Do you have the results of mammography or other results? . Normally the size is included there.
In regard to the Oncotype I think that we need to do what ever makes us feel more comfortable ...maybe you can research on your own if you are candidate for the oncotype or not with the lab doing the test.

I´m curious If your tumor was only 2 mm , how they detected? It was with mammography? , mine was only detected when was 1.5 cms ...