Central nervous system complications of immune checkpoint inhibitors: A comprehensive review

The ever-increasing use of immune checkpoint inhibitors (ICIs) has significantly improved cancer management, but at the cost of frequent immunologic side effects. Among them, neurologic immune-related adverse events (nirAEs) are less common but pose a challenge to clinicians due to their severity, heterogeneous nature and nonspecific clinical presentation, making diagnosis complex. The prognosis of these nirAEs, especially those related to the central nervous system (CNS), correlates with their rapid recognition and therapeutic management. Indeed, the therapeutic options are sometimes unfamiliar and may be further complicated by the lack of recommendations in the event of failure of a well-managed first-line treatment. Finally, the attribution of ICIs to certain CNS disorders is controversial and may lead to an incorrect decision to discontinue or contraindicate treatment, resulting in an irremediable loss of opportunity for the patient. Therefore, the aim of this review is to present known/suspected CNS nirAEs induced by ICI, their diagnostic approach and management through therapeutic advices for optimal treatment and rechallenge opportunities.

Neuro-ophthalmic complications of modern anti-cancer drugs

PURPOSE

Targeted cancer therapies have been responsible for a dramatic shift in treatment strategies for cancer, and the number of drugs, classes, and indications are continually growing. Neuro-ophthalmic complications of these medications are an uncommon but important subset of adverse events which profoundly impact vision. This review aims to collate studies and reports of known neuro-ophthalmic complications of targeted therapies and describe their management.

METHODS

The anti-cancer drugs included in the review were any drugs targeting specific molecules involved in the cancer disease process. PubMed, EMBASE, and Web of Science were searched using the generic names of each drug and keywords of neuro-ophthalmic conditions. The prescribing information published by the US Food and Drug Administration (FDA) for each drug was also reviewed.

RESULTS

Several classes of targeted anti-cancer drugs were found to cause neuro-ophthalmic adverse effects. Immune checkpoint inhibitors are responsible for a raft of immune-related adverse events such as optic neuritis, ischemic optic neuropathy, PRES, and myasthenia gravis. Therapies with anti-VEGF activity can provoke posterior reversible leukoencephalopathy, which commonly presents with visual loss and can be fatal if not treated promptly. Inhibitors of BCR-ABL1, VEGF, ALK, and proteasomes have all been linked to optic nerve disorders which can have debilitating consequences for vision.

CONCLUSION

The neuro-ophthalmic complications of modern anti-cancer drugs can limit or necessitate the withdrawal of these life-prolonging medications. Ophthalmologists should be alert for neuro-ophthalmic complications in these medications to facilitate prompt diagnosis and treatment and reduce the risk of severe and permanent consequences.

Encephalitis in a patient with hypopharynx cancer treated with immune checkpoint inhibitors and radiotherapy: a case report and review of the literature

Hypopharyngeal cancer (HPC) has one of the most unfavorable prognoses among head and neck squamous cell carcinomas. Immunotherapy in combination with chemotherapy, the same as conventional induction chemotherapy, has emerged as a vital part of the induction therapy protocol for HPC. Meanwhile, the incidence of immune-related adverse events is increasing. In this light, we present the first reported case of immune-associated encephalitis in a patient with hypopharyngeal cancer treated with Camrelizumab (a PD-1 inhibitor). After receiving immunotherapy combined with chemotherapy as induction therapy, along with concurrent chemoradiotherapy, the patient presented with symptoms of fatigue, tremors, drowsiness, and an abnormal signal in the right temporal lobe as shown on a brain magnetic resonance imaging (MRI). Despite the minor elevation in protein and IgG index observed in the lumbar puncture, there is no evidence of abnormal autoantibodies or evidence of pathogenic infection. Following a thorough multidisciplinary consultation, the patient is suspected to be afflicted with immune-related autoimmune encephalitis. Intravenous methylprednisolone was prescribed as an empirical treatment at an initial dosage of 120 mg/day for 3 days, followed by steroid tapering. Finally, the patient experienced complete neurologic and radiographic (brain MRI) recovery. This case serves as a critical reminder that encephalitis is a potential diagnosis that should never be overlooked in patients undergoing immunotherapy who present with abnormal signs of the brain. The timely diagnosis and initiation of immunosuppressive therapy are key components of treating ICI-associated encephalitis.

Psychiatric disorders associated with immune checkpoint inhibitors: a pharmacovigilance analysis of the FDA Adverse Event Reporting System (FAERS) database

Background

With the increasing use of immune checkpoint inhibitors (ICIs) for tumour immunotherapy, the immune-related adverse events (irAEs) caused by their collateral effect on the immune system pose a key challenge for the clinical application of ICIs. Psychiatric adverse events are a class of adverse events associated with ICIs that are realistically observed in the real world. We aim to provide a comprehensive study and summary of psychiatric adverse events associated with ICIs.

Methods

We obtained ICI adverse reaction reports during January 2012-December 2021 from the FDA Adverse Event Reporting System (FAERS) database. ICI reports underwent screening to minimize the influence of other adverse reactions, concomitant medications, and indications for medication use that may also contribute to psychiatric disorders. Disproportionality analysis was performed to find psychiatric adverse events associated with ICIs by comparing ICIs with the full FAERS database using the reporting odds ratio (ROR). Influencing factors were explored based on univariate logistic regression analysis. Finally, the Cancer Genome Atlas (TCGA) pan-cancer transcriptome data were combined to explore the potential biological mechanisms associated with ICI-related pAEs.

Findings

Reports of psychiatric adverse events accounted for 2.71% of the overall ICI adverse event reports in the FAERS database. Five categories of psychiatric adverse events were defined as ICI-related psychiatric adverse events (pAEs). The median age of reports with ICI-related pAEs was 70 (interquartile range [IQR] 24-95), with 21.54% of reports having a fatal outcome. Cases with indications for lung cancer, skin cancer and kidney site cancer accounted for the majority. The odds of ICI-related pAEs increased in older patients (65-74: OR = 1.44 [1.22-1.70], P < 0.0001: ≥75: OR = 1.84 [1.54-2.20], P < 0.0001). The occurrence of ICI-related pAEs may be related to NOTCH signalling and dysregulation of synapse-associated pathways.

Interpretation

This study investigated psychiatric adverse events highly associated with ICI treatment, their influencing factors and potential biological mechanisms, which provides a reliable basis for further in-depth study of ICI-related pAEs. However, as an exploratory study, our findings need to be further confirmed in a large-scale prospective study.

