title: Sustained response to standard dose osimertinib in a patient with plasma T790M-positive leptomeningeal metastases from primary lung adenocarcinoma.
abstract: A 44-year-old male, never smoker, suffers from stage IV adenocarcinoma of the right lung with epidermal growth factor receptor (EGFR) exon-21 L858R point mutation on initial presentation. After 23 months of treatment with gefitinib, intercalated with multiple courses of radiotherapy, leptomeningeal metastases (LMs) developed. Acquired T790M mutation was confirmed by the droplet digital polymerase chain reaction plasma EGFR test. After switching to osimertinib at the standard dose, his neurocognitive function improved clinically, coupled with sustained radiological improvement. As this clinical entity is underrepresented in clinical trials, the practicability of plasma EGFR testing and the optimal dose-response relationship of osimertinib in T790M-positive lung cancer complicated with LM deserves further exploration.
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China.
authors.forename: Oscar Siu-Hong
authors.initials: OS
authors.lastname: Chan
authors.affiliation: Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China.
authors.forename: Warren Kam-Wing
authors.initials: WK
authors.lastname: Leung
authors.affiliation: Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China.
authors.forename: Rebecca Mei-Wan
authors.initials: RM
authors.lastname: Yeung
mesh_terms: D000178:Acrylamides; D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000814:Aniline Compounds; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D010879:Piperazines / Q000494:pharmacology / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D007211:Indoles; D011743:Pyrimidines
chemical_list: D000178:Acrylamides; D000814:Aniline Compounds; D000970:Antineoplastic Agents; D010879:Piperazines; D047428:Protein Kinase Inhibitors; C000596361:osimertinib; D007211:Indoles; D011743:Pyrimidines
keywords: circulating tumor DNA; leptomeningeal metastases; lung cancer; osimertinib