Evista ( raloxifene) instead of Tamoxifen.

Is anyone using Evista for Stage 1 invasive ductal carcinoma instead of Tamoxifen to prevent recurrence after a mastectomy? It is a SERM, like Tamoxifen. I know that Evista is used as a Preventative for high risk for breast cancer women, but why can't it be used after having breast cancer if AIs and Tamoxifen can't be tolerated? Isn't it better than nothing? I am in a battle with my Oncologist over this. Does anyone have any information that could help me? Thanks