Treatment outcomes of endoscopic resection for rectal carcinoid tumors: an analysis of the resectability and long-term results from 46 consecutive cases.

Aim: In Japan, most of colorectal carcinoid tumors developed in rectum. The choice of treatment is important because surgical treatment may need to construct artificial anus. Although curative endoscopic resection (ER) is desirable from the point of quality of life, sufficient evidence of endoscopic treatment for rectal carcinoid tumors is not fully obtained.

Methods: Between April 2001 and August 2013, 46 rectal carcinoid tumors in 46 patients who underwent either with endoscopic mucosal resection with a ligation device (EMR-L) or endoscopic submucosal dissection (ESD) were analyzed retrospectively. The rates of en bloc resection, positive for lateral and/or vertical margin, curative resection, local recurrence, additional treatments, overall and disease-specific survival rate after ER were evaluated during follow-up (median observation period 61.6 months).

Results: Twenty-two lesions were treated by EMR-L and 24 lesions were treated by ESD. Both groups had similar mean tumor size (EMR-L: 6.2 mm, ESD: 6.0 mm). The rate of en bloc resection, negative for both lateral and vertical margins, and curative resection were, respectively, 73%, 63%, and 50% for EMR-L, 100%, 100%, and 83% for ESD. These results suggested that the rate of resectability and curability for ESD was significantly higher than EMR-L (p < 0.05). Complications such as perforation and bleeding did not occur in both groups. Fifteen patients were judged as non-curative and 3 patients underwent additional surgery and lymph node metastasis was evident in 1 patient. Remained 11 patients were carefully followed-up, and so far no obvious recurrence was found. Thirty-two patients (84%) were eligible for long-term follow-up and 5-year overall and disease-specific survival rates were 100% and 100%, respectively.

Conclusion: The long-term outcomes of ER for rectal carcinoid tumors were excellent. ESD has advantage for resectability and curability compared with EMR-L; therefore, ESD is more favorable procedure as treatment for rectal carcinoid tumors.