How many melanomas might be prevented if more people applied sunscreen regularly?

Summary

Background

Ultraviolet radiation causes cutaneous melanoma. Sunscreen prevents sunburn and protects skin cells against mutations. High-quality epidemiological studies suggest regular sunscreen use prevents melanoma.

Objectives

To calculate the potential impact fraction (PIF) for melanoma in the U.S.A. and Australia assuming a range of different intervention scenarios intended to increase sunscreen use.

Methods

We calculated the PIF, the proportional difference between the observed number of melanomas arising under prevailing levels of sunscreen use compared with the number expected under counterfactual scenarios. We used published melanoma incidence projections for Australia and the white population in the U.S.A. from 2012 through to 2031 as the baseline condition, with estimates for protective effects of 'regular sunscreen use' from the literature. Sunscreen prevalence was sourced from national or state surveys.

Results

Under a plausible public health intervention scenario comprising incremental increases in sunscreen prevalence over a 10-year implementation programme, we estimated that cumulatively to 2031, 231 053 fewer melanomas would arise in the U.S. white population (PIF 11%) and 28 071 fewer melanomas would arise in Australia (PIF 10%). Under the theoretical maximum model of sunscreen use, almost 797 000 (PIF 38%) and approximately 96 000 (PIF 34%) melanomas would be prevented in the U.S.A. and Australia, respectively between 2012 and 2031. A sensitivity analysis using weaker effect estimates resulted in more conservative PIF estimates.

Conclusions

Overall, interventions to increase use of sunscreen would result in moderate reductions in melanoma incidence, assuming no compensatory overexposure to the sun. Countries with a high incidence of melanoma should monitor levels of sunscreen use in the community.

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A Bispecific Antibody Based on Pertuzumab Fab Has Potent Antitumor Activity

Human epidermal growth factor receptor 2 (HER2) is frequently overexpressed and activated in metastatic breast cancers. Monoclonal antibodies targeting Her2, such as trastuzumab and pertuzumab, have become important targeted therapies for patients with HER2-positive breast cancer. Both trastuzumab and pertuzumab can reduce Her2 positive tumor burden by inhibiting Her2 signaling and inducing ADCC activities (antibody dependent cell-mediated cytotoxicity). In this study, we have generated a bispecific antibody, Her2(Per)-S-Fab, by linking the pertuzumab Fab to an anti-CD16 single domain antibody. The Her2(Per)-S-Fab can be expressed and purified efficiently from Escherichia coli. In vitro and in vivo experiments showed Her2(Per)-S-Fab had potent cytotoxicity against Her2-positive tumor cells. Thus, Her2(Per)-S-Fab may provide an alternative to treat Her2-positive cancer patients.

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CD11c-targeted Delivery of DNA to Dendritic Cells Leads to cGAS- and STING-dependent Maturation

Immunotherapeutic activation of tumor-specific T cells has proven to be an interesting approach in anticancer treatment. Particularly, anti-CTLA-4 and anti–PD-1/PD-L1 treatment looks promising, and conceivably, even better clinical results might be obtained if such treatment could be combined with boosting the existing tumor-specific T-cell response. One way to achieve this could be by increasing the level of maturation of dendritic cells locally and in the draining lymph nodes. When exposed to cancer cells, dendritic cells may spontaneously mature because of danger-associated molecular patterns derived from the tumor cells. Double-stranded DNA play a particularly important role in the activation of the dendritic cells, through engagement of intracellular DNA-sensors, and signaling through the adaptor protein STING. In the present study, we have investigated the maturational response of human monocyte-derived dendritic cells (moDC) and human monocytic THP-1 cells to targeted and untargeted DNA. We used an anti-CD11c antibody conjugated with double-stranded DNA to analyze the maturation status of human moDCs, as well as maturation using a cGAS KO and STING KO THP-1 cell maturation model. We found that dendritic cells can mature after exposure to cytoplasmic double-stranded DNA delivered through CD11c-mediated endocytosis. Moreover, we show that THP-1 cells matured using IL-4, GM-CSF, and ionomycin upregulate DC-maturation markers after CD11c-targeted delivery of double-stranded DNA. This upregulation is completely abrogated in cGAS KO and STING KO cells.

