I just watch a TED talk by David Agus on the next steps in the war on cancer, and it reminded me of a class I took last semester.
What I learned in my Bio of Cancer class last semester is that we’ve pretty much got clinical cancer diagnosis and classification all wrong.
Because we didn’t initially (and to some extent still don’t) have the tools to do much else, we look at the symptoms – a tumor in your lung, a lump in your brain, an overproliferation of white blood cells.
But that doesn’t help in treating the cancer. One breast cancer may have the protein HER2 amplified, while another may not. You can’t use Herceptin for both.
It’s true that certain mutations show up more often in certain cell types or body parts, because the pathways involved are the ones expressed in those cells. Still, there are usually plenty of other mutations that show up in the same cell types and even the same cells.
Just classifying cancers by their mutations isn’t enough though, because just as in real estate, location matters. The environment around the cells (extracellular matrix, blood vessels, neighboring cells) can help determine whether the abnormal cells can grow. There are carcinoma (epithelial cell cancers) cells that are provided with growth factors by the cancer-associated (but not cancerous themselves) fibroblasts surrounding them.
Look at all the cell types and growth factors involved in the tumor microenvironment!
(I stole this picture from the Pittet Lab at the Center for Systems Biology)
So what we need then is some integration of our current form of diagnosis and our knowledge of the cancer genome. I'll link to Agus's TedMed talk again, since it's pretty informative. Take a look.
Also, HTML does not show up on titles in a Google Reader. Oops.