@Sooz, the importance of AI therapy for oestrogen positive BC people is accepted by all the scientific-medical studies now and we are so lucky to have it as an option which was not the case in earlier times. But the side effects can be devastating for some, although there is no way of predicting accurately who will be in this camp and who won't. Many oncologists appear to be either oblivious or in denial. Most take the view that we should suck it up and be grateful. The extent to which AIs improve your outcomes in terms of survival depends on several factors especially the precise nature of your pathology, what kind of chemo you have had etc. The best online tool appears to be the British NHS calculator Predict. Many women on this network do not find statistical predictions helpful. I do, and am very grateful to have easy access to this information. My cancer was very well on the way at diagnosis with large tumours and a lot of positive nodes. So in my case the AI therapy adds a very large benefit to 5 year survival rate (but much less to 10) and I really need it to have a reasonable chance of a few more OK years. For others it may only add 1 or 2% benefit. So it's then a matter of weighing up risks vs comparitive benefits. I have been on Letrozole for 18 months now and although the joint pain can be blecchh at times I have been pretty lucky and wouldn't think of giving it up. But in the end it's up to you to consider your own situation. If you have a respectful oncologist to go through the issues with - one who is prepared to tell you the facts in your specific situation as far as possible and discuss it with you openly then that would be best.. Not everyone gets side effects, or at least finds ways to manage them. And new treatment options are developing all the time. Be strong, we're all on your team. Hugs, A.