Positive Lateral Margin Research Articles

Re-evaluation of the role of endoscopic submucosal dissection in the treatment of early gastric cancer based on additional gastrectomy results.

Endoscopic submucosal dissection (ESD) plays a pivotal role in treating early gastric cancer (EGC). Some patients require additional gastrectomy because of non-curative ESD. This study aimed to analyze the clinical factors associated with non-curative ESD and to re-evaluate the role of ESD according to its indication criteria. Altogether, 134 patients who had undergone additional gastrectomy with lymphadenectomy for non-curative ESD based on the pathological results of ESD specimens were included. Their data including pre-ESD diagnosis, reasons for requesting additional gastrectomy, and surgical outcomes were analyzed retrospectively. Of the 134 patients with EGC in the final pathology of ESD specimens, 56 underwent staging ESD for a diagnostic approach, of whom 28 were diagnosed with atypical glands and 28 with high-grade dysplasia (HGD) prior to ESD. The remaining 78 patients of the 134 were identified to have EGC and received ESD for therapy. Based on the pathological results of ESD specimens, additional gastrectomy was commissioned with non-curative ESD because of one or more causes such as deep submucosal invasion, lymphatic invasion, positive vertical margin, undifferentiated histology, positive lateral margin, and venous invasion. Regarding surgical specimens, 13 patients had lymph node metastasis (LNM) and 9 had local residual tumor; one of them had both LNM and a local residual tumor. In patients with atypical glands, 4 had LNM and 3 had a local residual tumor; one of them had both LNM and a local residual tumor, and then died of multiple organ metastasis. In patients with HGD, 4 had LNM and 1 had a local residual tumor. Additionally, 4 patients who were absolutely indicated for ESD had LNM, of whom 2 had atypical glands, and the other 2 had HGD. Similarly, in 6 patients with a local residual tumor absolutely indicated for ESD, 2 had atypical glands and 1 had HGD. Positive vertical margin, lymphatic invasion, and deep submucosal invasion were identified as independent risk factors for LNM. ESD may play diagnostic and therapeutic roles in determining the optimal treatment of EGC when the diagnosis is equivocal or insufficient in endoscopic assessments for gastric cancer screening.

Predictors of residual neoplasia after noncurative (R1) endoscopic submucosal dissection of lesions in the gastrointestinal tract.

Endoscopic submucosal dissection (ESD) is a minimally invasive resection technique that enables the en bloc resection of gastrointestinal lesions. Despite en bloc resection, pathological evaluation of lesions can reveal positive vertical or horizontal margins, which is referred to as R1 resection. Not all R1 lesions referred for surgical resection or endoscopic surveillance show evidence of residual tumor. We aimed to identify the predictors of residual neoplasia in patients with an R1 resection following ESD. All lesions resected via ESD between June 2016 and September 2021 at a tertiary referral center were retrospectively identified. Lesions with an R1 resection and adequate follow-up were eligible for inclusion. Patient, lesion, and procedural characteristics were analyzed to identify predictors of residual neoplasia. Of 614 lesions, 163 (28%) had R1 resection. Of these, 56 lesions in 51 patients had complete follow-up and were included. Thirteen patients (25.5%) underwent surgical resection and the remainder underwent endoscopic surveillance. Seven (12.5%) patients had residual disease. All patients with residual disease had esophageal carcinoma. Positive deep and lateral margins, severe submucosal fibrosis, and moderate/poorly differentiated tumors were identified as significant predictors of residual neoplasia. Most R1 lesions (87.5%) resected by ESD did not have residual disease on follow-up. Those without identified risk factors for residual disease, such as esophageal carcinoma, severe submucosal fibrosis, or both histological margin positivity, may benefit from a strategy of close endoscopic surveillance rather than referral for surgical resection.

En Bloc Versus Conventional Resection of Primary Bladder Tumor (eBLOC): A Prospective, Multicenter, Open-label, Phase 3 Randomized Controlled Trial

