You have way more small interest you are pondering. I was diagnosed Stage IIA/ Er+, PR-/HER2+, then 3 weeks later a genetic test revealed i had Brca2. My tumor was 5cm. They never spoke oncotype to me. I am at City of Hope in Ca.
Who told you about your distant risk at 9 years is 12%. Are the tumors in the same breast? I did have chemo first to shrink the tumor. It shrunk 1/2. I was supposed to have radiation, but the Radiation oncologist had his dr give me the low down on what the process would be and then i met with him. He said my cancer is in 2% of the population. Based on the statistics the oncologist said would give me a 2% better chance of the cancer not returning. He also said if i was family, he said the side effects may be worse than 2%. He would tell me not to do it.
It is only a choice you can make. Visit breastcancer.org too. Only women with breast cancer share and many have walked this road before us. Same as Mayo, but more to read. As more questions from your oncologist of why chemo over radiation.