Rectal Adenomas Research Articles

Simple Sugar and Sugar-Sweetened Beverage Intake During Adolescence and Risk of Colorectal Cancer Precursors

Recent increasing trends in early-onset colorectal cancer (CRC) strongly supports that early-life diet is involved in CRC development. However, data are lacking on the relationship with high sugar intake during early life. We prospectively investigated the association of adolescent simple sugar (fructose, glucose, added sugar, total sugar) and sugar-sweetened beverage (SSB) intake with CRC precursor risk in 33,106 participants of the Nurses' Health Study II who provided adolescent dietary information in 1998 and subsequently underwent lower gastrointestinal endoscopy between 1999 and 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression for clustered data. During follow-up, 2909 conventional adenomas (758 high-risk) and 2355 serrated lesions were identified (mean age at diagnoses, 52.2 ± 4.3 years). High sugar and SSB intake during adolescence was positively associated with risk of adenoma, but not serrated lesions. Per each increment of 5% of calories from total fructose intake, multivariable ORs were 1.17 (95% CI, 1.05-1.31) for total and 1.30 (95% CI, 1.06-1.60) for high-risk adenoma. By subsite, ORs were 1.12 (95% CI, 0.96-1.30) for proximal, 1.24 (95% CI, 1.05-1.47) for distal, and 1.43 (95% CI, 1.10-1.86) for rectal adenoma. Per 1 serving/day increment in SSB intake, ORs were 1.11 (95% CI, 1.02-1.20) for total and 1.30 (95% CI, 1.08-1.55) for rectal adenoma. Contrary to adolescent intake, sugar and SSB intake during adulthood was not associated with adenoma risk. High intake of simple sugars and SSBs during adolescence was associated with increased risk of conventional adenoma, especially rectal adenoma.

Multiparametric MRI-based machine learning models for preoperatively predicting rectal adenoma with canceration

To propose multiparametric MRI-based machine learning models and assess their ability to preoperatively predict rectal adenoma with canceration. A total of 53 patients with postoperative pathology confirming rectal adenoma (n = 29) and adenoma with canceration (n = 24) were enrolled in this retrospective study. All patients were divided into a training cohort (n = 42) and a test cohort (n = 11). All patients underwent preoperative pelvic MR examination, including high-resolution T2-weighted imaging (HR-T2WI) and diffusion-weighted imaging (DWI). A total of 1396 radiomics features were extracted from the HR-T2WI and DWI sequences, respectively. The least absolute shrinkage and selection operator (LASSO) was utilized for feature selection from the radiomics feature sets from the HR-T2WI and DWI sequences and from the combined feature set with 2792 radiomics features incorporating two sequences. Five-fold cross-validation and two machine learning algorithms (logistic regression, LR; support vector machine, SVM) were utilized for model construction in the training cohort. The diagnostic performance of the models was evaluated by sensitivity, specificity and area under the curve (AUC) and compared with the Delong's test. Ten, 8, and 25 optimal features were selected from 1396HR-T2WI, 1396 DWI and 2792 combined features, respectively. Three group models were constructed using the selected features from HR-T2WI (ModelT2), DWI (ModelDWI) and the two sequences combined (Modelcombined). Modelcombined showed better prediction performance than ModelT2 and ModelDWI. In Modelcombined, there was no significant difference between the LR and SVM algorithms (p = 0.4795), with AUCs in the test cohort of 0.867 and 0.900, respectively. Multiparametric MRI-based machine learning models have the potential to predict rectal adenoma with canceration. Compared with ModelT2 and ModelDWI, Modelcombined showed the best performance. Moreover, both LR and SVM have equal excellent performance for model construction.

