Predictive factors for the development of proteinuria in cancer patients treated with bevacizumab, ramucirumab, and aflibercept: a single-institution retrospective analysis

Machine learning application identifies plasma markers for proteinuria in metastatic colorectal cancer patients treated with Bevacizumab

BACKGROUND AND OBJECTIVES

Proteinuria is a common complication after the application of bevacizumab therapy in patients with metastatic colorectal cancer, and severe proteinuria can lead to discontinuation of the drug. There is a lack of sophisticated means to predict bevacizumab-induced proteinuria, so the present study aims to predict bevacizumab-induced proteinuria using peripheral venous blood samples.

METHODS

A total of 122 subjects were enrolled and underwent pre-treatment plasma markers, and we followed them for six months with proteinuria as the endpoint event. We then analyzed the clinical features and plasma markers for grade ≥ 2 proteinuria occurrence using machine learning to construct a model with predictive utility.

RESULTS

One hundred sixteen subjects were included in the statistical analysis. We found that high baseline systolic blood pressure, low baseline HGF, high baseline ET1, high baseline MMP2, and high baseline ACE1 were risk factors for the development of grade ≥ 2 proteinuria in patients with metastatic colorectal cancer who received bevacizumab. Then, we constructed a support vector machine model with a sensitivity of 0.889, a specificity of 0.918, a precision of 0.615, and an F1 score of 0.727.

CONCLUSION

We constructed a machine learning model for predicting grade ≥ 2 bevacizumab-induced proteinuria, which may provide proteinuria risk assessment for applying bevacizumab in patients with metastatic colorectal cancer.

Prevalence and management of proteinuria associated with vascular endothelial growth factor receptor-targeted tyrosine kinase inhibitor treatment in advanced renal cell carcinoma, hepatocellular carcinoma, and thyroid cancer

Vascular endothelial growth factor receptor-targeted tyrosine kinase inhibitors (VEGFR-TKIs) are often used for treatment of several types of cancer; however, they are associated with an increased risk of proteinuria, sometimes leading to treatment discontinuation. We searched PubMed and Scopus to identify clinical studies examining the incidence and risk factors for proteinuria caused by VEGFR-TKIs in patients with renal cell carcinoma, thyroid cancer, and hepatocellular carcinoma. The global incidence of proteinuria ranged from 6% to 34% for all grades of proteinuria, and from 1% to 10% for grade ≥3 proteinuria. The incidence of proteinuria did not differ significantly by cancer type, but in all three cancer types, there was a trend toward a higher incidence of proteinuria with lenvatinib than with other VEGFR-TKIs. In terms of risk factors, the incidence of proteinuria was significantly higher among Asians (including Japanese) compared with non-Asian populations. Other risk factors included diabetes mellitus, hypertension, and previous nephrectomy. When grade 3/4 proteinuria occurs, patients should be treated according to the criteria for dose reduction or withdrawal specified for each drug. For grade 2 proteinuria, treatment should be continued when the benefits outweigh the risks. Referral to a nephrologist should be considered for symptoms related to decreased renal function or when proteinuria has not improved after medication withdrawal. These management practices should be implemented universally, regardless of the cancer type.

Impact of preexisting proteinuria on the development of regorafenib-induced problematic proteinuria in real-world metastatic colorectal cancer treatment

Regorafenib is the first multikinase inhibitor for treating metastatic colorectal cancer (mCRC). Proteinuria is a frequently encountered adverse effect, regardless of prior administration of vascular endothelial growth factor inhibitors. Herein, we aimed to assess the impact of baseline preexisting proteinuria on regorafenib-induced problematic proteinuria during real-world mCRC therapy. Patients with mCRC receiving regorafenib (n = 100) were retrospectively assessed and divided into control and preexisting proteinuria (baseline grade of 1-2) groups. The primary endpoint was the development of grade ≥ 2 (grade ≥ 3 in case of baseline grade 2 patients) proteinuria. Propensity score-matching was performed to confirm the robustness of primary analyses. Defined proteinuria occurred in 30.7 and 57.9% of patients in the control and preexisting proteinuria groups, respectively, with significant differences in the all-patient population (P = 0.01). The preexisting proteinuria group exhibited significant defined proteinuria development within 7 days of regorafenib initiation, grade ≥ 3 symptoms, and treatment suspension owing to proteinuria. Similar results were obtained in the propensity score-matched population. According to multivariate logistic regression analysis, baseline proteinuria was a singular risk factor for defined proteinuria development (adjusted odds ratio; 3.76, 95% confidence interval; 1.45-9.75, P = 0.007). Collectively, our study revealed that patients with preexisting proteinuria develop regorafenib-induced proteinuria degradation.

