Treatment of mutation-positive non-small cell lung cancer complicated by Trousseau syndrome with gefitinib followed by osimertinib: a case report.

Malignant tumors can induce a hypercoagulable state known as Trousseau syndrome that increases the risk for venous thromboembolism including disabling cerebral infarction. Anticoagulant therapy without anticancer treatment is not effective for amelioration of this coagulation abnormality. Most patients with lung cancer positive for activating mutations of the epidermal growth factor receptor (EGFR) are sensitive to EGFR tyrosine kinase inhibitors (TKIs), but the efficacy and safety of EGFR-TKIs in such patients with a poor performance status (PS) due to Trousseau syndrome has been unclear. We here describe a patient with mutation-positive lung cancer who developed disabling cerebral infarction due to Trousseau syndrome. Administration of the EGFR-TKI gefitinib and anticoagulant therapy resulted in a partial tumor response and recovery from both the coagulation abnormality and the severe neurological symptoms. After the development of resistance to gefitinib, the EGFR-TKI osimertinib was safely administered until disease progression without recurrence of the coagulation abnormality. This case suggests that gefitinib followed by osimertinib may be a safe and effective treatment option for patients with mutation-positive lung cancer who experience disabling cerebral infarction due to Trousseau syndrome.