Surveillance colonoscopy after polypectomy – how frequent? Dr Chu Ming Leong Tuen Mun Hospital 1

Introduction  Colorectal cancer is the second commonest cancer in Hong Kong, third commonest cancer killer (Hong Kong Cancer Registry 2006)  Risk of colorectal cancer can be reduced by up to 90% after removal of adenomatous polyp (Winawer et al. NEJM 1993;329: )  Frequency for follow-up colonoscopy after polypectomy has much impact on allocation of clinical resources 2

Aim  To review on literature for evidence to give recommendations on surveillance interval after polypectomy for adenomas 3

Aim of surveillance  To detect any missed polyp in index colonoscopy  Tendency to develop new adenomas 4

Risk factors for recurrence of advanced adenoma  Multiplicity (≥ 3 adenomas)  Size (≥ 1cm)  Histological features (villous features, high grade dysplasia)  Incomplete index colonoscopy  Concurrent proximal and distal adenomas  Parental history of CRC 5

Risk factors for recurrence of advanced adenoma AuthorN% advanced adenoma recurrence Risk factors – recurrence of advanced adenoma: OR Yang et al % over 16yr FUVillous features: 8.1 ( ) Severe dysplasia 14.4 ( ) >1cm: 4.2 ( ) Winawer et al % at 3 yr 8% at 6 yr ≥ 3 adenomas: 5.2 ( ) Age ≥ 60 and parent with CRC 4.3 ( ) Noshirwani et al % at mean 18 month FU Polyp ≥ 1cm: 3.7 ( ) Each additional adenoma: 1.25 ( ) Martinez et al % at 3 yr>1cm: 2.3 ( ) Proximal colon: 1.7 ( ) Proximal and distal colons: 2.7 ( ) Liebermann et al % over 5.5 years>3 adenoma: 5.01 ( ) >1cm: 6.4 ( ) Villous adenoma: 6.05 ( ) HGD: 6.87 ( ) Cancer: ( ) 6

Surveillance interval  National polyp study (Winawer et al. NEJM 1993;328:901-6)  1418 patients with adenoma at index colonoscopy were randomized to receive surveillance colonoscopy in 1 and 3 years, and 3 years 7

Surveillance interval  No statistically significant difference in number of high risk polyps detected with less frequent interval  Advise for 3-yearly surveillance 8

Risk stratification and Surveillance interval  Atkin et al. NEJM 1992;326:  Cohort study of 1618 individuals with rectosigmoid adenomas (mainly detected with rigid sigmoidoscopy) with polypectomy  No colonoscopy was done  Average FU period was 14 years 9

Risk stratification and Surveillance interval 10 SIR 3.6, 95 %CI overall SIR 6.6, 95% CI, for multiple adenomas SIR 0.5 (95%CI, ) Suggested to FU as general population

Risk stratification and Surveillance interval Size of largest baseline adenoma No. of baseline adenoma Significant histology / size at surveillance (%) Development of multiple adenoma at surveillance (%) <1cm130.9 <1cm <1cm <1cm ≥4≥ ≥ 1cm ≥ 1cm ≥ 1cm ≥ 1cm ≥4≥ Noshirwani et al. Gastrointest Endosc 2000;51:433-7

Special cases  Incomplete colonoscopy  Inadequate bowel preparation  Large sessile lesion with piecemeal removal  Need earlier re-scope to confirm clearance before surveillance programme 12

After first surveillance…  No high level evidence for follow up programme after the first surveillance colonoscopy  Recommendations from professional bodies according to expert opinion 13

14 Atkin et al. Gut 2002;51(Suppl V): v6-9 Index colonoscopy Low risk 1-2 adenoma <1cm No high risk histological features Intermediate risk 3-4 adenoma, <1cm Or At least one ≥ 1cm High risk histological features High risk ≥ 5 adenoma, < 1cm Or ≥ 3 at least one ≥ 1cm AB C No surveillance or 5 yrs 3 yr 1 yr No adenomaNo FU Low risk adenomaA Intermediate risk B adenoma High risk adenomaC 1 negative examB 2 negative examsNo FU Low or intermediate risk B adenoma High risk adenomaC Negative, low or B Intermediate risk adenoma High risk adenomaC

Guidelines from U.S. OrganisationSolitary tubular adenoma < 1cm Multiple non- advanced adenomas Advanced adenomas Follow up American Society of Gastrointestinal Endoscopy 5 years3 years If normal at surveillance, FU no earlier than 5 years American Cancer Society 5-10 years (1-2 adenoma) 3-10: 3 years >10: within 3 years 3 yearsFor low risk group, if surveillance normal -> average risk screening For high risk group, Back to average risk screening if FU colonoscopy normal x 2 (3 yrly) American College of Gastroenterology 5 years (1-2 adenomas) 3 years If surveillance negative -> repeat 5 years Selected patients (old patients with co- morbidities) -> no FU 15

Conclusion  Optimal surveillance interval after polypectomy lacked conclusive evidence  Current guidelines were mainly based on result of few studies, knowledge on adenoma-carcinoma sequence and expert opinion 16

Take home message  Interval of surveillance is based on finding at index colonoscopy  Risk stratification by  Number  Size  Histology 17

Questions? 18

Thank you 19

Missed rate in colonoscopy 20 Rex et al. Gastroenterology 1997;112:24–28

Adenoma-Carcinoma Sequence 21 Normal Epithelium Early Adenoma Intermediate Adenoma Late Adenoma Invasive Cancer APCK-rasDCC SMAD 4 p53 DCC SMAD4

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Risk factors for recurrence of advanced adenoma  Saini et al. Gastrointestinal Endoscopy 2006;64:  Meta-analysis: incidence of advanced adenoma at 3 yr surveillance colonoscopy among high and low risk patients 23

24 RR of advanced adenoma at 3-year surveillance colonoscopy in patients with >=3 versus 1 to 2 adenomas at index colonoscopy RR of advanced adenoma at 3-year surveillance colonoscopy in patients with large (>=1 cm) versus small (<1 cm) adenomas at index colonoscopy.

25 RR of advanced adenoma at 3-year surveillance colonoscopy in patients with tubulovillous/villous versus tubular adenomas at index colonoscopy. RR of advanced adenoma at 3-year surveillance colonoscopy in patients with Non-mild dysplasia versus mild dysplasia at index colonoscopy

Risk factors for recurrence of advanced adenoma  Risk of advanced adenoma (statistically significant)  >= 3 adenomas (RR 3.26, 95%CI )  Non-mild dysplasia (RR 1.84, 95%CI )  Risk of advanced adenoma (trend)  Size >=1cm (RR 1.39, 95% CI )  Villous features (RR 1.26, 95% CI ) 26

Risk factors for recurrence of advanced adenoma  Most current literatures do not stratify patients according to risk factors  Few studies were selected: 15  Pooling data are only extracted from 5 studies 27

Genetic cancer syndromes  Separate surveillance programme 28 Age FAP Yearly3-5 Yearly OT if polyp develops Yearly1-2 Yearly