by OCT2-overexpressing cells. In rat kidney slices, the ratio of unbound tissue accumulation of TKIs to extracellular concentration ranged from 2.05 to 3.93. Prediction of the influence of TKIs on SCr based on the renal creatinine clearance and plasma maximum unbound concentrations of TKIs suggested that crizotinib and imatinib might increase SCr by more than 10% in the clinical context. Accordingly, it is necessary to be cautious in diagnosing TKI-induced renal failure only on the basis of an increase of SCr.

Hypertension in malignancy-an underappreciated problem

Hypertension is one of the most common comorbidities in cancer patients with malignancy, in particular, in the elderly. On the other hand, hypertension is a long-term consequence of antineoplastic treatment, including both chemotherapy and targeted agents. Several chemotherapeutics and targeted drugs may be responsible for development or worsening of the hypertension. The most common side effect of anti-VEGF (vascular endothelial growth factor) treatment is hypertension. However, pathogenesis of hypertension in patients receiving this therapy appears to be associated with multiple pathways and is not yet fully understood. Development of hypertension was associated with improved antitumor efficacy in patients treated with anti-antiangiogenic drugs in some but not in all studies. Drugs used commonly as adjuvants such as steroids, erythropoietin stimulating agents etc, may also cause rise in blood pressure or exacerbate preexisiting hypertension. Hypotensive therapy is crucial to manage hypertension during certain antineoplastic treatment. The choice and dose of antihypertensive drugs depend upon the presence of organ dysfunction, comorbidities, and/or adverse effects. In addition, severity of the hypertension and the urgency of blood pressure control should also be taken into consideration. As there are no specific guidelines on the hypertension treatment in cancer patients we should follow the available guidelines to obtain the best possible outcomes and pay the attention to the individualization of the therapy according to the actual situation.

Inhibitory Effect of Crizotinib on Creatinine Uptake by Renal Secretory Transporter OCT2

Crizotinib, a tyrosine kinase inhibitor, exhibits some cases of an increase in serum creatinine levels. Creatinine is excreted by not only glomerular filtration but also active secretion by organic cation transporters such as organic cation transporter 2 (OCT2). In the present study, we evaluated in vitro inhibitory effect of crizotinib on OCT2 by directly measuring creatinine uptake by OCT2. Coincubation of crizotinib reduced uptake of [¹⁴C]creatinine by cultured HEK293 cells expressing OCT2 (HEK293/OCT2) in a concentration-dependent manner with IC₅₀ values of 1.58 ± 0.24 μM. Preincubation or both preincubation and coincubation (preincubation/coincubation) with crizotinib showed stronger inhibitory effect on [¹⁴C]creatinine uptake compared with that in coincubation alone with IC₅₀ values of 0.499 ± 0.076 and 0.347 ± 0.040 μM, respectively. These IC₅₀ values of crizotinib on [³H]N-methyl-4-phenylpyridinium acetate uptake by OCT2 were 10-20 times higher than those of [¹⁴C]creatinine uptake. Furthermore, preincubation of crizotinib inhibited creatinine uptake by OCT2 in an apparently competitive manner. In conclusion, crizotinib at a clinically relevant concentration has the potential to inhibit creatinine transport by OCT2, suggesting an increase of serum creatinine levels in clinical use.

Influence of Tyrosine Kinase Inhibitors on Hypertension and Nephrotoxicity in Metastatic Renal Cell Cancer Patients

Renal cell carcinoma (RCC) is one of the most common kidney malignancies. An upgraded comprehension of the molecular biology implicated in the development of cancer has stimulated an increase in research and development of innovative antitumor therapies. The aim of the study was to analyze the medical literature for hypertension and renal toxicities as the adverse events of the vascular endothelial growth factor (VEGF) signaling pathway inhibitor (anti-VEGF) therapy. Relevant studies were identified in PubMed and ClinicalTrials.gov databases. Eligible studies were phase III and IV prospective clinical trials, meta-analyses and retrospective studies that had described events of hypertension or nephrotoxicity for patients who received anti-VEGF therapy. A total of 48 studies were included in the systematic review. The incidence of any grade hypertension ranged from 17% to 49.6%. Proteinuria and increased creatinine levels were ascertained in 8% to 73% and 5% to 65.6% of patients, respectively. These adverse events are most often mild in severity but may sometimes lead to treatment discontinuation. Nephrotoxicity and hypertension are related to multiple mechanisms; however, one of the main disturbances in those patients is VEGF inhibition. There is a significant risk of developing hypertension and renal dysfunction among patients receiving anti-VEGF treatment; however, there is also some evidence that these side effects may be used as biomarkers of response to antiangiogenic agents.