Efficacy and safety of atezolizumab plus bevacizumab in patients with portal hypertension for unresectable hepatocellular carcinoma

AIM

Atezolizumab plus bevacizumab combination therapy (Atezo + Beva) is used as the first-line therapy for unresectable hepatocellular carcinoma (u-HCC). Serious adverse events (AEs), including rupture of esophagogastric varices, have been seen during treatment. Therefore, the relationships of efficacy, safety, and portal hypertension (PH) were analyzed.

METHODS

A total of 146 patients with u-HCC and Child-Pugh Scores of 5-7 received Atezo + Beva. Prophylactic treatment for varices was performed for patients with the risk of rupture of varices before the start of Atezo + Beva. A propensity score-matched cohort was created to minimize the risk of potential confounders. Efficacy was assessed in 41 propensity score-matched pairs. AEs were assessed between patients without PH (n = 80) and with PH (n = 66).

RESULTS

In patients without PH and with PH, median overall survival was 18.4 months and 18.8 months (p = 0.71), and median progression-free survival was 8.6 months and 5.8 months (p = 0.92), respectively. On the best radiological response evaluation for Response Evaluation Criteria in Solid Tumors, the objective response rate was 31.7% and 26.8% (p = 0.81), respectively. Variceal rupture occurred in three patients with PH, but there were no significant differences in the occurrence of variceal rupture (p = 0.090) and Grade 3-4 AEs between patients without and with PH.

CONCLUSIONS

No significant differences in efficacy and safety were observed with PH. Prophylactic treatment for varices before the start of Atezo + Beva would allow treatment to continue relatively safely.

Evidence to Date: Clinical Utility of Tremelimumab in the Treatment of Unresectable Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide and is associated with significant health care costs and burden. Management of HCC is guided based on the Barcelona Clinic Liver Cancer (BCLC) system and includes liver transplantation, surgical resection, and liver-directed and systemic therapies. In recent years, there have been significant advancements in understanding the immunogenicity of HCC and this has led to approval of different targeted agents as well as immunotherapy for advanced HCC. Tremelimumab is a cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) blocking antibody and has recently been approved in combination with durvalumab (a programmed death-ligand 1 [PDL1] inhibitor) as first-line therapy for advanced (Barcelona Clinic Liver Cancer Stage C) HCC. In this article, we review the different available systemic therapies for advanced HCC with special focus on the clinical utility of tremelimumab for the treatment of unresectable HCC.

Risk Factors for Early Onset of Proteinuria in Patients Receiving Atezolizumab Plus Bevacizumab for Unresectable Hepatocellular Carcinoma

Introduction

Proteinuria is one of the adverse events of atezolizumab plus bevacizumab combination therapy (Atezo + Bev) and can cause interruption in the use of Bev. However, the risk factors for proteinuria in patients with hepatocellular carcinoma (HCC) who are receiving Atezo + Bev have not yet been investigated. The aim of this study was to identify the risk factors for early onset of proteinuria in Atezo + Bev for patients with unresectable HCC.

Methods

Sixty-four patients with Child-Pugh scores of 5-7, an Eastern Cooperative Oncology Group performance status of 0 or 1, and low level of proteinuria (1+ or less on a dipstick test and urine protein-to-creatinine ratio (UPCR) less than 2.0 g/g Cr) at the initiation of therapy were analyzed. The level of proteinuria was evaluated based on the Common Terminology Criteria for Adverse Events version 5.0. We adopted the UPCR for the quantitative test instead of a 24-h urine collection. The incidence of proteinuria and changes in liver function were retrospectively investigated.

Results

The cumulative incidence of proteinuria over a 24-week period was 34.4%. Multivariate analysis showed that a low estimated glomerular filtration rate (hazard ratio [HR], 3.807; 95% confidence interval [CI], 1.579-9.180; p = 0.003), treatment for hypertension (HR, 6.224; 95% CI, 1.614-24.010; p = 0.008), and high systolic blood pressure (SBP) (HR, 2.649; 95% CI, 1.133-6.194; p = 0.025) were risk factors for proteinuria. Serum albumin levels and albumin-bilirubin scores in patients with proteinuria worsened. In addition, a mean SBP ≥135 mm Hg during treatment was the only risk factor for the development of severe proteinuria (UPCR >2 g/g Cr).

