Interstitial pneumonia in a patient treated with TAS-102 for metastatic colorectal cancer: a case report

BACKGROUND: TAS-102, a new treatment option for patients with metastatic colorectal cancer that is refractory or intolerant to standard therapies, has been improving survival with acceptable tolerability and adverse events. Adverse hematological events associated with TAS-102 treatment were extensively profiled in the RECOURSE trial, but pulmonary toxicities associated with TAS-102 therapy are distinctly uncommon. In a recent early post-marketing phase vigilance on TAS-102 in Japan, seven cases of pulmonary disease were reported, but patient follow-up in this study was incomplete. Here, we present the first case of interstitial lung disease occurring in association with TAS-102 treatment. CASE PRESENTATION: A 57-year-old Japanese man who had previously received two standard treatments was admitted in 2014, at which time we administered TAS-102 (110 mg/day) as a third-line chemotherapy. He was safely treated with TAS-102 for the first planned cycle; however, approximately 4 days after receiving the second cycle of TAS-102, he complained of high fever and subsequent dyspnea with severe hypoxemia and went to the emergency room. A chest X-ray revealed diffuse coarse reticular shadows with ground-glass opacity on both lungs. Furthermore, a chest computed tomography scan showed thickening of the bronchovascular bundles with extensive ground-glass opacification and pleural effusions in both lung fields. In addition, a peripheral blood lymphocyte stimulation test with TAS-102 showed higher values compared with control samples. Consequently, we suspected drug-induced interstitial pneumonia, and discontinued treatment. Our patient was given an initial administration of high-dose methylprednisolone (1000 mg/day) for 3 days and oxygen. Our patient was discharged with oral prednisolone (20 mg/day) and improved symptomatically and radiologically. CONCLUSIONS: These findings suggest that interstitial pneumonia is a rare complication of TAS-102 chemotherapy, but the possibility of interstitial pneumonia should always be considered when a patient presents with a respiratory disorder while undergoing TAS-102 systemic chemotherapy. Prompt discontinuation of TAS-102 and treatment with high-dosage corticosteroids is needed to avoid exacerbating respiratory symptoms.