BackgroundEn bloc transurethral resection of the bladder (eTURB) might improve the surgical management of non–muscle-invasive bladder cancer (NMIBC) in comparison to conventional TURB (cTURB). ObjectiveTo evaluate whether eTURB is superior to cTURB in resection of NMIBC and specimen retrieval. Design, setting, and participantsThis was a randomized, multicenter trial in patients with up to three cTa–T1 NMIBC tumors of 1–3 cm in size, who were enrolled from January 2019 to January 2022. InterventionParticipants were randomized 1:1 to undergo eTURB (n = 192) or cTURB (n = 192). Outcome measurements and statistical analysisThe primary outcome was the prevalence of detrusor muscle (DM) in the specimen retrieved. Secondary endpoints included bladder perforation, persistent disease at second-look TURB, positive lateral resection margin, positive deep resection margin, operation time, perforation rate, obturator reflex, conversion from eTURB to cTURB, recurrence-free survival, and disease recurrence at 3 mo. Results and limitationsA total of 384 patients were randomized to undergo eTURB or cTURB. A total of 452 tumors were resected and analyzed for the primary outcome. eTURB was superior to cTURB in retrieval of DM (80.7% vs 71.1%; mixed-model p = 0.01). Bladder perforation (5.6% vs 12%; difference −6.4%; 95% confidence interval [CI] −12.2% to −0.6%) and obturator reflex (8.4% vs 16%; difference −7.6%; 95% CI −14.3% to −0.9%) were less frequent in the eTURB arm than in the cTURB arm. Operation time did not differ between the two techniques (26 min, interquartile range [IQR] 20–38 for eTURB vs 25 min, IQR 17–35 for cTURB; difference 1 min, 95% CI –25.9 to 4.99). Second-look TURB was performed in 24 patients in the eTURB arm and 34 in the cTURB arm, with no difference in the rate of residual papillary disease (pTa/pT1: 56% vs 55.9%; difference 0.1%, 95% CI −25.5% to 25.7%). At median follow-up of 13 mo (IQR 7–20), 18.4% of the patients in the eTURB arm and 16.7% in the cTURB arm had experienced bladder cancer recurrence (Cox hazard ratio 0.87, 95% CI 0.49–1.52; p = 0.6). ConclusionsIn patients with clinical NMIBC with up to three tumors of 1–3 cm in size, tumor removal via eTURB resulted in a higher rate of DM in the pathologic specimen in comparison to cTURB. Moreover, eTURB was associated with lower frequency of obturator reflex and bladder perforation than cTURB was. While improving on the quality indicators for NMIBC, the long-term differential oncologic benefits of eTURB remain uncertain. Patient summaryWe compared two techniques for removal of bladder tumors and found that tumor removal in a single piece, called en bloc resection, provides a better-quality specimen for pathology analysis and fewer complications in comparison to the conventional method.This trial is registered at ClinicalTrials.gov as NCT03718754.

Long-term outcomes of endoscopic papillectomy for ampullary adenoma with high-grade dysplasia or adenocarcinoma: a propensity score-matched analysis.

Evidence of endoscopic papillectomy (EP) for ampullar adenoma with high-grade dysplasia (HGD) or adenocarcinoma is insufficient. Here we investigated the long-term outcomes of the advanced ampullary tumors treated by EP with careful surveillance comparing to subsequent surgery after EP. Patients treated with EP for ampullary adenoma with HGD or adenocarcinoma from the multi-center retrospective Korean cohort of ampulla of Vater tumor were categorized into EP alone versus EP with subsequent surgery groups. The overall survival (OS) and recurrence-free survival (RFS) were analyzed for unmatched and matched cohorts using propensity score with nearest neighbor method. During a median 43.3months of follow-up, 5-year OS was not significantly different between the EP alone and EP surgery groups (91.9% vs. 82.3%, P = 0.443 for unmatched cohort; 89.2% vs. 82.3%, P = 0.861 for matched cohort, respectively). Furthermore, 5-year RFS was not significantly different between the two groups (82.1% vs. 86.7%, P = 0.520 for unmatched cohort; 66.1% vs. 86.7%, P = 0.052 for matched cohort, respectively). However, the patients with positive both (lateral and deep) margins showed significantly poorer survival outcomes than those with negative margins within the EP alone group (P = 0.007). EP alone with careful surveillance showed comparable survival outcomes to those of EP with subsequent surgery for ampullar HGD or adenocarcinoma. Resection margin status could be a parameter to determine whether to perform subsequent radical surgery after EP.

Additional endoscopic treatments for patients with positive lateral margins after endoscopic resection of early esophageal squamous cell carcinoma.

There are currently no well-established treatment strategies for early esophageal squamous cell carcinoma (ESCC) for patients with only positive lateral margin (LM+) following endoscopic resection (ER). The present study aimed to find a treatment strategy for patients with early ESCC with non-curative resection (non-CR) and only LM+ following ER. In total, 511 patients with early ESCC treated at the Fourth Hospital of Hebei Medical University (Shijiazhuang, China) with ER were retrospectively analyzed, 41 of which (8%) were patients with only LM+ after non-CR. Of these, 28 patients received re-ER and 13 received additional surgical treatment. The clinicopathological characteristics of patients were analyzed and those who underwent additional surgery vs. re-ER were compared. Residual cancer cells were found in 27 patients (27/41, 65.9%) following re-ER or additional surgery. A significant increase in residual cancer cells was observed in patients with poorly differentiated cancer and patients with multiple LM+ (P=0.03 and P=0.015, respectively). Older patients and patients with single LM+ tended to choose re-ER (P=0.023 and P=0.038, respectively). In addition, there were three cases (3/13, 23.1%) of lymph node metastasis in the additional surgery group. However, within the limited follow-up time (mean, 36.1±24.1 months), no recurrence or metastasis was found in the remaining patients. The results showed that re-ER may be a more suitable additional therapy compared with surgery for patients with LM+ following non-CR, at least in the medium-term.

Oesophagectomy within 30 days after noncurative endoscopic resection for oesophageal cancer: are we able to follow this 'golden' interval?

