I had LCIS 6 years ago and then 4 years ago I was diagnosed with invasive lobular carcinoma. So, I'm that case where the LCIS might turn into invasive cancer, might not turn into invasive cancer..........mine became invasive cancer. For what it's worth.....the LCIS was in the left breast and the invasive lobular was in the right breast....so not really a continuation of the same original site. I will preface this with the following.........I had a long history with fibroids in my breasts, cysts and hormone issues that dogged me my whole life. I'm just saying this because it's so hard not to panic when you get that first diagnosis. It's common for many people to get LCIS or DCIS and then never have invasive cancer. I opted for the bi lateral mastectomy because the cancer or potential for cancer was in both breasts and in fact post surgery the tests showed not only LCIS in the tissue and invasive lobular but also Ductal Carcinoma in situ (DCIS) and other things starting as well. I was unable to tolerate any of the AI drugs so I didn't have that advantage and still don't today. I'm hopeful that there will be new meds researched and available in the near future. I'm low risk for recurrance but I was also low risk for the LCIS growing into an invasive cancer.....so I try to stay on top of options and new information. I hope that clarifies things a bit. Hugs