Minimal Residual Disease using a Plasma-Only Circulating Tumor DNA Assay to Predict Recurrence of Metastatic Colorectal Cancer Following Curative Intent Treatment.

PURPOSE: Minimal residual disease (MRD) detection can identify the recurrence in patients with colorectal cancer (CRC) following definitive treatment. We evaluated a plasma-only MRD assay to predict recurrence and survival in patients with metastatic CRC who underwent curative intent procedures (surgery and/or radiotherapy), with or without (neo)adjuvant chemotherapy. The primary objective of this study was to assess the correlation of postprocedure tumor cell-free DNA detection status with radiographic disease recurrence. EXPERIMENTAL DESIGN: Preprocedure and postprocedure longitudinal samples were collected from 53 patients and analyzed with a multiomic MRD assay detecting circulating tumor DNA (ctDNA) from genomic and epigenomic signals. Preprocedure and postprocedure ctDNA detection correlated with recurrence-free and overall survival (OS). RESULTS: From 52 patients, 230/233 samples were successfully analyzed. At the time of data cutoff, 36 (69.2%) patients recurred with median follow-up of 31 months. Detectable ctDNA was observed in 19/42 patients (45.2%) with ctDNA analyzed 3 weeks postprocedure. ctDNA detection 3 weeks postprocedure was associated with shorter median recurrence-free survival (RFS; HR, 5.27; 95% CI, 2.31-12.0; P < 0.0001) and OS (HR, 12.83; 95% CI, 3.6-45.9; P < 0.0001). Preprocedure ctDNA detection status was not associated with RFS but was associated with improved OS (HR, 4.65; 95% CI, 1.4-15.2; P = 0.0111). Undetectable ctDNA preprocedure had notable long-term OS, >90% 3 years postprocedure. CONCLUSIONS: In this cohort of oligometastatic CRC, detection of ctDNA preprocedure or postprocedure was associated with inferior outcomes even after accounting for known prognostic clinicopathologic variables. This suggests ctDNA may enhance current risk stratification methods helping the evaluation of novel treatments and surveillance strategies toward improving patient outcomes.

ATM Mutations Associate with Distinct Co-Mutational Patterns and Therapeutic Vulnerabilities in NSCLC.

PURPOSE: Ataxia-telangiectasia mutated (ATM) is the most frequently mutated DNA damage repair gene in non-small cell lung cancer (NSCLC). However, the molecular correlates of ATM mutations and their clinical implications have not been fully elucidated. EXPERIMENTAL DESIGN: Clinicopathologic and genomic data from 26,587 patients with NSCLC from MD Anderson, public databases, and a de-identified nationwide (US-based) NSCLC clinicogenomic database (CGDB) were used to assess the co-mutation landscape, protein expression, and mutational processes in ATM-mutant tumors. We used the CGDB to evaluate ATM-associated outcomes in patients treated with immune checkpoint inhibitors (ICI) with or without chemotherapy, and assessed the effect of ATM loss on STING signaling and chemotherapy sensitivity in preclinical models. RESULTS: Nonsynonymous mutations in ATM were observed in 11.2% of samples (2,980/26,587) and were significantly associated with mutations in KRAS, but mutually exclusive with EGFR (q < 0.1). KRAS mutational status constrained the ATM co-mutation landscape, with strong mutual exclusivity with TP53 and KEAP1 within KRAS-mutated samples. Those ATM mutations that co-occurred with TP53 were more likely to be missense mutations and associate with high mutational burden, suggestive of non-functional passenger mutations. In the CGDB cohort, dysfunctional ATM mutations associated with improved OS only in patients treated with ICI-chemotherapy, and not ICI alone. In vitro analyses demonstrated enhanced upregulation of STING signaling in ATM knockout cells with the addition of chemotherapy. CONCLUSIONS: ATM mutations define a distinct subset of NSCLC associated with KRAS mutations, increased TMB, decreased TP53 and EGFR co-occurrence, and potential increased sensitivity to ICIs in the context of DNA-damaging chemotherapy.

CD70 is a therapeutic target upregulated in EMT-associated EGFR tyrosine kinase inhibitor resistance.

