Objectives: MET exon 14 skipping alterations (METex14+) represent a heterogeneous subgroup of non-small cell lung cancer (NSCLC) with distinct biological and genomic features. We characterized this heterogeneity in a large cohort, integrating genomic and transcriptomic profiling with clinical outcomes, to elucidate the histologic and molecular traits and survival patterns of METex14+ NSCLC., Materials and Methods: NSCLC tissue samples (n = 28,739) underwent DNA-based next-generation sequencing (592 genes, NextSeq) or whole-exome sequencing (NovaSeq), RNA-sequencing including whole transcriptome sequencing (WTS, NovaSeq), and PD-L1 IHC (Dako 22C3) at Caris Life Sciences. Immune cell fractions were estimated from bulk RNA sequencing (quanTIseq). Real-world survival data (mOS) was calculated from insurance claims. Statistical analyses employed Chi-square, Fisher's exact, or Mann-Whitney U and log-rank tests and were corrected for hypothesis testing where applicable., Results: A total of 711 METex14+ cases were detected. Of 575 cases of defined histology, 77 (13.6 %) were squamous (Sq), 474 (82.3 %) were nSq (non-squamous), and 24 (4.1 %) were adenosquamous. Mutations in POT1 and BRCA2 were enriched, and amplifications in MDM2, HMGA2, CDK4, and MET were common in METex14+ tumors. TMB-high and TP53 mutated tumors were reduced in METex14+ independent of histology. KEAP1 (2.1 vs 14.7 %) and STK11 mutations (0.8 vs 17.1 %) were reduced only in METex14+ nSq (vs METex14+ Sq, q < 0.05). While the prevalence of PD-L1 high tumors was enriched in METex14+ independent of histology, T-cell inflamed tumors were enriched only in nSq METex14+. B-cells and CD8+ T-cells (1.07-1.43-fold) were enriched in nSq METex14+, and dendritic cells (0.32 fold) were reduced only in METex14+ Sq. METex14+ tumors had a modest improvement in mOS compared to METex14- tumors (mOS = 22.9 m vs 18.6 m, HR = 0.914, p = 0.04). Moreover, METex14+ tumors who received immunotherapy (IO) had a modest improvement in survival (mOS = 27.5 m vs 21.8 m; HR = 0.803, p = 0.03) compared to those who did not receive IO. METex14+ nSq tumors were associated with improved mOS compared to METex14+ Sq tumors (mOS = 27.7 vs 8.9 m, HR = 0.493, p < 0.0001)., Conclusion: METex14+ alterations are a heterogeneous subgroup of NSCLC. Our analysis reveals that METex14+ nSq exhibit improved survival compared to METex14+ Sq. The distinct genomic and transcriptomic variations across histologies warrant clinical consideration., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jennifer Marks holds R&D authorship with Janssen Scientific Affairs. Nishant Gandhi, Joanne Xiu, Phillip Walker, and Matthew J. Oberley are employed by Caris Life Sciences. So Yeon Kim receives institutional grant funding from Boehringer Ingelheim, Astra Zeneca, Genentech, BMS, Loxo-Lilly, Genmab, and Dynamicure. Additionally, she has consulted for Amgen.Balazs Halmos receives institutional grant funding from Boehringer Ingelheim, Astra Zeneca, Merck, BMS, Advaxis, Amgen, AbbVie, Daiichi, Pfizer, GSK, Beigene, Janssen, Black Diamond Therapeutics, Forward Pharma, Numab, and Arrivent. He also serves on the Data Safety Monitoring Board/Advisory board for BMS, TPT, Apollomics, eFECTOR, and City of Hope. Melina E. Marmarelis reports research funding from Eli Lilly (Inst), AstraZeneca (Inst), Merck (Inst), Genentech (Inst), and holds a consulting role with Astra Zeneca, Novocure, Boehringer Ingelheim, Janssen, Takeda, Blueprint Pharmaceuticals, Bayer, Bristol Myers Squibb, Ikena, Regeneron. She also receives honorarium from Thermo Fisher and holds stock in Merck and Johnson & Johnson. Lyudmila Bazhenova reports a professional medical writing service funded by Mirati Therapeutics Inc, along with consulting roles with Pfizer, Genentech, Janssen, Novocure, Daiichi Sankyo, Anheart, BMS, Sanofi, Gilead, Teligene, Boehringer Ingelheim, Neuvogen, Bayer, BioAtla, Summit Therapeutics, Merck, Abbvie, Regeneron, Intervenn, Elevation Oncology, and Mirati. Additionally, she has institutional consulting with Takeda and Astra Zeneca, serves on the Data Safety Monitoring for ORIC Pharmaceuticals and Neuvogen, and holds stock in Epic Sciences. Stephen V. Liu holds a consulting role with AstraZeneca, Bristol-Myers Squibb, Catalyst, Daiichi Sankyo, Eisai, Elevation Oncology, Genentech/Roche, Gilead, Guardant Health, Janssen, Jazz Pharmaceuticals, Merck, Merus, Novartis, Regeneron, Sanofi, and Takeda. He also receives research institutional grant funding from Alkermes, Bristol-Myers Squibb, Elevation Oncology, Genentech, Gilead, Merck, Merus, Nuvalent, Pfizer, RAPT, and Turning Point Therapeutics, and serves on the Data Safety Monitoring Board for Candel Therapeutics. The remaining authors have no relevant financial disclosures to report., (Copyright © 2024 Elsevier B.V. All rights reserved.)