Diagnosis and Treatment of Rectal Neuroendocrine Tumors (NETs)

Dae Kyung Sohn 대한외과학회 2021 대한외과학회 학술대회 초록집 Vol.2021 No.11

Colorectal Surgeon"s View

Dae Kyung Sohn 대한외과학회 2017 대한외과학회 학술대회 초록집 Vol.2017 No.11

Does hyaluronic acid stimulate tumor growth after endoscopic mucosal resection?

Sohn, Dae Kyung,Chang, Hee Jin,Choi, Hyo Seong,Jeong, Seung-Yong,Kook, Myeong-Cherl,Kim, Chan Gyoo,Choi, Il Ju Blackwell Publishing Asia 2008 Journal of gastroenterology and hepatology Vol.23 No.8

<P>Abstract</P><P>Background and Aim: </P><P>A submucosal injection of sodium hyaluronate is widely used for mucosal elevation in endoscopic mucosal resection (EMR) or endoscopic submucosal dissection procedures; however, the oncologic safety of sodium hyaluronate remains unknown. Hyaluronate is the main ligand for CD44 and this interaction was reported to promote tumor progression in <I>in vitro</I> or animal studies. This study aimed to evaluate the effects of sodium hyaluronate on tumor growth after EMR for gastrointestinal cancers.</P><P>Methods: </P><P>The study included 18 consecutive patients who underwent surgery for locally-recurrent or remnant gastrointestinal cancers after EMR from January 2001 to December 2006. The immunohistochemical expression levels of Ki-67, CD44, ErbB2, and epidermal growth factor receptor (EGFR) were evaluated in the primary tumor tissue and the recurrent tumor. The protein expression in recurrent or remnant lesions was also compared between the sodium hyaluronate group and non-sodium hyaluronate group.</P><P>Results: </P><P>Sodium hyaluronate was used in nine of 14 cases with EMR for gastric cancers and in one of four cases for colon cancers. The time to operation after EMR was 133 days (5–687 days). An analysis of the immunohistochemical expression levels between primary and recurrent or remnant tumors showed no significant differences in the expression levels of Ki-67, CD44, ErbB2, and EGFR with or without sodium hyaluronate.</P><P>Conclusions: </P><P>We found no evidence that sodium hyaluronate stimulates the growth of remnant tumors after EMR.</P>

Selection of Cap Size in Endoscopic Submucosal Resection with Cap Aspiration for Rectal Carcinoid Tumors

Sohn, Dae Kyung,Han, Kyung Su,Hong, Chang Won,Chang, Hee Jin,Jeong, Seung-Yong,Park, Jae-Gahb Mary Ann Liebert 2008 Journal of Laparoendoscopic & Advanced Surgical Te Vol.18 No.6

<P>BACKGROUND: Small rectal carcinoid tumors (<or=1 cm in diameter) can be treated by endoscopic resection, but complete resection may be difficult if tumors are located in the deep submucosal layer. This study was performed to identify the clinicopathologic factors affecting the complete resection of small rectal carcinoid tumors, using the endoscopic submucosal resection with cap aspiration technique (ESMR-C). MATERIALS AND METHODS: Forty-one consecutive patients with 42 rectal carcinoid tumors who underwent ESMR-C from October 2003 to November 2006 were assessed. Complete resection was defined as a clean margin that was free of tumor invasion at the lateral and inferior edges. RESULTS: The rate of complete tumor removal by ESMR-C was 85.7% and no complications occurred. The tumor size, location, and method of resection did not significantly affect the completeness of resection. Univariate analysis showed that the rate of complete resection was significantly higher when using 19.2-mm, compared with 13.9-mm, caps (96.0 vs. 70.6%; P = 0.032). Multivariate analysis showed that the cap size was an independent factor predicting the completeness of resection. CONCLUSION: The use of large-sized caps increases the completeness of the resection of rectal carcinoid tumors when using ESMR-C.</P>

Reducing the unexpectedly high rate of injuries caused by NOTES gastrotomy creation.

