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Oct 9, 2017 07:10PM
Oct 9, 2017 07:21PM
No question is dumb - and that goes double or triple with LCIS. Almost everything about LCIS (including the name) is controversial.
(Classic) LCIS was first described in 1941 by two pathologists, Foote and Stewart, by looking at breast tissue slides. (DCIS was first described in roughly the 1890s.) Foote and Stewart did NOT know the natural history of LCIS - in other words, they didn't know what happened to untreated LCIS women. They thought LCIS was analogous to DCIS. If untreated, DCIS will turn into IDC. Foote and Stewart thought LCIS was like DCIS, that everyone with LCIS would eventually get ILC, so they recommended bilateral mastectomies. They didn't know that, at least for classic LCIS, that the majority of LCIS women would NEVER go on to get DCIS or invasive breast cancer. They stopped routinely doing prophylactic bilateral mastectomies for LCIS in roughly the 1990s. It was the 1990s that pathologists also first described atypical LCIS such as pleomorphic LCIS (which is more unusual than classic LCIS.)
Usually cancer is described as uncontrolled growth of cells - in other words, the cells just keep on growing and growing. But some people have other definitions.
The anatomy of the breast is that there is a complex system of ducts and lobules which end up in the nipple, but it is thought that the ducts don't intersect. (One pathologist painstakingly injected wax into a cadaver's breast and dissolved away the tissue, showing the complex anatomy of the ducts.) I don't think they know if the lobules are/could be connected to each other, but I may be wrong about this.
This might be analogous to the streets of a town that lead to a freeway (the nipple). But this is a strange town: in this town there are NO intersections. All of the streets are lined with sidewalks (which in the breast would be the basement membrane.) Non-invasive cancer is when the cancers are restricted to the street pavement: they do NOT ever cross the sidewalks into the houses or the backyards. Invasive cancers are when the cancers cross the sidewalks (the basement membrane) into the rest of the breast tissue (the stroma). Invasive cancers then have the potential of traveling to the lymph nodes, and from there anywhere in the body (metastasizing).
Of course, you cannot see cells growing in a microscopic slide. The cells in a microscopic slide are dead: they have been killed and stained and thinly sliced so light can pass through them so we can look at them in a microscope. You can estimate how many cells are trying to divide though (are undergoing mitosis.) There are cells that look totally normal, and other cells that look totally cancerous (beast up and irregular). There is also a continuum of cells between the two: there are cells that look somewhat normal and somewhat cancerous. That's why you need pathologists. Some pathologists disagree on what is LCIS and what is ALH, and disagreement on a lot of other things.
DCIS is mainly in the ducts, and LCIS is mainly in the lobules. Since both DCIS and LCIS do NOT cross the basement membrane (the sidewalk), they are NOT invasive breast cancers. In a literal sense, they are NOT uncontrollably dividing because they are held by the basement membrane. If they kept on growing, they would break/pass through the basement membrane, and thus become invasive cancer.
Some members here with LCIS and nothing worse (in other words, no DCIS or invasive breast cancer) have been told by their doctor they they DO have cancer. But I think MOST if not all doctors now believe LCIS is NOT a cancer.
Its really hard to study LCIS because we can't RELIABLY tell that a tissue is LCIS without looking at it under the microscope. In order to do that, you obviously have to remove the tissue from the breast, so you can't study the LCIS tissue growing undisturbed in the breast over time. We have no idea how many women are walking around with LCIS and don't know it because they've never had a breast biopsy.
So I'm not sure what 'pre-cancer' is and what 'pre-pre-cancer' is.
To partly answer your question, its not POSSIBLE to RELIABLY 'remove all LCIS from a breast' without doing a mastectomy. Even with a mastectomy, you inevitably leave some breast tissue behind. They know that LCIS is almost always multifocal and usually bilateral, because between 1941, when LCIS was first described, and roughly 1990, most LCIS women got bilateral mastectomies, and they could sample the mastectomy specimens. There is NOT a way to reliably know if any particular area of the breast has LCIS without biopsying it.
When I first got diagnosed with LCIS in 2005, they thought that LCIS was 'just' a marker for higher risk for breast cancer'. Now, according to this 2015 paper, they think it may be a more complex scenario (although of course as with almost everything in LCIS there is controversy.) They think that approximately 70% of LCIS lesions seem to be clonally related to synchronously diagnosed invasive lesions by copy number analysis,31 and the frequency of common mutations in microdissected LCIS and infiltrating lobular carcinoma32 suggest that LCIS is a heterogenous lesion representing both a nonobligate precursor lesion and a high-risk marker.
This means that these authors think that about 70% of LCIS lesions have genetic mutations in common with ILC. If I understand this correctly, this means that some LCIS lesions have the mutations of an invasive lobular cancer, but may or may not grow slowly enough to become an ILC, and that some LCIS lesions just have 'something unknown' that puts the breast at risk for DCIS and invasive breast cancer. Most (over 50%) LCIS women who do go on to get invasive breast cancer do get IDC, but the incidence of ILC is higher than in the general female population (without known LCIS).
But still, at least with classic LCIS and no other risk factors such as a known deleterious BRCA mutation, probably less than half of classic LCIS women will EVER go on to get DCIS or invasive breast cancer in their lifetimes.
Hope this helps.
Classic LCIS.If knowledge can create problems, it is not through ignorance that we can solve them- Isaac Asimov
12/8/2005, LCIS, ER+/PR-
1/24/2006 Lumpectomy: Left
7/15/2006 Tamoxifen pills (Nolvadex, Apo-Tamox, Tamofen, Tamone)