Gastrointestinal perforation following dabrafenib and trametinib administration in non-small cell lung carcinoma with BRAF V600E mutation: a case report and literature review.

Gastrointestinal perforation related to mitogen-activated protein kinase kinase (MEK) inhibitors has been reported previously; however, there has been no case report of such a condition in patients with non-small cell lung cancer (NSCLC). Herein, we report a case of small intestinal perforation secondary to dabrafenib and trametinib administration, but not related to tumor regression. A 62-year-old man with non-small cell lung cancer harboring BRAF V600E mutation was treated with dabrafenib and trametinib. Four months after the initiation of treatment, a small intestinal perforation was diagnosed. Dabrafenib and trametinib rechallenge was performed after gastrointestinal perforation. The patient responded well to therapy and did not experience recurrence of gastrointestinal perforation. To the best of our knowledge, this is the first report of gastrointestinal perforation in a patient with NSCLC treated with a MEK inhibitor. The mechanism and risk factors of trametinib-induced perforation are currently unknown. Physicians should be aware of such severe gastrointestinal side effects of trametinib.