Friday Dec 6, 2013 – Brandon, my mom, my dad, and I sit around a round table at Mount Sinai hospital in Toronto anxiously awaiting for the genetic counsellor to join us. Brandon playing with a peg game in the room while my mom, dad and I discuss where to eat lunch that day after the appointment. It’s 11am. The genetic counsellor joins us at the table. Mom and Dad have been here before. This same meeting occurred Sept 29th, 2009 for my mom.
‘We received the results from your blood test and unfortunately, you tested positive for the CDH1 gene mutation’.
Before I go on any further, let me briefly explain what this means. Everyone has 2 copies of the CDH1 gene. I receive one copy from my mom and one from my dad. Dad has 2 healthy copies. Mom has 1 healthy and 1 not so healthy. This mutation has an autosomal dominant inheritance pattern. If you think back to genetics 101, this means that mom had a 50% chance of getting it from her father and she did. Bummer. I had a 50% chance of inheriting this gene from my mother. For those of you who know of my infamous board game dice rolling skills, I figured I could control this outcome too and end up negative. Shockingly this was not the case, proving to mom that I am as much like my mother as my father. So basically when dad’s healthy gene gets tired and throws in the towel, mom’s CDH1 mutated gene takes over.
The CDH1 gene codes for a product known as E-cadherin. So why is it important? From what I understand, this protein is involved with cell-to-cell adhesion. It tells cells where to go and where not to go. When there is a dysfunction in this protein the cells have no idea where their boundaries are and they can invade surrounding tissues. People who have a mutation in this gene have an increased risk of developing hereditary diffuse gastric cancer (HDGC) as well as lobular breast cancer. What’s the risk? There is an 83% lifetime risk that I will develop this cancer before 80 (for men its 67%) and a 40% chance that I will develop breast cancer. The mean age that people develop HDGC is 38 years old. My grandfather died at 30 with stomach cancer. I’m 30 next year. This is scary stuff!
But Rachel, can’t you screen for stomach cancer? Yes and no. The most common type of stomach cancer is intestinal type gastric cancer. HDGC accounts for 1-3% of all stomach cancers. Most endoscopy’s don’t pick this type of cancer up. Why? Because it is diffuse and it lies in the submucosal layer of the stomach. Taking regular biopsies is like finding a needle in a hay stack. You can be asymptomatic until one day…you feel very ill and then it is too late. So what can you do to prevent it? Well, the genetic counsellor has discussed with me , I have been reading many research articles myself and you can prevent it by…..drum roll….removing your stomach entirely! WHAT?? You can live without a stomach. Yes, many people with this gene have done so and are living healthy lives. My mom is a prime example. Is it an extreme measure? I used to think so but I don’t anymore. When you look at the research, all stomachs that have been prophylacticly removed have been tested and all have come back with cancer in them. It seems like the obvious decision to make. As for the breast cancer risk, routine mammograms are still the way to go. Research is limited on getting prophylactic mastectomy at this point for this gene.
So yes, this is scary. But is it bad. It could be if you really wanted to look at it that way. But I choose to look at it this way, I have been given a choice. I tell people I received bad news but ultimately good news. I can prevent getting cancer. On December 5th, 2013 I had a solid 5 year plan. On December 6th, everything changed. This is my blog and my story about living with the CDH1 gene mutation.
For more information on HDGC and CDH1 click here.