Regression of Lung Squamous Cell Carcinoma after the Withdrawal of Cyclosporin A Combined with Pirfenidone Treatment in a Patient with Idiopathic Pulmonary Fibrosis

A 72-year-old man was treated with prednisolone and cyclosporine A for idiopathic pulmonary fibrosis. A nodule with a diameter of 19 mm was found in the right lung and diagnosed as lung squamous cell carcinoma. Anti-cancer treatments were not performed because of the presence of advanced interstitial pneumonia and chronic respiratory failure. Cyclosporine A was tapered to avoid suppression of anti-tumor immunity, and pirfenidone was initiated. Within 2 months, the tumor had shrunk to 10 mm in diameter and remained regressed for 9 months. This is the first report of a non-hematologic solid organ tumor responding to the discontinuation of immunosuppressants.