LCIS Situ new to the forum

Thank goodness your genetic testing for 32 panels came back positive!

Nothing is really good for detecting LCIS, except by looking at a piece of tissue under the microscope. LCIS is only definitely diagnosed by looking at a piece of tissue under the microscope. Don't be worried about that though, because many women have multiple spots of LCIS in a breast and it is often bilateral (in both breasts). They know this because they used to routinely do bilateral mastectomies on women before, say, the mid-1990s, and they could section the mastectomy specimens and look at the slices under the microscope. If a woman with LCIS goes on to later get breast cancer, the cancer is often in a place in the breast, or, less likely, the other breast, that by all other imaging looked normal previously. I was initially diagnosed with LCIS in one breast, and about 10 years later, they found more LCIS in the other breast. But my breast cancer risk may be just as high if I only had one LCIS spot in one breast.

LCIS is an uncommon condition, and its really difficult to do studies to find out how LCIS confers breast cancer risk. To make sure you have a spot of LCIS, you have to remove the spot and look at it under the microscope. So, since you removed that spot of tissue, even if you left some LCIS in the breast, you have disturbed that spot which could very well change how that LCIS spot responds. You can't study it to see what a spot of LCIS does over time. Sometimes it is thought some LCIS does evolve into ILC (sometimes a spot of LCIS is genetically related to a nearby spot of ILC), but sometimes LCIS women go on to get IDC or another invasive breast cancer.

Know the numbers they give you about your risk of breast cancer are VERY inaccurate. They don't have information about LCIS women in particular, because there are way too few of them. But even for the ordinary, normal woman who has never had breast cancer and doesn't have a family history of breast cancer (which would be most women), the breast cancer risk models are not very helpful at all for you as a person.

They can know pretty well how many women in a large population will get breast cancer, but the models we have are horrible for predicting whether one particular woman will get breast cancer or not, perhaps with the exception of women with a BRCA1 and/or 2 mutation. https://academic.oup.com/jnci/article/98/23/1673/2...

The highest lifetime risk I was given was almost 90% in a model that was NOT peer reviewed, and the lowest risk I was given was by a person in a tertiary care center who said my risk was 'somewhere between 10% and (?40%); I'd have to go to the literature to see more.' Well, I had done literature searches, and there was nothing more. That's a pretty big range between 10% and 90%. (Not to mention that 10% is below the lifetime risk of the 'average' woman in the USA.)

Many studies conflict, or partly conflict. For example, this recent study found a correlation with breast density https://www.ncbi.nlm.nih.gov/pmc/articles/PMC61430..., but this older study found breast density did not significantly increase the accuracy for one specific woman. https://academic.oup.com/jnci/article/98/23/1673/2...

As far as I know, there have certainly not been studies that focus on the future risk of breast cancer INDIVIDUALS who have LCIS. But, for plain, ordinary LCIS, probably as a group, probably less than 50% will eventually get breast cancer. And most women who do get breast cancer do survive breast cancer. Even my grandmother, who got breast cancer in the early 1950s survived breast cancer. (This was definitely before chemotherapy, and she probably didn't get radiation either.)

Now that I'm about 15 years out of my initial LCIS diagnosis, there are certainly months and maybe years that go by and I don't think of LCIS. (I do have other, more risky and unusual conditions.) But it took a number of years to get to where I am today.

Best,

leaf

hi Lea777, did you have surgery??