I did a lot of Googling when I was offered the EndoPredict, as prior to that I had only heard of the Oncotype one. I was worried that because it's cheaper it may be 'less'. However, the studies I found and in some of the information for doctors on their website (Myriad Genetics) show that it more accurately predicts risk.
For all intents and purposes, OncotypeDX, EndoPredict, Prosignia all test the genetics of the tumour based on what is known about tumour growth. They analyse the tumour cells and give a score that can help when deciding if benefits outweigh risks of chemo. They do not test patient genetics (eg. will not identify BRAC etc risks).
If you google "Oncotype vs Endopredict" you'll get heaps of side-by-side comparisons too.
