**please** help with information

Hi Momstrong:

I have posted previously regarding (4) HER2 testing and DCIS, and reproduce the information here for you.

As explained below, current guidelines do not require HER2 testing of apparently pure DCIS. You should not be concerned if your biopsy sample showed apparently pure DCIS (no evidence of invasion) and was not tested for HER2 status.

Pure DCIS can be either HER2 positive or HER2 negative.

However, pure DCIS, which is non-invasive, is not treated with chemotherapy or HER2-targeted therapy even if it is known to be HER2-positive.

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. Consistent with the quote above, 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 current treatment guidelines, 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.

If invasive disease is later found at surgery, it may or may not have the same HER2 status as the associated DCIS.

BarredOwl

Just one thing to add to BarredOwl's excellent posts - you asked if you should be seeing a medical oncologist in addition to the surgeon and radiation oncologist. The only reason to see a medical oncologist for pure DCIS is if you are contemplating hormonal therapy such as Tamoxifen. In your original post, you said you were ER/PR negative, in which case that wouldn’t be an option for you, so I don't see any reason at this point for you to see one, although you could ask whoever is heading your team (in my case it was the surgical oncologist) for their opinion about it.

It’s customary to wait about 6 weeks between surgery and radiation, and your radiation oncologist will discuss any risks/side effects, but yes, fatigue and redness are the most common things to expect.

Hi momstrong,

Excellent questions. We all had different experiences, and for me, every step in the process brought new insight and questions. My biopsy indicated DCIS. My lumpectomy verified pure DCIS grade 3 with >95% ER and PR +. For me, HER2 testing was not indicated. I did rads and Tamoxifen. Neither we're problematic.

I was fortunate to have fabulous providers who laid it all out and made sure I understood what to expect and explained all the options as well as the pros and cons of each, every step of the way. Beesie's posts were invaluable, as were the experiences of so many here.

Questions are sure to arise as you move through your specific tx. Take it all one step at a time, and stay in touch with bco. You'll never go wrong with the people here.

Mostly the same. Stayed DCIS, but the Grade changed from 2 to 3.

LisaAlissa

My needle biopsy found a small area of DCIS with an even smaller area of invasive. The subsequent lumpectomy found no more cancer, meaning the entire lesion was removed in the needle biopsy, so my diagnosis definitely stayed the same.