Lynch Syndrome

[Shy999]

Does anyone have experience with Lynch Syndrome/Genetic Testing?  My doctor has recommended I have genetic testing done to see if I carry the defective gene my Grandmother and Father had.  I am just curious if anyone else has been through the testing and what is to be expected.

[Fernando Roque, MD]

Hi.  Lynch syndrome, also known as hereditary non-polyposis colon cancer (HNPCC) is the most common form of genetic predisposition to colon cancer.  Patients who have the gene for this syndrome have a lifetime risk for developing colon cancer of around 80%.  Since you have two first degree relatives who have been identified to be carrying the genes for this condition, it is imperative that you undergo genetic screening, which involves a blood test which detects the mutations in the DNA mismatch repair genes (MLH1, MSH2, MSH6 and PMS2) responsible for the syndrome.  If you test positive for the genetic defect, you have to undergo surveillance colonoscopy every 1-2 years "staring at age 25 or ten years younger than the youngest age at diagnosis in the family, whichever comes first".

[Shy999]

Thank you for your comment back.

[Shy999]

Here is another question, if there is anyone that can answer it.  I was referred to a GYN Onc. originally because of the problems I have been having.  My PCP was concerned about possible Ovarian Cancer.  My U/S came back fine, my Pap showed LSIL and the GYN Onc. thinks I may have endometriosis.  We are scheduling a Lap for that after the genetic testing. The doc told me that if the testing were to come back positive for the genetic defect, he would want to do a full hysterectomy.  I am only 25, I have one child and wish to have more if possible.  Is it really necessary to have a hysterectomy right away if I do have the gene, or should I get a second opinion.  I can understand his concern, for one, the possibility of getting the cancer, and also for passing the gene along.  But, if we know I have the gene, at least we know what to look for in my children at an early age.  Any help would be great!

[Fernando Roque, MD]

Hi.  The National Comprehensive Cancer Network (NCCN) guidelines state that removal of the uterus and ovaries is not routinely recommended even for those with full-blown Lynch syndrome (those who already have colon cancer).  Hysterectomy/oophorectomy is, however, a reasonable option for those who have Lynch syndrome, as well as those who carry the gene.  So to answer your question: you probably would benefit from having the hysterectomy/oophorectomy done, but you may opt to do it at a later time, after you've had the additional number of children you want.  However, bear in mind that your risk for developing ovarian and endometrial cancer continues as long as your uterus and ovaries have not been removed.