Endoscopic mucosal resection (EMR) is considered the first-line treatment for early-stage intramucosal lesion pT1a (m1-3) and carefully selected pT1b (sm1) non-circumferential oesophageal carcinomas [1]. This endoscopic treatment strategy has great advantages compared to surgical oesophageal resection, with a reduced invasiveness, decreasing morbidity and mortality rates and allowing the organ preservation with subsequent improvement in patients’ quality of life. Moreover, recent data demonstrated that EMR has equivalent long-term outcomes when compared to both oesophagectomy for intramucosal tumour (m1-3) or limited to the invasion of few microns of the muscularis mucosa with favourable histopathological factors (sm1), with an acceptable low risk of positive lymph node (LN) occurring in <5% of cases [2]. However, there are many circumstances in which EMR has to be deemed as noncurative, leading to consider radical oesophagectomy because of the high risk of recurrence or LN metastases. These circumstances are: tumour size >2 cm, invasion >sm1, excavated or polypoid lesion, circumferential lesion, positive lateral and/or vertical margin, poorly differentiated tumour, evidence of lymphovascular or perineural invasion and suspicion of positive LN [3]. If oesophagectomy is the recommended treatment option for noncurative EMR, the question that remains unclear is the optimal interval between the 2 procedures regarding the surgical risk if the delay is too short due to post-resection inflammation, and the risk of a pathological upstaging if the delay is too long due to local disease progression.

Clinical outcomes of endoscopic resection of superficial nonampullary duodenal epithelial tumors: A 10-year retrospective, single-center study.

BACKGROUNDAlthough premalignant duodenal lesions such as adenomas are uncommon, the incidences of these lesions have increased in recent times, and thus, the demand for minimally invasive treatments such as endoscopic resection (ER) has also increased. However, ER in the duodenum is more challenging than ER in other locations of the gastrointestinal tract.AIMTo evaluate the safety and efficacy of ER for superficial nonampullary duodenal epithelial tumors (SNADETs)METHODSWe performed a retrospective observational study on 56 consecutive patients (58 lesions) diagnosed with SNADETs that underwent ER from January 2011 to December 2020 at Yeungnam University Hospital. Patient demographics, lesion characteristics, and procedural and technical data were collected, and clinical outcomes, including procedure-related complications, completeness of resection, and recurrence were analyzed.RESULTSMedian patient age was 57 years [range, 26–77, 30 (53.6%) men]. Endoscopic mucosal resection (EMR) was performed on 57 lesions (98.3%) and snare polypectomy on one (1.7%). Lesions consisted of 52 adenomas with low-grade dysplasia (89.7%), 3 adenomas with high-grade dysplasia (5.2%), and 3 intramucosal adenocarcinomas (5.2%). There were 16 cases of intraprocedural bleeding (27.6%) and 1 case of delayed bleeding (1.7%), and all these 17 cases were successfully managed endoscopically. No perforation or procedure-related death occurred. Larger lesion size was associated with an increased risk of EMR-related bleeding (P = 0.033). During a median follow-up period of 23 mo (range 6–100 mo), no local recurrence occurred, despite the fact one-third of the patients (19 lesions, 32.8%) underwent piecemeal resection and 3 patients (3 lesions, 5.2%) that underwent en bloc resection had a pathologically determined positive lateral margin. No patient died from a primary duodenal neoplasm. CONCLUSIONThe majority of SNADETs can be safely and curatively resected by EMR, and thus, based on consideration of the high incidence of fatal complications attributable to ESD, we conclude EMR, including piecemeal resection, should be considered the treatment of first choice for SNADETs.

As time goes by–developments in surgery for esophageal cancer in the new millennium

Summary Background In the last two decades, both treatment options and epidemiological features of cancer have changed. We studied the influence of related parameters on the outcome of patients undergoing resection for esophageal carcinoma. Methods We analyzed 499 consecutive patients who underwent esophagectomy for carcinoma since January 2000, comparing 2000–2010 with 2011–2021 and examining changes over time. Results The percentage of men (87.9 vs. 86.9%; p = 0.74) in the two groups was unchanged, whereas mean age increased significantly from 60.8 to 65.2 years (p = 0.000). There was a trend towards an increase of adenocarcinoma (gamma = 0.120, ASE = 0.055). Despite significantly increasing use of induction chemoradiotherapy (p = 0.000) from 7.14% in 2000 to 68.9% in 2021 the distribution of pT, pN stage, grading and the rate of positive lateral resection margins remained unchanged. When comparing the two periods, the overall 30-day mortality was 4.4 vs. 4.2% (p = 0.56), recurrence-free survival was 36.9 vs. 38% at 60 months and 33.9 vs. 36.4% at 120 months (p = 0.93). Tumor-associated survival was 41.1 vs. 45% at 60 months and 35.5 vs. 38.7% at 120 months (p = 0.78). None of the survival rates differed significantly. A multivariable analysis of year of surgery, age, sex, histological subtype, grading, pT, pN, lateral resection margin, and induction therapy showed that only higher pT (p = 0.01), positive pN (p = 0.000), positive lateral margin (p = 0.003), squamous cell carcinoma (p = 0.04) and higher grading (p = 0.026) had a statistically significant, independent, negative influence on prognosis. Conclusion Optimized noninvasive and invasive therapeutic modalities have produced only marginal improvement in the prognosis of esophageal cancer within the last two decades.