Funding

This work was supported by the Natural Science Foundation of Guangdong Province (2018A030313846 and 2021A1515012593), the Science and Technology Planning Project of Guangdong Province (2019A030317020) and the National Natural Science Foundation of China (81802257, 81871859, 81772457, 82172750 and 82172811). Guangdong Basic and Applied Basic Research Foundation (Guangdong - Guangzhou Joint Fouds) (2022A1515111212). This work was supported by Key Research and Development Projects of Sichuan Science and Technology (2022YFS0221, 2022YFS0074, 2022YFS0156 and 2022YFS0378). Sichuan Provincial People's Hospital Hospital Young Talent Fund (2021QN08).

Evaluation and management of acute high-grade immunotherapy-related neurotoxicity

Immune checkpoint inhibitor monoclonal antibodies allow the host's immune system to attack tumors, which has revolutionized cancer care over the last decade. As the use of immune checkpoint inhibitors has expanded, so have autoimmune-like complications known as immune-related adverse events. These include the infrequent but increasingly more common, potentially deadly neurological immune related adverse events. When feeling acutely ill, patients will often seek care not from their oncologist but from their family physician, clinics, emergency, and urgent care sites, or other available providers. Thus, while assessing acutely ill cancer patients who are experiencing neurological symptoms, non-oncologists should be prepared to recognize, diagnose, and treat neurological immune related adverse events in addition to more familiar conditions. This narrative review is designed to update acute care clinicians on current knowledge and to present a symptom-based framework for evaluating and treating neurological immune related adverse events based on the leading immunotoxicity organizations' latest recommendations.

Neurology of cancer immunotherapy

BACKGROUND

Immunotherapy is nowadays considered a mainstay of cancer treatment, dramatically affecting the disease-free survival rate in several aggressive malignancies. Unfortunately, cancer immunotherapy can also trigger life-threatening autoimmune neurological complications named "neurological adverse effects" (NAEs). NAEs can affect both the central nervous system (CNS), as in ipilimumab-related aseptic meningitis, and the peripheral nervous system (PNS), as in nivolumab-induced myasthenia gravis.

CURRENT EVIDENCE

The incidence of NAEs is highly variable, ranging from 2 to 4% using checkpoint inhibitors to 50% using blinatumomab. Looking at these numbers, it appears clear that neurologists will soon be called more and more frequently to decide upon the best therapeutic strategy for a patient receiving immunotherapy and experiencing a NAE. Most of them can be treated or reverted withholding the offending drug and adding IVIg, plasmapheresis, or steroids to the therapy. Sometimes, however, for oncological reasons, immunotherapy cannot be stopped so the neurologist needs to know what countermeasures have proven most effective. Moreover, patients with a pre-existing autoimmune neurological disease (AID), such as myasthenia gravis or multiple sclerosis, might need immunotherapy during their life, risking a severe worsening of their symptoms. In that setting, the neurologist needs to properly counsel patients about the risk of a therapy-related relapse.

CONCLUSION

In this article, we describe the most frequently reported NAEs and aim to give neurologists a practical overview on how to deal with them.

Mepolizumab-Induced Posterior Reversible Encephalopathy Syndrome (PRES), a new patient report

BACKGROUND

Posterior Reversible Encephalopathy Syndrome (PRES) is a neurotoxic state characterized by seizures, headache, vision change, paresis, and altered mental status. PRES has an important place in medicine due to the wide variety of causative diseases, infections, and medications that precipitate its mysterious onset. Although exposure to medications, particularly immunosuppressants, cancer chemotherapy, and biologic drugs, is a common occurrence in patients who develop PRES, Mepolizumab has never before been associated.

CASE PRESENTATION

This report of a 67-year-old male patient outlines the first reported case of Mepolizumab-induced PRES in the literature.

CONCLUSIONS

Treatment of severe asthma, asthma-exacerbations, and diseases such as eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss) with Mepolizumab is rapidly gaining popularity ever since the drug's recent FDA-approval. This report aims to raise awareness of this potentially life-threatening and previously unreported side effect of Mepolizumab since early identification of the causative agent is the key to preventing the severe neurologic disability and possible death that may occur from the delayed treatment of PRES.

Rituximab in Refractory Myositis and Acute Neuropathy Secondary to Checkpoint Inhibitor Therapy

Checkpoint inhibitor immunotherapies have been one of the latest advances through the last decade in the treatment of various cancers. As their use is increasing so is the knowledge of their complications which can affect various organ systems including the central and peripheral nervous systems. Management of these complications requires stopping the offending agent and in some cases treating with immunosuppressive agents like intravenous steroids. Physicians can face challenging situations if patients are unresponsive to steroids, intravenous immunoglobulins (IVIG), and plasmapheresis (PLEX). There are no formal guidelines to help in the management of such patients. 

We present an 85-year-old male with a past medical history of renal cell carcinoma status post nephrectomy who was admitted with diplopia, eyelid ptosis, dysphagia, dysphonia, dyspnea, and generalized weakness. He was started on nivolumab and ipilimumab 10 days prior to presentation. Laboratory studies showed an elevated erythrocyte sedimentation rate, C-reactive protein, and creatine phosphokinase, and an unrevealing lumbar puncture. Acetylcholine receptor (AChR) and muscle-specific kinase (MuSK) antibodies were negative. Electromyography and nerve conduction studies showed axonal and demyelinating sensorimotor neuropathy with no significant decrement on 3 Hz repetitive stimulation. Thyroid function tests were concerning for thyroiditis and anti-thyroid peroxidase antibodies were positive. Together, these findings led to the diagnosis of refractory myositis and acute neuropathy along with autoimmune thyroiditis from nivolumab and ipilimumab immunotherapy. His symptoms were unresponsive to a 5-day course of steroids, intravenous immunoglobulins, and plasmapheresis. He was then started on rituximab with significant improvement in ptosis, dysphagia, dysphonia, and proximal weakness. Immune checkpoint inhibitors (ICI) are associated with an increased risk for the development of various autoimmune conditions. Treatment involves discontinuation of the offending drug and initiation of immunosuppressive therapy.

This case is interesting as it demonstrates the importance of the awareness of the neurological complications of the checkpoint inhibitor therapies and the beneficial role of rituximab in patients who are unresponsive to initial immunosuppressive therapies including steroids, IVIG, and PLEX.

