system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is cancer common in organs like the prostate and breasts, but is not in other organs such as the heart or stomach?
gpt
The cells in some organs work very differently than in other places. In your heart for example, the cells stop dividing very early in your life. This is why the heart is pretty much incapable of healing any injuries it gets. The cells increase in size as you age, but new ones arent created.

Since cancers come about as a result of mutations arising during cell division, it makes it extremely difficult for a tumor to form in your heart. and the majority of times it does get a tumor, its the result of a tumor somewhere else in a nearby organ spreading to it.