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Background and Aims: Therapy failure in patients with metastatic colorectal cancer (mCRC, ∼80% occur in the liver) remains an overarching challenge. Preclinical studies demonstrated that HER3 promotes CRC cell survival, but therapies blocking the neuregulin-induced canonical HER3 signaling have made little impact in the clinic. Recent studies suggest that the liver microenvironment promotes CRC growth by activating HER3 in a neuregulin-independent fashion, thus elucidation of these mechanisms may reveal new strategies for treating patients with mCRC., Methods: Patient-derived primary liver endothelial cells (ECs) were used to interrogate EC-CRC crosstalk. We conducted proteomic analysis to identify EC-secreted factor(s) that triggers non-canonical HER3 activation in CRC, and determined the subsequent effects on mCRC using diverse murine mCRC models. In vitro studies with genetic and pharmacological interventions were used to map the non-canonical HER3 pathway., Results: We demonstrated that EC-secreted leucine-rich alpha-2-glycoprotein 1 (LRG1) directly binds and activates HER3 and promotes CRC growth distinct from neuregulin, the canonical HER3 ligand. Blocking host-derived LRG1 by gene knockout or a neutralizing antibody impaired mCRC outgrowth in the liver and prolonged mouse survival. We identified protein synthesis activated by the PI3K-PDK1-RSK-eIF4B axis as the biologically relevant signaling cascade downstream of the LRG1-HER3 interaction, which was not blocked by conventional HER3-specific antibodies that failed in prior clinical trials., Conclusions: LRG1 is a novel HER3 ligand and mediates liver-mCRC crosstalk. The LRG1-HER3 signaling axis is distinct from canonical HER3 signaling and represents a new therapeutic opportunity to treat patients with mCRC, and potentially other types of liver metastases., (Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Introduction: Upper gastrointestinal (UGI) cancers require multidisciplinary treatment, but surgery provides the only potentially curative option. We sought to understand reasons for attrition before surgery within our regional hospital network., Methods: We performed chart reviews of patients (age 18-80) with stage I-III UGI cancers (gastroesophageal junction, gastric, and hepatopancreatobiliary adenocarcinomas) in our multihospital cancer registry from 2015 to 2021. Our primary outcome was reasons for surgical attrition. Univariable analysis identified factors related to surgical attrition and the Kaplan-Meier method estimated overall survival based on surgery receipt., Results: Seven hundred and ninety-two patients were included in our analysis, of whom 107 (13.5%) did not undergo curative surgery. Reasons for not undergoing surgery included medical comorbidities (30.8%), patient preference/nonmedical barriers (24.3%, which included: not interested without further explanation, worried about complications, nonadherence to appointments, insurance issues, did not wish for blood transfusion, lack of social support, preferring home care, and worried about recurrence), psychosocial (5.6%), progression while on neoadjuvant therapy or waiting for transplant (15.0% and 7.5%), poor performance status (3.7%), side effects of neoadjuvant therapy (3.7%), and death unrelated to treatment or unknown cause (9.4%). Nonsurgical management was not associated with race, socioeconomic status, or distance traveled for care. Survival was greatly improved for patients who underwent surgery (158 vs. 63 weeks, p < 0.05)., Conclusion: Nearly one in seven patients (18-80 years old) with UGI cancers evaluated at our academic cancer center did not undergo surgical resection. Reasons for surgical attrition included potentially modifiable issues, and addressing these barriers could help overcome inequities in cancer treatment and survival., (© 2024 Wiley Periodicals LLC.)

Introduction: The NCCN considers "baseline staging" (whole body CT or PET scan +/- brain MRI) for all asymptomatic melanoma patients with a positive sentinel lymph node biopsy. The true yield of these workups is unknown., Methods: We created cohorts of adult malignant melanoma patients, using the National Cancer Database (2012-2020) to mimic three common scenarios: (1) clinically node negative, with positive sentinel lymph node(s) (SLNB[+]); (2) clinically node negative, with negative sentinel lymph node(s) (SLNB[-]); (3) clinically node positive with confirmed lymph node metastases (cN[+] and pN[+]). Multivariable regression, supervised decision trees, and nomograms were constructed to assess the risk of metastases based on key features., Results: 10,371 patients were SLNB[+], 55,172 were SLNB[-], and 4,012 were cN[+] and pN[+]. The proportion of patients with any metastatic disease (brain metastases) were as follows: SLNB[+]: 1.4% (0.3%); SLNB[-] 0.3% (<0.1%); cN[+] and pN[+] 11.6% (1.6%). On multivariable regression, Breslow depth > 4, ulceration, and lymphovascular invasion were associated with greater risk of metastatic disease. A supervised decision tree for SLNB[+] and SLNB[-] patients found the only groups with >2% risk of metastases were T4 tumors or T2/T3 tumors with ulceration and LVI. Most groups had a negligible risk (<0.1%) of brain metastases., Conclusion: This is the first large analysis to guide the use of imaging for cutaneous melanoma. Among clinically node negative patients, metastatic disease is uncommon and brain metastases are exceedingly rare. Further investigation could promote a tailored approach to metastatic workups guided by individual risk factors., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Pancreatic cancer is the third leading cause of cancer death in the United States, and while conventional chemotherapy remains the standard treatment, responses are poor. Safe and alternative therapeutic strategies are urgently needed 1 . A ketogenic diet has been shown to have anti-tumor effects across diverse cancer types but will unlikely have a significant effect alone. However, the diet shifts metabolism in tumors to create new vulnerabilities that can be targeted (1). Modulators of glutamine metabolism have shown promise in pre-clinical models but have failed to have a marked impact against cancer in the clinic. We show that a ketogenic diet increases TCA and glutamine-associated metabolites in murine pancreatic cancer models and under metabolic conditions that simulate a ketogenic diet in vitro. The metabolic shift leads to increased reliance on glutamine-mediated anaplerosis to compensate for low glucose abundance associated with a ketogenic diet. As a result, glutamine metabolism inhibitors, such as DON and CB839 in combination with a ketogenic diet had robust anti-cancer effects. These findings provide rationale to study the use of a ketogenic diet with glutamine targeted therapies in a clinical context.