It is important to note that all new bowel cancer (colorectal adenocarcinoma) diagnoses should now have a reflex tumour-based test, which looks for changes which might suggest Lynch syndrome.
Lynch is the most common inherited bowel cancer condition. This test will be arranged in secondary care and should allow more families with Lynch syndrome to be detected.
Lynch syndrome
Testing for Lynch syndrome – what you need to knowColorectal polyposis
Familial Adenomatous Polyposis (FAP) is much rarer than Lynch syndrome.
This condition, plus other rare inherited polyposis conditions, generally present with multiple (>10 polyps) of the large bowel.
Such patients should generally be flagged in secondary care for genetic testing to be considered, plus familial screening recommendations.
Do seek advice from genetics if this does not appear to have considered.
Family history of bowel cancer
If your patient is concerned about having a strong family history of bowel or related cancers, please use the following referral guidelines to determine whether a referral to clinical genetics is indicated.
All relatives used in a risk assessment should be on the same side of the family unless otherwise stated.
If you are not sure about a referral indication based on the structure below, please contact the genetics department, including via advice and guidance.
Population (low) risk
No genetics referral or further advice indicated:
- 1 fdr diagnosed with bowel cancer over the age of 50 years
Risk possibly increased
Refer for further assessment, ideally with completed FHQ:
- 1 fdr diagnosed when under 50 years
- 2 fdr diagnosed at any age (includes both parents)
- 1 fdr and 1 sdr diagnosed at any age
- 3 or more relatives diagnosed at any age
- A family history of a known hereditary colorectal cancer syndrome eg. Lynch syndrome*, Familial Adenomatous Polyposis (FAP), Peutz-Jeghers syndrome (PJS), MYH-associated Polyposis
Lynch-related cancers include endometrial, gastric, ovarian, pancreatic and urothelial cancers.
- fdr = first degree relative (parent, sibling or child)
- sdr = second degree relative (grandparent, aunt/uncle or grandchild)
