@troubletwo, I'm curious why your doctor would stop Tagrisso after 3 years. When I went to MD Anderson for a second opinion for my metastatic (to the brain) lung cancer, their oncologist told me two things:
1. No need to come back. Your doctors are doing everything I would have done. Do what they tell you.
2. His plan at the time was Tag for 3 years, followed by 3 more years of 3-month monitoring. If there was no recurrence, he would declare me "cured." (The only time I've ever heard that word.)
Ahh, the heady days of early discovery. A year later, my current oncologist told me he had no plan to stop Tagrisso until "the side effects become unbearable." (For me, those side effects include heart problems, but I'm being monitored by a cardiologist for a leaky valve anyway. Also, financial toxicity because I'm too young for Medicare.) I'll be on it 4 years in December, and I know another lung cancer advocate who has been on it for 9.

I know you haven't asked, but my recommendation is to ask your husband's oncologist why he would stop a successful treatment.

I still get 3-month brain MRIs, and probably will forever, which is how long I plan to live or die trying. 🙂 After 3 1/2 years, my CT scans are being reduced to every 6 months because my chest and abdomen have been clear all this time.

Your husband's doctor considers your husband's age, medical history, overall health, etc., which I don't know. But I am curious about the persistence of this 3-year "rule" for Tagrisso that I thought was over.

I wish you and your husband all the best!