Positive Lateral Margin Research Articles

931 Surveillance of Duodenal Carcinoids and the Importance of Tumor Margins: A Single Center Retrospective Study at the Moffit Cancer Center

INTRODUCTION: The incidence of gastrointestinal neuroendocrine tumors (GI-NETs) is increasing in recent times reflecting the widespread use of endoscopy, and an increased awareness among clinicians. Duodenal carcinoids are rare and accounting for 1%-3% of primary duodenal tumors. Duodenal carcinoids < 10 mm in size and limited to the submucosal layer are amenable for endoscopic resection. Despite the increase in incidence, the natural history of duodenal carcinoid tumors has not yet been well defined. The aim of our study was to evaluate the recurrence rate following endoscopic resection of well differentiated duodenal carcinoid tumors from 2006-2016 at our institution. METHODS: We performed a retrospective analysis on 39 patients who underwent endoscopic resection of duodenal carcinoids from 2006-2016 at the Moffitt Cancer Institute. The indications for endoscopic resection were lesions ≤ 10 mm in diameter, confined to the submucosal layer, and without lymph node or distant metastasis. Endoscopic resection was accomplished using endoscopic mucosal resection (EMR) and biopsy forceps. The patients were followed for a mean of 3 years. RESULTS: Among the 39 patients meeting criteria for endoscopic resection, 28 patients underwent surveillance endoscopies post EMR and were included in final analysis . EMR was performed in 12 tumors while biopsy forceps resection in 11 patients. Pathological complete resection(R0) was achieved in 20 patients (71%), without evidence of recurrence in 9 (45%) patients followed for at least 3 years and in the 11(55%) patients followed for lesser than 3 years. On the contrary, in the 8 patients (28%) had recurrence in the 3 year follow up period of which that was recurrence,6 (75%) had either positive lateral or deep margins on initial resection (Table 1). There were no post procedural complications in any of the patients in the follow up period. CONCLUSION: Endoscopic resection appears to be a safe and effective treatment for duodenal carcinoid tumors measuring ≤ 10 mm in diameter and confined to the submucosal layer. This retrospective study showed that the main predictor of recurrence is the presence of positive tumor margins at initial resection. Patients with negative and margins had no recurrences in the 3 year follow up period, thus alleviating the need for long term surveillance in this patient population. Larger multicenter studies are required to determine the optimal surveillance stragey in patients undergoing endoscopic resection of duodenal carcinoid tumors.

Is additive treatment necessary for patients with a positive lateral margin after endoscopic submucosal dissection of early gastric cancer?

Is additive treatment necessary for patients with a positive lateral margin after endoscopic submucosal dissection of early gastric cancer?

Mo1216 WIDE-FIELD ENDOSCOPIC SUBMUCOSAL DISSECTION FOR THE TREATMENT OF NEOPLASTIC BARRETT’S ESOPHAGUS (WF-ESD)

Identification and delineation of Barrett’s esophagus (BE) neoplasia is challenging even in referral centers using enhanced endoscopy. Endoscopic submucosal dissection (ESD) for the treatment of BE neoplasia has been reported in some small series with suboptimal results, mostly due to positive lateral resection margins. From 2015 our center started to perform wide-field ESD (WF-ESD) of neoplastic BE. With this new approach resection is performed, as described for wide-field colorectal EMR, with wider (5-10mm) free margins, after careful BE assessment. We aim to compare the outcomes of WF-ESD for resection of BE neoplasia comparing it to conventional ESD (C-ESD).

Clinical feasibility of endoscopic submucosal dissection with minimum lateral margin of superficial esophageal squamous cell carcinoma.