Antineoplastic Treatment and Renal Injury: An Update on Renal Pathology Due to Cytotoxic and Targeted Therapies

Cancer patients experience kidney injury from multiple sources, including the tumor itself, diagnostic procedures, hypovolemia, infection, and drug exposure, superimposed upon baseline chronic damage. This review will focus on cytotoxic or targeted chemotherapy-associated renal injury. In this setting, tubulointerstitial injury and thrombotic microangiopathy (vascular injury) are more common than other forms of kidney injury including glomerular. Cisplatin, pemetrexed, and ifosfamide are well-known causes of acute tubular injury/necrosis. Acute interstitial nephritis seems underrecognized in this clinical setting. Interstitial nephritis is emerging as an "immune-related adverse effect" (irAE's) with immune checkpoint inhibitors in small numbers of patients. Acute kidney injury is rarely reported with targeted therapies such as BRAF inhibitors (vemurafinib, dabrafenib), ALK inhibitors (crizotinib), and mTOR inhibitors (everolimus, temsirolimus), but additional biopsy data are needed. Tyrosine kinase inhibitors and monoclonal antibodies that block the vascular endothelial growth factor pathway are most commonly associated with thrombotic microangiopathy. Other causes of thrombotic microangiopathy in the cancer patients include cytotoxic chemotherapies such as gemcitabine and mitomycin C, hematopoietic stem cell transplant, and cancer itself (usually high-stage adenocarcinoma with marrow and vascular invasion). Cancer patients are historically underbiopsied, but biopsy can reveal type, acuity, and chronicity of renal injury, and facilitate decisions concerning continuation of chemotherapy and/or initiation of renoprotective therapy. Biopsy may also reveal unrelated and unanticipated findings in need of treatment.

Proteinuria with first-line therapy of metastatic renal cell cancer

Background

Vascular endothelial growth factor receptor inhibitors, mammalian target of rapamycin inhibitors, and tyrosine kinase inhibitors are approved for metastatic renal cell cancer. Proteinuria can occur, but there is limited data regarding the incidence, monitoring, and management in metastatic renal cell cancer patients.

Objective

Our primary objective was to describe the incidence and severity of proteinuria in metastatic renal cell cancer patients treated in the first-line setting with pazopanib, bevacizumab, or everolimus.

Methods

We conducted a retrospective review of patients with metastatic renal cell cancer enrolled from January 2011–April 2013 in a phase II trial. Baseline and toxicity data were extracted from the electronic medical record. Descriptive statistics were used.

Results

In all, 129 patients were eligible for analysis. The overall incidence of proteinuria was 81%, with most events being Grade 1 or 2. The incidence of proteinuria was 80% ( n = 35) for pazopanib, 64% ( n = 25) for bevacizumab, and 96% ( n = 44) for everolimus. At peak proteinuria, 80% ( n = 28), 64% ( n = 16), and 80% ( n = 35) of patients on pazopanib, bevacizumab, and everolimus, respectively, were managed with continued monitoring at the same dose. The overall incidence of Grades 3 and 4 events was 24% ( n = 6) and found in the bevacizumab group.

Conclusion

A high incidence of proteinuria with minor severity within each class was demonstrated. It may be reasonable to continue therapy at the same dose for Grade 1 or 2 proteinuria. Treatment modification or discontinuation of therapy may be warranted with Grade 3 or 4 proteinuria.

