HER2 Support Group Forums - View Single Post - DCIS

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, 06:19 PM	#5
dlaxague Senior Member Join Date: May 2006 Posts: 221	Re: DCIS - Chemo 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?