Background Esophageal stricture following endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell cancer (SESCC) has been associated with wide mucosal defects greater than three-quarters of the luminal circumference. Some patients developed dysphagia and required repeated endoscopic balloon dilation even after steroid therapy. As iodine staining clearly visualized the margin of SESCC, we made a longitudinal mucosal incision close to the margin of the lesion to avoid a mucosal defect involving over three-quarters of the luminal circumference for large lesions. This retrospective study aimed to clarify the clinical feasibility of ESD with minimum lateral margin of SESCC. Patients and methods Between 2005 and 2013, 94 patients with 94 initial SESCCs had lesions greater than half of the luminal circumference. Of those, 70 patients with 70 SESCCs had achieved endoscopic clearance for the initial SESCC. In this study, endoscopic clearance was defined as en bloc resection of SESCC histologically confined to the mucosa without lymphovascular invasion and with a free deep margin regardless of the lateral margin. This study evaluated the short- and long-term outcomes in patients undergoing endoscopic clearance. Results In total, 61.4 % (43/70) of the patients had mucosal defects involving over three-quarters of the luminal circumference and 38.5 % (27/70) had a positive or indeterminate lateral margin. However, there was no local or nodal recurrence during the median follow-up period of 3.8 years; the 3-year overall survival rate was 98.5 % and the 3-year disease-free survival rate was 100 %. Conclusion Using our institutions’ strategy, ESD for SESCCs with minimum lateral margins was oncologically acceptable; this approach could reduce the known risk factor of post-ESD stricture.

The relationship between local recurrence and positive lateral margin after en bloc resection of colorectal neoplasm

Background: The factors associated with recurrence of colonic neoplasm after endoscopic resection with a positive lateral margin are not well known. Thus, we evaluate the relationship between recurrence and positive lateral margin after endoscopic en bloc resection of colorectal neoplasm.Methods: A retrospective review of 9302 patients who underwent colonic endoscopic resection from January 2008 to January 2015. Of these, a total of 76 patients with positive lateral margins with clear evidence of the its location on endoscopic picture after endoscopic en bloc resection of colorectal neoplasm (>10 mm) were included.Results: Ten of 76 (13.2%) patients experienced recurrence during the follow-up period (mean f/u month, 21.7 ± 15.6). In cases with positive lateral margins, the 3- and 5-year local recurrence rate of colorectal neoplasm was 28.1% and 40.1%, respectively. The histological features of the recurrence group were as follows: one case of adenocarcinoma [from low-grade adenoma (LGA)]; two cases of high-grade adenoma (HGA) (one from HGA and one from LGA); and seven cases of LGA (four from adenocarcinoma, two from LGA, and one from HGA). The mean age of patients, locations of the lesions, and histologic type were not significantly associated with local recurrence. In multivariate Poisson regression analyses, total length of lateral margin involvement ≥8 mm (relative risk 12.51; 95% CI 1.11–140.34, p = .040) was a significant predictor of local recurrence.Conclusions: Positive lateral margins ≥8 mm may be a reliable predictor of local recurrence after endoscopic en bloc resection of colorectal neoplasm.

RA08.01: WIDE-FIELD ENDOSCOPIC SUBMUCOSAL DISSECTION IN THE TREATMENT OF BARRETT’S ESOPHAGUS NEOPLASIA (WF-ESD)

Abstract Background The role of ESD on Barrett's esophagus (BE) neoplasia has been studied in some small series with suboptimal results, mainly due to positive lateral margins (LM). We started ESD of neoplastic BE on 2011. Due to early suboptimal results because of positive lateral margins (LM), we decided to start performing wide-field ESD of Barrett's neoplasia from 2015. With the new approach resection is performed, as described for wide-field colorectal EMR with wider (5–10mm) free margins, after careful BE assessment. Our aim was to evaluate the feasibility, safety and efficacy of wide field ESD (WF-ESD) for resection of BE neoplasia comparing it to conventional ESD (c-ESD). Methods We asessed the patients and tumor characteristics and technical issue in all ESDs compared with c-ESD with WF-ESD. In order to reduce stricture risk, from 2015, oral steroids were used in patients with more than 3/4 resection of all circumferential lumen of the esophagus. The primary outcomes were the rates of en bloc, R0 and curative resection rates. The secondary outcomes were the rate of negative LM and adverse events rate such as bleeding, perforation and stricture rate. This study was approved by the Stockholm Regional Ethical Committee (2013–596-31). Results Total sixty-four consecutive ESD cases of early Barrett neoplasia were performed in 50 patients in our center between 2011–14 and 2015–17. The mean age was 67.1 ± 9.9 vs 67.2 ± 10.0, the male/female was 13/6 vs 25/6 in c-ESD and WF-ESD. In primary outcomes, en-block resection rate was 91.3 vs 100% (21/23 vs 41/41), R0 resection rate was 69.6 vs 85.4% (16/23 vs 35/41), curative resection rate was 56.5 vs 78.0% (13/23 vs 32/41) (P > 0.05). In the secondary outcomes, negative rate in LM was 26.1 vs 2.4% (6/23 vs 1/41), adverse event rate including perforation and bleeding was 4.3 vs 9.8%(1/23 vs 4/41) and stricture rate was 21.7 vs 2.4% (5/23 vs 1/41) with P < 0.01 for LM and P < 0.05 for stricture rate. Conclusion Wide field ESD is associated with improved efficacy and good safety profile in the treatment of neoplastic BE. More studies are necessary to confirm its role in the management of BE. Disclosure All authors have declared no conflicts of interest.

