Experience with intrapleural natural beta interferon in the treatment of malignant pleural effusions.

Malignant pleural effusion is a common complication of cancer. Intrapleural beta interferon has been recently tested, and responses were obtained in about 1/3 of the patients without considerable side effects. We treated 22 patients with recurrent symptomatic malignant pleural effusions with intrapleural beta interferon at increasing doses (5-15 million units) for a maximum of three courses and obtained only two responses. In our opinion, this schedule cannot be recommended for routine use.