Pembrolizumab-Related Side Effects: Acute Renal Failure and Severe Neurological Toxicity

Immunotherapy with immune checkpoint inhibitors represents nowadays a marked improvement in cancer treatment. Nevertheless, they can cause severe toxicities that put the patient at high risk, often requiring aggressive treatment. We present the case of a female patient who developed a severe immune-related adverse reaction to Pembrolizumab prescribed for melanoma treatment. Her array of symptoms, which presented a few days after last drug administration, consisted of severe neurological deficit, severe renal failure, polymyositis, and hyperthyroidism. Treatment required the immediate interruption of the trigger drug, infusion of high dose steroids, renal replacement therapy, plasmapheresis, and methimazole, as will be further discussed.

Neurotoxicity of Tumor Immunotherapy: The Emergence of Clinical Attention

Tumor immunotherapy brings substantial and long-term clinical benefits that can even cure tumors. However, the accumulation of evidence suggests that immunotherapy also induces severe and complex neurologic immune-related adverse events (ir-AEs) and even leads to immunotherapy-related death, which arouses the concern of clinicians. The timely and accurate identification of neurotoxicity helps clinicians detect and treat these complications early, thereby enhancing treatment efficiency and improving the prognosis of patients. At present, the mechanism of neurotoxicity caused by immunotherapy has not been completely elucidated. This paper mainly reviews the clinical features, pathogenesis, and therapeutic strategies of neurologic ir-AEs.

Neurological Adverse Events Induced by Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer: Current Perspectives and New Development

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of multiple malignancies, especially in non-small cell lung cancer (NSCLC). With the extensive application of ICIs in clinical practice, clinicians have to manage their toxicities, which are often termed immune-related adverse events (irAEs). Several ICIs, such as nivolumab, pembrolizumab, atezolizumab, and durvalumab, have been approved by the US Food and Drug Administration (FDA) to treat advanced NSCLC, accompanied by a broad spectrum of toxicity reactions. However, ICIs-associated neurological toxicities, regarding polyneuropathy, Bell palsy, encephalopathy, and myasthenia gravis, as uncommon emerging toxicities have not been well recognized, present a challenge for clinicians to improve awareness of supervision, recognition, and management before death from them. Herein, we have summarized the incidence, diagnosis, clinical manifestations, potential mechanisms, treatments, and outcomes of ICIs-related neurotoxicity and optimized the management approach for NSCLC patients. Prompt recognition and proper management are indispensable to reduce the morbidity of these patients with immune-related neurological toxicities.

Weekly Paclitaxel given concurrently with Durvalumab has a favorable safety profile in triple-negative metastatic breast cancer

Therapeutic anti-PD-L1 antibodies are safe as a monotherapy, albeit with minimal efficacy in triple-negative breast cancer (TNBC). This trial aimed to test the safety and efficacy of Durvalumab and Paclitaxel in metastatic TNBC. In this open-label, one-arm trial, five cycles of weekly paclitaxel were delivered intravenously (IV) concurrent with Durvalumab that was given IV every 2 weeks. The combination was preceded by one cycle of paclitaxel alone, for immunological priming, followed by Durvalumab solo until disease progression or unacceptable toxicity. Between 2017 and 2019, 14 patients received at least one cycle of the combination therapy. The therapy was safe with no-dose limiting toxicity, except one case of skin lesions. Adverse events (AEs) were reported in 71% of patients, and there was no death due to the combination therapy. Regardless of grade, the most common AEs were headache and peripheral neuropathy, as each happened in four patients (29%), followed by fatigue and skin rash in three patients (21%) each. Grade 3/4 AEs were experienced by three patients (21%), with the most common being headache and anemia, which happened in two patients (14%). The confirmed objective response rate (ORR) was observed in five patients with a median duration of 10.0 months. Median Progression-free survival (PFS) and overall survival (OS) were 5 and 20.7 months, respectively. The combination of Durvalumab and Paclitaxel is safe, leaving room for additional agents. This is the first report on the combination of Durvalumab and Paclitaxel in the treatment of TNBC (NCT02628132).

Central nervous system injury from novel cancer immunotherapies

PURPOSE OF REVIEW

Neurotoxicity from antineoplastic treatment remains a challenge in oncology. Cancer treatment-induced central nervous system (CNS) injury can be therapy-limiting, severely disabling, and even fatal. While emerging cancer immunotherapies have revolutionized oncology during the past decade, their immunomodulatory properties can cause immune-related adverse effects (IRAE) across organ systems, including the nervous system. Central neurologic IRAEs from chimeric antigen receptor T cells (CAR-T) and immune checkpoint inhibitors (ICPI) are challenging complications of such therapies.We aim to provide clinicians with a comprehensive review of the relevant forms of CAR-T and ICPI-associated CNS toxicity, focusing on clinical features of such complications, diagnostic workup, predictive biomarkers, and management considerations in affected patients.

RECENT FINDINGS

Unique forms of CAR-T and ICPI-related CNS toxicity have been characterized in the recent literature. CAR-T-related neurotoxicity is common and clinically well delineated. ICPI-related CNS toxicity is relatively rare but includes a heterogenous spectrum of severe and diagnostically challenging conditions. While putative risk factors, neurotoxicity biomarkers, imaging correlates and treatment strategies have been put forward, development of tailored diagnostic and management consensus guidelines awaits further clinical investigation.

SUMMARY

As CAR-T and ICPI become more widely adopted, early recognition, documentation, and management of immunotherapy-related CNS toxicity are of paramount importance in the clinical setting.

A systematic review of immune checkpoint inhibitor-related neurological adverse events and association with anti-neuronal autoantibodies

Introduction: Immune checkpoint inhibitors (ICI) therapy has led to a paradigm shift in cancer drug development and in the clinical evaluation of approaches to combination cancer treatment. Dysregulation of the immune system by ICI therapy may also elicit autoimmune phenomena and consequently manifest clinically as immune-related adverse events (irAEs) including neurological irAEs. Areas Covered: The purpose of this review is to explore the role of autoantibodies in the diagnosis and prediction of neurological irAEs and to evaluate their pathogenicity. We searched Pubmed and Embase for neurological irAEs and associated autoantibodies and found 28 patients with central and peripheral neurological irAEs. Of these patients, up to 40% had encephalitis, 34.4% with myasthenia gravis and 22% of patients with peripheral neuropathy and Guillain-Barre Syndrome had autoantibodies. Expert Opinion: Overall, our survey suggested a causal relationship between neurological irAEs and autoantibodies. Detection of autoantibodies may help to diagnose neurological irAEs and inform their clinical management.