Dairy intake during adolescence and risk of colorectal adenoma later in life

BackgroundHigher dairy intake during adulthood has been associated with lower colorectal cancer risk. As colorectal carcinogenesis spans several decades, we hypothesised that higher dairy intake during adolescence is associated with lower risk of colorectal adenoma, a colorectal cancer precursor.MethodsIn 27,196 females from the Nurses’ Health Study 2, aged 25–42 years at recruitment (1989), who had completed a validated high school diet questionnaire in 1998 and undergone at least one lower bowel endoscopy between 1998 and 2011, logistic regression for clustered data was used to calculate odds ratios (ORs) and 95% confidence intervals (CI).ResultsColorectal adenomas were diagnosed in 2239 women. Dairy consumption during adolescence was not associated with colorectal adenoma risk (OR highest vs. lowest [≥4 vs. ≤1.42 servings/day] quintile [95% CI] 0.94 [0.80, 1.11]). By anatomical site, higher adolescent dairy intake was associated with lower rectal (0.63 [0.42, 0.95]), but not proximal (1.01 [0.80, 1.28]) or distal (0.97 [0.76, 1.24]) colon adenoma risk. An inverse association was observed with histologically advanced (0.72 [0.51, 1.00]) but not non-advanced (1.07 [0.86, 1.33]) adenoma.ConclusionsIn this large cohort of younger women, higher adolescent dairy intake was associated with lower rectal and advanced adenoma risk later in life.

Transanal endoscopic microsurgery under spinal anaesthesia.

Background:Transanal endoscopic microsurgery (TEM) is considered the procedure of choice for rectal adenomas non-amendable for endoscopic excision and for early rectal cancer. TEM may gain more importance in patients who are considered unfit for major surgery. The option of spinal anaesthesia may offer many advantages for patients undergoing TEM while maintaining the principles of complete tumour excision. The aim of this study is to report the outcome of patients undergoing TEM under spinal anaesthesia.Methods:Demographic and clinical data pertaining patients undergoing TEM under spinal anaesthesia between 2004 and 2015 were retrospectively collected.Results:A total of 158 TEM procedures were recorded in the study period. Twenty-three patients (15%) underwent the procedure under spinal anaesthesia and were included in the study; 13 of them were male and ten were female. The mean age of the patients was 69.1 ± 10.6 years. Seventeen (74%) rectal lesions were adenomas, two (9%) were adenocarcinoma and four (17%) had involved margins after polypectomy. The mean tumour size was 2.1 cm (range, 0.5–3). Distance from the anal verge was 7.7 ± 2.2 cm. Seventeen (74%) lesions were in the posterior wall. The operative time was 73 min (range, 46–108) No adverse anaesthesia-related events were recorded, and the post-operative pain was reduced. The median time of hospitalisation was 2 days (range, 1–4). No major complications were noted, and the minor complications were treated conservatively. The surgical margins were free of tumour in all cases.Conclusion:TEM under spinal anaesthesia had short duration of surgery, no increase in operative and post-operative complications or hospital length of stay. Avoiding the use of general anaesthesia, in such challenging procedure, may open new opportunities for patients determined to be unfit for general anaesthesia.

Long-term outcomes of endoscopic submucosal dissection and transanal endoscopic microsurgery for the treatment of rectal tumors.

Endoscopic submucosal dissection and transanal endoscopic microsurgery are good options for the treatment of rectal adenomas and early rectal carcinomas, but whether long-term outcomes of these procedures are comparable is not known. The aim of this study was to address this question. A retrospective single-center study evaluating 98 consecutive procedures between June 2008 and December 2017 was performed in a tertiary cancer center. Consecutive patients who had undergone either endoscopic submucosal resection or transanal endoscopic microsurgery for rectal adenomas and early rectal carcinomas were evaluated, and long-term recurrence and complication rates were compared. Both groups were similar regarding sex, age, preoperative surgical risk, and en bloc resection rate (95.7% in the endoscopic and 100% in the surgical group, P=0.81). Mean follow-up period was 37.6months. Lesions resected endoscopically were significantly larger (68.5mm) than those resected by transanal resection (44.5mm), P=0.003. Curative resections occurred in 97.2% of endoscopic resections and 85.2% of the surgical ones (P=0.04). Comparing resections that fulfilled histologic curative criteria, there were no recurrences in the endoscopic group (out of 69 cases) and two recurrences in the transanal group (8.3% of 24 cases), P=0.06. Late complications occurred in 12.7% of endoscopic procedures and 25.9% of surgical procedures (P=0.13). In our experience, endoscopic submucosal resection seems to have advantages over transanal endoscopic microsurgery, with similar en bloc resection rate and lower rate of late complications and recurrences. Multicenter randomized controlled trials are needed to support our findings.

