Successful EGFR-TKI rechallenge of leptomeningeal carcinomatosis after gefitinib-induced interstitial lung disease.

We report the case of a 49-year-old non-smoking Japanese woman with backache and difficulty in walking. She was diagnosed as having advanced lung adenocarcinoma, and an epithelial growth factor receptor mutation (in-frame deletions in exon 19) was found. After radiation therapy of bone metastases with spinal cord compression and brain metastases, gefitinib was administered. On day 2, she developed acute interstitial lung disease. Gefitinib therapy was discontinued and treatment with high-dose steroid therapy improved the interstitial lung disease. Cisplatin plus pemetrexed was initiated as second-line chemotherapy, but she was hospitalized again for leptomeningeal carcinomatosis. Considering the poor prognosis of leptomeningeal carcinomatosis, we decided that erlotinib was our only choice of treatment. As a third-line treatment, erlotinib was administered after informing the patient about the high risk of interstitial lung disease. Neurological symptoms were improved within a week and interstitial lung disease did not recur. The patient has received erlotinib successfully for 18 months without the recurrence of leptomeningeal carcinomatosis. Erlotinib rechallenge after gefitinib-induced interstitial lung disease must be carefully chosen based on the balance of a patient's risk and benefit.