Paraneoplastic Neurological Syndromes and Beyond Emerging With the Introduction of Immune Checkpoint Inhibitor Cancer Immunotherapy

Paraneoplastic neurological syndromes are more commonly seen with malignancies such as small cell lung cancer, thymoma, gynecological malignancies, and breast cancer as well as seminoma. With the introduction of immune checkpoint inhibitor (ICI) cancer immunotherapy we see an increase of autoimmune neurological complications in patients with malignancies not traditionally associated with paraneoplastic neurological syndromes, such as melanoma and renal cell carcinoma. Immune checkpoint inhibitors enhance antitumor immune responses resulting often in immune-related adverse effects that can affect any organ, including the central and peripheral nervous system, neuromuscular junction and muscle. Neurological complications are rare; neuromuscular complications are more common than central nervous system ones but multifocal neurological presentations are often encountered. The vast majority of neurological complications appear within 3 months of ICI initiation, but have been described even after ICI cessation. Neural autoantibody testing reveals autoantibodies in approximately half of the patients with CNS complications. Early suspicion and diagnosis is critical to avoid worsening and improve outcomes. Therapeutic strategies depend on the severity of the symptoms and initially typically involve discontinuation of ICI and high dose steroids. Further immunosuppression might be necessary. Outcomes are dependent on patient's characteristics and clinical presentations.

Neurological complications of immune checkpoint inhibitor cancer immunotherapy

Neurological autoimmunity is increasingly recognized as a complication of immune checkpoint inhibitor (ICI) cancer immunotherapy. ICIs act by enhancing endogenous anti-tumor immune responses and can also lead to autoimmunity affecting all organs. ICI-related neurological autoimmunity is rare, most often manifests with neuromuscular involvement and more rarely affects the central nervous system. Neurological complications often often present in the first three months of ICI treatment but can also appear after ICI discontinuation. These can occur in patients with tumors not traditionally associated with paraneoplastic neurological autoimmunity, such as melanoma and renal-cell carcinoma and should be suspected when a new neurological symptoms present while on ICI and cannot be explained by disease progression or as a consequence of metabolic dysfunction. Treatment consists of ICI discontinuation or withdrawal depending on the severity with or without immunosuppression. Generally, improvement is observed depending on the patient's baseline characteristics and neurological presentation.

Anticancer Drugs and the Nervous System

PURPOSE OF REVIEW

This article reviews the clinical features, prognosis, and treatment of neurotoxicity from anticancer drugs, including conventional cytotoxic chemotherapy, biologics, and targeted therapies, with a focus on the newer immunotherapies (immune checkpoint inhibitors and chimeric antigen receptor T cells).

RECENT FINDINGS

Whereas neurologic complications from traditional chemotherapy are widely recognized, newer cancer therapies, in particular immunotherapies, have unique and distinct patterns of neurologic adverse effects. Anticancer drugs may cause central or peripheral nervous system complications. Neurologic complications of therapy are being seen with increasing frequency as patients with cancer are living longer and receiving multiple courses of anticancer regimens, with novel agents, combinations, and longer duration. Neurologists must know how to recognize treatment-related neurologic toxicity since discontinuation of the offending agent or dose adjustment may prevent further or permanent neurologic injury. It is also imperative to differentiate neurologic complications of therapy from cancer progression into the nervous system and from comorbid neurologic disorders that do not require treatment dose reduction or discontinuation.

SUMMARY

Neurotoxicity from cancer therapy is common, with effects seen on both the central and peripheral nervous systems. Immune checkpoint inhibitor therapy and chimeric antigen receptor T-cell therapy are new cancer treatments with distinct patterns of neurologic complications. Early recognition and appropriate management are essential to help prevent further neurologic injury and optimize oncologic management.

Neurologic Adverse Events of Immune Checkpoint Inhibitors: A Systematic Review

OBJECTIVE

To define the clinical characteristics, management, and outcome of neurologic immune-related adverse events (n-irAEs) of immune checkpoint inhibitors (ICIs).

METHODS

Systematic review of the literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

A total of 694 articles were identified. Two hundred fifty-six articles, with 428 individual patients, met the inclusion criteria. Reports regarding neuromuscular disorders (319/428, 75%) were more frequent than those on CNS disorders (109/428, 25%). The most common n-irAEs reports were myositis (136/428, 32%), Guillain-Barré syndrome and other peripheral neuropathies (94/428, 22%), myasthenic syndromes (58/428, 14%), encephalitis (56/428, 13%), cranial neuropathies (31/428, 7%), meningitis (13/428, 3%), CNS demyelinating diseases (8/428, 2%), and myelitis (7/428, 2%). Other CNS disorders were detected in 25/428 (6%) patients. Compared with the whole sample, myasthenic syndromes were significantly more Ab positive (33/56, 59%; p < 0.001). Anti-programmed cell death protein 1/programmed cell death ligand 1 was more frequent in myasthenic syndromes (50/58, 86%; p = 0.005) and less common in meningitis (2/13, 15%; p < 0.001) and cranial neuropathies (13/31, 42%; p = 0.005). Anti-cytotoxic T-lymphocyte antigen-4 ICIs were more frequent in meningitis (8/13, 62%; p < 0.001) and less common in encephalitis (2/56, 4%; p = 0.009) and myositis (12/136, 9%; p = 0.01). Combination of different ICIs was more frequent in cranial neuropathies (12/31, 39%; p = 0.005). Melanoma was more frequent in patients with peripheral neuropathies (64/94, 68%; p = 0.003) and less common in encephalitis (19/56, 34%; p = 0.001). The highest mortality rate was reached in myasthenic syndromes (28%).

CONCLUSION

Considering the increasing use of ICI therapy in the forthcoming future, this information can be valuable in assisting neurologists and oncologists in early n-irAEs diagnosis and treatment.

