Sessile serrated polyps, or SSPs, are associated with interval colon cancers. SSPs represent about 10% of colon polyps and have a "boot-shaped" histopathology. They are often incompletely resected, with around 50% of large SSPs (10-20mm) being incompletely removed. Recognizing and completely removing SSPs is important due to their relevance as markers for missed lesions and future neoplasia. Proper technique including retroflexion examination of the right colon can help increase detection rates. Follow-up recommendations after removal are similar to adenomas, with larger SSPs requiring surveillance in 3 years. Serrated polyposis syndrome,

1. Serrated polyps,
the canaries of the colon.
Recognition and management.
Douglas Riegert-Johnson, MD
Mayo Clinic Florida
Gastroenterology and Genetics
Riegertjohnson.douglas@mayo.edu
Florida GI Society - September 11, 2016
Open access to other slide sets on slideshare.net
Hyperlink
Additional slides at end of presentation.

2. They are associated with interval colon cancers.
Fortunately, interval cancers are uncommon.
(1 per 1075 colonoscopies® , 1 per 166 colonoscopy where adenoma found)
• Causes of interval colon cancer
– Not seen about ½ (50%)
– New lesions about ¼ (25%)
– Incomplete resection (19%)
– Failed biopsy detection (5%)
Systematic review and meta analysis of interval colorectal cancers: American J Gastro 2014.
Colorectal cancers soon after colonoscopy: a pooled multicohort analysis. Gut 2014
Relevance of Sessile Serrated Polyps

3. Scott Haldene
British physiologist 1860 - 1936
“Animal Sentinel”
Last use in the UK in 1986
“Colonic sentinel”
Red cap.
Increased likelihood
Interval colon cancer
Dr. Emina Torlakovic coined
the term sessile serrated A/P
Deadly CO in coal mines

4. Lifetime
odds of
colorectal
cancer
diagnosis
1/300 Postulated lower limit
(1/300 individuals have a hereditary syndrome
pre disposing to rapid polyp growth eg Lynch syndrome)
1/300
1/10
1/150
Lifetime colorectal cancer risk with no screening
Draining the Lake with Colonoscopy
Lifetime risk for patients in colonoscopy
program
All odds are approximated.
Relevance of SSPs
Illustrated with the lake of colorectal cancer risk
Risk Stratification
What is still left in the lake?
Polyps.
Not seen
Newly formed
Not completely removed

5. Proof of Relevance of SSPs
Risk Stratification for Colorectal Cancer in the future
Patients with serrated polyps had higher 10 year colon cancer risk than
patients with advanced adenomas (3.7% @ 10 years)
A population-
based randomized
trial, 12 955
individuals aged
50-64 years were
screened with
flexible
sigmoidoscopy.
Norway Gut 2014

6. Terminology
The classification of polyps is unnecessarily
confusing, conflicting and not clinically
relevant.
Sessile serrated adenoma or
sessile serrated polyp are both accepted.
Current trend is to use sessile serrated polyp.

7. 1 in 3 polyps is serrated, 1 in
10 polyps is a sessile serrated polyp
Colon polyps
30% Serrated
Polyps
10 % SSPs
Complete Adenoma Resection Study (CARE): Gastroenterology 2013

8. There are three types of serrated polyps
by pathology.
The boot. The red fern.The powder sugar cookie.

9. Hyperplastic polyp
“The powdered
sugar cookie”
Sessile Serrated
Polyp
“The boot”
Traditional serrated
adenoma
“The red fern”

10. This talk will focus on
sessile serrated polyps as they are
the most relevant to clinical practice.
Serrated polyposis syndrome (SPS)
will be discussed at end.