Clinicopathological spectrum of kidney diseases in cancer patients treated with vascular endothelial growth factor inhibitors: a report of 5 cases and review of literature

Recently, cancer therapies have been supplemented by vascular endothelial growth factor (VEGF) inhibitors as anti-angiogenic agents. However, kidney-related adverse reactions associated with these agents clinically manifest as hypertension and proteinuria, the most severe form being thrombotic microangiopathy (TMA). We present the spectrum of pathological features in VEGF inhibitor-associated kidney disease. Clinicopathological findings of kidney disease were retrospectively studied in 5 cancer patients treated with anti-VEGF agents. Although 4 cases received bevacizumab (anti-VEGF-A), one was given sorafenib (small molecule tyrosine kinase inhibitor affecting VEGF-R2). All patients presented with acute kidney injury, hypertension, and/or proteinuria. All kidney biopsies showed recent and chronic endothelial injury of varying severity and vascular sclerosis, including 2 with typical active features of TMA. Furthermore, acute tubular injury with focal necrosis was seen in all cases. While administration of VEGF inhibitor was discontinued in 4 cases, it was resumed for 5 more doses, following steroid therapy in 1 case. Cessation of VEGF inhibitor therapy was successful in reversing anemia and led to improvement of hypertension and proteinuria in 4 of the 5 cases. One case with TMA progressed to end-stage renal disease. A range of renal pathologic lesions secondary to endothelial injury are noted often accompanied by acute tubular damage following anti-VEGF therapy, the most severe being TMA. While most of the clinical manifestations are reversible with discontinuation of therapy, the role of other nephrotoxic chemotherapeutic agents in enhancing renal injury including severe TMA and other host factors with possible poor outcome should be considered.

Nephrotic syndrome associated with tyrosine kinase inhibitors for pediatric malignancy: case series and review of the literature

BACKGROUND

Tyrosine kinase (TK) inhibitors are increasingly being used to treat a variety of pediatric malignancies. Reports in adult patients describe a range of effects of TK inhibitors on the kidney, including hypertension, proteinuria, acute kidney injury, and thrombotic microangiopathy (TMA); however, there are only a few reports of TK-inhibitor-associated nephrotic syndrome.

METHODS

We report four pediatric patients with various malignancies (chronic myelogenous leukemia, acute lymphoblastic leukemia, and glioma/renal cell carcinoma) who developed nephrotic syndrome during treatment with TK inhibitors (imatinib, sunitinib, dasatinib, and quizartinib). One of the four patients also had clinical features of TMA.

RESULTS

Three of the four patients achieved complete remission of nephrotic syndrome with discontinuation of the TK inhibitor and have had no additional nephrotic syndrome relapses to date. The temporal relationship of nephrotic syndrome onset to TK-inhibitor therapy and resolution of nephrotic syndrome with cessation of therapy strongly imply an association in these patients.

CONCLUSIONS

TK inhibitors are important therapies in pediatric cancer, and their use is expanding. Nephrotic syndrome with or without features of TMA is a potential complication of these therapies in children.

Renal adverse effects of sunitinib and its clinical significance: a single-center experience in Korea

BACKGROUND/AIMS

Sunitinib is an oral multitargeted tyrosine kinase inhibitor used mainly for the treatment of metastatic renal cell carcinoma. The renal adverse effects (RAEs) of sunitinib have not been investigated. The aim of this study was to determine the incidence and risk factors of RAEs (proteinuria [PU] and renal insufficiency [RI]) and to investigate the relationship between PU and antitumor efficacy.

METHODS

We performed a retrospective review of medical records of patients who had received sunitinib for more than 3 months.

RESULTS

One hundred and fifty-five patients (mean age, 58.7 ± 12.6 years) were enrolled, and the mean baseline creatinine level was 1.24 mg/dL. PU developed in 15 of 111 patients, and preexisting PU was aggravated in six of 111 patients. Only one patient developed typical nephrotic syndrome. Following discontinuation of sunitinib, PU was improved in 12 of 17 patients but persisted in five of 17 patients. RI occurred in 12 of 155 patients, and the maximum creatinine level was 3.31 mg/dL. RI improved in two of 12 patients but persisted in 10 of 12 patients. Risk factors for PU were hypertension, dyslipidemia, and chronic kidney disease. Older age was a risk factor for RI. The median progression-free survival was significantly better for patients who showed PU.

