Wierd Question, I Guess.
 

This is a wierd question, I guess but something I've always kind of wondered about. If I'm understanding her2 correctly, we all have the gene. It's when it overexpresses that a problem occurs. My question................why having it overexpress did we get a breast tumor and not another kind of cancer? Can her2 cancer originate in another part of the body other than the breast?

Thanks.

Mary Jo

As far as I understand it, it is an overexpressing gene in the breast cancer. You were not born with it, and it is not known to be inherited at this time.
Best regards,
Barbara H.

My friend's ex-husband is being treated with Herceptin for an oral sarcoma (unless she got her drugs wrong). She told me that sarcomas are very much like breast cancer.

Karen

What happens is that the gene for Her2 (we have 2 of them - one on each of the pair of chromosomes (I think its located on Chromosome 17 but I am not sure). Somehow, the cell divides wrong and (let's say), instead of 2 chromosomes in each (of the new cells), 3 are in one cell and 1 is in the other cell. Perhaps the cell with one chromosome can't "make" it (unless it got 3 chromosomes of something else (lets say the gene for the estrogen receptor (ER)) but the cell with 3 does and it reproduces and divides wrong again (I think you get the picture) and then you have surviving cells that have too many copies of the Her2 gene (this is what the FISH test tests for). Too many copies produce too much protein (this is what the IHC test tests for). The same reproductive prinicipal holds for ER, PR, Her1 etc.


Remember too that other genes are located on these chromosomes too and chromosomes can "swap" pieces of themselves during the reproduction process. This is why we are all so unique AND our cancers are actually unique too (like snowflakes, none of our cancers are alike - nor are we). I hope this is clear enough. Let me know.

For the record - cells that don't have the right amount of chromosomes are called aneuploid.

PS - all cells have the Her2 gene. Ovarian cancer can be Her2+ too but Herceptin doesn't tend to work well on them. Many, many forms of cancer are Her1+ (aka EGFR).

It was explained to me by my oncologist that we all have the Her2 gene...it is what kicks in during puberty for example and causes growth spurts. In a normal case scenario it kicks in, does its thing, and then shuts down. When it overexpresses (in breast cancer tumors for ex.) that is when it turns nasty, causing rapid growth, etc. I know this is not at all technical, but it made sense to me!

My oncologist told me that I could get cancer in another part of my body - it would be the same cancer that I had in my breast but it could show up in my bones etc.

The heart muscle also has Her2 cells, which is why Herceptin can sometimes affect heart function...

<3 Lolly