Conclusion

Our study found that controlling blood pressure is extremely important for the management of proteinuria in patients with HCC who are receiving Atezo + Bev.

Bevacizumab versus Ramucirumab in EGFR-Mutated Metastatic Non-Small-Cell Lung Cancer Patients: A Real-World Observational Study

The combination of bevacizumab or ramucirumab with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy, chemotherapy, or immunotherapy for non-small-cell lung cancer (NSCLC) patients with EGFR mutations could have survival benefits. However, no study, to date, has been conducted to compare the efficacy and safety of these two antiangiogenic therapies (AATs). Stage IIIB to IV EGFR-mutated NSCLC patients who received first-line EGFR-TKIs between January 2014 and May 2022 were enrolled. These patients were divided into two groups: those receiving bevacizumab and those receiving ramucirumab as a combination therapy in any line of treatment. Ninety-six patients were enrolled in this study's final analysis. The progression-free survival (PFS) of patients who received front-line AATs combined with EGFR-TKI therapy was longer than that of patients receiving later-line AATs combined with other therapies (19.6 vs. 10.0 months, p < 0.001). No difference in overall survival (OS) was observed between front-line and later-line therapy (non-reach vs. 44.0 months, p = 0.261). Patients who received these two different AATs did not differ in PFS (24.1 vs. 15.7 months, p = 0.454) and OS (48.6 vs. 43.0 months, p = 0.924). In addition, these two AATs showed similar frequencies of the T790M mutation (43.6% vs. 38.2%; p = 0.645). Multivariate Cox regression analysis indicated several AAT cycles as an independent good prognostic factor in OS. The incidence of some adverse events such as bleeding and hepatitis was higher for bevacizumab than for ramucirumab but it was not significant. Front-line AAT and EGFR-TKI combination therapy improved the PFS of stage IV EGFR-mutated NSCLC patients. The effectiveness and safety of the two AATs were similar.

A Case of Duodenal Variceal Rupture during Atezolizumab and Bevacizumab Treatment for Hepatocellular Carcinoma

Duodenal varices are detected infrequently, and their rupture is very rare. We encountered an 87-year-old man who developed duodenal varices rupture during chemotherapy with atezolizumab and bevacizumab (ATZ/BV) for hepatocellular carcinoma. We identified massive bleeding of a ruptured varix in the horizontal portion of the duodenum with emergency esophagogastroduodenoscopy (EGD). Successful hemostasis was achieved by endoscopic injection sclerotherapy with Histoacryl. Although ATZ/BV can cause esophageal varices rupture, there have been no cases of duodenal varices rupture. We should take care to check the duodenal varices as well as esophagogastric varices before ATZ/BV treatment.

Evaluation of lung toxicity with bevacizumab using the spontaneous reporting database

This study was undertaken to determine the risk of bevacizumab-induced lung toxicity, time to onset, and post hoc outcomes using the Japanese Adverse Drug Event Report database. We analysed data for the period between April 2004 and March 2021. Data on lung toxicities were extracted, and relative risk of adverse events (AEs) was estimated using the reporting odds ratio. We analysed 5,273,115 reports and identified 20,399 reports of AEs caused by bevacizumab. Of these, 1679 lung toxicities were reportedly associated with bevacizumab. Signals were detected for nine lung toxicities. A histogram of times to onset showed occurrence from 35 to 238 days, but some cases occurred even more than one year after the start of administration. Approximately 20% of AEs were thromboembolic events. Among these, pulmonary embolism was the most frequently reported and fatal cases were also reported. The AEs showing the highest fatality rates were pulmonary haemorrhage, pulmonary infarction, and pulmonary thrombosis. In conclusion, we focused on lung toxicities caused by bevacizumab as post-marketing AEs. Some cases could potentially result in serious outcomes, patients should be monitored for signs of onset of AEs not only at the start of administration, but also over a longer period of time.

