Everyone who is diagnosed with colorectal cancer should be tested for an inherited genetic condition called Lynch syndrome (LS), NICE has recommended in new draft guidance published for consultation.
LS is the most common cause of hereditary bowel cancer, and people with it also have an increased risk of developing other cancers including womb, ovarian and stomach. Testing for the condition helps to identify whether the patient’s family may also be at increased risk of cancer, meaning they could be monitored more closely if needed.
The draft guidance recommends that microsatellite instability testing or immunohistochemistry should be used to detect abnormalities that might mean the presence of LS.
Where these tests show the person has a risk of having LS the draft guidance recommends further tests are carried out to confirm the diagnosis. Because LS is an inherited condition, a positive test can lead to testing for family members.
Diagnosing LS may also help with the choice of treatments for colorectal cancer; for example, to direct chemotherapy or surgery.
People with LS who develop colorectal cancer generally do so at a younger age, usually between the aged of 40-50 or younger.
Expanding testing to all people with colorectal cancer will increase the detection of LS and identify families who could benefit from genetic testing to determine if other family members have the condition. This could lead to increased surveillance and consequently improved patient outcomes through earlier diagnosis and treatment.
LS accounts for about 3.3% (1 in 30) of colorectal tumours, and the condition is estimated to lead to more than 1,100 colorectal cancers a year in the UK. An estimated 175,000 people in the UK have LS, a large proportion of whom will be unaware that they have the condition.
Professor Carole Longson MBE, Director of the Centre for Health Technology Assessment at NICE, said: “While these tests have been available for a while the committee heard that there is currently wide variation in the provision of testing for Lynch syndrome and other inherited colorectal cancers; it is estimated by Bowel Cancer UK that only 50% of centres provide tests to assess the risk of Lynch syndrome in people diagnosed with colorectal cancer under the age of 50.
“The committee concluded that using these tests to assess the risk of Lynch syndrome in all patients diagnosed with colorectal cancer could have substantial benefits for patients and their families.”
Deborah Alsina MBE, Chief Executive of Bowel Cancer UK, said: “Lynch syndrome has a devastating impact on families. We hear every day how generations have been affected by cancer because of this genetic condition. By testing everyone diagnosed with colorectal cancer we can identify more people who have Lynch syndrome and ensure they receive regular colonoscopy, which can reduce their chance of dying from bowel cancer by up to 72%.”