Using the Baculillus Calmette-Guerin (BCG) – the germ commonly used to inoculate against tuberculosis (TB), researchers have found a potential new mechanism to stimulate the body’s own ability to fight cancer. The discoveries are published online this week in the British Journal of Cancer.

The investigators, Dr Wai Liu and Professor Angus Dalgleish from St George’s, University of London, say this new information suggests a mechanism by which vaccines may increase the anti-cancer activity of therapies which are available at present. Although, they warn that this investigation is in its primary stages and a lot more research is needed before patients will benefit.

Human tumor cells outside of the body were conducted in laboratory-based experiments; they showed that a small amount of BCG can instruct white blood cells to create chemicals called cytokines, raising the chances of tumor cells being detected by the body’s immune system.

Lead investigator Dr Wai Lui explains:

“Cancerous cells are known to camouflage themselves as healthy cells. This means our blood cells responsible for immunity aren’t able to recognize the cancerous cells as being a problem and so the disease is able to continue to spread.

This study found that a small quantity of BCG – similar to the amount that is administered in a TB inoculation – can help the immune system recognize the cancer cells as ‘foreign’. The immune system can then attack these cells in the same way it would any other infection.”

Cytokines produced as a result of the BCG injection trigger a chain of events that starts with the hijacking of the tumor and forcing it to switch off its camouflage, making it visible to the immune system, so the white blood cells in charge of destroying “foreign” cells now have targets to attack.

The BCG jab was tested on human cells from lung, breast, colon, pancreatic and skin cancer. The scientists results revealed that in lung, breast and colon cancer, the restoration of their visibility to immune cells was increased. Within the limits of the laboratory-based investigation, cancer cells with less camouflage were then successfully targeted by white cells in charge of destroying cancer cells.

Scientific knowledge around drug use to stimulate the immune system against cancer is becoming more prominent. These discoveries give more proof that, in future, this treatment method could enable further choices for cancer patients that could be used in conjunction with existing drug treatment, the researchers believe.

Dr Liu says:

“Using the body’s own immune system is a relatively new way of thinking in the development of cancer treatments, and scientists are still building up a knowledge base about it. If successful, this method of treatment could be used in combination with existing cancer drugs. It could potentially see patients taking less medication, having fewer and less severe side effects and recovering quicker.”

He concludes:

“This research is at an early stage of investigation, and so far has analyzed the reaction of human blood outside of the body, so more work is needed before these findings can be used in practice. The next stage will be to develop a compound suitable for clinical trials.”

Written by Grace Rattue