11. Recognition of Sessile Serrated Polyps
• Not detected by FIT, about ½ by sDNA+FIT
• SSP detection rate on colonoscopy –
about 2% (> 10 mm per 100 c- scope).
• Image enhanced endoscopy (e.g. NBI) no clear
benefit
• Colonoscopy technique
– Predominance in the right colon.
– Can try repeat examination of right colon (increase
ADR by 3%). Retroflexion no better than repeat examination.
– Mucus cap!
Image enhanced endoscopy for SSP http://www.ncbi.nlm.nih.gov/pubmed/27223636.
GIE 2013 Spain PrevColon 1.8% LSP rate.
Gut 2016 Sessile serrated adenoma detection rate in Italy (EquIPE study).
ADR increase by repeat forward examination of right colon:
Retroflexion no better than forward viewing. (http://www.ncbi.nlm.nih.gov/pubmed/21679946)

12. SSP completely and easily seen on retroflex.
Note mucus cap.

13. Same SSP, incompletely
seen with difficulty on
forward view.

14. Removal
How often are sessile serrated polyps
incompletely resected?
From the Complete Adenoma Resection study
(CARE Gastroenterology 2013, Vermont), what
percentage of sessile serrated polyps 10 mm –
20 mm were incompletely resected?
• A. 15%
• B. 30%
• C. 50%
Complete Adenoma Resection Study (CARE): Gastroenterology 2013

15. Removal
Answer: 50%
SSPs are often incompletely resected
• After complete polypectomy by visible
inspection, for small polyps 2 marginal biopsies
were taken adjacent to polypectomy site, for
large polyps 4 biopsies were taken.
• For large (10-20 mm) SSPs, 48% were
incompletely removed.
• For SSPs overall, 30% were not completely
resected (13/42).
• Of 346 neoplastic polyps removed by 11
gastroenterologists, 10% were incompletely
resected.
Complete Adenoma Resection Study (CARE): Gastroenterology 2013

16. Regrowth of sessile serrated
polyp at site of polypectomy in a
61 year old man with serrated
polyposis syndrome.

17. Sessile Serrated Polyp Case A
Beginning of margin biopsies.
(from DRJ practice)
• 54 yo female presented for first time
colonoscopy for colorectal cancer prevention.
• No family history of colorectal cancer.

18. Recognition

19. Recognition
Mucus cap

20. Review for other neoplasia
• 1 in 3 patients with an SSP will have an
adenoma
• DRJ: Before attempting to remove a large
suspected SSP, I always search for others!

21. Removal > 5mm
? Saline lift polypectomy,
Sometimes use contrast

22. Removal
cautery snare.
All visible polyp tissue removed.

23. Removal
Marginal bx

24. Removal
Sessile Serrated Polyp Case A Outcome
• Polyp found to be SSP.
• Marginal biopsies showed a fragment
suggestive of sessile serrated polyp.
Take away:
If possible, need a visible normal margin on
snare polypectomy.

25. Removal
• Most important step is removal of all visible polyp
tissue and attempt marginal bx.
• Margin biopsies
– Can complete an incomplete resection.
– Rapid and focused feedback to endoscopist.
– Clinical significance of microscopic residual polyp
unclear. Does a positive marginal mean closer follow
up is needed?
• Less data than the other option (APC to margin
APC to margin 2002).

26. Sessile Serrated Polyp Case B
After a year of margin biopsies.
DRJ practice
• 62 year old man. First colonoscopy.

28. Reminder to
Review for other
neoplasia

29. Return
Consensus recommendations for sessile serrated
adenomas and traditional serrated adenomas are similar
to that for adenomas
Histology Size Number Interval in years
SSA/P or TSA Large (≥10 mm) 1 3
SSA/P or TSA Small (<10 mm) 1 or 2 5
SSA/P or TSA <10 mm 3 or more 3
Serrated lesions: Recommendations from an expert panel 2012.
For any location. Piecemeal resection follow up 3-6 month.
Follow up for hyperplastic polyps included as addendum.

30. Return
What to do if pathology interpreted as
hyperplastic, when thought to be SSP?
• Recommendation:
Treat as a sessile serrated polyp.
• Reason: Dx of SSP varies by pathologist. 2014
Septin 9 study the % of polyps dx as SSPs
ranged from 0% to 9%.

31. Serrated Polyposis Syndrome (SPS)
* Any type of serrated polyp.
20 serrated polyps totaled all time,
any location in the colon.
WHO criterion 3. 80% of patients with
serrated polyposis meet this criteria,
remaining 20% meet Criterion 1.
WHO Criterion 1. At least 5 serrated polyps proximal
to the sigmoid colon, of which 2 measure at least
10 mm in diameter). 5 × 2 = 10.