Prediction of surgical margin status and location after radical prostatectomy using positive biopsy sites on 12-core standard prostate biopsy

We evaluated the surgical margin status after radical prostatectomy according to sites positive for prostate cancer on standard 12-core transrectal ultrasound-guided prostate biopsy. Among patients who underwent radical prostatectomy at Boramae Medical Center, 520 patients with preoperative prostate-specific antigen (PSA) level < 20 ng/mL and locally confined prostate cancer on preoperative magnetic resonance imaging, treated with nerve-sparing radical prostatectomy, were included in the analysis. The surgical margin was positive for cancer in 166 (31.9% of the total) patients. The preoperative PSA level (9.3 vs. 8.0, ng/mL p = 0.001) and number of positive cores on 12-core prostate biopsy (4.1 vs. 3.4, p = 0.003) were significantly higher in patients with positive surgical margins. Moreover, the biopsy Gleason grade was higher in patients with positive surgical margins (p = 0.001). However, the pathologic Gleason grade and tumor volume were equivalent between the 2 groups. On multivariate analysis, the detection of prostate cancer on anterior lateral biopsy was associated with an increased rate of positive surgical margins (hazard ratio [HR]: 1.781, p = 0.008) after adjusting for other variables. Anterior lateral (HR: 1.919, p = 0.020), basal lateral (HR: 9.176, p < 0.001), basal medial (HR: 3.302, p = 0.031), and mid lateral (HR: 2.501, p = 0.044) biopsies were associated with positive apical, posterior, basal, and lateral surgical margins, respectively, after adjusting for other variables. The sites of prostate cancer on standard 12-core prostate biopsy could be useful for predicting surgical margin positivity after radical prostatectomy. In other words, clinicians should consider the sites of prostate cancer on prostate biopsy to reduce margin positivity after radical prostatectomy.

Persistent or recurrent Barrett's neoplasia after an endoscopic therapy session is associated with DNA content abnormality and can be detected by DNA flow cytometric analysis of paraffin-embedded tissue

Endoscopic therapy is currently the standard of care for the treatment of high-grade dysplasia (HGD) or intramucosal adenocarcinoma (IMC) in patients with Barrett's esophagus (BE). Visible lesions are treated with endoscopic mucosal resection (EMR), which is often coupled with radiofrequency ablation (RFA). However, endoscopic therapy may require multiple sessions (one session every 2-3 months) and does not always assure complete eradication of neoplasia. Furthermore, despite complete eradication, recurrences are not uncommon. This study assesses which potential risk factors can predict a poor response after endoscopic sessions. Forty-five BE patients who underwent at least one endoscopic session (EMR alone or ablation with or without preceding EMR) for the treatment of HGD/IMC, low-grade dysplasia (LGD), or indefinite for dysplasia (IND) were analyzed. DNA flow cytometry was performed on 82 formalin-fixed paraffin-embedded samples from the 45 patients, including 78 HGD/IMC, 2 LGD, and 2 IND. Eight non-dysplastic BE samples were used as controls. Three to four 60-micron thick sections were cut from each tissue block, and the area of HGD/IMC, LGD, or IND was manually dissected. Potential associations between clinicopathologic risk factors and persistent/recurrent HGD/IMC following each endoscopic session were examined using univariate and multivariate Cox models with frailty terms. Sixty (73%) of the 82 specimens showed abnormal DNA content (aneuploidy or elevated 4N fraction). These were all specimens with HGD/IMC (representing 77% of that group). Of these 60 HGD/IMC samples with abnormal DNA content, 42 (70%) were associated with subsequent development of persistent/recurrent HGD/IMC (n = 41) or esophageal adenocarcinoma (EAC; n = 1) within a mean follow-up time of 16 months (range: 1 month to 9.4 years). In contrast, only 6 (27%, all HGD/IMC) of the 22 remaining samples (all with normal DNA content) were associated with persistent/recurrent HGD/IMC. For outcome analysis per patient, 11 (24%) of the 45 patients developed persistent/recurrent HGD/IMC or EAC, despite multiple endoscopic sessions (mean: 3.6, range: 1–11). In a univariate Cox model, the presence of abnormal DNA content (hazard ratio [HR] = 3.8, p = 0.007), long BE segment ≥ 3 cm (HR = 3.4, p = 0.002), endoscopic nodularity (HR = 2.5, p = 0.042), and treatment with EMR alone (HR = 2.9, p = 0.006) were significantly associated with an increased risk for persistent/recurrent HGD/IMC or EAC. However, only abnormal DNA content (HR = 6.0, p = 0.003) and treatment with EMR alone (HR = 2.7, p = 0.047) remained as significant risk factors in a multivariate analysis. Age ≥ 60 years, gender, ethnicity, body mass index (BMI) ≥ 30 kg/m2, presence of hiatal hernia, and positive EMR lateral margin for neoplasia were not significant risk factors for persistent/recurrent HGD/IMC or EAC (p > 0.05). Three-month, 6-month, 1-year, 3-year, and 6-year adjusted probabilities of persistent/recurrent HGD/IMC or EAC in the setting of abnormal DNA content were 31%, 56%, 67%, 79%, and 83%, respectively. The corresponding probabilities in the setting of normal DNA content were 10%, 21%, 28%, 38%, and 43%, respectively. In conclusion, in BE patients with baseline HGD/IMC, both DNA content abnormality and treatment with EMR alone were significantly associated with persistent/recurrent HGD/IMC or EAC following each endoscopic session. DNA content abnormality as detected by DNA flow cytometry identifies HGD/IMC patients at highest risk for persistent/recurrent HGD/IMC or EAC, and it also serves as a diagnostic marker of HGD/IMC with an estimated sensitivity of 77%. The diagnosis of HGD/IMC in the setting of abnormal DNA content may warrant alternative treatment strategies as well as long-term follow-up with shorter surveillance intervals.

