All cancers have hereditary factors which potentially increase risk; however, this is especially true in cancer of the rectum and colon, commonly known as colorectal cancer (CRC).
Currently, genetic causes have still not been identified in all types of cancer. However, there are cancers, including colorectal, in which several germline genetic mutations have already been identified, causing syndromes which increase the risk of developing colorectal cancer.
It is estimated that between five and ten in every hundred patients will develop colorectal cancer due to hereditary factors. Consulting a specialist in genetic counselling, who will determine whether genetic testing is appropriate, is recommended.
A positive test result, from what is a simple blood test, will determine a strategy for prevention or early diagnosis through continuous medical monitoring, including periodic consultations with gastroenterology specialists as well as screening tests, such as colonoscopy. Monitoring can save lives through detection of colorectal tumours at an early stage, with a survival rate of around 90 per cent.
There are different types of hereditary syndromes, the most common in colorectal cancer are considered to be: Lynch Syndrome, familial adenomatous polyposis, serrated polyposis, Peutz-Jeghers Syndrome and juvenile polyposis.
All of these display common features which should be considered:
Identification of these characteristics is the first step, and if indicated, genetic testing can confirm increased susceptibility to cancer in comparison to the general population. Detection of a mutation helps to identify which family members have inherited the genetic abnormality and, therefore, which have a higher risk of developing cancer.
At HC Marbella we provide genetic testing for hereditary colorectal cancer including for Microsatellite Instability and impaired DNA Mismatch Repair (MMR). This test is performed on a piece of a tumour to determine the risk of hereditary colorectal cancer and familial syndromes, such as Lynch Syndrome. Instability also results in tumours being sensitive to immunotherapy treatment.
Sources: Dr. José Miguel Rosales / HC Marbella / MSKKC / cancer.gov
January 9, 2020
Read other news