The CHEK 2 Gene and Its Relationship to Colon Cancer
Last updated: November 2021
A few years ago I had some genetic testing done. I actually had gotten this testing to rule out that I had a BRCA gene mutation that means I am more susceptible to breast and ovarian cancers. I wanted this done because I had made the decision that I was going to be getting a hysterectomy in the next couple of years to treat adenomyosis (which is when the endometrial cells that usually line the uterus and shed during menstruation instead penetrate the uterus).
Knowing if I had this mutation would help me make a decision about whether or not to keep my ovaries (as the ovaries release hormones associated with breast and ovarian cancers, their removal for those with this gene mutation can significantly reduce their chances of developing these cancers). This is because though no one had breast or ovarian cancer on my mother's side, I wasn't as familiar with my father's side of the family and I knew vaguely two of his sisters died rather young of cancer, one of an undefined "female cancer."
My CHEK 2 gene mutation
Ultimately, I tested negative for the BRCA gene mutation, which was a relief (so I did decide to keep my ovaries). However, the genetic testing did find I tested position for a different kind of mutation: CHEK 2.
I had never heard of this mutation before. The doctor explained to me while it doesn't pose as much risk as a BRCA gene, it does modestly raise my risk for breast cancer. Not only that, but the CHEK 2 gene mutation also moderately raises my risk for colon cancer. Even though IBS is not at all associated with increasing one's risk for developing colon cancer, it's still hard for me to not feel especially vulnerable to it, given my long, painful issues with GI symptoms (which can make it hard to know if one day they are something more or less than just IBS).
Furthermore, my maternal grandfather developed colon cancer that almost killed him when he was in his early seventies (though he did beat it with surgery and treatment and lived another decade). Usually, family history is considered if the close relative developed colon cancer under 60. However, since I had both the CHEK 2 mutation AND a close family member who developed an aggressive form of colon cancer, my GI doc thought it was best for me to start early screenings for cancer, at 40 rather than 50.
Screenings for cancer
At 40 though, I had my hysterectomy, and the GI doc thought it was ok to wait until I was 100 percent recovered from that surgery to start screening for colon cancer (which in this case, meant a colonoscopy, something I was not looking forward to). Then as I was just getting to the point to be recovered enough for a screening, the COVID pandemic hit, and many non-emergency screenings and procedures were postponed by months. In the meantime, I actually did start to develop pretty bad constipation. Even though this constipation might have been a fallout of the hysterectomy, I started to worry. And though I initially was happy to postpone a colonoscopy, I then started to want one just for the peace of mind that I didn't have cancer or another complication.
Finally, the restrictions on screenings lifted and I had my colonoscopy, just days before Thanksgiving. It was unpleasant (I had had one before, 20 years earlier, to rule out IBD and get a definitive diagnosis of IBS, when I first started to have GI issues). However, I did get the peace of mind of knowing that I didn't have cancer or anything the scope could find. And eventually, with time and supplementation, and dietary tweaks, constipation alleviated. I was told by my doctor due to the CHEK to gene mutation, I need to have a screening every few years unless further studies of the mutation find it's not as necessary.
While I hated having the screening, I am glad to know about my genetic predisposition to colon cancer and be able to screen for it, especially as my IBS would make it difficult for me to know something has changed just my GI symptoms (since I have those already from the disorder).
Have you tested for the CHEK 2 gene? If so, have you been screened to rule out colon cancer? Please feel free to share your experiences in the comments below!
Which of the following symptoms of IBS do you experience most frequently?