Long-term Outcomes of Additional Endoscopic Treatments for Patients with Positive Lateral Margins after Endoscopic Submucosal Dissection for Early Gastric Cancer.

Background/AimsIt is uncertain whether additional endoscopic treatment may be chosen over surgery in patients with positive lateral margins (pLMs) as the only non-curative factor after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to compare the long-term outcomes of additional endoscopic treatments in such patients with those of surgery and elucidate the clinicopathological factors that could influence the treatment selection.MethodsA total of 99 patients with 101 EGC lesions undergoing additional treatment after non-curative ESD with pLMs as the only non-curative factor were analyzed. Among them, 25 (27 lesions) underwent ESD, 29 (29 lesions) underwent argon plasma coagulation (APC), and 45 (45 lesions) underwent surgery. Clinicopathological characteristics and long-term outcomes were compared.ResultsResidual tumor was found in 73.6% of cases. The presence of multiple pLMs was associated with higher risk of residual tumor (p=0.046). During a median follow-up of 58.9 months, recurrent or residual lesions after additional ESD and APC were found in 4% (1/25) and 6.8% (2/29) of patients, respectively. However, all were completely cured with surgery or repeated ESD. There were no extragastric recurrences after additional endoscopic treatment. Lymph node metastasis was identified after additional surgery in one (2.2%) patient with an EGC showing histological heterogeneity.ConclusionsGiven the favorable long-term outcomes, additional ESD or APC may be an acceptable choice for patients with pLMs as the only non-curative factor after ESD for EGC. However, clincopathological characteristics such as multiple pLMs and histological heterogeneity should be considered in the treatment selection.

Transanal endoscopic surgery with a 3D printed device.

The aim of this study was to investigate the effectiveness of devices manufactured with 3D printing for performing transanal endoscopic procedures without pneumorectum. Functional devices were designed in the Polytechnic School of Engineering of Gijón from 2016 to 2018 using three-dimensional (3D) solid modelling software (Solid-Works®), that allows customization of the device (diameter and length). The devices were made in acrylonitrile butadiene styrene (ABS) by additive manufacturing using an HP Designjet 3D Printer, with fused deposition modelling (FDM) technology. Tests were carried out on mixed simulators (with viscera) and cadavers with a prototype in the form of an open cylindrical base ellipsoid spindle with two bars. In this paper, we present the information of the first series of patients in which this device has been used to perform a full-thikness endoscopic resection of the rectal wall without pneumorectum. The characteristics of the patients, size, and location of the lesion, the type of anesthesia used, the duration of the procedure, hospital stay, complications, and pathology were analyzed. An endoscopic follow-up was also carried out for at least 2 years. Seven interventions were carried out in six patients. The lesions were located at a mean distance of 5 cm from the anal verge and an average area of 11.8 cm2. Four of the procedures were performed with general anesthesia and 3 with spinal anesthesia. Histopathology examination identified 3 adenomas, 3 pT1 and 1 pT2 adenocarcinomas. All excisions were full thickness. En bloc excision was possible in all cases. In only one case of a benign polyp there was a positive lateral margin. As regards complications, there was one case of postoperative rectal bleeding without the need for transfusions. There were no readmissions and no postoperative mortality. An innovative device made with a 3D printer can be used successfully in transanal endoscopic resections of the rectal wall, with spinal anaesthesia and avoiding the need for pneumorectum.

Wide-field endoscopic submucosal dissection for the treatment of Barrett's esophagus neoplasia.