32. Serrated polyposis syndrome is
uncommon (but not rare) and requires
yearly follow up
• About one in 150 patients in FIT based
colorectal cancer prevention programs.
• 1-year surveillance interval recommended by
US Multi-Society Task Force on Colorectal
Cancer and the European Society of
Gastrointestinal Endoscopy.
Serrated lesions: Recommendations from an expert panel.

33. Colonoscopy for family members of SPS patients is
recommended.
• First degree relatives of SPS should have
colonoscopy at age 40 or 10 years prior to
proband’s diagnosis of SPS
• 4/10 significant polyp, 1/7 will have serrated
polyposis syndrome Serrated polyposis family member
reference.

34. For most patients,
the cause of SPS is known
• Smoking causes SPS. Usually patients with hyperplastic SPS, rather than
sessile serrated polyps. Stopping smoking results in polyp regression.
• Genetic evaluation yield is very low, but is recommended in European
guidelines.
– Genetic DDX includes
• MYH associated polyposis (MAP) 0.8% SPS patients positive.
• Newly described genes, for which testing is not available (RNAF4
gene.)
• Patients can be referred to a genomic counselor using an online database
(www.nsgc.org).
• Without family history of colon cancer, and age >50 yo I usually do not
offer genomic testing.
MUTYH mutations in patients with hyperplastic polyposis syndrome. Gastroenterology. 2009.

35. Surgery not often needed for SPS
• Usually 3 colonoscopies needed to remove all
polyps.
• In patients were all polyps appear to have
been removed, follow up cancers are rare with
colonoscopy every year
(260 SPS pts, 2 had eventual CRC dx
1 CRC for about every 500 years of screening).
• TIP: Yearly colonoscopy should be scheduled
with the expectation of EMR.
Clinical risk factors for cancer in SPS. Dutch 2015.26603485.

36. Summary 5 R’s
• Sessile serrated polyps (adenoma) represent 1 in 10 colon
polyps, and have a “boot” histopathology.
• Relevance. SSPs may be canary signal to interval colon cancer
as they are associated with missed lesions
• Recognition. Repeat exam of the right colon increases yield ?
retroflexion.
• Review. If SSP found, other polyps are common so search for
them.
• Removal. Frequently incomplete, consider lift with cautery
snare with margin of normal tissue, ?marginal bx, ?APC.
• Return. Current recommendations for SSP surveillance are
similar to those for adenomas
– SSP more than or = 10 mm in size, follow up in 3 years
• Serrated polyposis syndrome (SPS) requires yearly follow up
colonoscopy and colonoscopy is recommended for family
members.

38. Supplemental Slides
Will not be discussed during talk

39. Relevance of SSPs
Lesions not seen:
Maybe SSPs themselves not so important,
but are markers for danger like canaries in a coal mine
• Low CA risk for sessile serrated adenomas
– Twenty-three large serrated polyps (>10 mm) found at
screening were left in situ for a median of 11.0 years. None
developed into a malignant tumour.
• Sessile serrated polyps as markers for present
and future neoplasia.
– Present : 1 of 3 colonoscopies where a SSA is found, a
conventional adenoma will also be found.
– Future neoplasia > Next slide.
Norway Gut 2014
2014 USA Septin 9 trial data on SAs per center

40. Norwegian Study
Conclusion
“The excess risk of
CRC in patients
with large serrated
polyps may not be
due to malignant
growth of the
serrated polyp, but
to a ‘field’-effect in
the patient with
these polyps.”
Norway Gut 2014
Macaronesia, home of the canary

41. My predictions for the future of clinical
management of SSPs
• For the individual large SSA, removed with the
optimal technique and negative marginal
biopsies close follow will not be needed.
Question: Is there malignant potential to the
individual SSP? SSP incomplete polypectomies,
really much ado about nothing.
• For the “field defect”, life long increased
surveillance with colonoscopy every ? 7 years.
APC following piecemeal polypectomy