The general current rule of thumb is that aromatase inhibitors may reduce the risk of ER+ breast cancer recurrence by about 42-50%.

For someone with a high risk of recurrence, that 45-50% reduction is significant. Conversely, aromatase inhibitors won't significantly reduce an already low risk.

The tricky part therefore is knowing what the baseline drug-free risk is. If your oncologist ordered genomics or other testing that yielded a risk of recurrence that you can have confidence in, you could calculate the expected possible benefit of the drugs. There are no guarantees with any of this stuff so it's hard to come up with a perfect answer while balancing actual (unknown) risk, perceived risk, quality of life and myriad possible side effects. But a second opinion, from a different doctor, may shed more light on the decision choices and relative risk.