Background and study aims Implementation of endoscopic submucosal dissection (ESD) for the treatment of Barrett’s esophagus neoplasia (BEN) has been hampered by high rates of positive margins and complications. Dissection with wider margins was proposed to overcome these problems, but was never tested. We aim to compare Wide-Field ESD (WF-ESD) with conventional ESD (C-ESD) for treatment of BEN. Patients and methods This was a cohort study of all ESDs performed in our center during 2011 to 2018. C-ESD was the only technique used before 2014, with WF-ESD used beginning in 2014. In WF-ESD marking was performed 10 mm from the tumor margin compared to 5 mm with C-E. Results ESD was performed in 90 cases, corresponding to 74 patients, 84 % male, median age 69. Of these, 22 were C-ESD (24 %) and 68 were WF-ESD (76 %). The en bloc resection rate was 95 vs 100 % (ns), the positive lateral margin rate was 23 % vs 3 % ( P < 0.01), the R0 rate was 73 % vs 90 %, and the curative resection rate was 59 % vs 76 % in the C-ESD and WF-ESD groups, respectively, (both P > 0.05). The procedure speed was 4.4 and 2.3 (min/mm) in the C-ESD and WF-ESD groups ( P < 0.01), respectively. WF-ESD was associated with less post-operative strictures, 6 % vs 27 % ( P = 0.01), with no local recurrence but no significantly reduced risk of metachronous recurrence (Hazard Ratio = 0.46, 95 %CI = 0.14–1.46), during a follow-up of 13.4 and 9.4 months in the C-ESD and WF-ESD cohorts, respectively. Conclusions WF-ESD is associated with a reduction in positive lateral margins, faster dissection, and lower stricture rates. Further prospective, multicenter studies are warranted to evaluate its role in clinical practice.

Long-term outcomes and surveillance timing of patients with large non-pedunculated colorectal polyps with histologically incomplete resection in endoscopic resection.

Histologically incomplete resection of large colorectal polyps is frequently encountered; however, the long-term outcomes or surveillance timing is not well known. We evaluated the incidence rate and time of recurrence of these cases during a long-term follow-up. We performed a retrospective analysis of patients who underwent endoscopic resection for large (≥10mm in size) non-pedunculated colorectal polyps at a tertiary academic hospital. Patients who had positive or indeterminate lateral margin in the histology and underwent completed surveillance colonoscopy first at 3-12months and finally at ≥2years after initial resection were included. Of 169 polyps (148 patients), 37 (21.9%) and 132 (78.1%) polyps had positive and indeterminate lateral margins, respectively. The median time intervals of the first and last surveillance from the initial resection were 6 (3-12) and 48 (24-114) months, respectively. The recurrence rate was 9.5% (16/169) during follow-up, and the mean time to recurrence was 31.9months. Thirteen (81.3%) polyps recurred after ≥12months. Most (14/16, 87.5%) recurrent polyps were benign, and 2 cases had advanced cancer. The only factor that was significantly associated with recurrence in the univariate and multivariate analyses was ≥3 piecemeal resections (odds ratio in the multivariate analysis, 16.92; 95% CI, 1.19-241.81; p = 0.037). During the long-term follow-up, the only factor that was significantly associated with recurrence was ≥3 piecemeal resections, and most recurrences occurred after ≥12months. Thus, a histologically incomplete resection with ≤2 piecemeal resections and no findings of suspected submucosal cancer may be considered as complete resection, and these patients may undergo first surveillance colonoscopy after 1-2years.

Differences Between Recommended Surgical Margins and Measured Histological Margins in Malignant Melanoma In Situ and Malignant Melanomas.

Wide local excision (WLE) using appropriate surgical margins is the standard surgical management for malignant melanoma in situ (MMIS) and primary cutaneous malignant melanoma (MM). The actual width of the histologic margins is frequently not assessed, whereas narrow histologic margins are associated with an increase in local melanoma recurrence. Our objective was to analyze the actual measured histological margins of WLE specimens of MMIS and MM cases and compare them with their recommended surgical margins. A retrospective study of formalin fixed specimens of MMIS and invasive MM treated with WLE from a large university-affiliated dermatopathology laboratory was conducted. Among a total of 164 MMIS and 128 MM cases, 14 MMIS (8.5%) and 7 MM (5.9%) had positive lateral margins. The median histologic margin for MMIS, after a 15% tissue shrinkage adjusted, was 2.7 mm [1.3-3.9] for LM type and 3.9 mm [2.3-5.6] for non-LM type, in contrast to the recommended 5-mm margin. In 96 MM of T1 type (≤1.0 mm), the median adjusted histologic margin was 6.7 mm [3.5-9.1] in contrast to the recommended 10-mm margin. These results show that measured and adjusted median histologic margins in WLE specimens in both MMIS and MM of T1 type were significantly narrower than the recommended surgical margins, regardless of anatomic location. These differences are concerning, whether they reflect clinicians' intentional or unintentional deviation from recommended guidelines.

Effectiveness of dermoscopy in the demarcation of surgical margins in slow Mohs surgery.

There is a need for adjuvant imaging techniques that would allow reducing the number of slow Mohs stages. This study aimed to evaluate the use of dermoscopy in the demarcation of basal cell carcinoma (BCC) surgical margins for slow Mohs surgery. This was a retrospective study over 3 years (2016-2019), including patients with BCC excised using slow Mohs surgery. On the basis of the treatment received, the patients were divided into 2 groups: group 1 (28 BCC) and group 2 (26 BCC). In group 2, BCC margins were demarcated using dermoscopy. A total of 54 patients were enrolled in the study. The number of positive lateral margins was significantly lower in the group where BCC margins were demarcated using dermoscopy (19% vs 53%, P = .012). In this group, the number of Mohs stages needed to achieve complete clearance was significantly lower. However, the mean interval between the first Mohs excision and Mohs clearance was not significantly different between the 2 groups (9 ± 4 vs 12 ± 7 days). In conclusion, preoperative dermoscopy is useful for reducing the number of positive lateral margins and the number of slow Mohs stages in treating BCC especially pigmented tumors.

