Minimum length of time on tamoxafen

Hi, just wondering if there is a minimum length of time you should take tamoxafen. I am 38 years old but had my overies removed two weeks ago. My BC was Er+ 8/8
I have been taking tamoxafen since Christmas last year so about 9 months and believe at some point because now I’m post menapause I will change to a different AL. Is there a minimum length of time you should stay on tamoxafen to make sure it has been successful for example should I push to stay on it another few months complete a year or longer before I swap??

My oncologist has suggested i do 2 years on Tamoxifen before swapping to Zoladex + AI (I refuse to have my ovaries removed).  Apparently this replicates a research study done.  However, I don’t think there is any particular benefit to staying on Tamoxifen for a particular length of time before swapping to an AI once you are post-menopausal because the AIs are more effective at suppressing the cancer cells.  But you might want to ask your oncologist about managing osteoporosis risk with AIs and any other side effects that might be problematic for you. Good luck.  

I was debating for ages if I should have the injections rather than have my overies out especially as I haven’t had children yet but decided just to go for it in the end along with a hysterectomy!! I have just had a bone density scan a couple of days ago so they can monitor my bones every couple of years and know from this starting scan if any deterioration. Lack o led eastrogen has many health complications I’m finding out now!!! But a reoccurrence or new cancer would be worse so I have to keep reminding myself that it was a good thing to do!!