Comprehensive Assessment of Diet Quality and Risk of Precursors ofEarly-Onset Colorectal Cancer.

The role of poor diet quality in the rising incidence of colorectal cancer (CRC) diagnosed younger than age 50 years has not been explored. Based on molecular features of early-onset CRC, early-onset adenomas are emerging surrogate endpoints. In a prospective cohort study (Nurses' Health Study II), we evaluated 2 empirical dietary patterns (Western and prudent) and 3 recommendation-based indexes (Dietary Approaches to Stop Hypertension [DASH], Alternative Mediterranean Diet [AMED], and Alternative Healthy Eating Index [AHEI]-2010) with risk of early-onset adenoma overall and by malignant potential (high-risk: ≥1 cm, tubulovillous or villous histology, high-grade dysplasia, or ≥3 adenomas), among 29 474 women with 1 or more lower endoscopy before age 50 years (1991-2011). Multivariable logistic regressions were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). We documented 1157 early-onset adenomas with 375 at high risk. Western diet was positively associated, whereas prudent diet, DASH, AMED, and AHEI-2010 were inversely associated with risk of early-onset adenoma. The associations were largely confined to high-risk adenomas (the highest vs lowest quintile: Western, OR = 1.67, 95% CI = 1.18 to 2.37; prudent, OR = 0.69, 95% CI = 0.48 to 0.98; DASH, OR = 0.65, 95% CI = 0.45 to 0.93; AMED, OR = 0.55, 95% CI = 0.38 to 0.79; AHEI-2010, OR = 0.71, 95% CI = 0.51 to 1.01; all Ptrend ≤ .03), driven by those identified in the distal colon and rectum (all Ptrend ≤ .04, except AMED: Ptrend = .14). Poor diet quality was associated with an increased risk of early-onset distal and rectal adenomas of high malignant potential. These findings provide preliminary but strong support to the role of diet in early-onset CRC.

Transanal minimally invasive surgery vs endoscopic mucosal resection for rectal benign tumors and rectal carcinoids: A retrospective analysis.

BACKGROUNDTransanal minimally invasive surgery (TAMIS) is a good choice for resection of rectal neoplasms. Endoscopic mucosal resection (EMR) is also widely used in the treatment of benign rectal tumors such as rectal polyps and rectal adenomas. However, no studies have compared the outcome of TAMIS and EMR.AIMTo compare the short-term outcomes after TAMIS and EMR for rectal carcinoid and benign tumors (including rectal polyps and adenomas).METHODSFrom January 2014 to January 2019, 44 patients who received TAMIS and 53 patients who received EMR at The Fifth People’s Hospital of Shanghai were selected. Primary outcomes (surgical-related) were operating time, blood loss, length of postoperative hospital stay, rate of resection margin involvement and lesion fragmentation rate. The secondary outcomes were complications such as hemorrhage, urinary retention, postoperative infection and reoperation.RESULTSNo significant differences were observed in terms of blood loss (12.48 ± 8.00 mL for TAMIS vs 11.45 ± 7.82 mL for EMR, P = 0.527) and length of postoperative hospital stay (3.50 ± 1.87 d for TAMIS vs 2.72 ± 1.98 d for EMR, P = 0.065) between the two groups. Operating time was significantly shorter for EMR compared with TAMIS (21.19 ± 9.49 min vs 49.95 ± 15.28 min, P = 0.001). The lesion fragmentation rate in the EMR group was 22.6% (12/53) and was significantly higher than that (0%, 0/44) in the TAMIS group (P = 0.001). TAMIS was associated with a higher urinary retention rate (13.6%, 6/44 vs 1.9%, 1/53 P = 0.026) and lower hemorrhage rate (0%, 0/44 vs 18.9%, 10/53 P = 0.002). A significantly higher reoperation rate was observed in the EMR group (9.4%, 5/53 vs 0%, 0/44 P = 0.036).CONCLUSIONCompared with EMR, TAMIS can remove lesions more completely with effective hemostasis and lower postoperative hemorrhage and reoperation rates. TAMIS is a better choice for the treatment of rectal carcinoids.