Trans-anal minimally invasive surgery for rectal neoplasia: Experience from single tertiary institution in China.

AIMTo evaluate the feasibility and safety of trans-anal minimally invasive surgery (TAMIS) from single institute in China.METHODSA retrospective review was conducted for patients with rectal neoplasia, who underwent TAMIS using single incision laparoscopic surgery-Port from January 2013 till January 2016 by a group of colorectal surgeons from Gastrointestinal Center Unit III, Peking University Cancer Hospital. Patients’ demographic data, surgical related information, post-operational pathology, as well as peri-operative follow-up were all collected.RESULTSTwenty-five patients with rectal neoplasia were identified consequently. Complete full-thickness excision was achieved in all cases without conversion. 22 (88%) cases had rectal malignancies [6 were adenocarcinomas and 16 were neuroendocrine tumors (NET)], while 3 patients had adenomas. Mean surgical duration was 61.3 min, and mean post-operative stay were 2.7 d. Post-operational examination demonstrated 5 cases had positive resection margin: 2 adenocarcinoma cases and 1 NET case with positive lateral margin, and the other 2 NET cases with positive basal margin. The curve of operation time for TAMIS cases suggested a minimum of 10 cases for a laparoscopic surgeon proficient with this technique.CONCLUSIONTAMIS was demonstrated to be reproducible and safe, with a relatively short learning process for laparoscopic surgeons in selected cases for rectal neoplasia. Long-term oncological outcome needs to be determined by further investigation.

Local or extragastric recurrence after incomplete endoscopic submucosal dissection of early gastric cancer: risk factors and the role of CT.

To investigate the risk factors of local and extragastric recurrence after incomplete endoscopic submucosal dissection (ESD) of early gastric cancer and the role of CT in the surveillance of extragastric recurrence. Institutional review board approval was obtained for this retrospective study with waiver of informed consent. From January 2005 to April 2017, 2086 ESDs were performed. Among them, 202 patients who received incomplete ESDs with positive lateral or deep margins comprised our study population(M:F = 108:94, mean age = 63.3years). Histopathology, size and depth of the tumor, margin status, and the presence of lymphovascular invasion(LVI) were recorded. The patients were followed-up for a mean period of 38.5months (range 0.8-139months). Univariate and multivariate statistical analyses were performed to assess the risk factors of local and extragastric recurrence. 96 patients had (+) lateral margins, 90 had (+) deep margins and 16 had (+) lateral and deep margins. On subsequent surgery and follow-up, local gastric recurrence was found in 54 patients and extragastric recurrence was present in 13 patients. On multivariate analysis, (+) lateral margin [hazard radio (HR) 6.002; P < 0.0001] and tumor size(HR 1.372; P = 0.009) were demonstrated to be significant risk factors for local recurrence and (+) LVI was shown to be the only significant variable for extragastric recurrence(HR 6.798, P = 0.002). A positive lateral margin and tumor size were significant risk factors for local recurrence while positive LVI was shown to be the only significant variable for extragastric recurrence. Therefore, if LVI is positive in patients who received incomplete ESD, subsequent surgery or follow-up with CT is recommended.

