The other sidelight on this is that I was listening to an abridged version of a book by Prof Tim Spector (could it have been 'The Science of Eating Well') in which he was reported as writing that by middle age all of us are harbouring hundreds of microtumours, kept in check by the immune system - and occasionally one gets away. If this has been a widely held viewpoint, it's surprising that we haven't seen more of immunotherapy earlier.
FWIW, it's no surprise to me. It's always seemed unlikely on statistical grounds that you just get cancer in one cell on one occasion, and then it's deadly. There was also the recent death of the wife of a friend with cancer in which the immune system, instead of attacking the cancer, turned into an auto-immune condition in which the brain cells were attacked with predictable and highly distressing results. But again, confirmation that the immune system has an important part to play everywhere at all times.
(Paraneoplastic Encephalomyelitis if you want to look it up)
War does not determine who is right, only who is left - Bertrand Russell
Chichester 12m asl