Sohn, Dae Kyung,Turner, Brian G,Gee, Denise W,Willingham, Field F,Sylla, Patricia,Cizginer, Sevdenur,Konuk, Yusuf,Brugge, William R,Rattner, David W Springer International 2010 Surgical endoscopy Vol.24 No.2

<P>Despite the wide range of natural orifice transluminal endoscopic surgery (NOTES) procedures reported to date using a transgastric endoscopic approach, complications associated with gastrotomy creation have not been described. This study was conducted to identify the incidence and types of complications related to gastrotomy creation with the needle knife puncture and balloon dilatation technique for NOTES access to the peritoneal cavity.</P>

Endoscopic assessment of tumor regression after preoperative chemoradiotherapy as a prognostic marker in locally advanced rectal cancer

Sohn, Dae Kyung,Han, Kyung Su,Kim, Byung Chang,Hong, Chang Won,Chang, Hee Jin,Baek, Ji Yeon,Kim, Min Ju,Park, Sung Chan,Oh, Jae Hwan,Kim, Dae Yong Elsevier 2017 Surgical oncology Vol.26 No.4

<P><B>Abstract</B></P> <P><B>Purpose</B></P> <P>This study was designed to evaluate tumor regression endoscopic criteria for predicting the post-chemoradiotherapy (CRT) prognosis of patients with locally advanced rectal cancer.</P> <P><B>Material and methods</B></P> <P>A total of 425 patients with rectal cancer who received radical surgery after CRT were included in this study. All patients were divided into two groups according to post-CRT preoperative endoscopic findings: 1) good response (E-GR): scar, telangiectasia, or erythema; 2) minimal or no response (E-MR): nodules, ulcers, strictures, or remnant tumor. Cox proportional hazard models were used to analyze the effect of preoperative clinicopathological variables on disease-free survival (DFS) and overall survival (OS).</P> <P><B>Results</B></P> <P>The independent prognostic factors for DFS were tumor location less than 5 cm from anal verge (hazard ratio [HR] 1.92, 95% confidence interval [CI] 1.27 to 2.88), pre-CRT carcinoembryonic antigen (CEA) > 5 ng/mL (HR 2.10, 95% CI 1.41 to 3.14), histologic high grade (HR 2.96, 95% CI 1.51 to 5.81), and E-GR (HR 0.26, 95% CI 0.08 to 0.83). The independent prognostic factors for OS were age over 65 years, tumor location, pre-CRT CEA, histologic grade, and E-GR (HR 0.13, 95% CI 0.02 to 0.99).</P> <P><B>Conclusions</B></P> <P>Post-CRT endoscopic findings were predictors of prognosis in patients with rectal cancer. If endoscopic findings are simultaneously used with certain preoperative prognostic factors, rectal cancer patients will potentially have more treatment options.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Endoscopic findings after chemoradiotherapy are an independent prognostic factor. </LI> <LI> Endoscopic good responses include scarring, telangiectasia and erythema. </LI> <LI> Endoscopic minimal responses include nodule, ulcer, stricture and remnant tumor. </LI> </UL> </P>

Validation of an automated adenoma detection rate calculating system for quality improvement of colonoscopy

Dae Kyung Sohn,Il Won Shin,Jeonghwa Yeon,Jin Yoo,Byung Chang Kim,Bun Kim,Chang Won Hong,Kyung Su Han 대한외과학회 2019 Annals of Surgical Treatment and Research(ASRT) Vol.97 No.6

Purpose: This study aimed to validate an automated calculating system developed for determining the adenoma detection rate (ADR). Methods: To calculate the automated ADR, the data linking processes were as follows: (1) matching the selected colonoscopy results with the pathological results, (2) matching the polyp number from colonoscopy with that from pathology and confirming the histopathological results of each colonic polyp, and (3) confirming the histopathological results, especially the adenoma status of each colonic polyp. To verify the accuracy of the automated ADR calculating system, we manually calculated the ADR for 3 months through medical record review. Accuracy was calculated by measuring the error rate for each value. The cause of error was analyzed by additional order and chart review. Results: After excluding 318 cases, 2,543 patients (1,351 men and 1,192 women; median age, 57.9 years) who underwent colonoscopy were included in this study. When the automated calculating system was used, polyps were found in 1,336 cases (52.6%) and adenomas were found in 1,003 cases (39.4%). When the manual calculating system was used, polyps were found in 1,327 cases (52.2%) and adenomas were found in 1,003 cases (39.4%). The accuracies of the polyp detection rate and ADR according to the automated calculating system were 99.3% and 100%, respectively. Conclusion: We developed a system to automatically calculate the ADR by extracting hospital electronic medical record results and verified that it provided satisfactory results. It may help to improve colonoscopy quality.

