Response to EGFR-TKI in patients with gastrointestinal metastasis from primary lung adenocarcinoma: report of two cases

Lung cancer is the leading cause of cancer-related mortality worldwide. The most common sites of lung cancer metastasis are the lymph nodes, brain, liver, bones, and adrenal glands, whereas the gastrointestinal (GI) tract is rare. Here we report two cases of non-small cell lung cancer with GI metastases. Both patients were given epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) during treatment. The patient of case 1 died soon after being given icotinib for late-stage multiple organ failure. The patient of case 2 with wild-type EGFR achieved 13 months of progression-free survival after erlotinib therapy, and the most recent follow-up evaluation suggested a stable condition in which no lesions demonstrated progression. Through these two cases, we observed different clinical effects and prognosis after EGFR-TKI-based therapy for these patients, but the mechanism of action requires further elucidation.