Neurologic Complications of Immune Checkpoint Inhibitors in Thoracic Malignancies

Immune checkpoint inhibitors (ICIs) have transformed the prognosis of cancers previously considered lethal. The spectrum of therapeutic indications is rapidly expanding, including the vast majority of thoracic malignancies. By enhancing the immune responses against cancer, the ICI treatments lead to the development of immune-related adverse events (irAEs) that may affect any organ. Severity varies from mild to fatal clinical manifestations. Neurologic involvement is relatively rare and highly heterogeneous, including central and peripheral nervous system diseases associated with neural-specific autoantibodies or not, central nervous system vasculitis, and granulomatous and demyelinating disorders. Symptoms often manifest within the first four cycles of treatment and can develop regardless of the class of ICI used. An unfavorable outcome is found in up to one-third of patients and is generally associated with the patients' clinical characteristics (e.g., age, coexistence of systemic adverse events), cancer type (e.g., lung cancer versus other), and specific clinical setting (e.g., ICI treatment in patients with preexisting paraneoplastic neurologic autoimmunity, ICI rechallenge after a first neurologic irAE). Diagnosis should be suspected in patients with new-onset neurologic symptoms while on ICI treatment which are not explained by metastatic disease or other metabolic/infectious disorders. Recommended treatment is based on clinical severity and consists of ICI discontinuation with or without immunosuppressive/immunomodulatory therapy, although alternative approaches are reasonable depending on cancer status (e.g., aggressive immunosuppression without discontinuing ICI in patients with initial cancer response). Early recognition and appropriate treatment of these neurologic irAEs are crucial for improved patient outcomes and therapeutic planning.

Current progress and prospect of immune checkpoint inhibitors in hepatocellular carcinoma

In recent years, the incidence of liver cancer has increased and is currently the sixth most common tumor and the second leading cause of cancer-associated mortality worldwide. Most cases of liver cancer are hepatocellular carcinoma (HCC). Surgery, including liver transplantation or resection, and radiofrequency ablation therapies are all considered to be the curative treatment options for early-stage HCC. However, most patients have advanced HCC at the time of diagnosis, contributing to a poor prognosis. Therefore, improved treatment for late-stage HCC is needed. Immune checkpoint inhibitors (ICIs), among which programmed death receptor 1 (PD-1)/PD-ligand 1 and cytotoxic T lymphocyte-associated protein 4 are the representative immunological checkpoints, have shown great promise and progress for HCC treatment. The present review summarizes recent studies that have focused on ICIs and discusses the present limitations affecting the development of new therapeutic strategies.

Posterior reversible encephalopathy syndrome in an oncological normotensive patient: evidence for a pathogenic role of concomitant low magnesium serum levels and chemotherapy treatment

Background:

Posterior reversible encephalopathy (PRES) is a rare syndrome characterized by headache, confusion, seizures, visual changes and white matter edema at radiological imaging. Its pathophysiology is not clarified and different causes, including uncontrolled hypertension, eclampsia, chemotherapy and hypomagnesemia have been suggested.

Case report:

A woman affected by stage IV breast cancer with lower extremity deep vein thrombosis treated with low-molecular-weight-heparin, currently in therapy with Palbociclib/Fulvestrant (antiCDK4 and 6/estrogen receptor antagonist) but previously treated with several other chemotherapy lines (including VEGF inhibitor bevacizumab), was admitted to our Internal Medicine department because of ascites and abdominal pain. She was treated with diuretics (and paracentesis). Recently (six-month earlier) a pan-encephalic radiotherapy was done because of brain and skull metastasis. Among blood tests, low serum levels of hypomagnesemia were observed. She developed PRES that rapidly progressed to lethargy, unresponsiveness till coma without changes in blood pressure. Magnetic Resonance Imaging study showed bilateral parieto-occipital edema and a thrombosis of left transverse and sigmoid sinuses. Anti-edema therapy, intravenous supplementation of magnesium and decoagulation were started, with complete and rapid recovery (within 18 hours) of clinical and radiologic changes.

Conclusions:

PRES diagnosis was based on the rapid clinical recovery after antiedema treatment and magnesium supplementation. Low magnesium level related to both diuretic and Fulvestrant/Palbociclib therapies and recent radiotherapy can represent potential mechanisms favouring PRES development. The previous bevacizumab treatment may also be involved as a PRES predisposing factor. The concomitant occurrence of cerebral thrombosis can have precipitated the clinical situation. (www.actabiomedica.it)

Treatment Considerations for Patients with Unresectable Metastatic Melanoma Who Develop Pembrolizumab-Induced Guillain-Barré Toxicity: A Case Report

Immunotherapy has improved outcomes in many malignancies, most notably in melanoma, lung cancer, and bladder cancer. Understanding the side effects associated with these medications is an important part of managing our patients. Although fatigue, rash, and diarrhea are commonly reported side effects, it is important to be cognizant of rarer ones, such as neuropathy. Amongst the different neurological toxicities that have been reported in the literature, Guillain-Barré-like neuropathies are quite rare. However, the occurrence of such neuropathies in a patient can be life threatening. The problem this poses in treating cancers such as melanoma is that it eliminates an effective class of medication available to the patient, which can ultimately affect their prognosis. We present a case of a 65-year-old female with unresectable metastatic melanoma who developed Guillain-Barré-like neuropathy after two doses of pembrolizumab. Her clinical course was complicated by three separate hospitalizations over 3 months due to recurring bouts of neuropathy, which resulted in a significant decline in performance status and delay in subsequent treatment of her melanoma. Her prolonged recovery eventually resulted in progression of her melanoma nearly 1 year later, while off therapy. Instead of discontinuing immunotherapy completely, she agreed to a re-challenge with ipilimumab. After one dose, her melanoma regressed and continues to show a sustained response nearly 1 year after treatment without any signs of relapse in her neuropathy. Guillain-Barré toxicity resulting from immune checkpoint inhibition poses a difficult challenge to an oncologist who is determining the next line of treatment for patients with unresectable metastatic melanoma that have progressed while off therapy and who have no targetable mutations. Our case raises the question of whether a re-challenge with a different class of immunotherapy agent is a reasonable option.

Immunotherapy in metastatic melanoma: a novel scenario of new toxicities and their management

Checkpoint inhibitors can cause an imbalance in immune tolerance that may clinically manifest as immune-related adverse events (irAEs). These events may involve many organs and tissues, including the skin, gastrointestinal (GI) tract, liver, endocrine system, kidneys, central nervous system (CNS), eyes and lungs. The incidence of irAEs appears to be lower with anti-programmed death antigen-1/programmed death antigen-ligand-1 agents than with the anti-cytotoxic T-lymphocyte-associated protein-4 antibody ipilimumab. Combined immunotherapy does not appear to be associated with novel safety signals compared with monotherapy, but more organs may be involved. Increased experience and the use of algorithms for the most common irAEs have resulted in severe toxicity and related deaths being reduced. However, continuous vigilance, especially regarding less common events, is needed to better characterize the wide spectrum of clinical manifestations.

