Encephalitis Induced by Immune Checkpoint Inhibitors: A Systematic Review.

Importance: Encephalitis is a severe immune-related adverse event secondary to treatment with immune checkpoint inhibitors (ICIs). The spectrum of ICI-induced encephalitis (ICI-iE) ranges from disease that resolves fully to lethal forms. Moreover, ICIs may unmask a paraneoplastic encephalitis. To our knowledge, the factors associated with ICI-iE prognosis are unknown. Objectives: To evaluate the presentation of ICI-iE and to identify features helpful in assessing outcomes. Evidence Review: This systematic review pooled case series from the published literature (n = 77) and medical records from 1 center (n = 5) to assess the association between the form of ICI-iE presentation and its prognosis. Eligibility criteria included references identified by searches of PubMed and Web of Knowledge databases in the English literature from June 2000 (first patient dose of ipilimumab) to April 17, 2020, that examined patients with encephalitis with presumed autoimmune etiologic features induced by ICIs. Information regarding clinical, cerebrospinal fluid, and neuroimaging (magnetic resonance imaging) features, as well as treatment given, were extracted. Findings: A total of 82 patients (52 men [63%]; median age, 61.0 years [interquartile range, 52.5-70.0 years]) were included. Most patients presented with focal syndromes (39 [48%]) or meningoencephalitis (36 [44%]). Seven patients (9%) had nonclassifiable ICI-iE. Neuronal autoantibodies were detected in 23 patients with focal syndromes and 1 patient with nonclassifiable ICI-iE. Most autoantibodies were onconeuronal (17 of 24 [71%]), targeting intracellular antigens. Patients without a focal syndrome or with a negative-antibody focal syndrome had a good prognosis (49 of 55 [89%]). Among patients with autoantibodies, those with anti-glutamic acid decarboxylase or anticell surface responded to treatment and had a favorable prognosis (100%). However, patients with other autoantibodies had poor outcomes (17 of 24 [71%]). Antineuronal autoantibodies (13 of 24 [54%] vs 5 of 41 [12%]; P < .001), focal syndrome (16 of 39 [41%] vs 4 of 43 [9%]; P = .001), and abnormal magnetic resonance imaging findings (14 of 39 [36%] vs 4 of 32 [13%]; P = .02) were associated with poor outcomes. Conversely, fever (21 of 23 [91%] vs 41 of 59 [70%]; P = .04) and more inflammatory changes in cerebrospinal fluid (30 of 31 [97%] vs 21 of 33 [64%]; P = .001) were associated with a better prognosis. Conclusions and Relevance: Immune checkpoint inhibitors may induce mainly 2 different encephalitic syndromes: a focal limbic or extralimbic encephalitis and a meningoencephalitis. Immune checkpoint inhibitor-induced encephalitis is associated with an overall favorable outcome, with a low rate of fatal events. An undetected preexisting paraneoplastic encephalitic syndrome may be triggered by ICIs, and this type of syndrome has the worst outcome among all the different types of ICI-induced encephalitis syndromes. Clinical presentation and systematic measurement of autoantibodies will be a helpful guide for the therapeutic strategy and for counseling regarding prognosis.

Investigating the concordance in molecular subtypes of primary colorectal tumors and their matched synchronous liver metastasis.

To date, no systematic analyses are available assessing concordance of molecular classifications between primary tumors (PT) and matched liver metastases (LM) of metastatic colorectal cancer (mCRC). We investigated concordance between PT and LM for four clinically relevant CRC gene signatures. Twenty-seven fresh and 55 formalin-fixed paraffin-embedded pairs of PT and synchronous LM of untreated mCRC patients were retrospectively collected and classified according to the MSI-like, BRAF-like, TGFB activated-like and the Consensus Molecular Subtypes (CMS) classification. We investigated classification concordance between PT and LM and association of TGFBa-like and CMS classification with overall survival. Fifty-one successfully profiled matched pairs were used for analyses. PT and matched LM were highly concordant in terms of BRAF-like and MSI-like signatures, (90.2% and 98% concordance, respectively). In contrast, 40% to 70% of PT that were classified as mesenchymal-like, based on the CMS and the TGFBa-like signature, respectively, lost this phenotype in their matched LM (60.8% and 76.5% concordance, respectively). This molecular switch was independent of the microenvironment composition. In addition, the significant change in subtypes was observed also by using methods developed to detect cancer cell-intrinsic subtypes. More importantly, the molecular switch did not influence the survival. PT classified as mesenchymal had worse survival as compared to nonmesenchymal PT (CMS4 vs CMS2, hazard ratio [HR] = 5.2, 95% CI = 1.5-18.5, P = .0048; TGFBa-like vs TGFBi-like, HR = 2.5, 95% CI = 1.1-5.6, P = .028). The same was not true for LM. Our study highlights that the origin of the tissue may have major consequences for precision medicine in mCRC.

Rechallenge with oxaliplatin and peripheral neuropathy in colorectal cancer patients.

BACKGROUND: Oxaliplatin (OXA) is a cornerstone in the treatment of colorectal cancer (CRC). Retreatment with OXA is frequently considered as salvage treatment. OXA-induced neuropathy (OIN) is the most frequent and feared long-term side effect. PATIENTS AND METHODS: CRC patients receiving at least twice OXA-based chemotherapy lines at our institution between June 2000 and July 2016 were reviewed. The aim of this study was to investigate whether retreatment with OXA increases the risk of developing new or worsening previous neuropathy. OIN was assessed by National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI), Total Neuropathy Score© (TNS) and nerve-conduction studies. RESULTS: 106 patients were included in the analysis. Median age at OXA-based retreatment was 61.5 (20-83) years. After the first OXA-based chemotherapy treatment, 63.4% of patients developed OIN, 30.7 and 8.9% grades 2 and 3, respectively, after a median of 11 (1-17) cycles. After 30 (11-90) months of median to retreatment with a median of 8 (1-14) OXA cycles, 39.6, 22.6, and 0% of patients developed grade 1, 2, and 3 OIN, respectively. Worsening of the previous OIN was observed in one-third (31.1%) of all patients. OXA-cumulative dose was independently associated with greater risk of worsening OIN (p < 0.001). Non-significant trend towards higher TNSc© scores after retreatment was observed [5 (0-11) vs 6 (3-13), p = 0.083]. CONCLUSION: Retreatment with OXA in CRC patients is a feasible option even in patients who previously developed moderate or severe OIN. One-third of patients' OIN was worsened by retreatment. Neurological monitoring should be considered.