Jeannie11440,
I am 71 and I had a double mastectomy last year for ILC in the L breast and IDC in the R breast. I opted for no reconstruction. I didn't like the "official" prostheses either. Too heavy and too hot in the summer. So I bought the lightweight breast forms from athleta.com which are comfy but they kept riding up in the mastectomy bra. I saw that someone mentioned a company that they bought bras and lightweight breast forms from that they said stayed in place. It's the bustedtank.com. Their bras and breast forms are great!! The bras are very soft and comfy and their breast forms are lightweight and the bra says in place! A woman who had a double mastectomy started the company because she couldn't find any bras and forms that she was happy with. They tell you not to size up in the bras because you need a snug fit so they won't ride up. True! But they are real soft so still comfy. Before I found these bras I was using the soft breast forms called Empower Pads from athleta.com. They were riding up all the time, so since I sew I went to the fabric store looking for something to alleviate the problem. I bought a pair of mitten clips, shortened the elastic and clipped one side to the bra band and the other side I clipped to my pants. I did that on both sides of my bra. It worked the hold the bra in place but was a pain to unclip and then reclip when using the bathroom. So the best alternative was finding the bras and forms from thebustedtank.com! They are very helpful if you ask a question online about which products will work best for you. They answer within a day or so. I love their products they are terrific! I hope they can help you and others on this site too. Sending love and wellness wishes to all on this site❤️