A Pictorial Essay of Immunotherapy: Complications that Internists Will See, Whether They Like it or Not

Immunotherapy agents for treatment of cancer have been investigated for decades, but effective agents have only recently been identified and are increasingly being used in multiple cancer types. There is growing recognition of adverse side effects in multiple organ systems mediated by dysregulation of the immune system, which can be exacerbated by comorbidities often found in cancer patients such as chronic lung disease, diabetes, and hypertension. As a result, internists and other nononcology clinicians are routinely encountering immunotherapy patients who present with a remarkably wide range of symptoms. Here, we present the radiographic manifestations of common side effects from immunotherapy agents. An accurate diagnosis is critical in these often-complex clinical settings in which the consequences of the underlying cancer and other comorbidities must be distinguished from the variable manifestations of treatment toxicity.

Posterior reversible encephalopathy syndrome induced by nivolumab immunotherapy for non-small-cell lung cancer

Posterior reversible encephalopathy syndrome (PRES) is a neurological syndrome characterized by vasogenic cerebral edema with predominantly posterior involvement. Uncontrolled severe hypertension and endothelial dysfunction have been implicated as two main mechanisms. Clinicians should notice the development of PRES in hypertensive patients accompanying neurological changes, such as impaired vision and consciousness.

Immune-related Adverse Events in Cancer Patients

The U.S. Food and Drug Administration has approved immune checkpoint inhibitors and chimeric antigen receptor T cells (CAR-T cells) as immunotherapy strategies for cancer. These therapies cause a wide variety of adverse events, which mimic other disease states and may emerge months after completion of treatment. This is important because ascertaining a past medical history of cancer treatment within the past year becomes necessary for many presentations. This narrative review summarizes the biology, pathophysiology, and adverse events associated with checkpoint inhibitors and CAR-T cells and provides a rational approach to management. Proper treatment begins with heightened awareness, rapid diagnosis, and discussion with the patient's oncologist. Treatment of these adverse effects requires only corticosteroids, infliximab, tocilizumab, or fluids or vasopressors when clinically indicated.

Immune checkpoint inhibitors in urothelial cancer: recent updates and future outlook

Bladder cancer is the sixth most common cancer in the US and most tumors have urothelial (transitional cell) histology. Platinum-based chemotherapy has long been the standard of care in advanced disease, but long-term outcomes have largely remained poor. Since the peak incidence of bladder cancer is in the eighth decade of life and beyond, medical comorbidities may often limit the use of chemotherapy. Immune checkpoint inhibitors with their favorable toxicity profiles and notable antitumor activity have ushered in a new era in the treatment of advanced urothelial cancer (UC) with five agents targeting the PD-1/PD-L1 pathway being recently approved by the US Food and Drug administration. A plethora of clinical trials are ongoing in diverse disease settings, employing agents targeting PD-1/PD-L1 and related immune checkpoint pathways. While reactivating anti-tumor immunity, these agents may lead to a unique constellation of immune-related adverse events, which may warrant discontinuation of therapy and potential use of immunosuppression. Novel combinations with various treatment modalities and optimal sequencing of active therapies are being investigated in prospective clinical trials and retrospective registries. At the era of precision molecular medicine, and since patients do not respond uniformly to these agents, there is a growing need for identification and validation of biomarkers that can accurately predict treatment response and assist in patient selection. This review discusses current updates and future directions of immunotherapy in advanced UC.

Miller Fisher Syndrome Associated With Immunotherapy for Metastatic Melanoma

Immunotherapy is a treatment strategy that has demonstrated survival benefit for metastatic melanoma. Ipilimumab and nivolumab are examples of immunotherapy, in which monoclonal antibodies antagonize cytotoxic T-lymphocyte-associated protein 4 and programmed death-ligand 1 receptors, respectively, resulting in upregulation of the host immune response to cancer cells. There is increasing recognition of immune-mediated adverse events associated with immune therapies in patients with cancer. We present a case report of a patient who developed Miller Fisher syndrome associated with these therapies for metastatic melanoma along with a discussion of its management.

A Case Report of Steroid Responsive Nivolumab-Induced Encephalitis

Nivolumab (Opdivo) approval for the treatment of non-small cell lung cancer (NSCLC) prompts recognition of its future use in various cancers. Although rare, occurring in 1% to 3% of treated cases, nivolumab along with other immune checkpoint inhibitors are associated with immune-related encephalitis. With its prospective use, nivolumab-induced encephalitis illustrates the necessity of early recognition and successful management to decrease morbidity and mortality. We describe a treated case of nivolumab-induced encephalitis. A 74-year-old male with a history of stage 4 squamous NSCLC presenting with insidious altered mental status following his first dose of nivolumab. After an extensive workup that proved negative, the patient received intravenous steroids with gradual improvement of mental status. Patient subsequently returned to baseline and was discharged with oral steroid taper. Nivolumab-induced encephalitis is a diagnosis of exclusion with nonspecific signs and symptoms. Immediate recognition of patients prescribed nivolumab chemotherapy could potentially prevent fatal complications of neurotoxicity.

Severe neurologic complications of immune checkpoint inhibitors: a single-center review

BACKGROUND

Immune checkpoint inhibitors (ICIs) are a promising class of anticancer drugs associated with immune-related adverse events (IRAEs). In registration studies of selected cancer populations, neurologic IRAEs were rare. Post-marketing experience describing their prevalence in clinical practice continues to be reported.

METHODS

A retrospective cohort of patients treated at our institution with ICIs from 2005 to 2017 was identified. Patients with new neurologic ICD codes documented during or after ICI treatment were enrolled. Comprehensive medical record review identified patients with neurologic IRAEs causally linked to ICIs. This study focused on CTCAE grade 2-4 IRAEs.

