From the Guidelines
Subcentimeter rectal carcinoids (less than 1 cm) are typically managed with endoscopic resection as the primary treatment approach, with no further surveillance required after complete resection, as suggested by the most recent guidelines 1. The management of these small lesions is based on the size of the primary tumor, and endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) is usually sufficient and curative.
- Complete resection with negative margins is essential, and the specimen should be carefully examined for depth of invasion, lymphovascular invasion, and mitotic rate.
- For lesions with concerning features such as muscularis propria invasion, lymphovascular invasion, or high mitotic rate, additional imaging with rectal MRI or endorectal ultrasound should be considered to evaluate for lymph node involvement, as recommended by previous guidelines 2.
- In cases with high-risk features, surgical resection with lymph node evaluation may be necessary despite the small size.
- The excellent prognosis for subcentimeter rectal carcinoids (5-year survival >95%) is due to their low metastatic potential, but proper initial management and appropriate surveillance are crucial for optimal outcomes, with the most recent study suggesting surveillance with endoscopy and EUS or magnetic resonance imaging at 6 and 12 months for lesions between 1 and 2 cm in size 1.
From the Research
Management of Subcentimeter Rectal Carcinoid
- The management of subcentimeter rectal carcinoid tumors can be achieved through endoscopic treatment, with various methods reported, including conventional polypectomy, endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD) 3.
- A study comparing EMR using band ligation (EMR-B) with ESD for the endoscopic treatment of rectal carcinoid tumors found that both methods had similar complete resection rates, but EMR-B resulted in a shorter procedure time 4.
- The selection of endoscopic treatment should be made after considering factors such as cost-effectiveness, expertise, and experience 3.
- For small rectal carcinoid tumors (< 10 mm in diameter) without atypical features and confined to the submucosal layer, endoscopic resection is a suitable treatment option 5.
- Tumor size is a predictive factor for metastasis, and localized rectal carcinoids can be safely and effectively removed via minimally invasive resection 6, 7.
- The incidence of rectal carcinoids is rising, and with widespread colorectal cancer screening, the incidence of rectal carcinoids is expected to continue to increase 7.
- Endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) are effective methods for the treatment of small rectal carcinoid tumors, with ESD offering a higher complete resection rate for larger tumors 3, 4.