Effective therapeutic strategies are needed for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations that acquire resistance to EGFR tyrosine kinase inhibitors (TKIs) mediated by epithelial-to-mesenchymal transition (EMT). We investigate cell surface proteins that could be targeted by antibody-based or adoptive cell therapy approaches and identify CD70 as being highly upregulated in EMT-associated resistance. Moreover, CD70 upregulation is an early event in the evolution of resistance and occurs in drug-tolerant persister cells (DTPCs). CD70 promotes cell survival and invasiveness, and stimulation of CD70 triggers signal transduction pathways known to be re-activated with acquired TKI resistance. Anti-CD70 antibody drug conjugates (ADCs) and CD70-targeting chimeric antigen receptor (CAR) T cell and CAR NK cells show potent activity against EGFR TKI-resistant cells and DTPCs. These results identify CD70 as a therapeutic target for EGFR mutant tumors with acquired EGFR TKI resistance that merits clinical investigation.

IL6 Mediates Suppression of T- and NK-cell Function in EMT-associated TKI-resistant EGFR-mutant NSCLC.

PURPOSE: Patients with advanced non-small cell lung cancer (NSCLC) harboring activating EGFR mutations are initially responsive to tyrosine kinase inhibitors (TKI). However, therapeutic resistance eventually emerges, often via secondary EGFR mutations or EGFR-independent mechanisms such as epithelial-to-mesenchymal transition. Treatment options after EGFR-TKI resistance are limited as anti-PD-1/PD-L1 inhibitors typically display minimal benefit. Given that IL6 is associated with worse outcomes in patients with NSCLC, we investigate whether IL6 in part contributes to this immunosuppressed phenotype. EXPERIMENTAL DESIGN: We utilized a syngeneic genetically engineered mouse model (GEMM) of EGFR-mutant NSCLC to investigate the effects of IL6 on the tumor microenvironment and the combined efficacy of IL6 inhibition and anti-PD-1 therapy. Corresponding in vitro studies used EGFR-mutant human cell lines and clinical specimens. RESULTS: We identified that EGFR-mutant tumors which have oncogene-independent acquired resistance to EGFR-TKIs were more mesenchymal and had markedly enhanced IL6 secretion. In EGFR-mutant GEMMs, IL6 depletion enhanced activation of infiltrating natural killer (NK)- and T-cell subpopulations and decreased immunosuppressive regulatory T and Th17 cell populations. Inhibition of IL6 increased NK- and T cell-mediated killing of human osimertinib-resistant EGFR-mutant NSCLC tumor cells in cell culture. IL6 blockade sensitized EGFR-mutant GEMM tumors to PD-1 inhibitors through an increase in tumor-infiltrating IFNγ+ CD8+ T cells. CONCLUSIONS: These data indicate that IL6 is upregulated in EGFR-mutant NSCLC tumors with acquired EGFR-TKI resistance and suppressed T- and NK-cell function. IL6 blockade enhanced antitumor immunity and efficacy of anti-PD-1 therapy warranting future clinical combinatorial investigations.

Molecular Mechanisms and Future Implications of VEGF/VEGFR in Cancer Therapy.

Angiogenesis, the sprouting of new blood vessels from existing vessels, is one of six known mechanisms employed by solid tumors to recruit blood vessels necessary for their initiation, growth, and metastatic spread. The vascular network within the tumor facilitates the transport of nutrients, oxygen, and immune cells and is regulated by pro- and anti-angiogenic factors. Nearly four decades ago, VEGF was identified as a critical factor promoting vascular permeability and angiogenesis, followed by identification of VEGF family ligands and their receptors (VEGFR). Since then, over a dozen drugs targeting the VEGF/VEGFR pathway have been approved for approximately 20 solid tumor types, usually in combination with other therapies. Initially designed to starve tumors, these agents transiently "normalize" tumor vessels in preclinical and clinical studies, and in the clinic, increased tumor blood perfusion or oxygenation in response to these agents is associated with improved outcomes. Nevertheless, the survival benefit has been modest in most tumor types, and there are currently no biomarkers in routine clinical use for identifying which patients are most likely to benefit from treatment. However, the ability of these agents to reprogram the immunosuppressive tumor microenvironment into an immunostimulatory milieu has rekindled interest and has led to the FDA approval of seven different combinations of VEGF/VEGFR pathway inhibitors with immune checkpoint blockers for many solid tumors in the past 3 years. In this review, we discuss our understanding of the mechanisms of response and resistance to blocking VEGF/VEGFR, and potential strategies to develop more effective therapeutic approaches.

