{"entity":{"id":"invasive-mucinous-adenocarcinoma-lung","kind":"cancer","name":"Invasive mucinous adenocarcinoma of the lung","aka":["Invasive mucinous adenocarcinoma","IMA","Mucinous bronchioloalveolar carcinoma (term retired in 2011)","Mucinous adenocarcinoma of the lung"],"tldr":"Invasive mucinous adenocarcinoma is a type of lung cancer whose cells look like stomach or bowel lining and fill the air spaces with mucus, often appearing as pneumonia-like shadows on a scan. Most cases carry a KRAS mutation, and many of the rest carry a gene fusion, including NRG1, that new drugs can target.","summary":"The IASLC/ATS/ERS classification of 2011 separated invasive mucinous adenocarcinoma from the non-mucinous lepidic tumours because of its distinct cells (goblet or columnar with abundant mucin), its tendency to spread through the airways as multifocal or lobar consolidation, and its biology (Travis 2011). Sequencing of 72 cases found KRAS mutations in 63 percent, with a distribution of nucleotide changes closer to gastrointestinal than to other lung tumours; among the KRAS wild-type cases were the fusions CD74-NRG1, VAMP2-NRG1, TRIM4-BRAF, TPM3-NTRK1 and EML4-ALK and mutations in ERBB2 and other genes (Shim 2015). Expression profiling identified a 143-gene mucinous signature, shared with mucin-producing gastrointestinal, pancreatic and breast cancers, in which the transcription factors FOXA3, SPDEF and HNF4A drive MUC5AC and MUC5B, and in which the checkpoint VTCN1 rather than PD-L1 is expressed (EMBO Molecular Medicine 2017).\n\nHow it differs from its parent: it is TTF-1-negative and expresses gut markers, so it can be mistaken for a metastasis; it is EGFR-mutant only rarely; and it is the lung cancer richest in NRG1 fusions, for which the HER2-HER3 bispecific antibody zenocutuzumab is approved.\n\nHow common: no share is given in the sources read; it is a minority of adenocarcinomas.\n\nTreatment: as lung adenocarcinoma by stage, with KRAS G12C inhibitors for that mutation, zenocutuzumab for NRG1 fusions, and the matching inhibitors for ALK, BRAF and NTRK fusions; multifocal disease that stays in the lung is sometimes resected repeatedly.","asOf":"2026-09-24","wikipedia":"https://en.wikipedia.org/wiki/Adenocarcinoma_of_the_lung","links":[{"label":"Travis 2011, JTO: IASLC/ATS/ERS international multidisciplinary classification of lung adenocarcinoma","url":"https://doi.org/10.1097/jto.0b013e318206a221"},{"label":"Nicholson 2022, JTO: the 2021 WHO classification of lung tumours","url":"https://doi.org/10.1016/j.jtho.2021.11.003"},{"label":"Shim 2015, JTO: unique genetic and survival characteristics of invasive mucinous adenocarcinoma of the lung","url":"https://doi.org/10.1097/jto.0000000000000579"},{"label":"EMBO Molecular Medicine 2017: gene signature driving invasive mucinous adenocarcinoma of the lung","url":"https://doi.org/10.15252/emmm.201606711"}],"tags":["subtype-page","wave4","lung"],"related":["nsclc","lung-adenocarcinoma","kras-g12c-nsclc","lung-adenocarcinoma-in-situ-and-minimally-invasive"],"cancers":[],"sections":[],"technologies":[],"targets":["kras","nrg1"],"drugs":["zenocutuzumab"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"group":"lung","burden":"A minority of lung adenocarcinomas; the defining genomic series studied 72 cases from the United States and Korea (Shim 2015). No registry share was found in the sources read.","subtypes":["KRAS-mutant invasive mucinous adenocarcinoma (63 percent)","NRG1 fusion-positive invasive mucinous adenocarcinoma","Invasive mucinous adenocarcinoma with ALK, BRAF or NTRK fusion","Mixed invasive mucinous and non-mucinous adenocarcinoma"],"biomarkers":["KRAS mutation (G12C and non-G12C)","NRG1 fusion","ALK, BRAF, NTRK1 and ERBB2 alterations in KRAS wild-type cases","TTF-1 negative, HNF4A and gut markers positive"],"standardOfCare":[{"setting":"All stages","approach":"Treated as lung adenocarcinoma by stage, with KRAS G12C inhibitors, zenocutuzumab for NRG1 fusions and matched inhibitors for other fusions when found.","refs":["lung-adenocarcinoma","kras-g12c-nsclc","zenocutuzumab"]}],"stateOfArt":[],"history":[],"pipeline":[],"openProblems":[],"parent":"nsclc"},"route":"/cancers/invasive-mucinous-adenocarcinoma-lung/","neighbours":{"cancer":[{"id":"lung-adenocarcinoma-in-situ-and-minimally-invasive","kind":"cancer","name":"Adenocarcinoma in situ and minimally invasive adenocarcinoma of the lung","route":"/cancers/lung-adenocarcinoma-in-situ-and-minimally-invasive/"},{"id":"lung-adenocarcinoma","kind":"cancer","name":"Adenocarcinoma of the lung","route":"/cancers/lung-adenocarcinoma/"},{"id":"kras-g12c-nsclc","kind":"cancer","name":"KRAS G12C-mutant non-small-cell lung cancer","route":"/cancers/kras-g12c-nsclc/"},{"id":"nsclc","kind":"cancer","name":"Non-small-cell lung cancer","route":"/cancers/nsclc/"}],"target":[{"id":"kras","kind":"target","name":"KRAS","route":"/targets/kras/"},{"id":"nrg1","kind":"target","name":"NRG1","route":"/targets/nrg1/"}],"drug":[{"id":"zenocutuzumab","kind":"drug","name":"Zenocutuzumab","route":"/drugs/zenocutuzumab/"}]}}