Overall Survival and Progression-Free Survival Comparison of Bevacizumab Plus Chemotherapy Combination Regiment versus Chemotherapy Only Regiment in Previously Untreated Metastatic Colorectal Cancer: Systematic Review and Meta-Analysis

BACKGROUND: Colorectal cancer is the third-most common cancer in the world, in which 15%–25% of patients already had metastatic colorectal cancer (mCRC) at the time of diagnosis. The overall survival (OS) of mCRC is poor with the use of chemotherapy. AIM: This systematic review and meta-analysis aim to examine the outcomes of OS and progression-free survival (PFS) of adding bevacizumab to different chemotherapy regiments compared to chemotherapy regiments only in the treatment of untreated mCRC. METHODS: Literature searching was done in databases such as PubMed, EBSCO, SCOPUS, and ScienceDirect. The primary outcome measured in this systematic review and meta-analysis was OS, while the secondary outcome was PFS. Hazard ratio (HR) was used as the main summary measure with 95% confidence interval (CI). Publication bias was measured using a funnel plot. RESULTS: Literature searching resulted in 11 selected studies, 9 selected for meta-analysis. Addition of bevacizumab showed significant better results in OS (HR 0.83, CI 95% 0.74–0.93; p = 0.002; I2 = 29%) and PFS (HR 0.62, 95% CI 0.51–0.75; p < 0.0001, I2 = 78%). CONCLUSION: The addition of bevacizumab to chemotherapy resulted in better OS and PFS in untreated mCRC. Further studies are needed to confirm PFS benefit from the combination of bevacizumab and chemotherapy due to significant heterogeneity.

Risk factors of proteinuria and potentially protective effect of renin-angiotensin system inhibitors in patients with renal cell carcinoma receiving axitinib

Purpose

Patients receiving vascular endothelial growth factor–tyrosine kinase inhibitors are at a risk of developing proteinuria. Renin–angiotensin system (RAS) inhibitors exert renoprotective effects and might reduce proteinuria risk in these patients. We investigated the risk factors for and protective effect of RAS inhibitors against proteinuria in patients with renal cell carcinoma (RCC) receiving axitinib.

Methods

We retrospectively reviewed the medical records of patients with RCC receiving axitinib at Kobe City Medical Center General Hospital between September 2012 and October 2020. Patients with proteinuria ≥ 2+ at baseline were excluded. The patients were categorized into RAS inhibitor user, non-RAS inhibitor user, and non-user groups. The severity of proteinuria was graded based on the Common Terminology Criteria for Adverse Events, version 5.0. A multivariate Cox proportional hazards model was employed to identify the risk factors for developing grade ≥ 2 proteinuria.

Results

Among 42 patients, 28 received antihypertensive drugs at baseline. Among these, 17 and 11 patients were in the RAS inhibitor and non-RAS inhibitor user groups, respectively. Twenty-three patients (54.8%) developed grade ≥ 2 proteinuria. The multivariate analysis revealed that the non-RAS inhibitor user group (P = 0.001) and patients with pre-existing grade 1 proteinuria (P = 0.022) were significantly associated with the development of grade ≥ 2 proteinuria, whereas the RAS inhibitor user group was not significantly associated with it.

Conclusion

In patients with RCC receiving axitinib, pre-existing proteinuria and non-RAS inhibitor use were significantly associated with grade ≥ 2 proteinuria development. Our preliminary data should be confirmed by further studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-022-04408-4.

Risk Factors of Proteinuria in Patients with Hepatocellular Carcinoma Receiving Lenvatinib

Proteinuria is one of the most frequently reported adverse events leading to the discontinuation of lenvatinib treatment in patients with advanced hepatocellular carcinoma (HCC). However, there are no reports regarding the risk factors of proteinuria in patients with HCC or patients receiving lenvatinib. We retrospectively reviewed the medical records of patients with HCC receiving lenvatinib at the Kobe City Medical Center General Hospital between April 2018 and December 2020. The severity of proteinuria was graded based on the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. A multivariate Cox proportional hazards model was employed to identify the risk factors of developing grade ≥2 proteinuria. Among the 37 patients included, 3 patients had grade-1 proteinuria at baseline and 10 patients had estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² at baseline. Grades 1, 2, and 3 proteinuria were observed in 15 (40.5%), 10 (27.0%), and 2 (5.4%) patients, respectively, during lenvatinib treatment. The median value of eGFR was significantly lower in patients who developed grade ≥2 proteinuria than those with grade ≤1 proteinuria (59.6 vs. 78.1 mL/min/1.73 m², p = 0.045). Multivariate analysis revealed that pre-existing proteinuria at baseline (hazard ratio (HR), 9.72; 95% confidence interval (CI), 1.29-52.21; p = 0.030), and eGFR <60 mL/min/1.73 m² at baseline (HR, 4.49; 95% CI, 1.32-16.07; p = 0.017) were significantly associated with developing grade ≥2 proteinuria. These patients should be monitored carefully, and our preliminary data should be confirmed by further studies.

