Criteria for Oncotypedx test

Just wondered if anyone knows what the criteria is for deciding whether an Oncotypedx test is required? And what score means that chemo is recommended? Thanks. 

Criteria is a 10 mm or more hormone positive breast cancer and less than three nodes being positive. For node negative patients, if you’re under 50, chemo will probably be recommended if your score is 21 and above and possibly recommended if it’s 16 through 20. Will not be recommended if it’s 15 or below. If you are above 50 and node negative, chemo will not be recommended if your score is 25 and below. Anything above 26 will always have a chemo recommendation despite the age. I don’t know how positive nodes reflect in that though. My guess is they either change the scores you get or your oncologist may decide chemo no matter what your score is.