Genetics shocker- CDH1 pathogenic variant positive
Updated: Jun 7, 2019
For an update on how I am coping with my CDH1 diagnosis a year later, see my post titled, "CDH1: A Year in Review."
I have said this before, but I have always assumed I would get breast cancer one day due to genetics. Because my mom had breast cancer so young, and now me too, it just didn't seem like it could be a coincidence. So, I went in to this whole genetics counseling and testing assuming I would test positive for one of the BRCA genes or one of many other common breast cancer causing gene mutations.
That is why I was shocked when my results showed that I tested positive for a gene mutation I hadn't given a second glance, CDH1. According to my final genetic test report from GeneDx, I am "heterozygous for a pathogenic variant in CDH1, consistent with Hereditary Diffuse Gastric Cancer. Pathogenic variants in CDH1 are associated with a a 59% to 80% risk for diffuse gastric cancer in men, a 44% to 69% risk for diffuse gastric cancer in women and a 23% to 68% risk of lobular breast cancer in women." Although mine and my mom's breast cancers were diagnosed as ductal and not lobular, CDH1 is a fairly new gene being tested for, it is fairly rare, and my genetic counselor says there is not enough data to definitively rule out higher rates of ductal breast cancers as well. For this reason, I am going to try and join national and local research registries to add to the data being collected on this rare gene mutation. As a person who is studying public health, I feel it is my duty to add to the data because I know how hard it is to find good and reliable data.
Hereditary diffuse gastric cancer (HDGC- I know, another acronym...) is nearly impossible to screen for and is rarely caught at an early stage as a result. In fact, someone with the CDH1 gene mutation is not considered to be screened for cancer, but surveilled, because the chances are so high that they will have it at some point in their lifetime. That is also why the National Comprehensive Cancer Network, the go to guidelines followed by physicians, recommends prophylactic total gastrectomy (stomach is removed before cancer is found) for anyone with the CDH1 gene mutation as the only preventative measure at this time.
My public health brain immediately went to prevention over surveillance as the best option, but living without a stomach?! That has got to have it's consequences right? I can't even imagine it at this point. I am still processing this news because basically it feels like I have breast cancer, which I could die from or which could recur at any time and now you tell me I will likely have stomach cancer which will almost certainly kill me?! DAMN cancer!!
Obviously, I have made no decisions about this yet and I need to focus on the current task at hand which is finishing up chemo and curing my breast cancer before worrying too much about this CDH1 gene mutation.
I was originally writing/journaling about my journey for my own benefit and honestly didn't think this cancer thing would have me down for long- it was temporary in my brain. But now with this whole genetics shock, I am thinking this will be a much longer road to recovery and not only do I want to keep others informed, but, selfishly, I will need the support. And, I want others to be able to read my story and know they are not alone in what they may be going through. This marks the beginning of my blogging journey...here goes!