[Strategy of therapy for interstitial lung disease due to chemotherapeutic drugs or radiation].

Pulmonary disease induced by chemotherapeutic drug or radiation is one of the major cause, of death in patients with lung cancer. Many of these patients die from interstitial lung disease despite discontinuation of the drug and addition of corticosteroid treatment. The clinical presentation is similar for all of the chemotherapeutic drugs. For the early detection of interstitial lung disease due to a chemotherapeutic drug, serial measurements of the CO diffusing capacity (DLco), serum LDH, and serum KL-6 are useful. The first step in treatment is withdrawal of the drugs, and pulse therapy by using methylprednisolone is used as a standard therapy for interstitial lung disease due to chemotherapeutic agents. Immunosuppressive agents, such as cyclophosphamide or azathioprine, might be used as second-line drugs in patients for whom drugs either failed or could not tolerate corticosteroid treatment. Thus the usefulness of this therapy is unknown, and it should be considered as a marginal therapy. To develop an investigational therapy for the chemotherapeutic drug-induced interstitial lung disease, we investigated the efficacy of a new specific neutrophil elastase inhibitor (ONO-5046.Na) in bleomycin-induced pulmonary fibrosis. The inhibitory effect of ONO-5046.Na was observed in bleomycin-induced pulmonary fibrosis in mice. This specific neutrophil elastase could be a investigational therapeutic agent for interstitial lung disease due to chemotherapeutic agents used against lung cancer.