CONCLUSIONS

The incidence of RAEs associated with sunitinib was lower than those of previous reports. The severity of RAEs was mild to moderate, and partially reversible after cessation of sunitinib. We suggest that blood pressure, urinalysis, and renal function in patients receiving sunitinib should be monitored closely.

Sunitinib induced nephrotic syndrome and thrombotic microangiopathy

Sunitinib is an oral, multitargeted receptor tyrosine kinase inhibitor of targets such as vascular endothelial growth factor and platelet derived growth factor receptor. It is used for the treatment of metastatic renal cell carcinoma (RCC). Use of sunitinib has been associated with renal dysfunction and nephrotic syndrome. However, simultaneous occurrence of nephrotic syndrome and renal dysfunction in a patient treated with sunitinib is rare. We report a case of metastatic RCC treated with sunitinib for 22 months who presented with nephrotic syndrome and renal dysfunction. Renal biopsy was diagnostic of thrombotic microangiopathy with diffuse effacement of podocytic foot process.

Dasatinib-induced nephrotic-range proteinuria

Since the introduction of imatinib, tyrosine kinase inhibition has been a mainstay in the treatment of many malignancies. The number of these medications is growing, as are the number of targeted tyrosine kinases. Off-target effects of these medications can have beneficial or adverse effects on the kidney. The onus of knowing the implications of these medications on kidney function, and appropriate treatment when such adverse effects occur, is on the nephrologist. We present a patient with chronic myelogenous leukemia who developed nephrotic-range proteinuria after initiation on dasatinib therapy that resolved after changing therapy to imatinib. The mechanism of kidney injury caused by dasatinib has not been described previously in the literature. We provide a review of vascular endothelial growth factor and its pharmacologic inhibition as it pertains to kidney pathology and propose possible mechanisms by which dasatinib induces kidney injury.

Development of nephrotic syndrome after administration of sorafenib in a case of metastatic renal cell carcinoma

Nephrotic syndrome, after administration of tyrosine kinase inhibitors, is uncommon and not well known. A 62-year-old male, who had experienced a left nephrectomy due to a traffic accident 38 years ago, underwent a partial nephrectomy for right renal cell carcinoma (RCC). Histologically, the tumor was a clear cell RCC. Two years later abdominal CT revealed para-aortic lymph node metastasis. During these two years, serum creatinine had increased from 2.0 mg/dL to 2.9 mg/dL along with the appearance of proteinuria. After only a week of sorafenib, 400 mg/day, fever developed and sorafenib was stopped. Although normotensive, his serum creatinine increased to 3.83 mg/dL and serum albumin decreased from 1.8 g/L to 1.0 g/L. Proteinuria also worsened to 27.5 g/day. He became edematous, and ascites and cardiac effusions also appeared. He was diagnosed with nephrotic syndrome. A retrospective review of the histology of the partial nephrectomy revealed no change in the glomeruli.

Sunitinib-induced nephrotic syndrome in association with drug response in a patient with Xp11.2 translocation renal cell carcinoma

We report the case of a patient with metastatic renal cell carcinoma with Xp11.2 translocation/transcription factor E3 (TFE3) gene fusion who had presented with sunitinib-induced nephrotic syndrome in association with favorable and durable treatment response. The nephrotic syndrome was managed successfully by discontinuing sunitinib and symptomatic treatment. The 27-year-old female patient presenting with right upper abdominal pain was diagnosed with Xp11.2 translocation renal cell carcinoma on the right side with multiple pulmonary and hepatic metastases. She underwent radical nephrectomy and took a daily dose of 37.5 mg sunitinib. Partial response to sunitinib was achieved and maintained for 5 months, but when nephrotic syndrome occurred, drug intake was discontinued. The nephrotic syndrome gradually resolved around 2 months after discontinuation of sunitinib and medical management. Our case highlighted the favorable response of a particular non-clear cell type renal cell carcinoma to sunitinib and the specific toxicity associated with the antiangiogenic effect of sunitinib.