Sa1263 LONG-TERM OUTCOME OF EARLY GASTRIC CANCER WITH LATERAL MARGIN POSITIVE AFTER ENDOSCOPIC RESECTION

The positive lateral margin after endoscopic resection(ER) of early gastric cancer(EGC), additional surgery or endoscopic submucosal dissection(ESD) are recommended. However, the additional surgery often difficult due to advanced age or patient’s comorbid conditions. The aims of this study is to investigate of long term outcome in patients with positive lateral margin after ER. We analyzed retrospectively 103 patients with positive lateral margin after ER from January 2005 to December 2015, in single tertiary center. Clinicopathological data were retrieved to assess the local recurrence rate, survival rate, procedure related adverse events. Of the 103 patients, 27 patients (26.4%) underwent re-do ESD in 17 patients and additional surgery in 10 patients within 3months. And 76 patients (73.6%) were observed under close surveillance. Median duration of follow-up period was 45.7(6-132) months. Recurrence rates of early re-treatment group(3.7%, n=1/27) was lower than surveillance group(18.4%, n=14/76; p=0.05). five-year survival rates not significantly different between the two groups, at 100%, 97.4% respectively. In close surveillance periods, 14 patients were confirmed to local recurrence by follow-up biopsy, then delayed re-treatment was performed. (7 patients in re-do ESD, 5 patients in surgery, mean time after initial ER=27.5months) Finally, a total of 24 patients were treated with re-ESD, and 17 patients were treated with additional surgery. Among these two groups, there were no significant difference in recurrence rates(8.3% vs. 0%) and five-year survival rates(both 100%). However, adverse events that related to treatment was more frequent in additional surgical group(2 ileus, 1 umbilical hernia). The additional treatment should be recommended for patients with positive lateral margin after initial ER for EGCs. In addition, re-ESD which have a similar efficacy and a better quality of life, compared to additional surgery is a favorable option for control of recurrence or residual EGCs.

Mo1689 LONG-TERM CLINICAL OUTCOMES OF PATIENTS WITH INDETERMINATE OR POSITIVE LATERAL MARGIN AFTER COMPLETE ENDOSCOPIC RESECTION AND RELATED FACTORS WITH RECURRENCE IN LARGE, SESSILE OR FLAT COLORECTAL POLYPS

Although incomplete resection in recognized as an important contributor to recurrence, recurrence rate in lesions with indeterminate or positive lateral margin on histology is unclear. We evaluated the long-term clinical outcomes of patients with indeterminate or positive lateral margin after complete endoscopic resection and related factors with recurrence in large, sessile or flat colorectal polyps. We retrospectively collected the data for 156 lesions (135 patients, males 102 (65.4%), mean age 64.9 years) with large size (≥10 mm), sessile or flat shape, indeterminate or positive lateral margin in histology and more than 24 months of follow-up intervals between Jan 2009 and Sep 2017. We retrospectively analyzed recurrence rate, time to recurrence, histology at recurrence and risk factors related with recurrence in these lesions. Of 156 neoplastic polyps, 97 lesions (62.2%) were indeterminate and 59 lesions (37.8%) were positive in lateral margin, respectively. During follow-up periods (24-86 months, mean 44.2), recurrence rate was 7.1% (11/156) and mean time to recurrence was 39.2 months (19.7-58.7). Histology at recurrence were low-grade adenomas (n=8), high-grade adenoma (n=1) and advanced cancers (n=2). Recurrence rate of cuff-off techniques were 3.15% (4/127) in en bloc, 9.09% (1/11) 2 piecemeal resection and 33.33% (6/18) in ≥3 piecemeal resection. All patients with recurrence except two patients with advanced cancer were treated by endoscopic resection. Two patients with advanced cancer in recurrence had morphologies of ≥deep submucosal cancer in initial endoscopic findings although low-grade adenoma in re-evaluation of initial histology. In analysis for risk factors related with recurrence, only ≥3 pieces of resection were significantly related with recurrence in both univariate analysis and multivariate analysis (OR 16.924 (95% CI 1.185-241.806), p=0.037) Following patients with indeterminate or positive lateral margin after complete endoscopic resection in large, sessile or flat colorectal polyp, recurrence rate was relatively low and time to recurrence was long than 12 months. Therefore, surveillance interval for these patients can be extended for more than 12 months. However, short-term and regular follow-up is mandatory in case of ≥3 piecemeal resections or suspected submucosal cancer in morphology because of risk of recurrence or interval cancer.Tabled 1Baseline Characteristics of PatientsParameterParameterAge (year)*64.97±8.67Resection method (%)Size (mm)*18.288±9.75Conventional EMR105 (67.3)F/U time (month)*44.21±16.77Hybrid EMR30 (19.2)Sex (%)ESD21 (13.5)Male102 (65.4)Cut-off technique (%)Female54 (34.6)En bloc127 (81.4)Margin status (%)2 Piecemeal11 (7.1)Indeterminate97 (62.2)≥3 Piecemeal18 (11.5)Positive59 (37.8)Initial histology (%)Location (%)LGD86 (55.1)Right88 (56.4)HGD21 (13.5)Left36 (23.1)SSA/P19 (12.2)Rectum32 (20.5)CIS30 (19.2)Polyp shape (%)Recurrence (%)Is64 (41)Yes11 (7.1)IIa92 (59)No145 (92.9)Complication (%)Yes14 (9)No142 (91)Data are expressed as mean±standard deviation Open table in a new tab Tabled 1Risk factors related with recurrence in univariate & multivariate analysisVariablesUnivariate analysisMultivariate analysisORp value95% C.IORp value95% C.IAge (years)1.0250.5080.753-1.1030.9680.5310.873-1.073SexFemale2.4250.1600.704-8.3482.9560.1790.608-14.369Size (mm)1.0520.0311.005-1.1020.9680.5170.877-1.068LocaztionRight (Ref.)0.3290.257Left0.3900.3920.513-7.4260.7020.7890.053-9.328Rectum1.9520.3260.513-7.4265.9360.1420.552-63.809ShapeIs0.8100.7450.227-2.8890.7110.7290.103-4.914Resection methodConventional EMR (Ref.)0.9160.846Hybrid EMR1.3470.6750.334-5.4290.5490.5630.072-4.199ESD0.0000.9980.000-0.0000.0000.9980.000-0.000Cut-off techniqueEn bloc (Ref.)0.0010.1112 Piecemeal3.0750.3350.313-30.1872.8740.4880.146-56.622≥3 piecemeal15.3750.0003.802-62.17016.9240.0371.185-241.806Complication4.5680.0421.058-19.7175.0900.1790.475-54.527Initial histologyLGD (Ref.)0.9370.553HGD0.5640.6020.066-4.8540.4250.4960.036-5.005SSA/P0.6270.6710.073-5.4201.3690.8150.098-19.141CIS0.8060.7950.158-4.1120.1540.1820.010-2.407Margin statusPositive3.1300.0790.875-11.1951.3060.8170.136-12.529F/U time (month)0.9800.2610.947-1.0151.0290.2400.981-1.080 Open table in a new tab

