Cancer after LCIS and Bilateral?

Looking forward to responses to your post.  I have not seen this happen here, but it could have happened, so we'll see.

Some other BCO members have posted research stats on this and it is a very rare event.  I think Leaf posted some stats??  Anyhow, we'll see if anyone had this happen.  Hope not!

I agree with Carol's interpretation.  The Chuba study is by far the most data we have on LCIS patients.  Unfortunately, we don't know very much about the family histories of the women in the Chuba study: we don't know if these women had a stronger family history and thus be more at risk for a BRCA or as-yet-undiscovered mutation, or how many took estrogenic hormones (birth control pills), antiestrogens, etc.

Clearly more studies are needed, but I don't expect to get firm answers anytime soon: LCIS is an unusual condition.

The incidence of cancer after prophylactic mastectomy when a person has already been diagnosed with a BRCA 1/2 or invasive breast cancer may be another story.  BRCA 1/2 women are at higher risk than LCIS women (at least LCIS women with no significant family history.)  So women with LCIS and a BRCA 1/2 gene (or other known or unknown hereditary single gene mutations that puts one at higher risk for breast cancer) may be at higher risk for breast cancer even after prophylactic mastectomies.   The picture gets a lot more complicated, because some women get LCIS along with DCIS or invasive breast cancer.

Most studies that look at prophylactic mastectomies are looking at women with BRCA 1/2 mutations, or women who had breast cancer in the contralateral breast.   But, at the other extreme, 'prophylactic mastectomy' also includes women who have metastatic breast cancer but have the 'good' breast removed.  These women obviously are at high risk of dying of breast cancer.

This Cochran study looked at women who got prophylactic mastectomies (due to various reasons, not just LCIS).  http://www.ncbi.nlm.nih.gov/pubmed/21069671  They conclude While published observational studies demonstrated that BPM was effective in reducing both the incidence of, and death from, breast cancer, more rigorous prospective studies (ideally randomized trials) are needed. BPM should be considered only among those at very high risk of disease. There is insufficient evidence that CPM improves survival and studies that control for multiple confounding variables are needed.

A friend had a BMX 8 years ago due to a small area of DCIS.  LCIS was also found.    She was recently diagnosed with Stage 3 ILC, so yes, it can happen.

Cleo, no matter how carefully a mastectomy is done there are always tiny remnants or bits of breast tissue left, so that is how.