COMPARATIVE EVALUATION OF MULTIPARAMETRIC ENDORECTAL ULTRASOUND AND ENHANCED IMAGING COLONOSCOPY IN THE DIAGNOSIS OF EARLY COLORECTAL CANCER

AIM: to compare multiparametric endorectal ultrasound (ERUS) and enhanced imaging colonoscopy in the diagnosis of early colorectal cancer.PATIENTS AND METHODS: the study included 78 patients with epithelial rectal tumor. All the patients underwent multiparametric ERUS and colonoscopy with examination by narrow beam imaging (NBI) at optical magnification. All the patients were operated.RESULTS: a morphological examination removed specimens revealed adenomas in 48 cases, in 19 specimens – adenocarcinomas in situ and T1, and in 11 specimens – adenocarcinomas with invasion of the muscle layer or deeper. When calculating the accuracy indicators of diagnostic methods for groups of patients with adenoma, Tis-T1 adenocarcinoma, and T2-T3 adenocarcinoma, the difference in the sensitivity and specificity of the methods in none of the presented groups did not reach the level of statistical significance (p>0.05).ROC analysis showed that ultrasound has a prognostic value comparable to colonoscopy. The area difference was 0.013 (p=0.85).CONCLUSION: endoscopy and ultrasound have similar value in the diagnosis of malignant transformation of rectal adenomas.

P-45 Applicable value of transanal endoscopic microsurgery for high-risk rectal adenoma and early rectal cancer: Experience from 126 cases

P-45 Applicable value of transanal endoscopic microsurgery for high-risk rectal adenoma and early rectal cancer: Experience from 126 cases

Hybrid precutting EMR-EFTR resection for a tricky rectal adenoma recurrence with high-grade fibrosis

Hybrid precutting EMR-EFTR resection for a tricky rectal adenoma recurrence with high-grade fibrosis

The utility of preoperative radiological evaluation of early rectal neoplasia: a systematic review and meta-analysis.

The diagnostic role for preoperative imaging of clinically benign rectal adenomas is unclear. The objective of this systematic review and meta-analysis was to examine the diagnostic accuracy of preoperative imaging in distinguishing benign adenomas from rectal cancer. A systematic search was performed for all studies published that correlated staging of clinically benign rectal adenomas with endorectal ultrasound (ERUS) or MRI and histology. Imaging was compared with postoperative histology and data on the numbers of true positives, false positives, true negatives and false negatives were extracted. Summary estimates of sensitivity and specificity with 95% CIs were calculated using a bivariate random effects model. The QUADAS2 tool was used to determine the methodological quality of included studies. Eleven studies describing 1511 patients were retrieved. A total of 1134 patients underwent local excision and 377 had a formal proctectomy. A benign rectal adenoma was diagnosed in 840 and 214 had a T1 rectal cancer. For confirming benign adenomas, the pooled sensitivity of ERUS was 0.81 (95% CI 0.69-0.89) and specificity was 0.85 (95% CI 0.68-0.93). For detecting occult T1 tumours, the pooled sensitivity of ERUS was 0.50 (95% CI 0.33-0.66) and specificity was 0.89 (95% CI 0.82-0.94). Quantitative analysis of MRI could not be performed due to insufficient studies. This study demonstrates the limited accuracy of preoperative ERUS in distinguishing benign adenomas from T1 rectal cancer. Preoperative imaging must be interpreted with caution to prevent over-staging and unnecessary proctectomy. We propose that clinically benign lesions may undergo local excision, with subsequent management based on final histology.

Art in Endoscopy: "Prehistoric cave art".

This image was observed after a macroscopically complete endoscopic mucosal resection of a rectal adenoma. Before resection the submucosa was injected with indigo carmine, resulting in a beautiful blue background with the unaffected red vessels looking remarkably like a prehistoric cave painting.

