This is a tricky question to answer because there are many genetic and molecular markers that you could look at. This review paper by McDermott, Longley & Johnston from 2002 gives a good overview and is available for free online.
In terms of metastases, you can look at a variety of different markers: increased expression of vascular endothelial growth factor (VEGF), epidermal growth factor receptors (EGFR), and matrix metalloproteinases (MMPs) have been all been associated with colon cancer metastases.
The recent investigations about complement therapy for colorectal cancer will make pleasant me. This field can include a wide area, from botanic and natural compounds to new synthetic materials.