In 1893, the American Journal of the Medical Sciences reported on ten patients whose large and hitherto incurable cancers had been injected with bacteria taken from skin infections. In every case, striking improvement was seen, marking the birth of “cancer immunotherapy” – using the power of the immune system to attack cancer.
The immune system is the body’s most powerful weapon against cancer and infection. For a cancer cell, surviving long enough to divide and eventually form a lump or tumour is the result of a brutal Darwinian process. To reach this point, cancer must adapt, hiding from immune detection and co-opting patients’ immune machinery to betray its original programming and instead protect the cancer.
Immunotherapy – which really started to take off just over a decade ago – is an attempt to artificially tip the balance back in favour of tumour elimination. Sometimes this can be done by taking off the brakes from immune cells already in the cancer.
