Question: Hello! My husband’s father was recently diagnosed with colon cancer at the age of close to 91. He had a right sided colectomy and pathology showed it was a medullary cancer of the cecum. Immunohistology showed it was deficit in MLH1 and PMS2. He met with a genetics counselor and has been sent for genetics testing as I understand it can be associated with Lynch Syndrome. His father has never had any other cancers, and his father’s parents both lived into low 90’s with no cancer. My husband had a colonoscopy six years ago which was perfectly clean, and his only sister has had clean colonoscopies as well; both are in their mid-fifties. There is no other cancer in the family as we know. We are very anxious while waiting several weeks for his fathers genetic testing results and we are praying it was just a somatic mutation. Given this information, I know you cannot guarantee anything with certainty, but given the clinical history would you tend to think this is somatic and not germline? Also I read about Lynch Like Symdrome, which will make me worried even if his father is negative for germline mutations. Any words of reassurance which you can give me on that? Thank you so very much!

Thank you so very much Dr. Ghosh! I had read that if there is (hopefully) no germline mutation, it can be considered a somatic mutation if there is a BRAF mutation or MLH1 promoter methylation. I do not have access to the tumor pathology report so I don’t know if the tumor itself was tested for those….if the tumor was not tested for those things, can they be tested as part of the genetic testing? Thank you again so very much for your time and kindness!

Thank you doctor! Yes, tumor testing was done but I’m not sure if they tested it for the BRAF mutation or MLH1 promoter methylation…I understand that if those were found they could show the tumor had a somatic mutation rather than germline.

That being the case, if there is no germline mutation found in the gene sequencing I was just wondering whether BRAF or MLH1 promoter methylation can be tested with the germline (or if those things could only be tested via the tumor)…? I guess I’m just hoping they can find evidence of a somatic cause so that I don’t always worry about Lynch-Like syndrome if there is no germline MLHI mutation.