Hereditary Colorectal Cancer Tests

Colorectal cancer refers to the cancer of the large intestine, which includes the colon and rectum. Most colorectal cancers begin as a growth on the lining of the colon, usually called a polyp. Over time, this polyp can become cancerous or remain benign.

Colorectal cancer is the most common cancer affecting both men and women in Singapore. A majority of colorectal cancer occurs by chance, while up to six percent of cases is inherited.

There are numerous types of Hereditary Colorectal Cancer. The most common types are Lynch Syndrome (also known was Hereditary Nonpolyposis Colorectal Cancer, or HNPCC), Familial Adenomatous Polyposis (FAP), Attenuated Familial Adenomatous Polyposis (AFAP), and MUTYH-Associated Polyposis (MAP). And of these, Lynch Syndrome is the most common, followed by FAP, then MAP.

Who should be tested for Hereditary Colorectal Cancer?

Individuals with the following personal or family medical history should consider genetic testing for colorectal cancer:

  • Early onset colorectal cancer, age 50 years old and below with several adenomas in the colon.
  • Multiple primary cancers including colorectal cancer in one individual.
  • More than 10 polyps in their lifetime.
  • Colorectal cancer exhibiting microsatellite instability or lack of immunostaining for a mismatch repair protein in tumor.
  • Several blood relatives affected with related cancers (eg. colon, uterine, ovarian and/or stomach cancer), spanning multiple generations.
  • Pattern of previously mentioned hereditary cancer syndromes, such as Lynch Syndrome, FAP, MAP, Cowden Syndrome and more.
  • Prior genetic testing performed due to family history suggestive of hereditary cancer disposition, with all negative results.

Tests for Hereditary Colorectal Cancer

Asia Genomics offers three genetic tests for Hereditary Colorectal Cancer:

Lynch Syndrome Test

Lynch Syndrome is a hereditary cancer syndrome that typically display cancers of the colon, rectum, endometrium, stomach, small bowel, ovaries, pancreas, biliary tract and urothelium. It is usually caused by mutations of the MLH1, MSH2, MSH6, EPCAM and PMS2 genes.

The Lynch Syndrome Test identifies mutations in these genes. It is a blood test ordered by your physician. Your DNA is extracted from the blood and analyzed. The test takes approximately four weeks to complete, and the results will be sent to your physician, who will explain the test results to you.

We will need two tubes of blood (about 4ml each) and a signed consent form from you to send to the laboratory. We recommend genetic counselling before genetic tests are ordered to discuss the implications of the testing and potential results.

Polyposis Syndrome Test

Individuals with Familial Adenomatous Polyposis (FAP) may present more than 100 adenomatous polyps in the colon, whereas those with Attenuated Familial Adenomatous Polyposis (AFAP) develop a smaller number of polyps at a later age. If these polyps are not removed, the chance of developing colorectal cancer will be over 90 percent. Individuals with FAP also have an increased risk of developing other cancers, including those in thyroid, pancreas, and brain.

Similar to AFAP, persons with MUTYH-associated polyposis (MAP) develop these polyps at fewer numbers and later age.

The Polyposis Syndrome Test identifies mutations in the APC gene, which is known to cause FAP and AFAP, and MUTYH gene, which is involved in MAP. It is a blood test ordered by your physician. Your DNA is extracted from the blood and analyzed. The test takes approximately four weeks to complete, and the results will be sent to your physician, who will explain the test results to you.

We will need two tubes of blood (about 4ml each) and a signed consent form from you to send to the laboratory. We recommend genetic counseling before genetic tests are ordered to discuss the implications of the testing and potential results.

Hereditary Colorectal Cancer Comprehensive Multigene Panel

For the most comprehensive test to identify mutations in all genes linked to Hereditary Colorectal Cancer, Asia Genomics offers the Hereditary Colorectal Cancer Comprehensive Multigene Panel. This test covers genes that are linked to Lynch Syndrome, FAP, MAP, other high risk genes, as well as newer-risk genes that have been identified in families with colorectal cancer, but where precise lifetime cancer risks have not been identified.

This is carried out as a blood test ordered by your physician. Your DNA is extracted from the blood and analyzed. The test takes approximately four weeks to complete, and the results will be sent to your physician, who will explain the test results to you.

We will need two tubes of blood (about 4ml each) and a signed consent form from you to send to the laboratory. We recommend genetic counseling before genetic tests are ordered to discuss the implications of the testing and potential results.

If you would like more information or advice on any of our tests and services, please contact us at +65 6336 2050 or info@asia-genomics.com.