TNBC Neoadjuvant vs Endocrine therapy

http://www.curetoday.com/index.cfm/fuseaction/news.showNewsArticle/id/5/news_id/1067

Edited by trip2 - May 18 2009 at 7:22am

it compared chemo before surgery and endocrine therapy before surgery.  i dont read in this article that having chemo before surgery or after has a different outcome.

My surgeon and Onc both have said that the outcome of survival going neoadjuvant is the same as going adjuvant. The benefits of going Neo is that they can actually watch what and how the tumor responds. If its out they cant watch it! Also, if the tumor shrinks enough that breast conservation is possible(with clear margins and no node involvement) I feel that I am ahead of the game. This is EXACTLY what mine is doing! I had my third chemo yesterday and the tumor has shrunk 25% and has almost broken in half! I am so UP WITH THAT!!!

The reason that survival does not change overall for patients who receive neoadjuvant chemotherapy is that survival only improves for people who have a complete pathologic response to the neoadjuvant chemotherapy.  If a person has a complete pathologic response (no remaining invasive cancer, the survival of those people goes up to ~95%.  Those who do not have a complete pathologic response goes down to ~68%.  All together these average 80%.  For adjuvant chemotherapy, there is no way of determining whether there is a response of any residual cancer cells, so some people do well and others do not, but one can't tell who is responding because there is no mass that can be followed, since it was surgically removed before the chemo.

Frenchie,
Additional chemo is not administered to adjuvant patients (or to many neoadjuvant patients without pCR) because as counterintuitive as it is, more chemo does not necessarily mean better odds.  They used to give chemo to women over two years, and experimented with really high doses.  Over time, clinical trials showed that all this did was lower quality of life.  It did not result in more cures.  That's why the current standard is a fairly short course of chemo. 

The only realm that's been overturned, as far as I know, is with hormonal therapies for ER+s.  There, longer therapy is indeed better, as one can see with the changing standards.  Now ER+s have 5 years of tamoxifen and some years of aromatase inhibitors after that.  It used to be that they were put on tamoxifen for just 3 years, and before that, just for 18 months.

The difference might be that hormone blockers don't really kill cancer - they just keep it quiet.   Then over time normal cell death rates can wipe out isolated interlopers.   The drugs we take are cytotoxics - they work by killing actively dividing cells.  For many women, the cancer contains cell subpopulations that are not sensitive to the drugs.  Therefore, higher concentrations or longer periods of therapy don't affect these cells.  Also, TNBC has a highly disordered genome, much more so than ER+s.  This might mean that they are genetically unstable, which means that they evolve rapidly.  Slightly resistant subpopulations can therefore possibly evolve to highly resistant subpopulations during therapy.

More is not always better.  We are in a primitive era of medicine.  Someday in the I hope not-too-distant future, people will look back at these treatments and shudder at how off base they are.  

We are largely at the mercy of luck.

-Denise

I don't understand what you mean Frenchie.

Pam, I believe Krisa and Frenchie are correct.  The article does not discuss neoadjuvant vs adjuvant.  Perhaps it would be good to change the topic title so others are not confused.

Suzanne

Edited by Suzanne - May 17 2009 at 8:48pm

I am curious where you are getting your statistics on survival for those who have achieved  pathological complete response with neoadjuvant therapy and the statistics for those who have not.  I would love to believe that I have a 95% survival rate since I had a  pathological complete response to my 7 cm node positive grade 3 IDC tumor after neoadjuvant chemo and lumpectomy and radiation.

Dear Lisalaw,