[halfmatthalfcat]

Cancer is cell-specific. Organs are made of different types of cells specific to that organ. Lung cancer is not the same as pancreatic cancer is not the same as breast cancer, etc. If cancer was not cell-specific, it would be much easier to synthesize treatments for.

[glenstein]

>Organs are made of different types of cells specific to that organ.

I think I broadly agree but with the important caveat that organs frequently share cell types and therefore can share cancers specific to those cells, across organs.