Yes, my oncologist gave me the statistical difference that each of my treatments give to people with a Cancer diagnosis similar to mine. My Cancer had spread to my lymph nodes and I think this is why Tamoxifen makes a 30% difference to my chance of recurrence. I never really saw that I had a choice so just set about doing what I could to help my body cope with the medication. I did swap brands of Tamoxifen late last year (because the chemist was out of my usual one) and found that I had worse side effects (aches and pains and very emotional), so quickly swapped back to my original one.
We are all different and just as there can be big differences in how we react to chemo etc, I think there can be differences with the hormone therapy too. I truly believe that a healthy lifestyle can help though. :)