HER2 Status for DCIS SO TOTALLY WORTHLESS & USELESS

peppopat, thank you so much for your post!  

There are a lot of women here who have voiced concern about the HER2 status of their DCIS.  I've been posting for years that it doesn't matter - both because there is no understanding yet of what HER2 status means for DCIS and also because the HER2 status might change as a cancer progresses from DCIS to IDC. Still, because HER 2 status is such a key indicator of aggressiveness for invasive cancer, those concerns inevitably to flow over to DCIS - no matter what someone may have been told.  So having your real life example is very helpful and hopefully will reassure a lot of women who have been concerned about this.  

The fact that there is no good understanding of what HER2 status means for DCIS is something that the scientific and medical communities need to address.  Fortunately there is research, including clinical trials, currently underway.  Hopefully these will tell us more about the differences between HER2- and HER2+ DCIS.  Unfortunately it likely will be years before we get any meaningful data from these studies.  

I always found this statement on Dr. Loves site interesting:

"First, HER2 is still an enigma. It is present in most ductal carcinoma in situ (DCIS), a precancerous breast disease, but is present in only about 25 percent of all invasive breast cancers."

She also states "Since DCIS usually doesn't progress to invasive cancer" … not so sure that's so true (Beesie can chime in here. I'm not as informed about DCIS).

source link  

Agada:  You can still request that your tissue be tested - most hospital's keep the tissue slides  and it is quite common to request a test on tissue already in archives.  The only problem with that is SOMETIMES (more often than I want to think of) the tissue slides go "missing"... Take Care!

Emaline, you gave me a good laugh.  If someone referred me to Wikipedia for information about DCIS (or any health issue, for that matter), I don't think I could stop myself from looking at them incredulously and saying "Are you really that stupid?".

The information that's floating out there on DCIS in many places is really concerning.  Dr. Love's comments (as referenced in lago's post) head the list.  My impression of Dr. Love is that she takes a tidbit of truth and then molds it in such a way as to meet the objectives of what she believes and wants to communicate.  

For example, she says that "HER2 is still an enigma. It is present in most ductal carcinoma in situ (DCIS), a precancerous breast disease, but is present in only about 25 percent of all invasive breast cancers."  To my understanding, she's right about the percentage of invasive cancer that is HER2 positive.  And she's right that DCIS is much more likely than invasive cancer to be HER2 positive.  But in all the reading I've done on this, the numbers that I find for the percent of DCIS that is HER2 positive range from 40% to 60%. That's hardly "most DCIS".

Then there is her comment that "DCIS usually doesn't progress to invasive cancer". While there's been a lot of discussion on this and a lot of speculation, the very few studies that have actually measured this have been done on women whose DCIS was so tiny that it was never discovered or removed.  For women who have that type of DCIS - tiny and usually low grade - it does appear that a large percentage (anywhere from 40% to 75%) might not become invasive for 10 years, 15 years or even more than 20 years.  Beyond that, nobody knows.  What is also known, however, and what Dr. Love herself has admitted, is that high grade DCIS and multifocal DCIS presents a much higher risk.  Dr. Love's has said that we "don't know" what percent of high grade DCIS will become invasive.  Other experts have estimated that 75% - 90% will become invasive and some have suggested that all high grade DCIS will eventually become invasive.  

I don't know what percent of DCIS is high grade although I recall reading somewhere that the majority of DCIS discovered is high grade (if someone can find info on this, it would be great).  IF that's true, then Dr. Love's statement that "DCIS usually doesn't progress to invasive cancer" - which she knows is true only for DCIS that is small and low grade - is an outrageous dangerous lie. Unfortunately Dr. Love is one of the best known breast cancer "experts" and her words are taken as gospel and quoted everywhere.  And this is why we have so many people, including many doctors, believing that DCIS isn't a big concern.

I keep coming back to one simple fact about DCIS.  We know that after treatment, if DCIS recurs, in approx. 50% of cases the recurrence won't be found until it has progressed to become invasive. This is DCIS that has for the most part been removed - the recurrence is driven by whatever small amounts of DCIS are left in the breast after surgery/treatment.  If 50% of DCIS recurrences are invasive, then what percent of DCIS will evolve to become invasive if the DCIS is not removed and treated? The way I see it, obviously a lot more than 50%!  

peppopat-

just clarification  re the herceptin/DCIS clinical trial - I declined the trial - but that was exactly the question I asked - what do you get infused with if you don't get herceptin and I was told that you enter the trial and your Her2 status is tested, if  you test Her2+, you are either assigned to the group who gets the herceptin or to the group who does not. If you are in the group not getting the herceptin - you don't get a placebo infusion.

Julie E

Letlet  there was some discussion about putting women on Tamox or Al that don't have a breast cancer diagnosis as a preventative, especially those who are high risk (family history, BRCA positive). In some cased if a recurrence should occur it doesn't always have the same biology. It might be a good idea.