Hi Sara, having a double mastectomy may be a good choice for you to give you more confidence that all the primary cancer that was found in your breast in has gone, in a way a lumpectomy and radiotherapy didn't give. But even women who have a double mastectomy are advised to take some hormone therapy to reduce the estrogen in their bodies and/ or have chemo of some kind or both. This is because surgery does not deal with any of the estrogen-fed rogue cancer cells that can have already spread in the blood or lymph even if your lymph nodes are clear, and can show up in months or years time as metastatic cancer in liver or lungs or bones etc.
Surgery removes the primary cancer. Then ttamaxifen and sometimes chemotherapy too, are used to help prevent secondary cancer especially distant/ metastatic cancer. This is a separate problem from the issue of removing all the primary cancer that has initially appeared. In breast cancer. I am not sure if you understood that if you choose not to have any other treatment, the risk that it could appear elswhere after months or years becomes higher because you still have lots of estrogen which can fire up any remaining estrogen-receptive cancer cells still in your body in a way they won't if the estrogen is blocked by tamaxofen. There are many different treatments that help prevent metastases ever happening, and many different ways of reducing the sideeffects of the different treatments, and the wise women on this board have a great deal of experience that could help you find a solution that works for you and gives you some action to take to help ensure you do not get fmetastatic cancer. Maybe the risk for you is low enough it is a sensible choice to take the risk and avoid the side effects of the drug, but maybe there are other ways to reduce your risks and also avoid the side effects.
This whole breast cancer journey is confusing and full of very hard decisions, and it is often hard to feel you have enough information and have understood it fully, and even when you do, the choices are often really difficult.
I hope you will manage to find solutions that work for you
best wishes