Colonic cancer screening in high risk groups

Alistair KingConsultant Gastroenterologist

BSG 2002

Family History One first degree relative diagnosed

<45yrs Two first degree relatives

diagnosed at any age Multiple generations affected

within family

NB Marginal benefit! (Grade B)

Screening protocol At presentation or aged 35-40yrs,

whichever is the later Repeat aged 55yrs

If polyps found polyp screening guidelines

Otherwise reassure

Risk

Age is a much stronger determinant! 70yrs with no FH: 4% risk in 10 years 40-60 with FH: 1.1% risk over 10 years

Other considerations 35-40yrs: 3618 colonoscopies to

prevent 1 death 55yrs: 213 colonoscopies to

prevent 1 death Colonoscopy perforation, bleeding,

mortality rate= 0.3%, 0.3% and 0.014%

Polyp surveillance Hyperplastic/metaplastic polyps

Predominantly small/rectal No malignant potential

Adenomas Malignant potential Number, size Average 10yrs cancer

Cut off age 75yrs

Conclusions FH – screening colonoscopy only

for those that fit the guidelines

Polyps Adenoma? Size? Number? Full colonoscopy? Age?