LCIS and 67% risk of invasive breast cancer

SassyMutt

I've lurked on these message boards the past few months as I've gone through a biopsy and lumpectomy for LCIS. Finally decided to join as I know there is so much more to learn. I'm grateful there is a place like this to turn to! Thank you in advance for listening.

I was recently diagnosed with LCIS and atypia after a biopsy for calcification found on my very first mammogram. Lumpectomy confirmed LCIS, but thankfully no cancer.

For others with LCIS, have you had your risk % calculated? And do you know the name of the calculation model used? Apparently there is only one that is applicable to LCIS. My doc told me, but I didn't write it down and now I can't find it when searching (I have a call back into my doc). My concern is my doctor has calculated my risk at 67% lifetime risk for invasive breast cancer which is so much higher than everything I've read for LCIS (everything I read was more like 20-30%).

I don't have a family history of breast cancer aside from one cousin. I'm 40 years old and have never had children, which I know increases my risk. My LCIS was considered “grade 2". So, it sound like a variety of factors are contributing, but I was surprised to hear it's that high.

I'm trying to research and understand all my options for managing LCIS with 67% risk. I'm tempted to try Tamoxifen and go through the MRI in March and see what happens. Although, I've also been that because told MRIs are so sensitive, they pretty much flag anything and can result in a lot of extra biopsies. And I've read lots of stories of women feeling like pin cushions and opting instead for mastectomies.

Prior to calculating my risk %, the docs have told me no need to discuss prophylactic mastectomies, but given the 67% risk level, I'm wondering if that should at least be on the table?

Any advice or guidance from those with LCIS diagnosis would be welcome and appreciated.

Thank you!

MsVeryDenseBreasts

Hi SassyMutt. I think you are wise to call the dr back to ask what model was used to calc that risk factor. My surgeon has told me that there is no risk model specifically for LCIS (unless one has been made available in the last 6 mod since I saw her). The Gail Model is the traditional one used to calc risk (generally speaking) and then surgeons try to adjust it as best they can for LCIS factors and it's my understanding they only do that in order to help justify to insurance companies why MRIs should be covered for people like us as an alternative screening method to mammos. The response I got as I recall was that my lifetime risk is 30% which is more in keeping with the range you thought LCIS represents. I also do not have any family history or lifestyle risk factors. I've been on close monitoring for 6.5 years now. No Tamoxifen. Best of luck.

caligirl3

Hello SassyMutt,

I too was diagnosed with LCIS, but I have the variant form called pleomorphic lcis (if you would like to read more about that I have posted in the LCIS section). My MD used the IBIS/Cuzick model. I was given a 60% risk. It was also based on the density of my breasts, age etc.(I was 48 at dx in April). I'm sorry you are going through this. I was told by a second opinion that she felt the 60% was a bit high since I dont have a family history or known genetic mutation. But she wouldn't tell me what she thought my true risk was. She said I should see a genetic counselor. My MD did explain to me how he came up with that risk and it made sense, since the average womans risk is about 12%. There is a lot of information and support on the the LCIS thread. I've done a ton of research on this. PM me and I can send you some of what I have found.