DCIS question for the experts

Mayk

I was told at my diagnosis that they didn't test DCIS for HER-2. After my BMX I was referred to an Oncologist just as a precaution. She said to me "you made a very wise decision being ER/PR negative and HER-2 positive". She also said they don't unusually test for it and as expected no follow up treatment is planned. I had a copy of my pathology report and thought I would ask if anyone else had been tested with non-invasive (which it says all over the report for every sample) for HER-2.

They performed the HER-2/neu Test on the Biopsy not the Surgical lab Test. It says in the results "For prognostic purposes, additional studies were ordered on this case by the attending pathologist" The HER-2/neu was positive (3+) (Overexpression).

In the surgical Pathology report it was confirmed to be Grade 3, maximum diameter of 1.9 cm, no invasion, clear margins grater than 1 cm of all sections and the breast tissue adjacent to the tumor demonstrated Fibrocystic Changes. Three Lymph Nodes were negative for malignancy, Soft Tissue Left Axilla negative for neoplasm and no lymphoid tissue present. Confirmation again of ER/PR negative status.

The BS didn't mention this just the ER/PR negative. I was told by the Nurse Navigator she thought all DCIS would test positive for HER-2 but could change in IDC.

Conflicting data is uneasy during this time even when most of it is "good decision".

Annette47

Not an expert, but I have read that DCIS is much more likely to be HER2+ than is IDC. To my understanding, it's not that (as your Nurse Navigator said) that all DCIS would test positive, but the chances of DCIS testing positive are much higher than the prevalence of HER2+ invasive cancer. At this point, the significance of HER2+ in DCIS is unknown - it doesn't seem to make it more aggressive like it does with invasive cancer, and is not known to make the DCIS more likely to turn invasive.

Because of this (the HER2+ not seeming to make a difference) many places do not bother to test DCIS for HER2 as it wouldn't change the treatment or prognosis. My DCIS was not tested, and my invasive component was too small to test (small enough it wouldn’t have generated a treatment change even if it was HER2+). I think that many oncologists who are used to dealing with invasive cancer, don’t always know much about DCIS, and may not be aware of how prevalent HER2+ DCIS really is. I found that my radiation oncologist seemed to have a much better understanding of DCIS than my medical oncologist.

Mommyathome

when I was diagnosed with Dcis I was told after my bmx that I didn't require radiation, tamoxifen of HER status testing. I go to bs and ps every 6 months for follow up. I was actually told I didn't need to meet with oncologist because it was Dcis. I pushed for a visit just to make sure that he also thought it was safe not to take tamoxifen and what I could do to help with low vitamin d due to the fact that I also had a total hysterectomy. Does it seem like the 6 month follow ups are enough to help prevent or catch recurrence

marijen

Mommyathome if your cancer is HER2+ it would make a difference. Read here

https://community.breastcancer.org/forum/80/topics/738946?page=

Doctors that don't want to test make me very nervous......

Mayk

Annette.. thank you.. that's about the most logical thing I've read on the DCIS and testing.. very helpful.

BarredOwl

Hi Mayk:

I am not an expert, but note the following.

Please note that the abstract in the thread linked by Marijen ("Does hormone receptor (HR) positivity affect the prognosis in breast cancers with human epidermal growth factor receptor 2 (HER2) overexpression?") appears to relate to invasive disease, and is not relevant to your questions regarding pure DCIS. For example, the patient group includes patients who received chemotherapy (never indicated for pure DCIS) and some node-positive patients, indicating they had invasive disease.

I agree that pure DCIS can sometimes be HER2 negative.

According to background information from a 2015 article (citations omitted, emphasis added), in contrast with invasive disease, the ". . .prognostic significance of HER2 status in DCIS is, however, less clear. Both the relation of HER2 to risk of recurrence and its role in the progression from in situ to invasive cancer have been debated. HER2 over-expression is reported to be more frequent in DCIS than in invasive cancer."

Regarding HER2 testing practices in pure DCIS, in general, the National Comprehensive Cancer Network (NCCN) guidelines for Breast Cancer (Version 1.2016) do not recommend routine assessment of HER2 for pure DCIS. This appears to reflect the current level of evidence regarding value as a prognostic marker in pure DCIS (unclear, weak), and that HER2-targeted treatments are not used in the pure DCIS setting (emphasis added):

"Although HER2 status is of prognostic significance in invasive cancer, its importance in DCIS has not been elucidated. To date, studies have either found unclear or weak evidence of HER2 status as a prognostic indicator in DCIS.(41-44) The NCCN Panel concluded that knowing the HER2 status of DCIS does not alter the management strategy and routinely should not be determined."

In accordance with the current treatment guideline, many patients with pure DCIS do not receive HER2 testing.

This might or might not change in the future, since it is an on-going area of research, and we may learn more from new studies about the prognostic implications of differing ER, PR and HER2 statuses in pure DCIS.

Your oncologist's remark refers to your entire status, including ER and PR negativity, so endocrine therapy is not being offered, which may factor in to her view of your particular case.

BarredOwl

Mayk

Barred owl

Wow thank you. I love this website. I'm not sure I understand 100% of all you referenced but I think I get the gist.

Not widely used mostly inconclusive at this time. Agreed OC reference to good decision was related to ER/PR negative which was certainly a concert of the breast surgeon. RO more about it being treatable with similar results to BMX. But for me being able to sleep at night was my priority.

Thank you for taking the time to post your response for me!

swimmersmom94

I too was never tested for HER2. I was diagnosed with DCIS in SITU, ER positive, stage 0 June 29th, 2015. BMX, nipple sparing on September 18th, 2015. exchange surgery Dec. 15th. My onco says there is no need for tamoxifen because I am post menopausal. I would love to hear from others with a similar situation. Also, how would you start a new discussion on here asking a similar question?

Kkubsky

I just started a thread on HER because I have been reading about it and totally scared myself....again. I was not tested after the biopsy and am hoping that after the lumpectomy pathology comes back, it will stay as pure DCIS. Am I the only one that gets totally terrified with the what ifs?