Limited Benefit from the Addition of Immunotherapy to Chemotherapy in TKI-Refractory EGFR-Mutant Lung Adenocarcinoma.

BACKGROUND: The benefit of chemotherapy combined with immunotherapy in EGFR-mutant lung adenocarcinoma (LUAD) patients whose tumor developed resistance to EGFR tyrosine kinase inhibitors (TKIs) is not thoroughly investigated. The goal of this retrospective cohort study is to assess the clinical efficiency of immunotherapy alone or in combination with chemotherapy in a real-world setting. METHODS: This retrospective cohort study enrolled LUAD patients with EGFR sensitive mutations whose tumor had acquired resistance to EGFR TKIs and received systemic treatment with chemotherapy (chemo; n = 84), chemotherapy combined with immunotherapy (chemoIO; n = 30), chemotherapy plus bevacizumab with or without IO (withBev; n = 42), and IO monotherapy (IO-mono; n = 22). Clinical progression-free survival (PFS) and overall survival (OS) were evaluated. Associations of clinical characteristics with outcomes were assessed using univariable and multi-covariate Cox Proportional Hazards regression models. RESULTS: A total of 178 patients (median age = 63.3; 57.9% females) with a median follow-up time of 42.0 (Interquartile range: 22.9-67.8) months were enrolled. There was no significant difference in PFS between chemoIO vs. chemo groups (5.3 vs. 4.8 months, p = 0.8). Compared to the chemo group, patients who received withBev therapy trended towards better PFS (6.1 months vs. 4.8; p = 0.3; HR 0.79; 95% CI: 0.52-1.20), while patients treated with IO-mono had inferior PFS (2.2 months; p = 0.001; HR 2.22; 95% CI: 1.37-3.59). Furthermore, PD-L1 level was not associated with PFS benefit in the chemoIO group. Patients with EGFR-mutant LUAD with high PD-L1 (≥50%) had shorter PFS (5.8 months) than non-EGFR/ALK LUAD patients who received chemoIO (12.8 months, p = 0.002; HR 0.22; 95% CI: 0.08-0.56) as first-line treatment. Chemotherapy-based therapy rendered similar benefit to patients with either EGFR exon19 deletion vs. L858R in the LUAD. CONCLUSIONS: This retrospective analysis revealed that immunotherapy provided limited additional benefit to chemotherapy in TKI-refractory EGFR-mutant LUAD. Chemotherapy alone or combined with bevacizumab remain good choices for patients with actionable EGFR mutations.

Estrogen Promotes Resistance to Bevacizumab in Murine Models of NSCLC.

INTRODUCTION: Subgroup analyses from clinical studies have suggested that among patients with metastatic NSCLC receiving chemotherapy, females may derive less benefit from the addition of the vascular endothelial growth factor (VEGF) monoclonal antibody bevacizumab (BV) than males. This has raised the question of whether estrogen may affect the response to antiangiogenic therapy. METHODS: To address this, we investigated the effects of estrogen on tumor growth, angiogenesis, and the response to BV in human xenograft models of NSCLC. RESULTS: We observed that estrogen induced marked resistance to BV, which was accompanied by a 2.3-fold increase in tumor vascular pericyte coverage (p = 0.01) and an up-regulation of proangiogenic factors, VEGF and platelet-derived growth factor-BB. We also investigated the role of infiltrating myeloid cells, a population that has been associated with resistance to anti-VEGF therapies. We observed that estrogen induced a greater than twofold increase (p = 0.001) in the recruitment of tumor-infiltrating myeloid cells and concomitant increases in the myeloid recruitment factors, G-CSF and CXCL1. Blockade of the estrogen receptor pathway using fulvestrant resensitized tumors to VEGF targeting as evidenced by reduced tumor vasculature and an increase in overall survival in our NSCLC xenograft models. CONCLUSIONS: Collectively, these data provide evidence that estrogen may promote resistance to VEGF-targeted therapies, potentially by enhancing pericyte coverage and myeloid recruitment, and suggest that estrogen receptor blockade merits further investigation as an approach to enhance the effects of antiangiogenic therapy.

