Study on ERBB mutations and ILC

Amelia01

Copying and pasting some perhaps pertinent information found on a FB forum. It seems that HER2- ILC tumors should be checked for gene mutations that might have HER2+ receptors.

"Stressing the need for genomic testing of the tumor biopsy sample: High Grade Lobular hormone-positive breast cancers are now being found to have a significant frequency of an odd ERBB2 or HER2 mutation that amplifies HER2 activity but does not get detected by standard pathology methods, especially when the cancer has spread to new locations or metastasized. They are discovering that HER2-targeted therapies, such as Herceptin, may be useful in these cases. I know of one woman who had this happen and only found out very late, as her cancer was very aggressive and advanced and her overall health deteriorated. She did genomic testing about 3 months ago, her doctor did not know what to do with the results. I provided the information from one of the cases discussed in this article to her to share with her new oncologist and he started her on Herceptin. We don't yet know what the outcome will be but the tumors are shrinking on Herceptin after simply raging out of control over the past year, after cycling through many non-HER2 therapies.

Again, this particular type of ERBB2 mutation, that may be treatable with drugs like Herceptin, appear to be found in approximately 15% or more of hormone-positive HER2-negative High Grade (like Grade 3) Lobular breast cancer, especially in the metastases, even if not detected on the original biopsy. So, this is another reason rebiopsy can be so important -- when a metastasis can be biopsied and then genomically analyzed.

Foundation One is just one of the companies that does this testing --...."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC53419...

beautifulbooks

Thanks Amelia -- I was just coming her to see if others were talking about this information. Felt funny to see my words show up. Thank you again. I know it is still so experimental but for at least several women I know, it seems to be changing their outcomes somewhat. Wishing you and everyone all the best.

Kristin

Amelia01

Sorry Kristin to not have cited my sources! but wanted to get the message out there!

I'm asking to be tested. I hope I can find a facility.

I wish some of the ILC ladies on these boards would chime in on their thoughts.

I wonder if there is a way to have a heads up about the HER2+ factor just by diagnosis. In my case (undiagnosed for years with u/s! and a May 2017 mammogram that showed nothing! 3d mammo in Oct 17 was spot on) I wonder how on earth it became 7cm and stage 3c. It seems to have happened overnight.

I'm ki67 13% and everyone's belief is that it is slow growing which doesn't explain the 17/21 lymph nodes that weren't even hinted at in May 2016 u/s. I'm going for the closer look to see about the mutation.

All of this is really maddening. At least my team knows that I will undergo any test possible to have the clearest picture.

Again, many thanks for bringing this to our attention!

xx