Recurrence rate of lateral margin-positive cases after en bloc endoscopic submucosal dissection of colorectal neoplasia.

We aimed to evaluate the recurrence rate of colorectal neoplasia showing histologic lateral margin involvement after en bloc endoscopic submucosal dissection (ESD). We reviewed 527 colorectal lesions that were removed by en bloc ESD from 2005 to 2013 and followed by endoscopy. Based on the postprocedural pathologic reports, the lesions were categorized as follows: lesions with clear deep and positive lateral margins (n = 63) and lesions with R0 resection (n = 299). The tumor size was 45.7 ± 21.1mm in the lateral margin-positive group and 30.6 ± 15.1 in the R0 group (P < 0.001). Procedure time was longer in the lateral margin-positive group than in the R0 group (94.3 ± 75.1 vs. 54.1 ± 48.9min; P <0.001). Lateral margin positivity was associated with ESD time ≥ 120min in the multivariate analysis. Compared with 0-I morphology, LST-G was significantly associated with the lateral margin positivity. The volume of ESD experience in endoscopists may also be associated with the lateral margin positivity. Histologic reassessment of the specimen suggested that 32.2% of lateral margin-positive cases based on the initial pathology report were false-positive lateral margin involvement. The 5-year cumulative recurrence rate was 0.6% in the R0 group and 5% in the margin-positive group (P = 0.198). The local recurrence rate was not higher in lateral margin-positive cases than in R0 resection cases if the colorectal epithelial neoplasia was removed in an en bloc manner using ESD. Meticulous pathologic interpretation may reduce unnecessarily frequent surveillance after en bloc ESD.

