I also wondered about the safety of a needle biopsy, pondering that the process itself might cause a dispersion of an otherwise stable colony of cancer cells, but was reassured by the fact that the protocol was for the radiologist to use a vacuum-assisted wide needle so the odds of that were very low. I also read a ton of research on Google Scholar and one oncologist studied just that risk and found that lone cancer cells tend to die off. That is, they need to achieve some critical mass with other cancer cells to be a risk. So those two things helped my decision to skip the radiation. A third factor was the idea that, should I be unlucky and cancer recur in that breast, I wouldn't be eligible for radiation a second time.

Your doctor misrepresented the data yielded by the OncotypeDX though. It's primary use is in determining, statistically, the risk v. benefits of chemo but it also yields an estimated 'risk of recurrence within 9 years' for specific breast cancer profiles if the person takes aromatase inhibitors. Aromatase inhibitors are currently presumed to reduce recurrence by approximately 45%. So one can use the OncotypeDX result to also calculate risk of recurrence if not taking aromatase inhibitors. So, for the breast cancers that are eligible for OncotypeDX testing (primarily small, low grade, early stage), it's a worthwhile test beyond just helping form a chemo decision in my opinion.

The follow-up regime I'm on is to have bloodwork, including for tumor markers, mammo and ultrasound every six months followed by a review appointment with both oncologist and post-surgical review surgeon. The mammo and ultrasound are both also done by the radiologist who found the original problem.

My contribution was to improve my diet significantly. The endocrinologist I also consulted mentioned that fat is an 'estrogen factory' so that got my attention and helped get me back to what I think of as 'eating like a sentient adult' and knocking off remaining lockdown weight. And I now go days without thinking about cancer. I figure that I'll deal with it, if it recurs, and at least be otherwise healthier from other changes I've made but that's all I can reasonably do.

I think cancer recurrence odds are, well, whatever they are. But find it interesting that men who've had successfuk treatment for prostate cancers with similar odds, tend to think of themselves as "cancer free" while women tend not to according to studies I've read. I think that some of that could be attributed to the fact that doctors want us to be aware of the nature of cancer and to continue with mammograms and other medical follow-up. So maybe recurrence is stressed so that people don't get a little negligent and figure that having had cancer once they are protected against it for life. But the downside of that can be kind of mentally living in Cancerland even in the absence of any currently identified cancer. So I think there's a balancing act between doing everything intelligent in respecting what a wiley foe cancer can be without letting it become a huge shadow over one's life.