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 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
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
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
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
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!!