Usefulness of endoscopic submucosal dissection for the treatment of rectal carcinoid tumors

Efficacy of endoscopic submucosal resection with a ligation device for small rectal neuroendocrine tumor: study protocol of a multicenter open-label randomized control trial (BANDIT trial)

BACKGROUND

Endoscopic resection is widely accepted as a local treatment for rectal neuroendocrine tumors sized ≤ 10 mm. However, there is no consensus on the best method for the endoscopic resection of rectal neuroendocrine tumors. As a simplified endoscopic procedure, endoscopic submucosal resection with a ligation device (ESMR-L) indicates a histologically complete resection rate comparable to that of endoscopic submucosal dissection (ESD). We hypothesized that ESMR-L than ESD would be preferred for rectal neuroendocrine tumors. Hence, this trial aimed to verify whether ESMR-L is non-inferior to ESD in terms of histologically complete resection rate.

METHODS

This is a prospective, open-label, multicenter, non-inferiority, randomized controlled trial of two parallel groups, conducted at the Shizuoka Cancer Center and 31 other institutions in Japan. Patients with a lesion endoscopically diagnosed as a rectal neuroendocrine tumor ≤ 10 mm are eligible for inclusion. A total of 266 patients will be recruited and randomized to undergo either ESD or ESMR-L. The primary endpoint is the rate of en bloc resection with histologically tumor-free margins (R0 resection). Secondary endpoints include en bloc resection rate, procedure time, adverse events, hospitalization days, total devices and agents cost, adverse event rate between groups with and without resection site closure, outcomes between expert and non-expert endoscopists, and factors associated with R0 resection failure. The sample size is determined based on the assumption that the R0 resection rate will be 95.2% in the ESD group and 95.3% in the ESMR-L group, with a non-inferiority margin of 8%. With a one-sided significance level of 0.05 and a power of 80%, 226 participants are required. Assuming a dropout rate of 15%, 266 patients will be included in this study.

DISCUSSION

This is the first multicenter randomized controlled trial comparing ESD and ESMR-L for the R0 resection of rectal neuroendocrine tumors ≤ 10 mm. This will provide valuable information for standardizing endoscopic resection methods for rectal neuroendocrine tumors.

TRIAL REGISTRATION

Japan Registry of Clinical Trials, jRCTs042210124. Registered on Jan 6, 2022.

Efficacy of Endoscopic Resection for Rectal Neuroendocrine Tumors Smaller than 15 mm

BACKGROUND

Local resection, including endoscopic resection, is recommended for rectal neuroendocrine tumors (NETs) < 15 mm in patients without risk factors for metastasis, though the short- and long-term outcomes are unclear.

AIMS

This study investigates the efficacy of endoscopic resection for rectal NETs < 15 mm.

METHODS

The short- and long-term outcomes of patients with rectal NETs < 15 mm who underwent endoscopic resection and the outcomes of each endoscopic technique were analyzed. The tumors were stratified as < 10 mm (small-size group, SSG) and 10-14 mm (intermediate-size group, IMG).

RESULTS

Overall, 139 lesions (SSG, n = 118; IMG, n = 21) were analyzed. All tumors were classified as G1 (n = 135) or G2 (n = 4) according to the 2019 World Health Organization grading criteria. The complete resection rate was not different between the groups (P = 0.151). Endoscopic submucosal dissection (ESD) and endoscopic submucosal resection with a ligation device (ESMR-L) achieved complete resection rates > 90% in the SSG. The ESMR-L procedure time (P < 0.001) and hospitalized period (P < 0.001) were significantly shorter than those of ESD. ESD achieved a complete resection rate of 80.0% in the IMG. The tumor size did not affect the overall survival or rate of lymph node/distant metastases.

CONCLUSIONS

Endoscopic resection is a feasible and effective treatment for patients with rectal NETs < 15 mm without the risk factors of metastasis. ESMR-L and ESD are optimal techniques for resecting tumors smaller than 10 mm and 10-14 mm, respectively.

Endoscopic submucosal resection with an endoscopic variceal ligation device for the treatment of rectal neuroendocrine tumors

BACKGROUND

Endoscopic resection is recommended for rectal neuroendocrine tumors < 1 cm in diameter; the three techniques (mucosal resection, submucosal dissection, and mucosal resection with variceal ligation device) of endoscopic resection of neuroendocrine tumor were reported; however, the optimal endoscopic technique remains unclear.

PURPOSE

We compared the efficacy and safety of three endoscopic rectal neuroendocrine tumor resection methods.

METHODS

We retrospectively enrolled 52 patients with rectal neuroendocrine tumors treated by endoscopy at Aichi Medical University Hospital and Nagoya City University Hospital between May 2003 and June 2017. We compared clinical outcomes in three groups based on the endoscopic treatment method.

RESULTS

Fifty-two patients underwent endoscopic rectal neuroendocrine tumor treatment (mucosal resection, 14; submucosal dissection, 19; mucosal resection with an endoscopic variceal ligation device, 19). In the endoscopic mucosal resection, submucosal dissection, and mucosal resection with variceal ligation device groups, R0 resection occurred in 50.0, 94.7, and 89.5%, respectively (mucosal resection vs. mucosal resection with variceal ligation device, p < 0.05; mucosal resection vs. submucosal dissection, p < 0.01), while the median procedure times were 6.5, 43, and 6.0 min, respectively (submucosal dissection vs. mucosal resection with variceal ligation device procedure times, p < 0.01; mucosal resection vs. submucosal resection procedure times, p < 0.01). Postoperative bleeding occurred after endoscopic mucosal resection (1/14) and endoscopic submucosal dissection (4/19), but not after endoscopic mucosal resection with a ligation device.

