Colonoscopy; Surveillance Indications

SR Brown

Colorectal Surgeon

Sheffield Teaching Hospitals

Colorectal cancer screening in high risk groups

Gut 2002;51(Suppl V)

Screening vs Surveillance

• Screening– Asymptomatic population

• Surveillance– Previous symptoms/high risk

High risk groups

• Previous colorectal cancer

• Acromegaly

• Ureterosigmoidostomy

• Hereditary and Familial bowel cancer

• IBD

• Previous polyps

Aims

• To discuss salient aspects of guidelines

• To highlight recent developments in colonoscopic surveillance

Colorectal cancer surveillance

Colorectal cancer surveillance; aims

• Detect recurrence

• Diagnose and treat metachronous neoplasia

• Evaluate anastomosis

Colorectal cancer surveillance

• ‘Incidence metachronous tumours 5-10%’

• Metachronous cancers – approx. 2%– Cochrane review 1.3% (18/1342)

• Metachronous adenomas– 22% (425/1923)

Colorectal cancer surveillance

• Synchronous/‘early’ metachronous cancers– 4%– 0.6% ‘missed’ due to incomplete colon exam

Familial cancer surveillance

Familial Cancer Summary

Family group Screening procedure

Age at initial screen Screening procedure and interval

2 FDR with CRC

Colonoscopy

At 1st consult or age 35-40 years (whichever later)

If initial clear repeat at age 55

1 FDR<45 yr with CRC

Colonoscopy

At 1st consult or age 35-40 years (whichever later)

If initial clear repeat at age 55

Lifetime risk of colorectal cancer

Risk Group Risk (of dying)

General population 1:50

Any family history 1:17

One affected relative <45 years

1:10

Two affected relatives 1:6

Houlston et al. 1970

Familial Cancer Summary

Family group Screening procedure

Age at initial screen Screening procedure and interval

2 FDR with CRC

Colonoscopy

At 1st consult or age 35-40 years (whichever later)

If initial clear repeat at age 55

1 FDR<45 yr with CRC

Colonoscopy

At 1st consult or age 35-40 years (whichever later)

If initial clear repeat at age 55

Chances of preventing death with screening colonoscopy

35 year old with FDR<45 years

• 1 in 25,000 people aged 30-39 develop colorectal cancer per year

• Relative risk = 5

• Risk of cancer = 1 in 5000 in per year

• Assume asymptomatic cancer dwell time of 3 years

• Chance of detecting cancer 1 in 1660

Familial Cancer Summary

Family group Screening procedure

Age at initial screen Screening procedure and interval

2 FDR with CRC

Colonoscopy

At 1st consult or age 35-40 years (whichever later)

If initial clear repeat at age 55

1 FDR<45 yr with CRC

Colonoscopy

At 1st consult or age 35-40 years (whichever later)

If initial clear repeat at age 55

Chances of preventing death with screening colonoscopy

55 year old with FDR<45 years

• 1 in 1,630 people aged 50-59 develop colorectal cancer per year

• Relative risk = 3

• Risk of cancer = 1 in 543 per year

• Assume asymptomatic cancer dwell time of 3 years

• Chance of detecting cancer 1 in 181

Hereditary cancer surveillance

Hereditary Cancer Summary

Family group Screening procedure

Age at initial screen

Screening procedure and interval

FAP Genetic testing Flexi sig+OGD

Puberty Flexi sig yearly

Colectomy if +ve

HNPCC Colonoscopy +/- OGD

25 yrs or 5 yrs before earliest CRC in family

2 yearly colonoscopy and OGD

Juvenile polyposis

Peutz-Jegher

Genetic testing

Colonoscopy + OGD

Puberty Flexi sig yearly

Colectomy if +ve

IBD surveillance

IBD Summary

Disease group Screening procedure

Age at initial screen Screening procedure and interval

UC or Crohn’s coloitis

Colonoscopy+ biopsies every 10cm

After 8 years for pan colitis, 15 years for left sided colitis

3 yrly 2nd decade, 2yrly 3rd decade, yrly thereafter

UC + PSC Colonoscopy

At diagnosis PSC Annually

Controversies

• ? Survival advantage (Cochrane review 2004)– No clear evidence – May allow earlier detection of cancer– ?lead-time bias

Controversies

• Ongoing inflammation increases risk

• Dysplasia as a marker for cancer– Reliability– Detection– Histological interpretation

Controversies;detection

• Pan-chromoscopy and targeted biopsy (Rutter 2004)– Back-to-back colonoscopy– Conventional then dye-spray– Conventional no dysplasia in 2904 random

biopsies– Targeted 157 biopsies 7 patients with dysplasia

Ileo-anal pouch surveillance

Pouch cancer

• 15 case reports – 10 residual rectal mucosa– 5 ??pouch mucosa– All pre-existing dysplasia– 8 had cancer in original resection– 9 had mucosectomy

Surveillance recommendations

• Pouchoscopy

• 1st year then 2-3 yearly

• Increased surveillance (yearly) if– Pre-existing dysplasia/cancer– PSC

• Mucosectomy if high risk

Polyp surveillance

Summary

• Read guidelines!!