A 45-year-old gentleman read about colorectal cancer screening in a local newspaper. He is asymptomatic and has no history of per rectal bleeding, change of bowel habits or constitutional symptoms. He is a smoker and is obese with a body mass index (BMI) of 28kg/m2. He has a past history of non-alcoholic fatty liver disease. His brother died of colorectal cancer at the age of 54. He attends your clinic for advice on colorectal cancer screening. Physical examination is unremarkable.
•Afebrile, pulse 80 bpm, BP 120/80mmHg, SaO2 98-100% on RA.
•Hydration is satisfactory.
•Examination of the hands reveals no clubbing and normal-appearing palmar creases.
•Head and neck examination is unremarkable.
•Cardiovascular: HS dual, no murmur.
•His chest is clear on auscultation.
•Abdominal examination reveals a soft, non-tender abdomen, with no peritoneal signs.
•No signs of oedema.
–WBC 9 x 109/L;
–platelets 304 x 109/L.
•Liver and renal function tests are normal.
What are the risk factors for colorectal neoplasm in this patient?
•Male gender 1.
•Positive family history 1.
•Cigarette smoking 1.
•Fatty liver disease 2.
In general, when should colorectal cancer screening commence?
•A diagnostic work-up should be commenced immediately in symptomatic patients 1.
•In asymptomatic patients, the timing for starting screening depends on the risk.
–screening begins at age 50 years 1;
–screening begins at age 45 years in African Americans 1.
•Positive family history:
–one first-degree relative affected at age ≥60 3:
■average-risk screening but beginning at age 40 1;
–two or more first-degree relatives affected or one first-degree relative affected at age <60:
■colonoscopy beginning age 40 or 10 years earlier than the youngest diagnosis in the family, whichever is earlier 1;
–hereditary non-polyposis colorectal cancer (HNPCC): age 20 to 25 or 10 years before the youngest case in the immediate family 4;
–familial adenomatous polyposis (FAP): age 10 to 12 4.
An algorithm for colorectal cancer screening is outlined in Figure 34.1.