Lung adenocarcinoma patient progression with gastrointestinal metastasis response to subsequent tyrosine kinase inhibitors (TKIs) from re-biopsy of new occurring driver gene mutation

Primary lung cancer frequently metastasizes to the lung, lymph nodes, brain, liver, adrenal glands and bones (1). The clinical incidence of gastrointestinal (GI) metastasis from lung cancer has been reported to be as low as 0.2–1.7% (2). Studies might be difficult to organize because the clinical incidence and associated mortality rates are low and due to its lack of symptoms; thus, true understanding of the clinical presentation of metastases of primary lung cancer to the GI tract is currently incomplete (3). Due to a lack of pathology and molecular detection, lung cancer with GI metastasis is reported to have a poor prognosis with a mean survival of only 4–8 weeks (4)