Renal thrombotic microangiopathy caused by anti-VEGF-antibody treatment for metastatic renal-cell carcinoma

Progressive bevacizumab-associated renal thrombotic microangiopathy

Vascular endothelial growth factor (VEGF) is integral to the integrity of the glomerular filtration barrier. Bevacizumab is a humanized monoclonal antibody directed against VEGF with expanding clinical applications for metastatic solid tumours. We describe a case of a 61-year-old female with ovarian cancer and baseline chronic kidney disease who received three doses of bevacizumab and subsequently developed progressive renal clearance dysfunction and nephrotic range proteinuria. A renal biopsy was performed 4 months after drug discontinuation and was consistent with TMA. At baseline, prior to bevacizumab exposure, her estimated glomerular filtration rate (eGFR) was 44 mL/min/1.73 m² and she had no proteinuria. At the completion of therapy, eGFR was 27 mL/min/1.73 m² with 1+ proteinuria on urinalysis. Her renal failure and proteinuria continued to progress 5 months after discontinuation of bevacizumab therapy, at which time eGFR was 11 mL/min/1.73 m² and proteinuria was 5.5 g/24 h. Non-remitting TMA after bevacizumab therapy in patients with pre-existing chronic kidney disease has not been previously reported. Further studies are needed to assess the safety of this drug in patients with chronic kidney disease.

Vascular complications of selected cancer therapies

Over the past decade, therapies for several previously untreatable types of cancer have emerged or have improved; thus, more focus has been given to long-term complications of cancer therapy. The most commonly known cardiac toxicities of cancer therapy are cardiac dysfunction or congestive heart failure. Vascular complications--such as ischemia, myocardial infarction, venous or arterial thrombosis, and newly developed or worsened hypertension--are also relatively common following cancer treatment, particularly in patients with advanced-stage cancer. Experimental studies have suggested a number of potential mechanisms that might account for vascular complications of cancer therapies, which include dysfunction or damage of endothelial cells, increased platelet aggregation, and modulation of nitric oxide levels. This Review describes the vascular complications of treatment with 5-fluorouracil, bevacizumab, and several new tyrosine kinase inhibitors, with special emphasis on thrombotic complications and hypertension.

[Thromboembolic risk associated with use of angiogenesis inhibitors used for the treatment of cancers]

Among antiangiogenic agents, thalidomide is not the most potent nor the most specific even so when venous thromboembolic events have been reported with the prescription of thalidomide in multiple myeloma. This side effect has been related to the antiangiogenic effect of this immunomodulator. In keeping with this observation venous thromboembolic events have been reported in other indications of thalidomide and with thalidomide analogues (Lenalidomide and Actimid). The thrombotic side effects are mostly venous but arterial thrombotic events are also observed with the use of these molecules. With the other and more specific antiagiogenic agents an increase in thrombotic events are also observed. This increase was not immediately evident since the situation in which they are prescribed (metastatic cancers) are already characterized by a high rate of thrombotic events. The prothrombotic effect of antiangiogenic agents are probably linked to an effect on endothelium (decrease of antithrombotic activities and stimulation of a prothrombotuic state). The other sides effects of antiangiogenic agents (hemorrhages, hypertension, proteinuria, microangiotpahia, delay in scaring) are also probably related to endothelial effects. The prothrombotic effect of antoangiogenic agents appears as potentiating the prothrombotic conditions of the disease (myeloma, cancer) and the prothombotic effects of the associated treatments (chemotherapy, high dose corticosteroids, erythropoietin). The increased thrombotic risk linked to prescription of antiangiogenic agents and specially of thalidomide and analogues for multiple myeloma is such that it is recommended to associate a preventive antithrombotic treatment. Some efficacy has been reported with the use of aspirin, oral anticoagulant or low molecular weight heparin. No head to head comparative trial do not allow to prefer one strategy. From published data full dose oral anticoagulants appear to confer the highest hemorrhagic risk and perhaps low molecular weight heparin the best benefit-risk ratio.

[Role of supportive care in lung cancer]

Lung cancer is a bad prognostic illness with a limited survival and many side effects related to treatment used. Supportive care in cancer attends to enhance patient care among cancer and treatments suffering. Opioids are one of the most important treatments in the management of dyspnoea and pain. Every new drug in supportive care is tested to diminish side effects of treatment like erythropoietin against anemia or aprepitant against emesis. Many trials are developed to enhance this supportive care especially in lung cancer management.

Complications from vascular disrupting agents and angiogenesis inhibitors: aberrant control of hemostasis and thrombosis

PURPOSE OF REVIEW

To discuss thrombotic and hemorrhagic complications from angiogenesis inhibitors and vascular disrupting agents, pathogenesis, and recommendations for prophylaxis and management of those complications.

RECENT FINDINGS

Venous thromboembolism has been a significant complication of the angiogenesis inhibitors thalidomide and lenalidomide. Prophylaxis with aspirin, low-molecular-weight heparin, or warfarin has been shown to decrease rates of venous thromboembolism in patients treated with these agents. Life-threatening hemorrhage and arterial thromboembolism have been observed in patients using treatments that inhibit the vascular endothelial growth factor signaling pathway. Patients should be screened for arterial thromboembolism and hemorrhage risk prior to using vascular endothelial growth factor signal inhibitors. It is not known how angiogenesis inhibitors and vascular disrupting agents upset normal hemostasis. It is likely that disruption of the function and/or integrity of vascular endothelium leads to an increased risk for thrombosis and/or hemorrhage.

SUMMARY

New angiogenesis inhibitors and vascular disrupting agents have been developed that have significant activity against neoplasms. Potentially life-threatening side effects of hemorrhage and thrombosis have been observed with many of these new agents. As new treatments that disrupt angiogenesis or existing tumor vasculature are developed, attention should be given to these toxicities in clinical practice and clinical trials.