DCIS - Chemo

harrie · 08-21-2009, 01:14 AM

Has anyone ever heard that chemo is not effective for cancer cells that are DCIS?
Someone mentioned this to me recently and I had never heard of such a thing.
I know that people with DCIS do not usually undergo chemo.
Consider this situation: A person has a lumpectomy due to invasive DCIS stage II bc. Chemo is given post-surgery. Will chemo destroy cancer cells in other possible areas of DCIS within the same breast or the other breast?

duga35 · 08-21-2009, 02:23 PM

I've never heard anything like that. I hope it's not true!

harrie · 08-21-2009, 03:52 PM

Really Duga, I have never heard of this either. I have heard that there is a barrier whereby chemo will not effect cancer in the brain. But if what was said is true about the DCIS, that would mean that chemo will not penetrate through the ducts. To me that doesn't sound right.

08-21-2009, 05:09 PM

Actually, that is true. They usually never give chemo for DCIS. I think it is because it is self contained, not invasive.

Karen

dlaxague · 08-21-2009, 06:19 PM

Cool question, Mary Ann. I don't know the answer but my guess is that it doesn't have anything to do with chemo not penetrating. It's that chemo only works on rapidly-dividing (aggressively growing) cancers and that's why it doesn't affect DCIS.

Just like chemo is not given for the less aggressive ERPR invasive cancers. Chemo has its best effect on rapidly dividing cells and so for the slower cancers it does not improve outcome.

OTOH, endocrine therapy does control slower hormone positive cancers and it is sometimes given with DCIS, right? To prevent more DCIS and/or invasive cancer from forming, I assume (but do not know this for sure). Because typically they've surgically removed the DCIS.

But then, (little voice asks) what about HER2+/ERPR negative DCIS? Would that be dividing faster because of the HER2/ERPR even though it's not invasive, and so WOULD it be susceptible to chemo and/or Herceptin? Not that they'd give it just for DCIS because there's no threat to life from DCIS, but like you say, what if some DCIS was leftover after the lumpectomy took out the invasive cancer? I don't know if that answer is known. I look forward to seeing more answers here about this.

There's a consensus conference on DCIS sponsored by NIH next month. You can register to watch the proceedings online, live or archived. It looks like it will be most interesting:

http://consensus.nih.gov/2009/dcisgetinvolved.htm

Maybe they'll discuss this topic. It will address these key questions:

What are the incidence and prevalence of DCIS and its specific pathologic subtypes, and how are incidence and prevalence influenced by mode of detection, population characteristics, and other risk factors?
How does the use of MRI or sentinel lymph node biopsy impact important outcomes in patients diagnosed with DCIS?
How do local control and systemic outcomes vary in DCIS based on tumor and patient characteristics?
In patients with DCIS, what is the impact of surgery, radiation, and systemic treatment on outcomes?
What are the most critical research questions for the diagnosis and management of DCIS?

08-21-2009, 08:11 PM

I totally agree with Debbie.

Karen S.

harrie · 08-22-2009, 01:19 AM

It is also interesting how chemo is not normally recommended for DCIS, whereas radiation and Tamoxifen is commonly recommended.
I believe the histologic grade of the cells found within the DCIS usually indicate the how quickly the cells are dividing.

jml · 08-22-2009, 04:11 AM

Just wanted to add, DCIS, by definition, is NON invasive, so I don't believe it's possible to have "invasive" DCIS.
Since the in situ cells aren't in the appropriate phase of cell division that can be affected/interrupted by chemotherapies, surgery, radiation & hormonal tx's are the only options.

From Wikipedia:
Carcinoma in situ (CIS) is an early form of carcinoma defined by the absence of invasion of surrounding tissues. In other words, the neoplastic cells proliferate in their normal habitat, hence the name "in situ" (Latin for "in its place").

harrie · 08-22-2009, 05:50 PM

DCIS by itself, contained within the ducts, is non-invasive. DCIS can become "invasive DCIS" if the part of the DCIS escapes the ducts and goes into the tissue.
It was my understanding, that the actual cells within the DCIS are technically "cancer" cells, same as the "cancer" cells found in invasive carcinoma.
The difference between DCIS and invasive CA is that if it is just DCIS and the breast tissue is clear of cancer cells, then there is no concern of cancer cells spreading. Thus there is no reason for the chemo.
The cells within the DCIS can be tested for hormonal positivity, even the HER2, as you would test the cells of the stage I breast cancer. Theoretically, the results can possibly predict the risks of future invasion.