Sessile Serrated Polyp: Recommended Treatment
Complete endoscopic resection is the recommended treatment for sessile serrated polyps (SSPs) to prevent colorectal cancer, as these lesions account for 15-30% of colorectal cancers through the serrated pathway. 1
Understanding SSP Malignant Potential
SSPs are precancerous lesions with established cancer risk:
- SSPs represent the major precancerous serrated lesion, found in 8-9% of screening colonoscopies and predominantly located in the proximal colon 1, 2
- These lesions account for up to 30% of all colorectal cancers through the CpG island methylator phenotype (CIMP) pathway with BRAF mutations 1, 3
- SSPs with cytologic dysplasia are considered more advanced lesions in the polyp-cancer sequence and carry higher malignant potential 1
Treatment Algorithm by Size and Features
For SSPs ≥10 mm or with dysplasia:
- Complete endoscopic resection is mandatory using endoscopic mucosal resection (EMR) techniques 1, 4
- Inject-and-cut EMR technique is safe and effective, with local recurrence rates <5% when performed properly 4
- Resection should be performed by operators with expertise in managing large non-polypoid colorectal polyps, particularly for proximal lesions ≥10 mm 1
For SSPs <10 mm without dysplasia:
- Standard polypectomy techniques should be applied, though the flat morphology can make them difficult to grip 1
- Cold snaring is preferred for proximal colon lesions <10 mm 1
- Submucosal lifting and stiff snares may help with flat lesions 1
Post-Resection Management
Immediate follow-up:
- For piecemeal EMR of lesions ≥20 mm: site check at 2-6 months to assess for residual tissue 1
- For lesions 10-20 mm resected piecemeal: endoscopist discretion regarding 2-6 month site check versus standard surveillance 1
Surveillance strategy:
- SSPs ≥10 mm or with dysplasia: one-off surveillance colonoscopy at 3 years 1
- SSPs <10 mm without dysplasia: no clear indication for surveillance unless meeting criteria for serrated polyposis syndrome 1
Critical Pitfalls to Avoid
Incomplete resection is the major concern:
- Up to 50% of large SSPs may be removed incompletely with standard techniques, contributing to interval cancer risk 4
- SSPs are more difficult to detect than conventional adenomas due to flat morphology and absence of surface blood vessels 1
- Pathologist variability exists in differentiating hyperplastic polyps from SSPs, leading to inconsistent reporting 1
Endoscopic features predicting dysplasia:
- Nodules or protrusions on the surface suggest cytologic dysplasia within SSPs 5
- Lesions ≥6 mm have increasing rates of dysplasia: 6.0% for 6-9 mm polyps, 13.6% for ≥10 mm polyps 5
When Surgery is Indicated
Surgical resection should be considered when:
- Lesions are not amenable to complete endoscopic resection due to size, site, or technical factors 1, 6
- Segmental colectomy is strongly recommended for incompletely resectable SSPs given their malignant potential 6
- In serrated polyposis syndrome with unresectable lesions, surgery options include segmental colectomy, total colectomy with ileorectal anastomosis, or proctocolectomy 1
Important caveat: Even after surgical resection in serrated polyposis syndrome, all patients develop recurrent polyps in retained colorectum, requiring ongoing surveillance 7
Special Consideration: Serrated Polyposis Syndrome
For patients meeting WHO criteria for serrated polyposis syndrome: