We ask our patients about family history when screening for colon cancer because there are a number of inherited syndromes that can increase your risk of developing colon cancer. Lynch Syndrome is by far the most common of these inherited syndromes.
Lynch Syndrome Increases your Risk for Cancer
Lynch Syndrome is also referred to as Hereditary Nonpolyposis Colorectal Cancer. Families with Lynch Syndrome have more instances of colon and rectal (colorectal) cancer, and cancers tend to occur at an earlier age, younger than age 50. We do not know exactly how many colorectal cancers are caused by Lynch Syndrome, but researchers estimate that it causes at least three percent of colorectal cancers. People with Lynch Syndrome are also at higher risk of other cancers including uterine/endometrial, ovarian, stomach, small bowel, pancreas, urinary tract, kidney, brain and skin cancer.
Lynch syndrome is hereditary, meaning that it is caused by inherited genetic mutations that can be passed from parents to children. Several genes have been identified that are linked to Lynch syndrome: MLH1, MSH2, MSH6, PMS2 and EPCAM. A mutation, or alteration, in any of these genes gives a person an increased risk of developing colorectal cancer and other related cancers during their lifetime. It is important to note, however, that not everyone with a mutation in these particular genes will develop cancer.
Normally, every cell has two copies of each gene: one inherited from the mother and one inherited from the father. Lynch Syndrome follows an autosomal dominant inheritance pattern, which means a mutation needs to happen in only one copy of the gene for the person to have an increased risk of getting that disease. A child whose parent has a mutation will have a 50% chance of inheriting that mutation. A brother, sister, or parent of a person who has a mutation also has a 50% chance of having the same mutation.
Diagnosis of Lynch Syndrome
These medical and family factors may lead me to suspect Lynch Syndrome:
In some cases, I may ask my patient to complete a written questionnaire to give me more detailed information about his or her family history. I will refer potential Lynch Syndrome patients to a genetic counselor for further testing. The purpose of genetic testing is to determine a patient’s risk of developing cancer or cancers.
Lynch Syndrome Patients are Monitored Closely
Once identified, many of the Lynch Syndrome associated cancers can be prevented or detected early when treatment is most effective. Your genetic counselor will work closely with you and your doctors to determine the best course of action.
I monitor my patients with Lynch Syndrome very closely for colon cancer. This means a screening colonoscopy will be performed at a younger age than recommended for the average person. Repeat colonoscopies will also be performed more frequently.
Learn more about Lynch Syndrome from Lynch Syndrome International or take a hereditary cancer quiz from Myriad Genetics.
Do you think you may have Lynch Syndrome or are you concerned about your family history and risk for colon cancer? Contact Richmond Gastroenterology Associates today if you would like to schedule an appointment.