Long-term outcomes after noncurative endoscopic resection of early gastric cancer: the optimal time for additional endoscopic treatment

We aimed to evaluate long-term outcomes with noncurative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) and surveillance strategies such as the optimal time for additional endoscopic treatment in patients with noncurative ESD. Of 2527 patients who underwent gastric ESD for EGC, 512 (20.3%) patients with noncurative resection were reviewed. Noncurative resection is defined as positive resected margins on histology, lymphovascular infiltration, or beyond the expanded criteria for ESD. The mean ± standard deviation follow-up duration was 79.0 ± 55.7 months. A total of 264 patients (51.6%) and 50 patients (9.8%) underwent surgery and endoscopic treatment after noncurative resection, respectively, whereas 198 patients (38.7%) were observed. Cancer-specific survival and disease-free survival rates were significantly different among the surgery, other endoscopic treatment, and observation groups (96.7%, 86.8%, and 86.2%, respectively; P=.030; and 92.5%, 73.6%, and 63.0%, respectively; P< .001). When patients who underwent surgery were excluded, the disease-free survival rate of recurrence was not significantly different between the endoscopic treatment and observation groups (73.6% vs 63.0%; P= .548). To exclude the potential for the presence of lymph node metastasis, we further analyzed disease-free survival of local recurrence by comparing the patients with only a positive lateral resection margin. The disease-free survival rate was higher in the endoscopic treatment group than in the observation group (89.2% vs 69.1%; P= .023). Moreover, additional endoscopic treatment within 3 months showed significant associations with lower risk of local recurrence on multivariate analysis (hazard ratio, 0.017; 95% confidence interval, 0.002-0.260; P= .003). In patients with noncurative ESD, additional surgery showed a better long-term outcome; moreover, when a positive lateral resection margin was the only noncurative factor, additional endoscopic treatment within 3 months could be considered to improve disease-free survival.

Indications and Outcomes From 32 Consecutive Patients for the Treatment of Rectal Lesions by Transanal Minimally Invasive Surgery.

The aim of this study was to evaluate the feasibility, safety, perioperative morbidity, and short-term outcomes of the transanal minimally invasive surgery (TAMIS) technique. This is a descriptive review of prospectively collected data from 32 consecutive patients who underwent TAMIS procedures in our colorectal unit over a 40-month period. GelPOINT Path port was used in all cases. Demographic data, indications, tumor characteristics, morbidity, and follow-up data were collected. Primary endpoints included feasibility, safety, perioperative morbidity, and resection quality. Fifteen adenomas, 12 carcinomas, 1 gastrointestinal stromal tumor, and 1 neuroendocrine tumor were locally excised. Additionally, 3 pelvic abscesses were drained transanally using the TAMIS port. Mean distance from the anal verge was 5.6 ± 1.5 cm. Early postoperative complications occurred in 22%, with only one case of major complication (3.1%) requiring reoperation, and no postoperative mortality. Four carcinomas were understaged (33.3%) and 1 adenoma overstaged (6.7%) preoperatively. Three carcinomas were not suspected preoperatively (25%). Microscopic positive lateral margin was found in one case, and no affected deep margin was found. Fragmentation rate was 6.9%, 2 cases, both lesions over 20 cm2. In cases of fit patients with high-risk carcinomas, 2 underwent immediate salvage surgery and another 2 refused and were treated with adjuvant radiotherapy. With a median follow-up of 26 months, the overall recurrence rate was 10.3%, 1 adenoma and 2 carcinomas. TAMIS seems to be a safe and reproducible procedure for local excision of well-selected rectal lesions with low morbidity and good functional outcomes.

Additive endoscopic resection may be sufficient for patients with a positive lateral margin after endoscopic resection of early gastric cancer

No well-established treatment strategies exist for lateral margin positivity (LM+) alone after endoscopic resection (ER) of early gastric cancer (EGC). Thus, we aimed to clarify a treatment strategy for non-curative resection (non-CR) with LM+ alone after ER in EGC. Among 2065 patients with EGC treated by ER, 76 (3.6%) with only LM+ after non-CR of EGC were reviewed retrospectively. Of these, 28 underwent gastrectomy, 25 underwent argon plasma coagulation (APC), and 23 underwent repeat ER (re-ER). We analyzed the clinicopathologic characteristics of all patients and compared those who underwent additive surgery, APC, or re-ER. Of the 76 patients, 28 (36.8%) fulfilled the absolute criteria and 48 (63.2%) the expanded criteria for ER. Among the latter patients, the proportion undergoing additive surgery was 75.0%, higher than that of patients in the former group (P= .014). Residual cancer cells were observed in 70.6% of patients after additive surgery or re-ER. Residual cancer cells were observed significantly more often in patients with undifferentiated-type than in those with differentiated-type EGC (P= .02). However, no lymph node metastasis was observed in any patient after additive surgery. Our results suggest that endoscopic treatment may be a sufficient additive therapy for patients with LM+ alone after ER, irrespective of whether the absolute or expanded ER criteria are used. However, as complete ablation of remnant cells cannot be guaranteed, re-ER is a better additive treatment than APC.