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Development of Bell’s Palsy After Treatment With Ipilimumab and Nivolumab for Metastatic Melanoma: A Case Report

Ipilimumab is a human monoclonal antibody that targets cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), and it is FDA approved for the treatment of unresectable or metastatic melanoma. Immune-related adverse events (irAEs) of gastrointestinal, dermatologic, and endocrine origin are commonly seen, ranging between 18% and 44%, with immune checkpoint inhibitors (anti-CTLA-4 and anti-PD-1/PD-L1). Rare irAEs include neurological, renal, and hematologic toxicities. Bell's palsy is a form of neurological toxicity that presents as an idiopathic paralysis of the muscles on one side of the face. We report a case of Bell's palsy in a 45-year-old male patient who received 1 dose of both ipilimumab and nivolumab for the treatment of metastatic melanoma. After the resolution of symptoms, ipilimumab was permanently discontinued and single-agent nivolumab administered. The patient has remained free of neurological symptoms. This case suggests that Bell's palsy is an irAE induced by ipilimumab.

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Preclinical Optimization of a CD20-specific Chimeric Antigen Receptor Vector and Culture Conditions

Chimeric antigen receptor (CAR)-based adoptive T-cell therapy is a highly promising treatment for lymphoid malignancies, and CD20 is an ideal target antigen. We previously developed a lentiviral construct encoding a third generation CD20-targeted CAR but identified several features that required additional optimization before clinical translation. We describe here several improvements, including replacement of the immunogenic murine antigen-binding moiety with a fully human domain, streamlining the transgene insert to enhance lentiviral titers, modifications to the extracellular IgG spacer that abrogate nonspecific activation resulting from binding to Fc receptors, and evaluation of CD28, 4-1BB, or CD28 and 4-1BB costimulatory domains. We also found that restimulation of CAR T cells with an irradiated CD20+ cell line boosted cell growth, increased the fraction of CAR-expressing cells, and preserved in vivo function despite leading to a reduced capacity for cytokine secretion in vitro. We also found that cryopreservation of CAR T cells did not affect immunophenotype or in vivo antitumor activity compared with fresh cells. These optimization steps resulted in significant improvement in antitumor activity in mouse models, resulting in eradication of established systemic lymphoma tumors in 75% of mice with a single infusion of CAR T cells, and prolonged in vivo persistence of modified cells. These results provide the basis for clinical testing of a lentiviral construct encoding a fully human CD20-targeted CAR with CD28 and 4-1BB costimulatory domains and truncated CD19 (tCD19) transduction marker.

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Life-threatening Autoimmune Cardiomyopathy Reproducibly Induced in a Patient by Checkpoint Inhibitor Therapy

Checkpoint inhibitors induce a plethora of immune-related adverse events (irAEs) including autoimmune colitis, hepatitis, endocrinopathies, and rarer side effects like neuritis. Here, a case of autoimmune cardiomyopathy (grade 3 CTCAE) and myocarditis under combination therapy with nivolumab plus ipilimumab in a 72-year-old melanoma patient is reported. Treatment induced a partial response for 14 months. However, after 10 infusions the patient developed dyspnea, edema of the legs, ascites and a weight gain of 10 kg because of a decompensated heart insufficiency with a reduced ejection fraction from formerly 48%–50% to 15%. Ischemia and viral infections were ruled out. Histopathology showed hypertrophic myocarditis with interstitial lymphocytes. Prednisolone improved the patient's condition within 3 days, leading to a 25% and 30% ejection fraction after 2 and 8 weeks, respectively, and clinical symptoms subsided completely. Importantly, reinduction of anti-PD1 therapy resulted in a flare of myocarditis. Awareness for potentially life-threatening irAE of checkpoint inhibitors like autoimmune cardiomyopathy and myocarditis is crucial to rapidly initiate adequate treatment.

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Management of Immune-mediated Cytopenias in the Era of Cancer Immunotherapy: A Report of 4 Cases

Recent advancements in immunotherapy have brought promising drugs to fight cancers; a subset of immunotherapy medications are known as checkpoint inhibitors. Their mechanism of action relies on upregulating antitumor response by reversing T-cell suppression; as a consequence the effect can also result in a spectrum of immune related complications. Reported complications to date include: skin, gastrointestinal mucosa, hypophysis, liver, endocrine system, nervous system, kidney, musculoskeletal system and the hematologic system. The management of immune related complications typically includes the use of steroids and other strategies of immunosuppression. The current recommendations are not organ-specific and little is known about the response and outcomes related to the hematologic system. Hereby we report four cases evaluated at the hematology service at the University of Texas MD Anderson Cancer Center for cytopenias after check point inhibitor therapies. All cases were responsive to conventional interventions for immune-mediated cytopenias.

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