TB Vaccine Associated With Lower Lung Cancer Risk

Results based on 60 years of follow-up of a placebo-controlled BCG study conducted among Native Americans

People who receive a tuberculosis vaccine early in life may reduce their risk of developing lung cancer as adults, according to a study published in JAMA Network Open this month. 

The Bacille Calmette-Guerin (BCG) vaccine is the only one approved for preventing tuberculosis. It is commonly used in other parts of the world, but rarely in this country because of the relatively low rates of TB. 

The results reported in JAMA Network Open were based on 60 years of follow-up of a clinical trial of the BCG vaccine that included 2963 participants vaccinated at a median age of 8 years. The researchers found that those who received the BCG vaccine had a subsequent lung cancer rate of 18.2 cases per 100 000 person-years compared with 45.4 cases per 100,000 among those who received a placebo.

The initial study was conducted between 1935 and 1938. Approximately 3,000 American Indian and Alaska Native tribes living in several different U.S. locations, were randomly given the BCG vaccine or a placebo. Between 1992 and 1998, researchers reviewed the participants health records.

While the study found no significant differences in overall cancer rates between the two groups, the odds of lung cancer were “significantly lower.”

Len Lichtenfeld, M.D., interim chief medical officer of the American Cancer Society, called the study’s findings noteworthy, if for no other reason than the duration of follow-up. But, he said, it was unlikely that BCG will be used for lung cancer prevention, if for no other reason than the fact that the vaccine is in short supply and would limit its use in other areas. 

Sources: HealthDay, October 1, and JAMA Network Open, September 25