Endoscopic tattooing of colorectal neoplasms and laparoscopic surgery: technical aspects and recommendations

Accurate mapping of colorectal neoplasms is needed in many clinical situations. Intraoperative mapping of small lesions previously detected by endoscopy is often challenging, especially during laparoscopic surgery. Tumor location assessed during colonoscopy may be inaccurate because of limitations of the procedure. Small flat neoplasms with signs of invasiveness, which are hard to detect by palpation, hold a special place. The same situation is observed for nonradical endoscopic resection of malignant polyps or early cancer, when visual examination shows that the tumor masses have been completely resected but histological examination reveals the positive lateral or horizontal resection margin. Endoscopic tattooing is an effective, safe, and economically sound method to mark intraluminal colorectal neoplasms, which allows one to perform minimally invasive surgeries without using additional operating room resources.

Risk factors for positive resection margins after endoscopic submucosal dissection of early esophageal squamous carcinomas and precancerous lesions

Objective To identify the risk factors for positive resection residues after endoscopic submucosal dissection(ESD) of early esophageal squamous carcinomas and precancerous lesions. Methods A retrospective analysis was performed in 315 patients with early esophageal squamous cancer and precancerous lesion who underwent ESD.The pathological features of all resection margins in the specimen and the follow-up outcome of the patients with positive resection margin were evaluated. Univariate and multivariate analysis were used to determine the risk factors for resection margin residues after ESD. Results In 315 lesions, there were 290 lesions with negative resection margins and 25 with positive resection margins.The number of lesions with positive lateral, basal, or both resection margins was 13, 8, and 4, respectively. Multivariate analysis showed that the depth of invasion(submucosal layer invasion, P=0.048) was the only independent risk factor for positive basal resection margin. The proportion of circumferential extension(≥3/4, P=0.014) and the depth of invasion(exceeding muscularis mucosa, P=0.007) were independent risk factors for positive lateral resection margin. Conclusion The diameter of the lesions and the depth of tumor invasion are independent risk factors for esophageal ESD positive resection margins. Accurate evaluation of lesion extension and invasive depth is critical to avoid residual or recurrent tumor after esophageal ESD. Key words: Endoscopic submucosal dissection; Early esophageal carcinoma; Precancerous lesion; Positive resection margin

Factors associated with incomplete gastric endoscopic submucosal dissection due to misdiagnosis.

Background and study aims: Endoscopic submucosal dissection (ESD) is widely accepted for treating early gastric cancer (EGC); however, there can be cases of incomplete resection due to not only technical problems, but also misdiagnosis. Our aim was to identify factors associated with incomplete gastric ESD due to misdiagnosis. Patients and methods: A total of 2,268 patients with solitary EGCs at initial onset underwent ESD with curative intent at our hospital from 1999 to 2008. We retrospectively assessed the clinicopathological factors by comparing the two groups of incomplete ESD cases due to misdiagnosis (cases with a positive lateral margins [LM] [Group A] or those with a positive vertical margins [VM] [Group B]) with complete ESD cases using multivariable analysis. Results: Complete ESD was achieved in 2,097 patients. The 171 patients with incomplete ESDs were divided into 109 with a positive LM and 80 with a positive VM (overlapped). Except 49 cases with a positive LM due to technical problems, a positive LM due to misdiagnosis was identified in 60 cases (Group A). Excluding 32 cases with a positive VM due to technical problems, a positive VM due to misdiagnosis was found in 48 cases (Group B). Significant independent factors (odds ratios [OR]; 95 % confidence intervals [CI]) for each group were as follows: Group A: size > 20 mm (5.4; 3.0 – 9.9), undifferentiated-type (4.1; 1.8 – 9.0), submucosal invasion (2.0; 1.1 – 3.4) and location of upper/middle (1.9; 1.0 – 3.6); Group B: size > 20 mm (3.0; 1.6 – 5.5), undifferentiated-type (3.0; 1.1 – 8.0) and location of upper/middle (2.4; 1.2 – 4.8). Conclusions: Endoscopists must be aware of these factors associated with incomplete gastric ESD due to misdiagnosis to further decrease their incidence.