Transanal endoscopic microsurgery: indications, tips and long-term results. A single center experience.

Transanal endoscopic microsurgery (TEM) was introduced to combine the curativeness of full thickness excision with minimum morbidity, while traditional rectal surgery is burdened by high morbidity and mortality rates. However, while it is still a matter of considerable debate whether local excision is an adequate approach for curative resection of rectal cancer, new minimally invasive operative techniques have been introduced. The purpose of this paper was to show the indications, the tips and long term results of this technique through the review of the largest single-center database available to date. The showed results derived from the single center experience of the Clinica Chirurgica of Polytechnic University of Marche. We retrospectively reviewed a 25-year database from May 1992 to May 2017. We divided the patients into three different groups of patients according to the preoperative diagnosis: rectal cancers, adenomas and other rectal lesions. Rectal adenomas were divided into two groups according to their diameter (> or <5 cm). Rectal cancer patients were divided into two groups according to the preoperative staging: early rectal cancer and irradiated rectal cancer. Among the 1324 patients who had rectal tumors excised with TEM at our institution, preoperative histology was rectal adenoma in 729 (55%) patients, adenocarcinoma in 536 (40.5%) patients and other lesions in the remaining 59 (4.4%) patients. 5 years overall survival (OS) and Recurrence free survival (RFS) were 93.3% and 98.6% for patients with rectal adenomas and 86.8% and 70.9% for patients with rectal cancer. TEM can be a valid alternative for the treatment of both benign and malignant rectal lesions, further studies are needed to define more specific indications to justify the survival of this technique in the future.

Reliability in villous tumors staging between preoperative MRI and histopathological examination.

This study aimed to assess the reliability of rectal villous tumors staging between rectal MRI and histological examination used as the Gold Standard and to investigate causes for discrepancies. The rectal 1.5T MR scans of 40 patients followed for a histologically proven rectal villous adenoma were retrospectively included. Two independent experienced radiologists staged each tumor according to the TNM classification and described the occurrence of retraction of the rectal wall or spiculations within the associated mesorectum. A third radiologist collected tumor's morphological characteristics. Among the 40 villous tumors studied, 25 (63%) were non-invasive and 15 (37%) were invasive. The mean volume of tumors with spiculations and retraction was significantly greater (p < 0.05) compared to tumors without these characteristics. Spiculations and retraction of the rectal wall were observed regardless of the definitive histological stage and did not represent a malignancy criterion. A weak interobserver reliability [Gwet's AC2: 0.31 (0.04-0.57)] in T-staging was observed between the two readers. Reader 1 showed a high reliability [Gwet's AC2: 0.90 (0.81-0.99)] in T-staging between Histopathological examination and preoperative MRI. In the opposite, reader 2 showed a weak reliability [Gwet's AC2: 0.31 (0.03-0.58)] in T-staging. He overstaged all tumors (100%) with spiculations (p < 0.05). MRI understaged rectal villous adenoma and was unable to detect degenerative criteria, along with slight Interobserver agreement. The typical worrisome signs of rectal tumor, such as retractions and spiculations, occurred in all stages and were responsible for misstaging in most cases, in particular bulky tumors.

Surgical and postoperative evaluations of rectal adenomas excised with a rigid proctoscope.

Purpose This study presents the surgical and postoperative results achieved with a rigid proctoscope using the transanal endoscopic technique to excise rectal adenomas. The results are compared to the results obtained with other currently employed transanal techniques.Methods We investigated the medical records of patients who underwent transanal endoscopic operations from April 2000 to June 2018 at two tertiary referral centers for colorectal cancer.Results This study included 99 patients. The mean age was 65.3 ± 13.3 years. The average size of the adenomas was 4.6 ± 2.3 cm, and their average distance to the anal border was 5.6 ± 3.3 cm. The average operative time was 65.3 ± 41.7 min. In 48.5% of the operations, the specimen was fragmented, and in 59.6% of the cases, the microscopic margins were free. The rates of postoperative complications and relapse were 5% and 19%, respectively. The mean follow-up was 80 ± 61.5 months.Conclusions The described proctoscope proved to be a viable technique with results similar to other techniques, with the advantage that it allowed greater accessibility for surgeons. Therefore, its use could be implemented and become widespread in surgical practice.

