This is how my oncologist explained it. I had a lumpectomy and 21 radiation treatments. She said surgery reduces the chances of it returning by 80%; radiation reduces the remaining 20% change by 50%, so now it's a 10% chance. The AI drug reduces that remaining 10% by another 50%. So now we're at a 95% chance it will not return. I hope I explained it correctly - but each treatment - reduces the chance. I hope to take it for a full 5 yrs at least. Only you can decide what risk to take. And I agree discuss this with your doctor. Not everyone has the side effects listed. And some are very livable - dry eyes & losing some hair. It's worth my life to me,. ALSO - if it returns, it will not necessarily be Breast cancer - it will come back in your Brain, Bones, Liver or Lungs. Keep that in Mind. If your doctor didn't tell you that - shame on them. Also keep in mind 85% of BC is now cured.