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Despite remarkable advances in immunotherapy, melanoma remains a significant cause of cancer mortality. Many factors concerning melanoma mortality are poorly understood, posing an obstacle to optimal care. We conducted a retrospective observational cohort study of 183 patients with metastatic melanoma who died following immunotherapy treatment to investigate sites of metastases at death, settings of death, and mechanisms of death. The median time from metastatic diagnosis to death was 16.1 months (range 0.3–135.1 months). Most patients experienced hospitalization within 3 months before death (80.3%), with 31.7% dying while hospitalized, 31.2% while in inpatient hospice, and 29.4% while in home hospice. The most common sites of metastases at death were distant lymph nodes (62.8%), lung (57.9%), liver (50.8%), brain (38.8%), and bone (37.7%). The most common causes of death were progressive failure to thrive (57.5%), respiratory failure (22.4%), and infection (21.8%); the vast majority (87.9%) of patients died from melanoma‐specific causes. Overall, 10.9% of patients in our cohort had survival >5 years after metastatic diagnosis, and 76.2% of long‐term survivors died due to melanoma. This study describes factors associated with melanoma mortality, highlighting an ongoing need for therapeutic advancements. [ABSTRACT FROM AUTHOR]

Most patients with cancer either do not respond to immune checkpoint blockade or develop resistance to it, often because of acquired mutations that impair antigen presentation. Here we show that loss of function of the RNA-editing enzyme ADAR1 in tumour cells profoundly sensitizes tumours to immunotherapy and overcomes resistance to checkpoint blockade. In the absence of ADAR1, A-to-I editing of interferon-inducible RNA species is reduced, leading to double-stranded RNA ligand sensing by PKR and MDA5; this results in growth inhibition and tumour inflammation, respectively. Loss of ADAR1 overcomes resistance to PD-1 checkpoint blockade caused by inactivation of antigen presentation by tumour cells. Thus, effective anti-tumour immunity is constrained by inhibitory checkpoints such as ADAR1 that limit the sensing of innate ligands. The induction of sufficient inflammation in tumours that are sensitized to interferon can bypass the therapeutic requirement for CD8.sup.+ T cell recognition of cancer cells and may provide a general strategy to overcome immunotherapy resistance.Deletion of the A-to-I double-stranded RNA-editing enzyme ADAR1 sensitizes tumour cells to immunotherapy., Author(s): Jeffrey J. Ishizuka [sup.1] [sup.2] [sup.3] , Robert T. Manguso [sup.1] [sup.3] , Collins K. Cheruiyot [sup.1] [sup.3] , Kevin Bi [sup.1] [sup.3] , Arpit Panda [sup.1] [sup.3] [sup.4] [...]

Purpose: IFN signaling in the tumor microenvironment is a critical determinant of both response and resistance of cancer to immune checkpoint inhibitors (ICI). We hypothesized that distinct patterns of IFN signaling in melanoma are associated with clinical response or resistance to ICIs., Experimental Design: Two tissue microarrays containing samples from 97 patients with metastatic melanoma who received nivolumab, pembrolizumab, or a combination of ipilimumab and nivolumab at Yale New Haven Hospital between 2011 and 2017 were randomized into discovery and validation cohorts. Samples were stained and visualized using multiplexed immunofluorescence microscopy for STAT1, STAT1 phosphorylated at Y701 (pSTAT1Y701), and PD-L1, and signals were quantified using the automated quantitative analysis method of quantitative immunofluorescence. Treatment response was assessed using RECIST, and overall survival was analyzed. For in vitro studies, human melanoma cell lines were stimulated with IFNγ and IFNβ, and Western blotting was performed., Results: Pretreatment STAT1 levels were higher in responders to ICIs [complete response/partial response/stable disease (SD) for > 6 months] than in nonresponders (SD < 6 months/progressive disease). Higher pretreatment STAT1 levels were associated with improved survival after ICIs in both the discovery and validation cohorts. Western blot analysis of human melanoma cell lines stimulated with IFN demonstrated distinct patterns of upregulation of STAT1 compared with pSTAT1Y701 and PD-L1. When combining STAT1 and PD-L1 markers, patients with STAT1highPD-L1low tumors had improved survival compared with those with STAT1lowPD-L1high tumors., Conclusions: STAT1 may better predict melanoma response to ICIs than current strategies, and combined STAT1 and PD-L1 biomarkers may provide insight into IFN-responsive versus IFN-resistant states., (©2023 American Association for Cancer Research.)

The nature of the epitopes recognized by tumor-infiltrating T cells is not clearly defined. In this issue of Immunity, Cheng et al. demonstrate that tissue-resident memory CD8 + T cells specific for hepatitis B virus-derived antigens exhibit potent anti-tumor properties and correlate with relapse-free survival in patients with resected hepatocellular carcinoma., Competing Interests: Declaration of interests J.J.I. is a consultant for Related Sciences and a founder of Danger Bio, owns founder’s equity in Kronos Bio, and serves as a consultant for Phenomic AI and Tango Therapeutics. J.W. reports no relevant competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)