I don't remember the cut-off between low and intermediate risk for the OncotypeDX but will try to find the report with that information. I'm not certain what you're referring to as "different margins for 50 and up" but the OncotypeDX looks at the genomics of the tumor tissue. I'm not aware that it takes age or other demographics into account. It might, but that's not my impression.

OncotypeDX results can be surprising. There is one case, I believe still on their website, of a stage 4, large tumor cancer that showed a very low risk of recurrence. And a stage 1, DCIS with a very high risk of recurrence. This is interesting to me because oncologists looking at the biopsies might assume totally different risk profiles for these tumors based on their experience. And might be inclined to underestimate the risk for the stage 1 DCIS or inadvertently undertreat it.