Transanal minimally invasive surgery short- and mid-term outcomes

Introduction: Transanal minimally invasive surgery (TAMIS) is a very efficient and safe technique for the management of rectal lesions that are large or not amenable to colonoscopic removal. Both benign and malignant lesions can be excised with higher rates of specimen nonfragmentation and margin negativity. Introduced in 2010 by Atallah it has undergone tremendous growth with respect to indications and instrumentation. We present our short- and mid-term experience in this novel technique. Materials and Methods: A retrospective study from September 2016 (when the first TAMIS case was done in our institution) up to February 2020 was carried out. Case records were analyzed and their outpatient follow-up was traced. Results: A total of 20 patients had undergone TAMIS from September 2016 to February 2020. The most common indication for undergoing TAMIS was rectal adenomas in 6 (30%) patients. This was followed by rectal carcinomas in situ or carcinoma suspected in a previously biopsied polyp in 4 (20%) patients. Hyperplastic polyps constituted 4 (20%) of the TAMIS procedures. We also had two patients with juvenile polyposis. There was no specimen fragmentation in any of the specimens. Only one patient had a positive margin and underwent low anterior resection. The final biopsy showed no residual tumor. There were no procedure-related complications. The average hospital stay was 24 h. All procures were done under general anesthesia. Our longest follow-up is 40 months. The mean follow-up was of 16.1 months. There has been no procedure-related complication. None of our patients have recurrence. Conclusion: TAMIS is a safe and effective technique for the management of benign and early rectal cancer lesions of the rectum. Our short- and mid-term outcomes are encouraging to continue using this technique for our patients.

Acute Hemorrhagic Incarceration of Prolapsed Giant Rectal Tubulovillous Adenoma: A Rare Case of Anorectal Emergency

Acute Hemorrhagic Incarceration of Prolapsed Giant Rectal Tubulovillous Adenoma: A Rare Case of Anorectal Emergency

Transanal endoscopic microsurgery for rectal villous tumours: Can we rely solely on preoperative biopsies and the surgeon’s experience?

Transanal endoscopic microsurgery has become the standard of treatment for rectal villous adenomas. However, the role of preoperative imaging for these lesions is not clear. The aim of this study was to compare the value of preoperative imaging and surgeon clinical staging in the preoperative evaluation of patients with rectal villous adenomas having transanal endoscopic microsurgery resection. We conducted a single-centre comparative retrospective cohort study of patients who underwent transanal endoscopic microsurgery surgery for rectal villous adenomas from 2011 to 2013. The intervention was preoperative imaging versus surgeon clinical staging. The primary outcome was the accuracy of clinical staging by preoperative imaging and surgeon clinical staging according to the histopathologic staging. A total of 146 patients underwent transanal endoscopic microsurgery surgery for rectal villous adenomas. One hundred and twelve (76.7%) of those patients had no preoperative imaging while 34 patients (23.3%) had either endorectal ultrasound (22 patients) or magnetic resonance imaging (12 patients). Surgeon staging was accurate in 89.3% of cases whereas staging by endorectal ultrasound was accurate in 40.9% cases and magnetic resonance imaging was accurate in 0% of cases. In the imaging group, inaccurate staging would have led to unnecessary radical surgery in 44.0% of patients. This study was subject to selection bias because of its retrospective nature and the limited number of patients with imaging. Patients with rectal villous tumours without invasive carcinoma on biopsies and without malignant characteristics on appearance in the judgment of an experienced colorectal surgeon might not benefit from preoperative imaging before undergoing transanal endoscopic microsurgery procedures.