Elucidation of optimal proteinuria management based on the risk of ramucirumab-induced proteinuria

Proteinuria is a dose-limiting adverse effect of ramucirumab treatment, which is an anti-angiogenic agent that targets the human vascular endothelial growth factor. The predictors of proteinuria have not been completely elucidated and there is currently no consensus. The present study aimed to identify the risk factors for ramucirumab-induced proteinuria and to determine an optimal proteinuria management. A total of 145 patients who received ramucirumab at Ogaki Municipal Hospital (Ogaki, Japan) between September 2015 and March 2021 were retrospectively studied. Multivariate logistic regression analysis was conducted to evaluate the association between the patient baseline characteristics and the development of proteinuria following ramucirumab treatment. Furthermore, the time of proteinuria onset and of the worst qualitative proteinuria were recorded. Proteinuria (>2+) following ramucirumab was independently associated with lung cancer [odd ratio (OR): 0.232, 95% confidence interval (CI): 0.061-0.874; P=0.031] and proteinuria at the start of treatment [qualitative test (+/-); OR: 4.760, 95% CI: 1.360-16.700; P=0.041]. The median time of onset of proteinuria was 56 days (time range, 7-414 days), and the median time when the worst qualitative results were observed was 83 days (time range, 7-442 days). The >2+ proteinuria in the qualitative test was observed in 27 out of the 82 patients with gastric cancer (P=0.041), 8/21 patients with colon cancer (P=0.188), and in 3 out of the 37 patients with lung cancer (P=0.003). The prevalence of proteinuria was low in patients with lung cancer, and proteinuria (>2+) was likely to occur when the proteinuria at the start of ramucirumab was (+/-) by qualitative test. The results from the present study indicated that particular attention should be paid to proteinuria at the start of treatment when monitoring proteinuria as an adverse event of ramucirumab treatment.

Nintedanib-Induced Renal Thrombotic Microangiopathy

Nintedanib is a unique tyrosine kinase inhibitor used to suppress fibrosis in patients with idiopathic pulmonary fibrosis (IPF). Nintedanib has been shown to suppress multiple processes of fibrosis, thereby reducing the rate of lung function decline in patients with IPF. Since vascular endothelial growth factor is one of this agent's targets, nephrotoxicity, including renal thrombotic microangiopathy (TMA), is a possible major adverse effect. However, only 2 previous cases of nintedanib-induced renal TMA have been published. Our patient was an 83-year-old man with IPF. As adverse effects including liver enzyme level elevation, diarrhoea, anorexia, and nephrotoxicity developed, the nintedanib dosage was reduced after 9 months. The digestive symptoms resolved promptly, but the proteinuria and reduced kidney function remained. Although the kidney injury had improved to some extent, we performed a percutaneous renal biopsy. The biopsy revealed typical TMA findings such as microaneurysms filled with pale material, segmental double contours of glomerular basement membranes, and intracapillary foam cells. After discontinuation of nintedanib, the patient's nephrotoxicity improved. Nintedanib-induced renal TMA is reversible and is possibly dose-dependent. Here, we report the clinical course of our case and review the characteristics of nintedanib-induced renal TMA.

Immunotherapy in hepatocellular carcinoma: evaluation and management of adverse events associated with atezolizumab plus bevacizumab

In light of positive efficacy and safety findings from the IMbrave150 trial of atezolizumab plus bevacizumab, this novel combination has become the preferred first-line standard of care for patients with unresectable hepatocellular carcinoma (HCC). Several additional trials are ongoing that combine an immune checkpoint inhibitor with another agent such as a multiple kinase inhibitor or antiangiogenic agent. Therefore, the range of first-line treatment options for unresectable HCC is likely to increase, and healthcare providers need succinct information about the use of such combinations, including their efficacy and key aspects of their safety profiles. Here, we review efficacy and safety data on combination immunotherapies and offer guidance on monitoring and managing adverse events, especially those associated with atezolizumab plus bevacizumab. Because of their underlying liver disease and high likelihood of portal hypertension, patients with unresectable HCC are at particular risk of gastrointestinal bleeding, and this risk may be exacerbated by treatments that include antiangiogenic agents. Healthcare providers also need to be alert to the risks of proteinuria and hypertension, colitis, hepatitis, and reactivation of hepatitis B or C virus infection. They should also be aware of the possibility of rarer but potentially life-threatening adverse events such as pneumonitis and cardiovascular events. Awareness of the risks associated with these therapies and knowledge of adverse event monitoring and management will become increasingly important as the therapeutic range broadens in unresectable HCC.