RESULTS

526 patients were screened; 55 candidate patients were identified; 5 cases met criteria for neurologic IRAEs, an incidence of 0.95% (n = 5/526). IRAEs identified were transverse myelopathy, demyelinating sensorimotor polyneuropathy, oculomotor nerve palsy, sensory neuropathy, and posterior reversible encephalopathy syndrome. ICIs were held in three patients, rechallenged in one, and dose-reduced in one. Corticosteroids were given in three patients, and response varied from complete symptom resolution to minimal response and ultimately death. Other treatments were based on IRAE presentation, including gabapentin, antihypertensives, and IV immunoglobulin. Patients with combination therapy appeared to suffer more severe IRAEs producing more substantial long-term morbidity and mortality.

CONCLUSION

In this clinical practice study, the incidence of neurologic IRAEs from ICIs was 0.95%. Although rare, neurologic IRAEs can be highly variable and severe, and patients with combination immunotherapy appeared to suffer more severe IRAEs. Neurologists play an important role in the early identification and management of IRAEs to reduce long-term morbidity and mortality.

Immune-related Neurological Symptoms in an Adolescent Patient Receiving the Checkpoint Inhibitor Nivolumab

Immune checkpoint inhibitors are a novel group of immunotherapeutic agents for the treatment of cancer. Immune-related adverse events, including neurological symptoms, have been associated with these agents. We present the case of an adolescent with refractory Hodgkin lymphoma treated with nivolumab, a PD1 inhibitor, who developed Hashimoto thyroiditis, posterior reversible encephalopathy syndrome causing seizures, as well as urinary retention, truncal/appendicular spasticity, dysphagia, and a progressive encephalopathy that was clinically consistent with a diagnosis of progressive encephalopathy with rigidity and myoclonus, a stiff-person-syndrome spectrum disorder. He showed response and ultimately full recovery to a combination of intravenous steroids, intravenous immunoglobulin, and plasma exchange. To our knowledge, this is the first documented report of an immune-related neurological reaction to nivolumab in an adolescent patient and expands the spectrum of known nivolumab-associated toxicities.

Programmed cell death-1 pathway inhibitors in genitourinary malignancies: specific side-effects and their management

PURPOSE OF REVIEW

Immune checkpoint inhibitors such as those that target the programmed cell death (PD)-1 pathway harness the host immune system to elicit an antitumor response. Their remarkable clinical benefit has led to regulatory approvals in several malignancies including the genitourinary cancers, renal cell carcinoma, and urothelial carcinoma. This review will focus on the management of the toxicities encountered with these agents.

RECENT FINDINGS

Although generally well tolerated, a small proportion of patients (10-20%) treated with PD-1 directed agents as monotherapy can develop severe autoimmune manifestations, also known as, immune-related adverse events. These include but are not limited to rashes, pneumonitis, endocrinopathy, colitis, and immune-mediated hepatic dysfunction. Combining these agents with the anti-CTLA-4 antibody ipilimumab can be associated with a higher incidence of these toxicities. Early initiation of immunosuppression with corticosteroids and other agents when needed can help mitigate these toxicities and to date has not been shown to compromise their clinical benefit.

SUMMARY

The development of immune checkpoint inhibitors represents significant advances in anticancer therapy but their efficacy may come at the cost of autoimmune toxicities secondary to their induction of the immune system. Early recognition of these effects and aggressive upfront management is essential to safely administer these agents in routine clinical practice.

Incidence and Management of Immune-Related Adverse Events in Patients Undergoing Treatment with Immune Checkpoint Inhibitors

PURPOSE OF REVIEW

The unleashing of the immune system in an effort to fight cancer has proven to be an incredible advance in the war on cancer. However that breakthrough has come with a price in the form of serious and potentially fatal immune-related adverse events (irAEs).

RECENT FINDINGS

Rapid recognition and early intervention is imperative to avoid significant morbidity and mortality. Additionally, providers need to be aware that there are still new, rare, and long-term emerging irAEs that were not previously reported in clinical trials. Because of the significant difference between irAEs and those caused by chemotherapy and/or targeted therapy, providers must have a thorough understanding of which events would be considered immune related and require treatment. This review will cover descriptions of the most common and uncommon but serious irAEs experienced by patients on immunotherapy, as well as management of these irAEs.

A multidisciplinary approach to toxicity management of modern immune checkpoint inhibitors in cancer therapy

Immune-related Adverse Events (irAEs) are the most significant toxicities associated with the use of checkpoint inhibitors, and result from disinhibition of the host's immune homeostasis. The adverse effects experienced from immunotherapy are significantly different from those of chemotherapy and, to a lesser extent, targeted therapy. Early recognition and diagnosis of these toxicities is often challenging, but is critically important because of the potentially life-threatening nature and associated morbidity. Gastrointestinal, dermatologic, endocrine, and liver toxicities are the most commonly observed. Less commonly, the eyes, pancreas, kidneys, lungs, bone marrow, or nervous system may be affected. Although most irAEs may resolve with supportive care or discontinuation of drug, in severe cases, they may require hospitalization and immune suppressants, such as steroids, and/or may even cause death. The management of immune-related side effects requires a multidisciplinary approach.

Neurological Adverse Events Associated with Immune Checkpoint Inhibitors: Diagnosis and Management

PURPOSE OF REVIEW

Immune checkpoint inhibitors represent a major step forward in the field of oncologic immunotherapy these last years and have significantly increased survival of cancer patients in an ever-growing number of indications. These agents block specific immune checkpoint molecules (programmed cell death protein 1 and its ligand as well as cytotoxic T-lymphocyte-associated antigen 4) that normally downregulate the immune response. These new agents show a specific range of adverse effects induced by abnormal immunologic activation.

RECENT FINDINGS

Many different neurologic adverse events have been described, including encephalitis, myelopathy, aseptic meningitis, meningoradiculitis, Guillain-Barré-like syndrome, peripheral neuropathy (including mononeuropathy, mononeuritis multiplex, and polyneuropathy) as well as myasthenic syndrome. Immune checkpoint inhibitors have shown promising results in cancer but can possibly induce autoimmune disorders. Although rare, neurological adverse events require prompt recognition and treatment to avoid substantial morbidity.

