Medication after 5 yrs of Aromatose Inhibitors

I am coming up to 5 yrs of taking Arimidex; a close friend has already passed the 5 yr mark taking Aromasin. We boh have a similar dx and prognosis, although I had WLE and total axillary removal, she had a mastectomy and total axillary removal. Both had chemo and rads, both ER+ and HER2-. My friend has just been told there is no further therapy. I haven’t discussed this yet with my bc surgeon as I only see him for annual review and bi-annual mammos. I haven’t seen the elusive Onc since finishing rads.
We are now concerned about any further anti-oestrogen therapy after the 5 years, to help prevent a recurrence. Can anyone offer any experience/advice?
Many thanks.
Liz.