DCIS and HER2/neu

I remember that there was a lot of discussion about this study when it first came out. It's interesting and it certainly leads to questions that should continue to be pursued. At this point though I wouldn't take this one to the bank.

First reason is the sample size, which was very small - only 106 women. Of those 106 women, 39 were HER2+ and 22 were found to have invasive cancer in addition to DCIS.  So we are talking here about the breakdown of the group of 22 women who had invasive cancer.  It certainly would be interesting to see if these results could be replicated in a larger study and hopefully that's underway now. But for me, it's hard to draw conclusions from results where the difference between one group and the other is less than 10 women.

Second reason is that while this is the most recent study, there have been other studies done that have looked at the same thing, and interesting, the results haven't always been the same. Here's an earlier study where the conclusion was exactly the opposite. This study compared the tumor pathology & HER2 status of 100 women with DCIS w/ a microinvasion vs. 100 women with pure DCIS. The conclusion here:  "We found that HER-2/neu gene amplification was inversely associated with the risk of invasive progression in DCIS patients, even though it correlated with high-grade lesions in both cases (DCIS-associated invasive cancer) and controls (DCIS alone)."  http://cebp.aacrjournals.org/cgi/content/full/11/6/587

I'm not suggesting that this 2nd study is any more reliable or credible than the first study. The sample sizes in both were simply too small.  But it points out that there is no clear answer to the question as to how HER2+ status affects DCIS.

Here's an article that talks about two other studies. Here again, each study came to a different conclusion.  HER-2/neu Overexpression as a Predictor for the Transition from In situ to Invasive Breast Cancer

Ultimately I wouldn't be surprised if it's found that having DCIS that is HER2+ does somewhat increase the risk of invasion.  But from anything I can find, we don't know that yet.  And there are some big questions that need to be answers, such as why it is that DCIS is about two times more likely to be HER2+ than IDC?  Does this mean that HER2 status changes as the cancer evolves from DCIS to IDC?  Or does it mean that fewer cases of HER2+ DCIS become invasive? Too many questions, not enough answers.  

I am ER- and PR positive, believe me it matters to my treatment. My oncologist wants me to take Tamoxifen which I would rather not take after all the side effects that she listed. I asked why do I have to since I am ER negative, she said that because I was PR positive and its a hormone and Tamoxifen is a hormone suppressant. I know if it matters that I have IDC not DCIS though...

I just posted this reply in the wrong HER2 thread.

There are currently 2 clinical trials underway testing Herceptin on women who have DCIS that is HER2+.  And there is another trial testing a vaccine on women with HER2+ DCIS.  

http://clinicaltrials.gov/ct2/results?term=DCIS+and+HER2+and+vaccine

http://clinicaltrials.gov/ct2/results?term=DCIS+and+HER2+and+Herceptin 

Shelley, I think it's great that you were in the trial - I have such admiration for those who participate in clinical trials. Finding out more about how HER2 status affects DCIS and whether there are treatments that might be beneficial to those with HER2+ DCIS is very important.  

However I would caution everyone against putting too much weight on the research that showed that HER2+ DCIS is 6 times more likely to progress to become invasive BC. That's really scary information for anyone who has HER2+ DCIS but what's important to understand is that this was one small study with only 106 women; within that group, only 22 of the women (HER2+ or not) developed invasive cancer.  And per the links that I included in my earlier post, there have been studies that have actually shown exactly the opposite, i.e. that HER2+ DCIS is less likely to become invasive. So I don't think that anyone knows yet what effect HER2+ status has on DCIS. And that's why research is so important. We need to get this answer.

Up until this  past  week 4/2011  I  wondered why  all  DCIS patients were not  tested  for  their  HER2+  status. IT  MEANS NOTHING  and  I  am  living  proof  of that concern and  hopeI  can  put  that  needless  concern to  rest, once and for all.   MY  old  report  had  me at  HER2++. Follow  me so  far?

 Specifically, I  was  core-needled  biopsied  for  suspicious  malignant  neoplasm as  the  first  step   8/2010.  A month later I was  given  conflicting  pathology  reports  (got a 2nd opinion) of the findings--one  being  only  DCIS without  testing for HER2  status and the other  being  DCIS  with  an apparent  pseudoinvasion  of  Tubular  with  HER2 status  being HER2++.  It  was  labeled  "pseudo"only  because  the slides  were badly  degraded  by  the  first  pathologist.  In  other  words, the conclusion for  pseudo was based upon sloppy  seconds.

 8  months  later  to  Apr 2011  fast  forward  with  a wide  local  excision  AKA  lumpectomy.  and 3  senitnal  nodes  dissection.

Bottom line?  I  did, in fact  have a  tumor  with  some DCIS  and  .25 cm  of  INVASIVE Tubular  which is supposed to be,  for the most  part,  unlikely  to spread. NOT!!!!!   My report  indicated that  my  invasive portion is  so  totally  negative for HER2  but,unfortunately  I ended up with a microinvasion of cancer in one of  3  sentinel nodes  tested.

I  will not  entertain  the thought of  completion  axillary node dissection  and. It is a tough  call, though.

My sig line  still shows me  with  inaccurate  Dx. I am now Stage IIA  and  I will  NOT do  chemo--no  way,  no  how. I  think  I  may  actually  be  abole to get  away  with not  having completion Axillary  dissection,either.    Microinvasion in  1  sentinel  node  is  not,anymore, reason to turn  to  chemo.  If yoiu  were  in  my  situation,  and given  the option, would you  radiate  your  axially  area, just  do MRIs until something  shows up, or  do  the  dissection?  Just  curious.