Characterization of the Immune Landscape of EGFR-Mutant NSCLC Identifies CD73/Adenosine Pathway as a Potential Therapeutic Target.

INTRODUCTION: Lung adenocarcinomas harboring EGFR mutations do not respond to immune checkpoint blockade therapy and their EGFR wildtype counterpart. The mechanisms underlying this lack of clinical response have been investigated but remain incompletely understood. METHODS: We analyzed three cohorts of resected lung adenocarcinomas (Profiling of Resistance Patterns of Oncogenic Signaling Pathways in Evaluation of Cancer of Thorax, Immune Genomic Profiling of NSCLC, and The Cancer Genome Atlas) and compared tumor immune microenvironment of EGFR-mutant tumors to EGFR wildtype tumors, to identify actionable regulators to target and potentially enhance the treatment response. RESULTS: EGFR-mutant NSCLC exhibited low programmed death-ligand 1, low tumor mutational burden, decreased number of cytotoxic T cells, and low T cell receptor clonality, consistent with an immune-inert phenotype, though T cell expansion ex vivo was preserved. In an analysis of 75 immune checkpoint genes, the top up-regulated genes in the EGFR-mutant tumors (NT5E and ADORA1) belonged to the CD73/adenosine pathway. Single-cell analysis revealed that the tumor cell population expressed CD73, both in the treatment-naive and resistant tumors. Using coculture systems with EGFR-mutant NSCLC cells, T regulatory cell proportion was decreased with CD73 knockdown. In an immune-competent mouse model of EGFR-mutant lung cancer, the CD73/adenosine pathway was markedly up-regulated and CD73 blockade significantly inhibited tumor growth. CONCLUSIONS: Our work revealed that EGFR-mutant NSCLC has an immune-inert phenotype. We identified the CD73/adenosine pathway as a potential therapeutic target for EGFR-mutant NSCLC.

Altered Regulation of HIF-1α in Naive- and Drug-Resistant EGFR-Mutant NSCLC: Implications for a Vascular Endothelial Growth Factor-Dependent Phenotype.

INTRODUCTION: The treatment of patients with EGFR-mutant NSCLC with vascular endothelial growth factor (VEGF) inhibitors in combination with EGFR inhibitors provides a greater benefit than EGFR inhibition alone, suggesting that EGFR mutation status may define a patient subgroup with greater benefit from VEGF blockade. The mechanisms driving this potentially enhanced VEGF dependence are unknown. METHODS: We analyzed the effect of EGFR inhibition on VEGF and HIF-1α in NSCLC models in vitro and in vivo. We determined the efficacy of VEGF inhibition in xenografts and analyzed the impact of acquired EGFR inhibitor resistance on VEGF and HIF-1α. RESULTS: NSCLC cells with EGFR-activating mutations exhibited altered regulation of VEGF compared with EGFR wild-type cells. In EGFR-mutant cells, EGFR, not hypoxia, was the dominant regulator of HIF-1α and VEGF. NSCLC tumor models bearing classical or exon 20 EGFR mutations were more sensitive to VEGF inhibition than EGFR wild-type tumors, and a combination of VEGF and EGFR inhibition delayed tumor progression. In models of acquired EGFR inhibitor resistance, whereas VEGF remained overexpressed, the hypoxia-independent expression of HIF-1α was delinked from EGFR signaling, and EGFR inhibition no longer diminished HIF-1α or VEGF expression. CONCLUSIONS: In EGFR-mutant NSCLC, EGFR signaling is the dominant regulator of HIF-1α and VEGF in a hypoxia-independent manner, hijacking an important cellular response regulating tumor aggressiveness. Cells with acquired EGFR inhibitor resistance retained elevated expression of HIF-1α and VEGF, and the pathways were no longer EGFR-regulated. This supports VEGF targeting in EGFR-mutant tumors in the EGFR inhibitor-naive and refractory settings.