Relevant risk factors for positive lateral margin after en bloc endoscopic submucosal dissection for early gastric adenocarcinoma.

This study aimed to systematically assess the relevant risk factors of positive lateral margin (LM) after en bloc resection of early gastric adenocarcinoma. A total of 242 patients who had undergone endoscopic submucosal dissection (ESD) due to early gastric lesions from January 2009 to March 2015 were included in the study. Clinicopathological features of the lesions and the risk factors related to positive LM were analyzed. The curative rate was 82.2% and positive LM was found in 12.4% of the lesions. Univariate analysis showed that positive LM was significantly associated with the tumor location (at the upper third of the stomach), size (>3 cm), histological findings, the presence of lymphovascular invasion and deeper invasion depth. Moreover, positive LM had a higher incidence of recurrent or residual tumors. A multivariate analysis showed that the location, tumor size and histological classification of tumors were independent risk factors for positive LM. Positive LM is closely related to the upper third of stomach, a tumor larger than 3 cm and a mixed-type carcinoma. Additionally, positive LM has a predilection for recurrent or residual tumors.

Prospective evaluation of the clinical utility of endoscopic submucosal dissection (ESD) in patients with Barrett's esophagus: a Western center experience.

Background and study aims: Endoscopic submucosal dissection (ESD) carries significant advantages over endoscopic mucosal resection. As such, ESD is an established therapy for esophageal squamous cell carcinoma but there are only limited data on ESD as therapy for Barrett’s esophagus (BE). Thus, we prospectively evaluated the outcomes of ESD in patients with BE with high-grade dysplasia (HGD) and early esophageal adenocarcinoma (EAC) performed in a Western center. Patients and methods: This is a prospective cohort study. Indications for ESD included: (1) early EAC defined as lesions with intramucosal cancer or superficial submucosal invasion; (2) early EAC with positive lateral margin after EMR; and (3) nodularity with HGD that could not be removed en-bloc with EMR Results: From October 2013 to July 2015, 36 consecutive patients (median age 69, 32 males) underwent ESD at our center. Median procedure time was 88 minutes, with median maximal diameter of resected specimens of 49 mm. En-bloc, R0, and curative resection rates were 100 %, 81 %, and 69 %, respectively. Intramucosal EAC was found in 13 patients (36 %), and submucosal invasion in 13 patients (36 %). In 59 % of the cases, there was discrepancy in the pre- and post-ESD histopathologic diagnosis.Adverse events occurred in 8 patients (22 %), including one episode of bleeding treated with endoscopy and seven esophageal strictures, which were successfully managed with dilations. Conclusions: ESD for BE with HGD/early EAC is feasible and safe with resulting very high en-bloc and R0 resection rates. ESD provided for more accurate pathologic evaluation and significant discrepancy between the pre- and post-ESD histopathological diagnosis was noted.

Evaluation of the Expanded Criteria of Endoscopic Submucosal Dissection for Early Gastric Cancers: A Meta-Analysis

Background: In 2010, undifferentiated early-stage gastric cancers (EGCs; ≤1 cm and confined to the mucosa) were included in the expanded criteria for endoscopic submucosal dissection (ESD), as established by the Japanese Gastric Cancer Association. Objective: To evaluate the safety and efficacy of the newly expanded criteria of ESD for EGCs. Methods: PubMed, Embase, and the Cochrane Library were searched for relevant studies published between January 1, 2010 and July 10, 2014. These studies were collected by 2 authors and then analyzed with RevMan 5.0. Results: Six studies including 6,687 patients were identified. Compared to the standard group (SG), the expanded group (EG) had higher bleeding (OR 1.66; 95% CI 1.02-2.68), perforation (OR 2.03; 95% CI 1.25-3.31), positive lateral margin rates (OR 16.88; 95% CI 3.83-74.5) and lower en bloc resection rate (OR 0.48; 95% CI 0.34-0.70). The local recurrence (OR 2.46; 95% CI 0.31-19.23) and total survival rates (OR 0.92; 95% CI 0.76-1.12) between the 2 groups were not statistically different. Conclusions: Considering the similar rates of local recurrence and total survival between the SG and EG, the use of ESD for the management of EGCs that meet the expanded criteria could be considered a safe and effective treatment method.