Bacteria Used to Fight Cancer

Bacteria used to vaccinate people against tuberculosis are more effective than a standard chemotherapy drug for treating a common type of bladder cancer, doctors from 46 U.S. medical centers have concluded. The vaccine is made from the bacteria Bacille Calmette-Guerin (BCG), which gives tuberculosis to cows and is used to prevent the disease in humans.

In recent years doctors have been testing BCG’s efficacy in fighting cancer, theorizing that injections might ignite the body’s immune system to attack a tumor. BCG has shown some effectiveness against malignant melanoma and cancers of the lung, colon, and breast.

In the new study by members of the Southwest Oncology Group, published in the New England Journal of Medicine, researchers injected either BCG or the chemotherapy drug doxorubicin into the bladders of 285 cancer patients. The investigators found that doxorubicin stopped working after five to 10 months while the BCG treatments kept the patients disease-free for an average of two to three years. Bladder cancer affects about 20,000 Americans and kills 10,000 Americans each year.