Feasibility of transanal total mesorectal excision in cases with challenging patient and tumor characteristics

Dae Kyung Sohn,Sung Chan Park,Min Jung Kim,Hee Jin Chang,Kyung Su Han,Jae Hwan Oh 대한외과학회 2019 Annals of Surgical Treatment and Research(ASRT) Vol.96 No.3

Purpose: To assess the feasibility of transanal total mesorectal excision in difficult cases including obese patients or patients with bulky tumors or threatened mesorectal fascias. Methods: We performed laparoscopy-assisted transanal total mesorectal excision in patients with biopsy-proven rectal adenocarcinoma located 3–12 cm from the anal verge as part of a prospective, single arm, pilot trial. The primary endpoint was resection quality and circumferential resection margin involvement. Secondary endpoints included the number of harvested lymph nodes and 30-day postoperative complications. Results: A total of 12 patients (9 men and 3 women) were enrolled: one obese patient, 7 with large tumors and 8 with threatened mesorectal fascias (4 patients had multiple indications). Tumors were located a median of 5.5 cm from the anal verge, and all patients received preoperative chemoradiotherapy. Median operating time was 191 minutes, and there were no intraoperative complications. One patient needed conversion to open surgery for ureterocystostomy after en bloc resection. Complete or near-complete excision and negative circumferential resection margins were achieved in all cases. The median number of harvested lymph nodes was 15.5. There was no postoperative mortality and 3 cases of postoperative morbidity (1 postoperative ileus, 1 wound problem near the stoma site, and 1 anastomotic dehiscence). Conclusion: This pilot study showed that transanal total mesorectal excision is also feasible in difficult laparoscopic cases such as in obese patients or those with bulky tumors or tumors threatening the mesorectal fascia. Additional larger studies are needed

The First Transcolonic Cholecystectomy in Korea

Dae Kyung Sohn,Seung-Yong Jeong,Yong Beom Cho,Ji Won Park,Woo Yong Lee,Gyu-Seog Choi,Ho-Kyung Chun 대한외과학회 2008 Annals of Surgical Treatment and Research(ASRT) Vol.75 No.1

Natural orifice translumenal endoscopic surgery (NOTES) is a new and rapidly evolving hybrid procedure in which the endoscope is introduced into the peritoneal cavity through the stomach, colon, vagina or urethra. A transcolonic approach is applicable for upper abdomen surgery. The present report describes a successful transcolonic cholecystectomy performed in a pig. The total operation time was 180 minutes. The pig survived without any complications for 7 days post-operatively. Necropsy after euthanasia showed no evidence of organ injury, bleeding or suppurative peritonitis, and it revealed that the colonic wall that had been incised and then closed using multiple endoscopic clippings was water-tight and air-tight. This is the first transcolonic cholecystectomy performed in Korea. This approach may represent a promising new method for performing NOTES.

Single Immunochemical Fecal Occult Blood Test for Detection of Colorectal Neoplasia

Dae Kyung Sohn,Seung Yong Jeong,Hyo Seong Choi,Seok Byung Lim,Jin Myeong Huh,Dae Hyun Kim,김대용,Young Hoon Kim,Hee Jin Chang,Kyung Hae Jung,Joong Bae Ahn,Hyun Kyung Kim,Jae Gahb Park 대한암학회 2005 Cancer Research and Treatment Vol.37 No.1

Purpose: This study was designed to investigate the validity of a single immunochemical fecal occult blood test (FOBT) for detection of colorectal neoplasia. Materials and Methods: A total of 3,794 average-risk screenees and 304 colorectal cancer patients admitted to the National Cancer Center, Korea, between May 2001 and November 2002, were studied prospectively. All screenees and admitted patients underwent FOBT and total colonoscopic examinations. Stools were self-collected, and examined using an immunochemical fecal occult blood test (OC-hemodia , Eiken Chemical Co. Tokyo, Japan) and an OC-sensor analyzer (Eiken Chemical Co. Tokyo, Japan). Results: Of the 3,794 asymptomatic screenees, the colonoscopy identified colorectal adenomas and cancers in 613 (16.2%) and 12 (0.3%) subjects, respectively. The sensitivities of a single immunochemical FOBT for detec- ting colorectal cancers and adenomas in screenees were 25.0 and 2.4%, respectively. The false positive rate of FOBT for colorectal cancer in screenees was 1.19%. For the total 316 colorectal cancer cases (including 12 cases from screenees), the FOBT sensitivities according to the T-stage were 38.5, 75.0%, 78.9 and 79.2% for T1, 2, 3 and 4 cancers, respectively. The sensitivities according to the Dukes stages A, B and C were 63.4, 79.3 and 78.6%, respectively. Conclusion: The sensitivities of a single immunochemical FOBT for detecting colorectal cancers and adenomas in screenees were 25.0 and 2.4%, respectively. The sensitivities of FOBT were about 80% for Dukes B or C colorectal cancers and 63.4% for Dukes A.