DCIS with BMX; MO says Tamoxifen is up to me

ducky179

DCIS ER+/PR+... In my initial appointment, I was told that I would have to take Tamoxifen if I opted for lumpectomy or unilateral mastectomy. Even though it wasn't the only reason I chose BMX, it certainly affected my decision. Now that I'm post-op, the oncologist said that while it's not in the guidelines to recommend Tamoxifen, there might be a reason for me to take it. Apparently there is no data to support it, only case studies, but she was saying that some women will have a new chest wall invasive cancer after BMX. She even said that they don't know if Tamoxifen would prevent it, just that it's something to consider. I even asked for percentage risk and she couldn't give me a number. Only that it was 100% for the women that get it.

Now I don't know if I should just go with what I want (which is to NOT take it and avoid menopausal side-effects, risk of clots, risk of uterine cancer) or if I should get a second opinion. I honestly can't imagine someone else telling me 100% that I should take it though. I expect I will either get another 50/50 wishy-washy almost recommendation, or I'll be told that I don't need it.

By the way, there was no invasion on my path report from the mastectomy. Clear sentinel nodes. No oncotype testing done. Strongly ER+, weakly PR+. Strong family history of breast cancer on both sides of the family, but BRCA negative. My posterior margin was only 1 mm, but my BS told me that she removed the fascia from my pectoralis muscles, so there was nothing left but muscle.

Any thoughts or advice??