{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T03:58:54Z","timestamp":1785383934732,"version":"3.55.0"},"reference-count":14,"publisher":"Wiley","issue":"7","license":[{"start":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T00:00:00Z","timestamp":1784073600000},"content-version":"vor","delay-in-days":14,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Respirology Case Reports"],"published-print":{"date-parts":[[2026,7]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>Osimertinib is the standard first\u2010line treatment for EGFR\u2010mutated non\u2013small cell lung cancer (NSCLC), although acquired resistance remains inevitable. The EGFR C797S mutation is a recognized on\u2010target resistance mechanism; however, the T790M\u2010negative\/C797S\u2010only subtype following frontline osimertinib\u2010based combination therapy is rarely reported. We describe a 44\u2010year\u2010old Vietnamese never\u2010smoking woman diagnosed with stage IV lung adenocarcinoma harbouring EGFR exon 21 L858R mutation. First\u2010line treatment with pemetrexed\u2013carboplatin plus osimertinib achieved a near\u2010complete response, followed by maintenance osimertinib monotherapy. After 26\u2009months of disease control, radiologic progression occurred with recurrent bilateral pulmonary metastases and right supraclavicular lymphadenopathy. Repeat biopsy and next\u2010generation sequencing identified persistent EGFR L858R (VAF 13.92%) and acquired EGFR C797S (VAF 6.19%) without detectable\u00a0T790M, consistent with a C797S\u2010only resistance profile. Subsequent gefitinib plus bevacizumab therapy produced a rapid radiologic response with near\u2010complete resolution of contralateral pulmonary lesions, suggesting retained sensitivity to reversible EGFR tyrosine kinase inhibitor\u2013based therapy in C797S\u2010only disease.<\/jats:p>","DOI":"10.1002\/rcr2.70673","type":"journal-article","created":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T05:11:01Z","timestamp":1784178661000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Treatment\u2010Emergent Isolated\n                    <scp>EGFR C797S<\/scp>\n                    Mutation Following First\u2010Line Osimertinib\u2010Based Combination Therapy: A Case Report and Literature Review"],"prefix":"10.1002","volume":"14","author":[{"given":"Thu Huong","family":"Nguyen","sequence":"first","affiliation":[{"name":"Lung and Breast Medical Oncology Department Hanoi Oncology Hospital  Hanoi Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hoang Gia","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Lung and Breast Medical Oncology Department Hanoi Oncology Hospital  Hanoi Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thu Ha","family":"Le","sequence":"additional","affiliation":[{"name":"Lung and Breast Medical Oncology Department Hanoi Oncology Hospital  Hanoi Vietnam"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,7,15]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.21.01626"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1097\/JTO.0000000000000033"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1713137"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1913662"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.esmoop.2021.100271"},{"key":"e_1_2_9_7_1","doi-asserted-by":"publisher","DOI":"10.1038\/nm.3854"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1093\/jjco\/hyad052"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-023-35961-y"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jtho.2023.11.016"},{"key":"e_1_2_9_11_1","doi-asserted-by":"publisher","DOI":"10.1158\/1078-0432.CCR-15-0560"},{"key":"e_1_2_9_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1470-2045(19)30035-X"},{"key":"e_1_2_9_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ccell.2021.07.005"},{"key":"e_1_2_9_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1470-2045(14)70381-X"},{"key":"e_1_2_9_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jtho.2020.10.006"}],"container-title":["Respirology Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/rcr2.70673","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/rcr2.70673","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/rcr2.70673","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T03:07:12Z","timestamp":1785380832000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/rcr2.70673"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7]]},"references-count":14,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2026,7]]}},"alternative-id":["10.1002\/rcr2.70673"],"URL":"https:\/\/doi.org\/10.1002\/rcr2.70673","archive":["Portico"],"relation":{},"ISSN":["2051-3380","2051-3380"],"issn-type":[{"value":"2051-3380","type":"print"},{"value":"2051-3380","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7]]},"assertion":[{"value":"2026-05-20","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-01","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-15","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e70673"}}