Abstract: Objective To determine the effects of intrapleural injection of Mycobacterium vaccae vaccine for patients with lung cancer and pleural effusion. Methods 40 patients with lung cancer and malignant pleural effusion were divided into study group and control group at random pair.Mycobacterium vaccae vaccine 1000μg were injected into the pleural cavity once weekly for 2～3 weeks for the control group. Results 90%(18/20) of the study group achieved partial relief and 60%(12/20) had complete relief. Both of which were significant higher than those of the control group(P<0.05),while 55%(11/20) of the control group achieved partial relief and 20%(4/20) had complete relief,after 1yr follow-up,the relapse rat of pleural effusion of the study group was 5%(1/18),and the control group was 46%(5/11),P<0.05. Conclusion As adjunct to chemotherapy,Mycobacterium vaccae vaccine is helpful for patients with lung cancer and malignant pleural effusion.

Key words: Mycobacterium vaccae, Pleural effusion, Lung cancer, Immunotherapy