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Small cell lung carcinoma (SCLC) is a highly aggressive malignancy that is typically associated with tobacco exposure and inactivation of RB1 and TP53 genes. Here, we performed detailed clinicopathologic, genomic, and transcriptomic profiling of an atypical subset of SCLC that lacked RB1 and TP53 co-inactivation and arose in never/light smokers. We found that most cases were associated with chromothripsis-massive, localized chromosome shattering-recurrently involving chromosome 11 or 12 and resulting in extrachromosomal amplification of CCND1 or co-amplification of CCND2/CDK4/MDM2, respectively. Uniquely, these clinically aggressive tumors exhibited genomic and pathologic links to pulmonary carcinoids, suggesting a previously uncharacterized mode of SCLC pathogenesis via transformation from lower-grade neuroendocrine tumors or their progenitors. Conversely, SCLC in never-smokers harboring inactivated RB1 and TP53 exhibited hallmarks of adenocarcinoma-to-SCLC derivation, supporting two distinct pathways of plasticity-mediated pathogenesis of SCLC in never-smokers. Significance: Here, we provide the first detailed description of a unique SCLC subset lacking RB1/TP53 alterations and identify extensive chromothripsis and pathogenetic links to pulmonary carcinoids as its hallmark features. This work defines atypical SCLC as a novel entity among lung cancers, highlighting its exceptional histogenesis, clinicopathologic characteristics, and therapeutic vulnerabilities. See related commentary by Nadeem and Drapkin, p. 8., (©2024 The Authors; Published by the American Association for Cancer Research.)

Background: Cachexia is characterized by weight loss and decline in muscle mass and function and is a poor prognostic factor among patients with cancer. Patients with metastatic EGFR-mutant non-small cell lung cancer (NSCLC) derive remarkable survival benefits with osimertinib, a third-generation EGFR tyrosine kinase inhibitor. It is not known whether patients treated with osimertinib experience any weight loss or whether weight loss impacts patient outcomes. Therefore, we sought to describe the frequency and consequences of weight loss in this patient population., Materials and Methods: We conducted a single-center retrospective pilot study of 56 patients treated with first-line osimertinib for metastatic EGFR-mutant NSCLC. We defined on-treatment weight loss as a loss of ≥5% body weight at 6 or 12 months of treatment. We described the characteristics of patients with and without on-treatment weight loss and differences in progression-free survival (PFS), time on treatment with osimertinib, and overall survival (OS)., Results: Forty-six percent (n = 26) of patients met the criteria for on-treatment weight loss. There were no significant differences in patient or disease characteristics between patients with and without weight loss. Compared to patients without weight loss, patients with weight loss had similar PFS and time on treatment with osimertinib. Yet, patients with weight loss had significantly worse overall survival (HR 4.91, 95% CI, 1.56-15.5, P = .007)., Conclusion: Weight loss was observed in nearly half of patients with metastatic EGFR-mutant NSCLC treated with osimertinib, and patients with weight loss had significantly worse overall survival., (© The Author(s) 2024. Published by Oxford University Press.)

Purpose: Preclinical studies demonstrated that dual inhibition of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) pathways delay the emergence of resistance to EGFR tyrosine kinase inhibitors (TKIs), and in trials with first-generation EGFR TKIs, the combination of EGFR VEGF pathway inhibitors prolonged progression-free survival (PFS)., Methods: The RAMOSE trial (ClinicalTrials.gov identifier: NCT03909334, HCRN LUN-18-335) is a randomized, open-label multicenter phase II study comparing osimertinib with ramucirumab (arm A) to osimertinib (arm B) for initial treatment of metastatic EGFR -mutant non-small cell lung cancer (NSCLC) with 2:1 random assignment. The primary end point is PFS for evaluable patients; secondary end points include objective response rates (ORRs), disease control rate (DCR), overall survival, and safety. The stratification criteria were EGFR mutation type and the presence of CNS metastasis., Results: At data cutoff on August 29, 2023, 160 patients consented, 147 patients received treatment, and 139 patients were evaluable with at least one scan. In this preplanned interim analysis, the median follow-up was 16.6 months. Among the evaluable patients, 57 PFS events occurred. The median PFS was 24.8 (A) versus 15.6 (B) months (hazard ratio, 0.55 [95% CI, 0.32 to 0.93]; log-rank P = .023), 12-month PFS rate was 76.7% (A) versus 61.9% (B; P = .026). No significant difference was observed in the ORRs and DCRs between arms. Any-grade (G) adverse events (AEs) occurred in 100% (A) and 98% (B) of patients, with no G5 treatment-related AE (TRAE), one G4 TRAE (hyponatremia, A), and 53% (A) versus 41% (B) G3 TRAEs. AE-related discontinuation occurred in 13 patients (9.7% in A and 8.7% in B). The safety profile was in line with known safety of each drug., Conclusion: Ramucirumab plus osimertinib significantly prolonged PFS compared with osimertinib alone in patients with TKI-naïve EGFR -mutant NSCLC. The combination is safe and well tolerated.