Box 3.

Familial colorectal cancer

• A 31 year old man presented with rectal bleeding due to haemorrhoids and mentioned to his general practitioner that cancer ran in the family. The doctor took a family history and found that the patient's father had developed colorectal cancer at the age of 48 and his paternal grandmother at 60. His paternal aunt had developed endometrial cancer at 55. The doctor referred him to the regional genetics clinic on the basis of locally agreed guidelines. After confirmation of the family history, the patient's father was contacted and offered diagnostic genetic testing. His father was found to carry a mutation in the MLH1 gene which causes hereditary non-polyposis colorectal cancer. After genetic counselling the patient chose to undergo predictive genetic testing and was found to carry the same mutation. He now undergoes regular colonoscopic surveillance for the detection and removal of adenomatous polyps.