Omental macrophages secrete chemokine ligands that promote ovarian cancer colonization of the omentum via CCR1.

The omentum is the most common site of ovarian cancer metastasis. Immune cell clusters called milky spots are found throughout the omentum. It is however unknown if these immune cells contribute to ovarian cancer metastasis. Here we report that omental macrophages promote the migration and colonization of ovarian cancer cells to the omentum through the secretion of chemokine ligands that interact with chemokine receptor 1 (CCR1). We found that depletion of macrophages reduces ovarian cancer colonization of the omentum. RNA-sequencing of macrophages isolated from mouse omentum and mesenteric adipose tissue revealed a specific enrichment of chemokine ligand CCL6 in omental macrophages. CCL6 and the human homolog CCL23 were both necessary and sufficient to promote ovarian cancer migration by activating ERK1/2 and PI3K pathways. Importantly, inhibition of CCR1 reduced ovarian cancer colonization. These findings demonstrate a critical mechanism of omental macrophage induced colonization by ovarian cancer cells via CCR1 signaling.

Vitamin E Acetate as a Plausible Cause of Acute Vaping-related Illness.

The United States Federal Centers for Disease Control and Prevention (CDC) has been working with state investigators on reported cases of lung illnesses linked to e-cigarette or vaping products. Symptoms of difficulty breathing, shortness of breath, chest pains, gastrointestinal sickness leading to serious lung damage and death has been linked to the risk behavior of using vaping products bought on the streets in healthy young people. CDC has detected vitamin E acetate as a chemical of concern among people with the lung injury. Vitamin E acetate is a condensing agent in vaping products, and all injured lung fluid samples appear to harbor this agent. The mysterious outbreak is identified in individuals vaping within the 90 days, ranging over a few days to developing over several weeks. There is growing evidence that vaping is hazardous to your health including immediate health dangers such as death from respiratory causes, long term health effects, cardiovascular events, depression which increases the risk of suicidal thoughts and suicide. This review article summarizes the growing knowledge of acute respiratory complications associated with vaping.

Old habits tie hard: an in vitro comparison of first-throw tension holding in Polyglycolic acid (Dexon S) and Polyglactin 910 (Coated Vicryl).

PURPOSE: To compare the first-throw tension holding property of two braided absorbable sutures commonly used in oculoplastic surgery. METHODS: The study was an in vitro experimental model. 6/0 Polyglycolic acid (Dexon S) and 6/0 Polyglactin 910 (Coated Vicryl) were compared using an experimental model to determine first-throw knot security. A polypropylene suture (Surgipro 2) was included as a benchmark to judge the apparatus by, ensuring that our experiment could be designed independently of the test suture materials. Increasing metric loads were applied to the first double throw of a surgical knot. Each suture was tested to the point of knot slipping and the critical tension recorded. All the sutures were kept wet during use. Three variations of the experiment were undertaken: experiment 1 -- two metal loops brought together by the test suture; experiment 2 -- two strips of tissue brought together by the test suture; and experiment 3 -- a knot tied over a metal bar coated in tissue. The tissue used was processed cross-linked porcine dermal collagen (Permacol). Each experiment was repeated three times for each suture type and the mean value taken. RESULTS: Experiment 1: Dexon S 12.2 g (11, 12, 13.5), Coated Vicryl 2.5 g (2.5, 2.5, 2.5) and Surgipro 2 2.3 g (2, 2, 3); experiment 2: Dexon S 33.33 g (30, 35, 35), Coated Vicryl 25 g (25, 25, 25) and Surgipro 2 5 g (5, 5, 5); experiment 3: Dexon S 100 g (100, 100, 100), Coated Vicryl 56.667 g (60, 55, 55) and Surgipro 2 5 g (5, 5, 5). CONCLUSIONS: Dexon S-braided absorbable suture has significantly better first-throw knot security when compared with Coated Vicryl. This is an important property when suturing tissues under tension as it minimizes slippage before the locking throw is tied.