Retrospective investigation of patients receiving additional surgery after endoscopic non-curative resection for early colorectal cancer

Objective: To investigate the clinical application of additional surgery after non-curative endoscopic resection for early colorectal cancer. Methods: A retrospectively descriptive cohort study was conducted. Inclusion criteria: (1) pathologically confirmed primary colorectal adenocarcinoma;(2) receiving additional surgery after endoscopic resection; (3) semi-elective operation. Exclusion criteria: familial adenomatous polyposis, appendiceal neoplasms, anal canal neoplasms, neuroendocrine tumors, and surgery because of perforation or bleeding after endoscopic resection. Indications of additional surgery: (1) pathologically positive lateral or basal resection margin; (2) submucosal invasion depth ≥ 1000 μm; (3) lymphovascular invasion; (4) poorly differentiated, undifferentiated or mucinous adenocarcinoma; (5) more than grade G2 in tumor budding; (6) incomplete resection or piecemeal specimen with margin impossible to evaluate; (7) patient's consent due to undetermined pathology. According to the above criteria, clinical data of 92 patients at the Colorectal Surgery Department, the First Affiliated Hospital of Nanjing Medical University between January 2013 and December 2018 were collected. Demographic data, pathological examinations, operative methods and outcomes were analyzed. Results: There were 61 (66.3%) male and 31 female (33.7%) patients with an average age of (58.2±10.7) years. The average BMI was (23.8±3.5) kg/m(2). The lesions located in the right-sided colon, left-sided colon and rectum in 19, 37 and 36 patients respectively. Sixteen patients received endoscopic snare resection, 45 received endoscopic mucosal resection and 31 received endoscopic submucosal dissection. Reasons for additional surgery included endoscopic specimen with pathologically positive margin (n=22, 23.9%), submucosal invasion depth ≥ 1000 μm (n=9, 9.8%), lymphovascular invasion (n=4, 4.3%), poorly differentiated, undifferentiated or mucinous adenocarcinoma (n=5, 5.4%), piecemeal resection (n=13, 14.1%), undetermined pathology (n=52, 56.5%). The median duration from endoscopic resection to additional surgery was 16 days. Thirty-four patients (37.0%) received preoperative endoscopic localization with carbon nanoparticles suspension injection and 5 (5.4%) were marked with titanium clip. Seventy-four patients (80.4%) received laparoscopic surgery, 17 (18.5%) received open surgery, while 1 patient (1.1%) was converted to open surgery due to missing titanium clip. Three patients (3.3%) were treated with transanal excision, 2 (2.2%) with bowel resection, and 87 (94.6%) with radical excision. After additional surgery, histopathological examination of surgical specimens revealed the presence of residual tumor in 5 patients (5.4%), lymph node metastasis in 8 (8.7%), lymphovascular invasion in 1 (1.1%) and tumor deposit in 1 (1.1%). Twelve patients (13.0%) developed postoperative complications, including 4 mid-low rectal cancer patients (4.3%) with anastomostic leakage or bleeding. After surgery, according to the TNM staging system, 83 patients (90.2%) were classified as TNM stage 0-I, 9 (9.8%) as TNM stage II-IV. One patient of stage IV with liver metastasis underwent concomitant hepatectomy. One patient of stage II received regular follow-up after operation. Seven cases of stage III and 1 of stage IV received postoperative chemotherapy. Eighty-five patients (92.4%) were followed up with a median time of 12.8 (IQR: 8.1, 24.3) months. No recurrence or metastasis was observed. Conclusions: Surgery is an effective salvage measure for non-curative endoscopic resection of early colorectal cancer. Since surgery may have complications, indications of the additional surgery should be considered carefully. Preoperative endoscopic localization should be performed in order to ensure the safety and efficacy of surgery.

Combined Endoscopic Mucosal Resection and Extended Laparoscopic Appendectomy for the Treatment of Periappendiceal, Cecal, and Appendiceal Adenomas

BackgroundSurgical resection is the gold standard in the treatment of neoplasia involving the appendiceal orifice (Ao). Endoscopic mucosal resection (EMR) of adenomas involving the Ao can be challenging because of the risk of appendicitis, perforation, or incomplete resection. Surgical resection of Ao lesions is limited by the difficulty of ensuring a negative lateral margin without compromising the ileocecal valve and usually necessitates ileocecal resection. Although combined endoscopic and laparoscopic surgery has become more widely accepted for a variety of conditions, a structured approach to lesions involving the Ao has yet to be described. We describe a novel approach to the treatment of periappendiceal, cecal, and appendiceal adenomas—and present an algorithm to guide decision-making regarding the application of these techniques. MethodsAll patients referred to our therapeutic endoscopy practice with tumors involving the Ao between August 2013 and July 2017 were included. Based on tumor size and involvement of the os, patients were either referred for extended laparoscopic appendectomy (ELA), EMR, or a combined approach. ResultsIn total, 47 patients were included; 25 patients underwent EMR only, 13 patients underwent ELA only, and nine patients underwent combined resection. Two patients undergoing EMR had postpolypectomy syndrome. One EMR-only patient with a positive lateral margin was referred for appendectomy, but declined. No patient required ileocecectomy. Pathologic examination revealed a high rate of sessile serrated adenoma (SSA; 36%). ConclusionsOur results introduce a decision algorithm and suggest that EMR combined with ELA is a safe and curative technique for the treatment of large cecal adenomas involving the Ao.

