Hi @nanna1948, I was intrigued by your statement and went on the search for a source confirming the claim about anastrozole's (Arimidex) ability to continue to protect against recurrence after completing 5 years of treatment.

I think this may be where you read it.
- What happens when you stop taking Arimidex? https://www.drugs.com/medical-answers/you-stop-taking-arimidex-3539770/

Excerpt:
"The protective effects of Arimidex continue even after you stop taking it, so long as you have been taking it for around five years.
The latest results from the IBIS-II prevention trial reports Arimidex continues to significantly reduce the incidence of breast cancer for at least 5.9 years (the current duration of the trial). The trial is ongoing."

Study cited:
- Effect of baseline oestradiol serum concentration on the efficacy of anastrozole for preventing breast cancer in postmenopausal women at high risk: a case-control study of the IBIS-II prevention trial https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(23)00578-8/fulltext

It's good to remember that just because we read something on the internet, doesn't make it true. Where possible I ask all members to provide links to information or medical claims. See the guidelines in our Community Guidelines about sharing experiences vs information https://connect.mayoclinic.org/blog/about-connect/tab/community-guidelines/