I was diagnosed with LCIS in 2013 at the age of 54 and with invasive Lobular Cancer two years later in 2015. With the LCIS I chose lumpectomy surgery and tried Tamoxifen. I couldn't tolerate the Tamoxifen at all and will never know if it might have helped me not to have invasive cancer, but.....I chose a bi lateral mastectomy with the invasive lobular because..the LCIS was in my left breast and the invasive was in the right (something lobular does, equal opportunity cancer - both breasts). I am happy with my decision to have the bi lateral mastectomy. I didn't want to have the worry and ongoing checks that i might miss it. I was lucky because my cancer was Stage 1 when I had the mastectomy and also because I also found out from the post operative tests that I had DCIS and LCIS in other breast tissue. It was the right decision for me. In hindsight, if I had know...I would have opted for the mastectomy when I had LCIS because despite just one lymph node being removed in my left side (the non invasive cancer side) there was a surgical error (dang) and I have bad lymphedema now and have had some very scary experiences due to that, including cellulitis resulting in sepsis and a long hospital stay. But, hindsight...ha ha......if only. With LCIS you don't have to get sentinel lymph nodes removed and I wouldn't have this chronic condition. But I do think I'm an outlier in that regard. I couldn't use any of the estrogen AI drugs. They all made me really sick (many meds do, lots of allergies), so I finally asked for blood tests to check my estrogen and progesterone levels. When they did they found that I had little to no estrogen and no progesterone. My cancer was estrogen positive 98%. I can attest to no estrogen now too. I have ALL the nasty stuff that happens when you don't have any hormones.....vaginal atrophy, joint degeneration, hair loss, dry eyes, skin, hair, mouth....all causing their own sets of problems. So, ask your doctors to check your hormone levels. That can be another tool in determining whether you should move forward with the drugs or surgery. All hard decisions. Hugs to all.