Long-term outcomes of endoscopically resected laterally spreading tumors with a positive histological lateral margin.

With advances in diagnostic endoscopy, the incidence of superficial colorectal tumors, including laterally spreading tumors (LSTs), has increased. However, little is known about the long-term results of LSTs with positive lateral margin after endoscopic treatment. This study aimed to evaluate the long-term clinical outcomes and risk factors for local recurrence of LSTs with positive lateral margin after initial endoscopic resection. We performed a retrospective analysis of the medical records of 324 patients who had 363 LSTs with positive lateral margin after endoscopic resection at a tertiary academic medical center. The medical records from 2011 to 2015 were analyzed. Local recurrence was confirmed through endoscopic finding and subsequent biopsy analysis. We assessed the local recurrence rate and performed multivariate analyses to identify the factors associated with local recurrence. Follow-up colonoscopy was performed in 176 of 363 LSTs. The local recurrence rate was 6.3% (11/176), with a median (interquartile range [IQR]) follow-up period of 19.8 (12.4-46.5) months. In multivariate analysis, local recurrence was associated with piecemeal resection (odds ratio [OR] 6.62, 95% confidence interval [CI] 1.28-34.33; p = 0.024) and inversely associated with thermal ablation (OR 0.033, 95% CI 0.00-0.45; p = 0.011). At surveillance colonoscopy, histology of the recurrent tumor was adenoma in 10 (90.9%) of 11; these were treated endoscopically. In this retrospective study, we found that endoscopically resected LSTs with positive lateral margin have a low recurrence rate. Piecemeal resection was associated with higher local recurrence, and thermal ablation was inversely associated with local recurrence. Endoscopic resection with positive lateral margin combined with thermal ablation leads to a low recurrence rate.

915 A Comparison of Endoscopic Submucosal Resection (EMR) vs. Endoscopic Submucosal Dissection (ESD) on Histologic Margins and Pathologic Evaluation for Endoscopically Managed Early Esophageal Adenocarcinoma

INTRODUCTION: Accurate histologic determination is important to determine the completeness of endoscopic resection for esophageal adenocarcinoma (EAC) and gauge risk of recurrence. EMR and ESD are both endoscopic resection techniques used for the treatment of early EAC. ESD advocates believe ESD specimens allow for more precise histopathologic analysis than EMR, but this has never been proven. We aim to determine the effect of EMR vs ESD techniques on histologic analysis in endoscopically treated early EAC. METHODS: This is a retrospective, single center study of EMR and ESD resection specimens with pathologic confirmation of HGD or T1 EAC between 1/15-12/18. Lesions with suspected invasion into the muscularis mucosa or beyond (T2 carcinoma or higher) were excluded. Endoscopic and histologic characteristics were collected. Pathology slides were re-analyzed by a blinded GI pathologist for typical pathologic features. RESULTS: 52 patients with early EAC were analyzed (23 ESD;29 EMR) [Table 1]. ESD-resected tumors were larger compared to those resected by EMR (20 mm [20.0, 28.0] vs 11 mm [9.0, 13.0], P &lt; 0.001) [Table 2]. As per Table 3, EMR specimens were more likely to have positive lateral margins compared to ESD (38% vs 13%, P &lt; 0.005) and have lower confidence in determining lateral margins. Reasons for lower confidence in the EMR group included cautery artifact (37.9%) and difficulty in orientation (20.7%). When accounting for differences in specimen thickness, EMR had a higher percentage of cauterized tissue per total tissue thickness (11.8% vs 3.9%, P &lt; 0.001). EMR specimens had cautery effect abutting the lesion while ESD did not (0 μm vs 2259 μm distance of lesion from nearest cautery, P = 0.001). Cautery effect was more likely to interfere with margin evaluation in EMR (38% vs 13%, P = 0.04). ESD specimens were well-oriented compared to EMR (P = 0.011). EMR and ESD had no difference in positive vertical margins (7% vs 9%, P = 0.33), lymphovascular invasion (P = 0.11), or submucosal invasion (P = 0.62). CONCLUSION: Cautery effect and the inability to orient the specimens appropriately play a role in limiting the evaluation of EMR specimens. EMR and ESD had similar rates of positive vertical margins but rates of positive lateral margins were significantly higher in EMR, despite a smaller lesion size resected with EMR. We postulate that this is a limitation of EMR technique and there is a certain lateral size that is unsuitable for EMR as it may not be able to resect enough of a “normal” margin to the tumor compared to ESD.