Vaccine on a tray

BCG Vaccine Linked to Lower Risk of Lung Cancer Interview with:
Naomi E Aronson, MD, FIDA, FACP

Professor and Director, Infectious Diseases Division
Uniformed Services University of the Health Sciences
Bethesda, MD What is the background for this study?

Response: BCG is a live attenuated mycobacteria vaccine used to prevent tuberculosis which has been reported to have associated nonspecific effects such as treatment of diabetes, bladder cancer, prevention of severe respiratory infections in children, and suppressed autoimmune responses.

In earlier reports in the 1970s, results of epidemiologic studies were divided as to whether BCG vaccine was associated with subsequent rates of malignancy, specifically leukemia (protective) and non Hodgkins lymphoma (higher rates).

To further evaluate these observations we studied cancer data collected in the 60 year follow up of a controlled trial of BCG in American Indian/ Alaska Native schoolchildren. What are the main findings?

Response: While overall all-cause malignancy was higher in women, and lower in those that received BCG vaccine these findings did not reach statistical significance. However, the BCG vaccinated participants had a significant 2.5 fold lower rate of lung cancer, independent of smoking, alcohol, tuberculosis, geographical location. What should readers take away from your report? 

Response: As lung cancer is one of the most immunologically active malignancies, and BCG vaccine effect may hone to the lungs we favor an immune mediated mechanism for this observation, possibly trained immunity. What recommendations do you have for future research as a result of this work? 

Response: Further immune assessment of the effect of BCG at the respiratory system level is needed.

We recommend that other long term controlled trials of BCG vaccine such as the MRC trial in the United Kingdom or health system data such as in Scandinavia be assessed and if this powerful observation is confirmed then the use of BCG vaccine during ages 8-11 (versus at birth) might be considered for risk reduction for lung cancer over a lifetime.  


Usher NT, Chang S, Howard RS, et al. Association of BCG Vaccination in Childhood With Subsequent Cancer DiagnosesA 60-Year Follow-up of a Clinical TrialJAMA Netw Open. Published online September 25, 20192(9):e1912014. doi:10.1001/jamanetworkopen.2019.12014



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Last Updated on September 28, 2019 by Marie Benz MD FAAD