I decided against radiation, But had mastectomy. I had lymphovascular invasion though and grade 3.

It helped me when a doc told me that everyone has cancer cells floating around and the immune system takes care of them. The doc told me it isn't about how many but about the cells' ability to travel and settle and multiply. With grade 1 and low Oncotype, it would seem your cells would be less dangerous, if they did "go unseen," but ask your doctor to discuss this!