Good luck to all with these difficult decisions. My story is on the negative side, so please consider that I am just one person and one experience. I had LCIS in my left breast, followed by invasive lobular cancer in my right breast two years later. I opted for bi lateral mastectomy and during surgery my lymph nodes were tested. Just two on the right where there was invasive cancer and only one on the left side. My nodes were clear and I considered myself very lucky. Unfortunately during surgery the surgeon created a lot of damage to my lypmh system on the left side and I developed lymphadema in my left arm and hand. It was mild (it seemed) and resolved after a revision surgery a year later. But, it didn't actually resolve at all. I got a small cut in Nov 2019 on my left hand ring finger and I ended up with cellulitis and sepsis and was hospitalized for 6 days. My hand continues to be very painful and isn't fully functional now and I am in active treatment for the lymphadema again. Now my lymphadema is considered a serious threat to my health (and was……sepsis, very scary).
If I had to make the choice whether to allow the lymph removal, knowing what I know now, would I? I don't know. I would still want to know if the cancer had spread so I could plan cancer treatment but my arm and hand are now damaged and painful and there is no really good treatment for lymphadema.
I was very concerned about lymphadema going into the surgery and I felt that the doctors dismissed my concerns and I had to fight for information and care. I have three close friends who have had breast cancer and bi lateral mastectomies and they all have some level of lymphadema, so it's not as uncommon as doctors may lead you to believe. It is the only way that doctors have to determine the real spread of your cancer however. Hugs and good luck.