If cancer can spread so easily throughout your body, why can’t it spread from person to person? Aka why isn’t it contagious?

Question

If cancer can spread so easily throughout your body, why can’t it spread from person to person? Aka why isn’t it contagious?

In: 9

Answer 1

Cancer is dangerous in large part because it’s your own cells, and the immune system has a harder time recognizing them as “enemies”. Other people’s cells are relatively easily recognized as “enemies” – that’s why organ transplant recipients need to take drugs that weaken their own immune systems.

So it’s really hard for someone else’s cancer cells to function well inside of you without getting killed by your immune system.