- American Indian and Alaska Native children who received the BCG tuberculosis (TB) vaccine were 62% less likely to develop lung cancer as adults.
- No association was observed with other types of cancer.
Why this matters
- These findings contradict earlier studies suggesting increased rates of leukemia and lymphoma.
- Post hoc analysis of a randomized, multistate clinical trial.
- 3287 American Indian and Alaska Native children from 9 tribes received BCG vaccine (n=1540) or a placebo (n=1423) between 1935 and 1938 at a median age of 8 years.
- 60-year follow-up.
- Funding: Indian Health Service and others.
- Overall incidence of cancer was not significantly different between groups (HR, 0.82; 95% CI, 0.66-1.02).
- After multivariable analysis, lung cancer incidence was significantly lower in the vaccine group (aHR, 0.38; P=.005).
- Lung cancer mortality was significantly lower in the vaccine group (HR, 0.32; 95% CI, 0.15-0.68).
- Prior TB was not significantly associated with lung cancer (HR, 0.66; 95% CI, 0.23-1.90).
- No difference between groups in incidence of any other type of cancer.
- Lung cancer rates were reduced in all 5 states and all 9 tribes.
- Retrospective design.