You can run Predict calc yourself here https://breast.predict.cam/ altho keep in mind this is just 1 calculator and there are other models, I dont think anyone (including the docs) really know which is the most accurate. The benefits of an AI are greater than tamoxifen for lobular than ductal (in general) from what I was told. However, as mentioned above, it really comes down to a solid discussion with your onco. If your onco has not yet directly told you the percent benefit in survival you would get with an AI, then they need to do that. If they refuse, get a new onco. They should be open to an honest discussion about risk/benefits of the cancer recurrence vs other disease and life expectancy so you can make the best decision for your situation.