Clinical and laboratory signs and risk factors for nephrotoxicity, associated with antiangiogenic drugs

Background. Anti-angiogenic anticancer drugs that block the vascular endothelial growth factor signaling pathway can cause renal damage. Assessment of the risk of nephrotoxicity allows developing optimal treatment approaches and ensuring the relative safety of therapy. Aim. To assess early clinical and laboratory manifestations and risk factors for nephrotoxicity of antiangiogenic drugs. Materials and methods. The study included 50 patients who received antiangiogenic drugs in different regimens of chemotherapy. Demographic factors, body mass index, blood pressure levels, type of antiangiogenic drug, and concomitant therapy were assessed. Before treatment and over a period of 8 weeks, the levels of hemoglobin, number of platelets and schistocytes, D-dimer levels, serum lactate dehydrogenase (LDH) levels, as well as daily proteinuria and serum creatinine and eGFRCKD-EPI were assessed. Linear regression analysis was performed to assess risk factors for nephrotoxicity and arterial hypertension (AH). Results. The median age of patients was 46 [3457] years, 22 (44%) men and 28 (56%) women. AH developed in 52%, a decrease in eGFR in 42%, along with a decrease in hemoglobin levels and an increase in LDH levels at 2 weeks of therapy. The numbers of schistocytes and platelets significantly decreased by 8 weeks of therapy. Risk factors for impaired renal function during treatment with antiangiogenic drugs were an initial decrease in GFR less than 80 ml/min/1.73 m2, an increase in D-dimer levels, and a decrease in hemoglobin levels by 8 weeks of treatment. The risk factors for AH during therapy were the initial decrease in eGFR less than 80 ml/min/1.73 m2 and no prophylactic anticoagulant therapy. Conclusion. Early signs of nephrotoxicity of antiangiogenic anticancer drugs were a decrease in eGFR and AH. The independent risk factors for nephrotoxicity were the initial decrease in eGFR, an increase in D-dimer levels, and a decrease in hemoglobin levels at 8 weeks of treatment, while the prophylactic use of anticoagulant therapy reduced this risk in our study.

VEGF-VEGFR2 inhibitor-associated hyaline occlusive glomerular microangiopathy: a Japanese single-center experience

BACKGROUND

Inhibitors of vascular endothelial growth factor (VEGF)-VEGF receptor 2 (VEGFR2) signaling, such as bevacizumab (Bmab), are used for the treatment of various advanced cancers. However, these inhibitors induce renal thrombotic microangiopathy (TMA). Recently, two European cohort studies showed a distinctive histopathological pseudothrombotic pattern different from TMA in Bmab-treated patients.

METHODS

We analyzed 9 renal biopsies from proteinuric cancer patients treated with VEGF-VEGFR2 inhibitors in our Japanese cohort. Clinical and laboratory features were also assessed in these patients.

RESULTS

All 9 patients had moderate to heavy proteinuria with normal or slightly elevated serum creatinine levels. On light microscopy, a patchy pattern of hemispherical/spherical lesions along glomerular capillary walls was a characteristic finding. On immunofluorescence microscopy, staining for immunoglobulins (IgM dominant) at varying intensities was observed mainly along glomerular capillary walls. Especially, hemispherical/spherical positive staining for immunoglobulins was a characteristic pattern. Immunohistochemical studies showed positive staining for immunoglobulins and negative staining for CD61-positive platelets in capillary hemispherical/spherical lesions and positive VEGF staining in podocytes. On electron microscopy, variably electron-dense material in dilated glomerular capillaries and partial effacement of podocyte foot processes were observed. After the withdrawal of VEGF-VEGFR2 inhibitors, proteinuria improved without any specific treatment in 8 patients.

CONCLUSIONS

Histopathological findings in our patients treated with VEGF-VEGFR2 inhibitors were consistent with those observed in the recently described new form of Bmab-associated hyaline occlusive glomerular microangiopathy. This form should be considered in proteinuric cancer patients treated with VEGF-VEGFR2 inhibitors. Discontinuing VEGF-VEGFR2 inhibitors may lead to improvement of glomerular microangiopathy induced by these drugs.

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

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