Clinicopathologic characteristics that affect the treatment and recurrence of rectal carcinoid tumor in Korea.

684 Background: The increase of colonoscopy procedures has led to an increase in the diagnosis of rectal carcinoid tumors. The aim of this study was to evaluate the clinical and pathological characteristics that affect the treatment and recurrence of rectal carcinoid tumors. Methods: Between 2003 and 2014, the medical records of patients with rectal carcinoid tumors were retrospectively reviewed. Patient and tumor characteristics, treatment and recurrence were analyzed. Results: The mean age was 51.7 ± 11.7 (range, 22-80 years) and the male to female ratio was 1:0.58. The mean tumor size was 8.7 ± 4.9 (3-27) mm. Four hundred-seven out of 424 patients were treated by endoscopy (mean size of tumor: 8.6 ± 3.6 mm) and 17 were treated by surgery (mean size of tumor: 12.5 ± 5.7 mm, p = 0.023). However, the histology showed that 87 patients treated by endoscopy had positive resection margins; 68 cases (16.0%) had a polypectomy and 19 cases (4.4%) had a endoscopic mucosal resection (p = 0.033). The mean follow-up duration was 29.1 ± 31.3 months, and there were five recurrences of rectal carcinoid tumors.All cases of recurrence of rectal carcinoid tumor were successfully re-treated by additional endoscopic resection. Conclusions: Endoscopic resection was an effective method for the treatment of rectal carcinoid tumors. Moreover, even for small rectal carcinoid tumors, follow-up examination should be performed to evaluate for tumor recurrence.The recurrence of rectal carcinoid tumor should be successfully controlled by additional endoscopic resection.