Intrapleural application of recombinant interleukin-2 in patients with malignant pleurisy due to lung cancer. A multi-institutional cooperative study.

Forty-three patients with malignant pleurisy due to lung cancer were entered into the trial to evaluate clinical efficacy of intrapleural instillation of recombinant interleukin-2 (RIL-2). Among 35 evaluable patients, serial cytological examinations of pleural effusion following the start of the treatment revealed disappearance of malignant cells in 26 (74%). Malignant cells were detected again in 7 of the 26, however, cytology remained negative in the other 19 patients for longer than 4 weeks. Pleural effusion disappeared roentgenographically in 13 of 35 evaluable patients. Additional 8 patients demonstrated marked decrease of pleural effusion. Complete response (CR) which means disappearance of both malignant cells and pleural effusion for longer than 4 weeks was obtained in 13 of the 35 patients (37%). No serious side effects were experienced in this trial. These results indicate that intrapleural RIL-2 is one of candidates to control intractable malignant pleurisy due to lung cancer.