Why don’t transplants from the elderly turn into cancer bombs?
I.
According to the tumor suppression theory of aging, the root of age-related Dysfunction lies in the accumulation of somatic mutation with age. Young cells are aligned with each other on cooperation, but years of life produce cheater cells that are better at competition and more fit for the environment. They gradually overtake the less competitive clones and are more cancer prone to compensate the body turns down its regenerative ability which makes it harder to recover from illnesses. At the limit of a very advanced age, the cells are so precancerous and the regeneration is so weak that the body has no other choice than to succumb to a degenerative illness, or to a cancer.
In this model, transplanting an organ from an old organism, from an old organism to a young organism, would be a terrible idea. Old organisms are constantly on the brink of cancer. In the old body, the system is extremely paranoid and restrictive. Transplanting an organ into a more permissive environment of a young person would then instantly unleash all those pent up protocancers that were hiding in the tissue the transplant would turn into a cancer bomb.
Does this actually happen? Seems like not really, and this is a very interesting challenge for the model.
II.