Mass spectrometry transanal minimally invasive surgery (MS-TAMIS) to promote organ preservation in rectal cancer

BackgroundTransanal minimally invasive surgery (TAMIS) is deployed for organ preservation in early rectal cancer and significant rectal polyps. Rapid evaporative ionisation mass spectrometry (REIMS) provides biochemical tissue analysis, which could be applied intraoperatively to give real-time tissue feedback to the surgeon and decrease the risk of an involved margin. However, the accuracy and feasibility of this approach have not been established.MethodsIn this prospective observational study, patients undergoing resection of rectal adenomas or carcinomas were recruited. An electrosurgical handpiece analysed tissues ex vivo using diathermy, with the aerosol aspirated into a Xevo G2-S ToF mass spectrometer. The relative abundance of lipids underwent predictive statistical modelling and leave-one-patient-out cross-validation. The outcomes of interest were the ability of REIMS to differentiate normal, adenomatous and cancerous tissue, or any disease subtype from normal. REIMS was coupled with TAMIS for in vivo sampling, assessing the accuracy of tissue recognition and distinguishing bowel wall layers.ResultsForty-seven patients were included, yielding 266 spectra (121 normal, 109 tumour and 36 adenoma). REIMS differentiates normal, adenomatous and cancerous rectal tissues with 86.8% accuracy, and normal and adenomatous tissue with 92.4% accuracy and 91.4% accuracy when differentiating disease from normal. We have performed the first five in-man mass spectrometry augmented TAMIS (MS-TAMIS). In real time, MS-TAMIS can differentiate rectal mucosa and submucosa based on their relative abundance of triglycerides and glycerophospholipids. The ex vivo accuracy distinguishing diseased and normal tissues is maintained in vivo at 90%, with negative predictive value of 95%. The system identified a deep and lateral involved tumour margin during TAMIS.ConclusionsREIMS distinguishes rectal tissue types based on underlying lipid biology, and this can be translated in vivo by coupling it to TAMIS. There is a role for this technology in improving the efficacy of resection of early rectal cancers.

2118 A Challenging Case of Recurrent Rectal Adenoma Despite Multiple Endoscopic Mucosal Resections (EMRs) and Trans-Anal Endoscopic Microsurgeries (TEMS)

INTRODUCTION: Detection and complete removal of colorectal adenomas is essential in reducing the incidence and mortality of cancer. Advanced rectal adenomas can be removed by a number of techniques including Endoscopic Mucosal Resection (EMR), Endoscopic Submucosal Dissection (ESD) and Trans-anal Endoscopic Microsurgery (TEMS). Despite complete resection, local recurrence remains a challenge in some patients. We report a rare case of a recurrent rectal adenoma despite multiple EMRs and TEMS procedures over a 5-year period. CASE DESCRIPTION/METHODS: A 63-year female was referred for EMR of a 2 cm rectal adenoma found on screening colonoscopy 5 years ago (Figure 1). Colonoscopy with en-bloc EMR was done without difficulty. On 6-month follow-up a recurrent adenoma was seen at EMR site. En-bloc EMR was again performed followed by argon plasma coagulation (APC) ablation of edges. Follow-up flexible sigmoidoscopy 6-months later again showed a recurrent adenoma. Patient was referred for TEMS; full-thickness resection was performed with negative margins on pathology specimen. Surveillance colonoscopy 6 months after TEMS revealed recurrent adenoma at the TEMS site. TEMS was repeated. Follow-up endoscopic examination and biopsy 2 months and 1 year after the second TEMS revealed no evidence of lesion recurrence (Figure 2). However her most recent colonoscopy, 3 years after the second TEMS, showed a recurrent 6 mm sessile adenoma at same site (Figure 3). After multidisciplinary consultation, she is scheduled to undergo a third TEMS procedure. DISCUSSION: The reported incidence of recurrent rectal adenoma is 4-11%. Factors affecting local recurrence include size of index polyp and completeness of resection. Despite complete resection, some patients will develop repeated recurrence. Ramkumar et al. reported 669 patients who underwent TEMS for treatment of rectal lesions; 15 pts required 3 or more TEMS procedures. Repeat TEMS was shown to be safe with similar postoperative complications and similar rates of margin clearance (81% vs 88%, P = 0.09) compared to primary TEMS 1 . In our patient, a rectal adenoma recurred despite 2 en-bloc EMRs and 2 TEMS. This demonstrates the need for close surveillance and the importance of a multi-disciplinary treatment approach in these patients.