CONCLUSION

Endoscopic mucosal resection with an endoscopic variceal ligation device was a safe, effective treatment for rectal neuroendocrine tumors.

Endoscopic submucosal dissection versus transanal local excision for rectal carcinoid: a comparative study

Aim

The aim of this study is to compare the short-term clinical outcomes between endoscopic submucosal dissection and transanal local excision for rectal carcinoid tumors.

Methods

Between 2007 and 2012, 31 patients with rectal carcinoid underwent endoscopic submucosal dissection at our hospital. They were compared with a matched cohort of 23 patients who underwent transanal local excision for rectal carcinoid between 2007 and 2012. Short-term clinical outcomes including surgical parameters, postoperative recovery, and oncologic outcomes were compared between the two groups.

Results

The mean size of tumors was significantly bigger in the transanal local excision group (0.8 ± 0.2 versus 1.1 ± 0.5 cm; P = 0.018). En bloc resection was achieved for 30 patients (97 %) in the endoscopic submucosal dissection group and all the patients in the transanal local excision group. The operation time was longer in the transanal local excision than that in the endoscopic submucosal dissection group (40.0 ± 22.7 min versus 12.2 ± 5.3 min; P < 0.001). Complications in the transanal local excision group were five cases of acute retention of urine. There was no local recurrence or distant metastasis in either group during the follow-up period.

Conclusion

For the treatment of rectal carcinoid tumors with diameter <1 cm, endoscopic submucosal dissection has better short-term clinical outcomes than transanal local excision in terms of faster recovery and possibly a lower morbidity rate. Transanal local excision may be the first therapeutic choice of scar-embedded rectal carcinoid tumors.

A comparison of endoscopic treatments in rectal carcinoid tumors

BACKGROUND

Various endoscopic techniques for rectal carcinoid tumors have been developed recently. In this study, we compared the outcomes of conventional endoscopic mucosal resection (EMR), strip biopsy, and EMR after circumferential precutting (EMR-P).

METHODS

From March 2004 to July 2014, the medical records of 188 patients (190 rectal carcinoid tumors) who were treated with an endoscopic procedure for rectal carcinoid tumors were investigated retrospectively. The characteristics of the patients and tumors, the selection of the treatment method, the rate of complete resection, and the rate of complications were analyzed retrospectively.

RESULTS

Forty-seven, 75 and 68 cases of EMR, strip biopsy and EMR-P were performed, respectively. The mean procedure time was not significantly different between the EMR, strip biopsy and EMR-P cases (5.6, 6.5 and 7.4 min, respectively, P = 0.119). En bloc resection was achieved in most of the cases (97.8, 98.7 and 95.5 % in the EMR, strip biopsy and EMR-P cases, respectively). However, histologic examination showed positive lateral or deep resection margins in 57 out of 190 cases (30.0 %). Multivariate analysis showed that the strip biopsy and EMR-P methods were independent factors for pathologic complete resection (negative in both lateral and deep resection margins), with odds ratios for margin involvement of 0.20 and 0.43 with 95 % confidence intervals from 0.08 to 0.47 and 0.19 to 0.96, respectively. In all the follow-up cases (81 of 190, 42.6 %), no local recurrence or distal metastasis was found.

CONCLUSIONS

Compared to conventional EMR, strip biopsy and EMR-P had a lower risk of incomplete resection. The procedure time and complication rate did not differ between the three groups, and no recurrence was detected during the follow-up period. Strip biopsy and EMR-P are safe and effective methods for the treatment of rectal carcinoid tumors.

Circumferential submucosal incision prior to endoscopic mucosal resection provides comparable clinical outcomes to submucosal dissection for well-differentiated neuroendocrine tumors of the rectum

BACKGROUND

Small rectal neuroendocrine tumors (NETs) can be treated with endoscopic resection. Endoscopic submucosal dissection (ESD) has been accepted as a reliable technique, but it is difficult. We evaluated the feasibility and efficacy of precut and endoscopic mucosal resection (CSI-EMR) for rectal NETs compared to ESD.

METHODS

Patients with rectal NETs were enrolled consecutively. ESD or CSI-EMR was performed at operator's discretion. Histological and clinical outcomes were measured and compared between the two treatment modalities.

RESULTS

Thirty-three patients were enrolled in the study. Seventeen NETs were treated by the ESD method and 16 were treated by CSI-EMR. Both groups had similar mean tumor diameters (ESD 7.53 ± 1.94 vs. CSI-EMR 6.63 ± 1.99 mm; p = 0.197). En bloc resection was achieved in 100 % of ESD group and 87.5 % of CSI-EMR group. Lateral margin involvement occurred in one patient in ESD group and two in CSI-EMR group. The histologically complete resection rate was 88.2 % (15 of 17) in the ESD group and 81.2 % (13 of 16) in CSI-EMR group (p = 0.592). One case of perforation occurred in both groups. Delayed bleeding did not occur. None of the measured outcomes were different between the two groups. Operating time was significant shorter in CSI-EMR group than in ESD group (9.69 vs. 20.12 min, respectively; p value = 0.004).

CONCLUSIONS

CSI-EMR results in reliable clinical outcomes for small rectal NETs comparable to those of ESD. CSI-EMR is technically feasible and more time saving.

Expanding indications for ESD: submucosal disease (SMT/carcinoid tumors)

Endoscopic submucosal dissection (ESD) is useful for submucosal tumors (SMTs) within the superficial submucosal layer, but perforation frequently occurs during ESD for SMTs located at the deeper layer. Endoscopic resection for small esophageal SMTs is acceptable, although candidates for endoscopic removal are rare. Laparoscopic assistance will be effective for minimally invasive endoscopic local resection for certain types of gastric SMT. Endoscopic mucosal resection with a ligation device would be better than ESD for rectal carcinoid in terms of simplicity and effectiveness.