LCIS is the Origin of ILC. No? Let's learn something

I know zero about LCIS, apart from that it is lobular.  My friend, here in the UK, was diagnosed with ILC, grade 3, straight away, so does this mean that LCIS was there prior?  Does this also mean that every person who is diagnosed with LCIS, will develop ILC ? 

Awb is right. In fact the within the group of women who develop invasive breast cancer after an LCIS diagnosis, 49% of them will be diagnosed with ductal breast cancer. Lobular cancer after original LCIS diagnosis happens only 23% of the time. So if diagnosed with LCIS one should statistically be more worried about ductal than lobular cancer.



Most women diagnosed with LCIS will not develop invasive cancer. Something like 70% of women with LCIS will never develop invasive cancer and that is over a 25 year time frame.



Had a long chat with my oncologist on this topic. The entity we understand as LCIS is not a true precursor lesion. In fact, women diagnosed with LCIS in one breast have an equal risk of cancer to either breast over time. He explained that while most cancers, breast or otherwise, run a through a biology of in situ/local/regional/metastatic, the cells we call LCIS are not part of this continuum. True invasive lobular cancer likely starts as In situ, but is a different entity than the cell group we identify here on this forum as LCIS or "lobular neoplasm" or "atypical lobular hyperplasia".



The incidence of lobular invasive carcinoma is less frequent than ductal carcinoma in people diagnosed with LCIS, but is still more than that of the general population. The thinking is that there are certain people who get LCIS who also have a germ line or somatic genetic defect that peferentially disposes subsequent invasive disease to lobular cells. This is under study at this time.



So no, your friend did not necessarily have LCIS prior to her diagnosis and no, not all LCIS will become lobular invasive cancer.

Very interesting report! I too had pleomorphic LCIS, which really is a large reason I chose BMX. There is not a lot of research on pleomorphic LCIS, but it is considered more aggressive and more likely to be a true precursor lesion to invasive cancer than regular LCIS. In fact in my case even the residual areas removed on excision biopsy, though not sufficiently filling the lobule to be LCIS (making them ALH), also demonstrated pleomorphic character. Thus the pleopmorphism, in my case, was not so much a function of the size of the atypical area, but more a function of its origninal biological character.



Potentially those cells were "born" pleomorphic rather than a progression from regular LCIS.



That plus my family history plus other risk factors led to my decision for BMX. I have never regretted it!



If however, I would have had classic LCIS and no family history I would have done Tamoxifen and surveillance.

Are we partly discussing about semantics/logistics?  Perhaps there are some differences of opinion about what ‘is’ is and what ‘all’ means.

Sometimes 'is' indicates part of a group,  but there are other things that belong to a different group.  For example 'Humans have two legs.'  Most humans have two legs, but some humans don't have two legs.  There are also other animals that have two legs.

When I see the word ‘all’, I assume this means 100%.  Not 99.999% or anything less.  Maybe that’s not the way that others see it.

I am using an example to try to reduce the polarity of the discussion. Compare these two sentences:
a) Women originate from girls.
b) All women originate from girls.

Does sentence a) imply that all women originate from girls?  Are the two sentences equivalent?  Does sentence a) allow some women to NOT originate from girls?  I know this depends on your definition of what a woman is, but how about the children that are raised one gender and at puberty have surgery to convert them to the opposite gender?  What about human genetic mosaicism (which is where one group of cells have a different genetic phenotype than other cells that grow from a single fertilized egg.)?

Would you agree that sentence b) implies that 100% of women originate from girls?

In the NIH source msippiqueen cites:

www.ncbi.nlm.nih.gov/pmc/artic...

they do NOT use the word ‘all’.   They use the word ‘model’ as in ‘The currently favoured model of human breast cancer evolution includes a stepwise progression of very early, morphologically definable precursor lesions with cellular atypia to carcinoma in situ and invasive breast cancer [5]….Therefore, it is believed that a linear progression pathway exists from low-grade precursor lesions to low-grade invasive breast cancer [10].’

They do not say this implicitly, but I’m sure the authors of this paper read at least the abstracts of the papers they cite.  In their paper they opine ‘Even more convincing is the fact that invasive lobular carcinoma indeed is clonally related to LN occurring years earlier [47].’   In the abstract for this reference that THEY cite [47] it states ‘Two cases of LCIS and ILC showed identical patterns of heteroplasmy. In one further case, additional mtDNA mutations were present in the ILC following LCIS. The remaining two cases of ILC and all 4 IDC were clonally unrelated to the previously diagnosed LCIS.‘ (emphasis mine)    

 I believe there IS a progression pathway that probably SOME LCIS does progress to ILC.  I agree that this is a model.   They do not use the word ‘all’.    They cannot directly observe the LCIS and prove that it is the LCIS directly originated from ILC.  We don’t presently have the tools to do that.

In the conventional interpretation of ‘all’, if someone can find ONE instance  that ILC did NOT originate from LCIS, then it wouldn’t be all.  In the paper they cited, there were TWO instances where the ILC was NOT clonally related to LCIS.

Perhaps you believe that 'all' means something less than 100%.

I'm still moving.  I will probably be ignoring this thread, since I think some people are entrenched in their views.

OK.  I am confused...  I had both ductal and lobular involvement along with necrotic evidence.  The doctors didn't seem to be any more concerned about the lobular involvement - does that mean that it spread from the ducts into the lobes, or what?

The mother of my best friend had high grade ILC in her left breast aprox 13 years ago.. She had a lumpectomy , chemo and rads. Ten years later she had ILC in her rigth breast. She had a new lumpectomy, no chemo, but had rads. Then this year they found a new lump in her left breast. She then had ILC and LCIS... She has now had a masectomy and remowed both breasths....

Shabby, I feel your pain! It is a concern and I had that worry too.



But the whole reason I responded on this thread (I don't like the thread and disagree with its primary intent) is to try and put some perspective out there so women dx with LCIS do not have unnecessary anxiety. Yes LCIS can indicate future trouble and yes it needs to be dealt with.



But trying to write a PhD on the biology of incipient ILC is way beyond the capabilities of anyone here and can frighten people.



So what is important is that women understand as best possible their risks so they can manage them.



The odds are with you that you'll not find ILC. You had been screened very closely. Hold those things near! Once you have surgery this will be behind you. Hoping for the very best outcome for you!!! (((hugs)))

Those are good figures awb, and show the odds in favor of Shabby being just fine.

In Shabby's particular case I believe she has already had excisional biopsy at the site.  Is that right Shabby?  I think the numbers awb is citing are those for women facing an exisional after a core biopsy.  If that is the case, Shabby, your odds are even better for finding no cancer since they have already removed more tissue and checked it. Does that seem right to you awb?

For what it's worth Shabby, I had same like you:  core, leading to exisional (no cancer found) followed by BMX (no cancer found). 

Everything is up in the air until the final path comes back, but hopefully it will all work out for you.

Beacon, Leaf or anyone...  can you tell me when PLCIS cell type came to be known???  Until this board I have not heard of it only LCIS. tks  Never mind, I found the info thanks to articles in Msippiqueen's post.