Identifying and managing the adverse effects of immune checkpoint blockade

Immunotherapy has revolutionized the field of oncology. By inhibiting the cytotoxic T-lymphocyte-associated protein (CTLA-4) and programmed death-1 (PD-1) immune checkpoint pathways, multiple studies have demonstrated greatly improved survival in locally advanced and metastatic cancers including melanoma, renal, lung, gastric, and hepatocellular carcinoma. Trials in other malignancies are ongoing, and undoubtedly the number of drugs in this space will grow beyond the six currently approved by the Food and Drug Administration. However, by altering the immune response to fight cancer, a new class of side effects has emerged known as immune-related adverse events (irAEs). These adverse events are due to overactivation of the immune system in almost any organ of the body, and can occur at any point along a patient's treatment course. irAEs such as endocrinopathies (thyroiditis), colitis, and pneumonitis may occur more commonly. However, other organs such as the liver, heart, or brain may also be affected by immune overactivation and any of these side effects may become life threatening. This review presents an approach to promptly recognize and manage these toxicities, to hopefully minimize morbidity and mortality from irAEs.

The confused oncologic patient: a rational clinical approach

PURPOSE OF REVIEW

The purpose of this review is to provide a practical clinical approach to confusion in the patient with cancer. Confusion in the cancer population has a broader differential diagnosis than in the general medical population. The clinician must consider the usual differential diagnoses as well as causes unique to the cancer patient including direct complications from the cancer and indirect complications related to cancer treatment.

RECENT FINDINGS

In the recent age of precision medicine, the oncologist now utilizes the genomic profile of both the patient and the tumor to provide advanced biologic therapies including targeted anticancer drugs, antiangiogenic agents, and immunotherapy. Such advances carry with them an emerging pattern of neurotoxicity which, although less well described in the literature, is now an important consideration to the clinical approach to confusion in cancer patients.

SUMMARY

Confusion is the most common neurologic complication in cancer and is associated with significant morbidity, mortality, and prolonged hospital stays resulting in increased healthcare costs. Early recognition and treatment of delirium is essential to improve clinical outcomes.

Neurologic complications of immune checkpoint inhibitors

PURPOSE OF REVIEW

In recent years, advances in the understanding of the regulatory mechanisms of the immune system has led to the development of new approaches for cancer treatment. Currently, immune checkpoint inhibitors are the first successful examples of this approach and several agents that target cytotoxic lymphocyte-associated protein 4 (CTLA-4) and programmed cell death-1 (PD-1) have been approved for various oncologic situations. The aim of this review is to describe the neurologic adverse event profiles for these new immune therapeutic approaches and to discuss their appropriate management.

RECENT FINDINGS

The immune checkpoint inhibitor ipilimumab against CTLA-4 and nivolumab or pembrolizumab against PD-1 show a unique spectrum of toxic effects. The most common toxicities include rash, colitis, hepatitis, endocrinopathies, and pneumonitis. Neurologic side-effects are rare but include cases of immune polyneuropathies, Guillain Barré syndrome, myasthenia gravis, posterior reversible encephalopathy syndrome, aseptic meningitis, enteric neuropathy, transverse myelitis as well as immune encephalitis.

SUMMARY

It is essential that neurologic immune-related adverse events are recognized and treated as soon as possible, as early treatment increases the odds of a complete recovery.

Inflammatory CNS disease caused by immune checkpoint inhibitors: status and perspectives

Cancer treatment strategies based on immune stimulation have recently entered the clinical arena, with unprecedented success. Immune checkpoint inhibitors (ICIs) work by indiscriminately promoting immune responses, which target tumour-associated antigens or tumour-specific mutations. However, the augmented immune response, most notably the T cell response, can cause either direct neurotoxicity or, more commonly, indirect neurotoxic effects through systemic or local inflammatory mechanisms or autoimmune mechanisms. Consequently, patients treated with ICIs are susceptible to CNS disease, including paraneoplastic neurological syndromes, encephalitis, multiple sclerosis and hypophysitis. In this Opinion article, we introduce the mechanisms of action of ICIs and review their adverse effects on the CNS. We highlight the importance of early detection of these neurotoxic effects, which should be distinguished from brain metastasis, and the need for early detection of neurotoxicity. It is crucial that physicians are well informed of these neurological adverse effects, given the anticipated increase in the use of immunotherapies to treat cancer.

Targeting T Cell Co-receptors for Cancer Therapy

Checkpoint-blocking antibodies can generate potent anti-tumor responses by encouraging the immune system to seek and destroy cancer cells. At this time, the United States Food and Drug Administration has approved three checkpoint-blocking antibodies in three disease indications, and additional approvals are expected to broaden the clinical scope of immunotherapy. Herein, we review the clinical development of CTLA-4-, PD-1-, and PD-L1-blocking antibodies across tumor types and briefly discuss areas of active investigation of potential biomarkers.

Pembrolizumab-Induced Encephalopathy: A Review of Neurological Toxicities with Immune Checkpoint Inhibitors

The use of immune checkpoint inhibitor (ICI) therapy in the treatment of solid organ malignancies is becoming increasingly common. This has prompted the recognition of a new class of immune-related adverse effects (irAEs) stemming from the upregulation of T-cell activity causing autoimmunity. Neurological irAEs are a rare complication of ICIs that can lead to long-term morbidity. We report a rare case of encephalopathy after treatment with pembrolizumab, to which the patient achieved durable disease response despite discontinuation of therapy. We also review the pathophysiology, incidence, clinical presentation, diagnosis, and management of neurotoxicity secondary to ICIs. Treatment requires early administration of high-dose corticosteroids, and cessation of ICI therapy is often necessary after grade 3 or 4 irAEs. However, early data suggest that neurological irAEs correlate with a favorable disease response. Consideration should also be given to the optimal duration of ICI therapy to minimize the risk of toxicity and optimize health care expenditure.

Rare side-effects of checkpoint inhibitors

PURPOSE OF REVIEW

The aim of this review is to draw the attention of the physicians and oncologists on the rare side-effects of checkpoint inhibitors not usually reported in clinical trials to treat them quickly and render their prognosis better.

RECENT FINDINGS

Rare side-effects of checkpoint inhibitors are mainly neurologic, haematologic, rheumatologic, renal, and cardiac. The majority of reported side-effects are consequent of the treatment by ipilimumab in patients diagnosed with melanomas. Neurologic side-effects have poorer prognosis compared with other rare side-effects. There is no relationship between developing rare side-effects and the outcome of the disease.

SUMMARY

It is important to be aware, when treating patients with checkpoint inhibitors, to detect as early as possible the unpredictable and uncontrollable rare side-effects of these agents. The large spectrum of these rare side-effects should be well documented and reported to assure to the physicians a road map for the diagnosis and the management of these toxicities.