If it works why change... ?

[mts]

I don't really have al the details but an Aunt of a friend of mine was on Tamoxifen for 5 years and doing fine. Her onc took her off the Tamoxifen because he told her ( as we have been told) that 5 years is all you get, and within months her cancer recurred. She was taking an AI. She is now on chemo and has been told her liver function is at 25% and that she needs to get her affairs in order- she is still continuing with chemo (don't know what kind).
If Tamoxifen was working for her so well, why not put her back on it ? I know 5 years is based off statistical info, but aren't there any women that have remained on tamoxifen for longer than 5 years ? Can one get back on it ? It seems there is nothing to lose by getting back on Tamoxifen!

Maria