I used to think we should avoid soy with cancers that are responsive to estrogen, but have since that is not true. I am not sure what other foods are estrogenic. But the Tamoxifen addresses the estrogen receptors so my understanding- check with your doc- is that in some ways it doesn't matter what level of estrogen is floating around in your body, the receptors are being shut off by the med and the estrogen is not getting to any potential cancer cells. I hope your doc can clarify this.

Aromatase inhibitors used after menopause, on the other hand, deal with the amount of estrogen in the body, not the receptors, so estrogenic foods would seem to be more of an issue there, but I am not aware of any so maybe someone else can enlighten us.