Completion total mesorectal excision after neoadjuvant radiochemotherapy and local excision for rectal cancer.

AIM: Local excision (LE) in selected cases after neoadjuvant radiochemotherapy (RCT) for locally advanced rectal cancer in clinically complete or major responders has been recently reported as an alternative to standard radical resection. Completion total mesorectal excision (cTME) is generally performed when high-risk pathological features are found in LE surgical specimens. The aim of this study was to evaluate the incidence of residual tumour and lymph node metastases after cTME in patients previously treated by RCT + LE. The secondary aims were to quantify the rate of postoperative morbidity and mortality and to evaluate the long-term oncological outcome of this group of patients. METHODS: All patients treated from 2007 to 2020 by LE for locally advanced rectal cancer with a clinically complete or major response to RCT who had a subsequent cTME for high-risk pathological factors (ypT >1 and/or TRG >2 and/or positive margins) were included in this multicentre retrospective study. Pathological data, postoperative short-term morbidity (classified according to Clavien-Dindo) and mortality and oncological long-term outcome after cTME were recorded in a database. Statistical analysis was performed using Wizard for iOS version 1.9.31. RESULTS: A total of 47 patients were included in the study. The rate of R0 resection was 95.7%, and a sphincter-saving procedure was performed in 37 patients (78.7%), with a protective stoma rate of 78.4%. In 28 cases (59.6%), it was possible to perform a minimally invasive approach. A residual tumour (pT and/or pN) on cTME specimens was found in 21 cases (44.7%). The rate of lymph node metastases was 12.8%. The overall short-term (within 30 days) postoperative morbidity was 34%, but grade >2 postoperative complications occurred in only nine patients (19.1%), with a reoperation rate of 6.4%. No short-term postoperative deaths occurred. At a median follow-up of 57 months (range: 21-174), the long-term stoma-free rate was 70.2%, and the actuarial 5-year overall survival (OS), disease-free survival (DFS) and local control (LC) were 86.7%, 88.9% and 95.7%, respectively. CONCLUSION: When patients exhibit high-risk pathological factors after RCT + LE, cTME should be suggested due to the high risk of residual tumour or lymph node involvement (44.7%). The results after cTME in terms of the rate of R0 resection, sphincter-saving procedure, postoperative morbidity and mortality and long-term oncological outcome seem to be acceptable and do not represent a contraindication to use LE as a first-step treatment in patients with major or complete clinical response after RCT.

Efficacy and safety of salvage endoscopy in the treatment of residual or recurrent colorectal neoplasia after endoscopic resection: a systematic review and meta-analysis.

OBJECTIVE: To systematically review and meta-analyze the efficacy and safety of salvage endoscopy for residual or recurrence of colorectal tumors after endoscopic resection. METHODS: Multiple databases including PubMed, EMBASE and the Cochrane Library were searched to screen for eligible studies and perform data extraction and pooled analysis. RESULTS: Sixteen studies on salvage endoscopy for residual or recurrent colorectal cancer after endoscopic resection were included, covering approximately 994 patients. The results of the meta-analysis demonstrated that salvage endoscopic therapy for residual or recurrent colorectal tumors following endoscopic resection achieved an en bloc resection rate of 92% (95% CI 0.85-0.97; I2 = 91%) and an R0 resection rate of 82% (95% CI 0.75-0.87; I2 = 78%). The rates of intraoperative or postoperative bleeding and perforation were 10%/1% and 5%/2%, and the recurrence rate was 2%. CONCLUSIONS: Salvage endoscopic resection is an effective and safe treatment strategy for residual or recurrent colorectal tumors after endoscopic resection.

Measurable residual disease monitoring in patients with acute myeloid leukemia treated with lower-intensity therapy: Roadmap from an ELN-DAVID expert panel.

With the availability of effective targeted agents, significant changes have occurred in the management of patients with acute myeloid leukemia (AML) over the past several years, particularly for those considered unfit for intensive chemotherapy. While testing for measurable residual disease (MRD) is now routinely performed in patients treated with intensive chemotherapy to refine prognosis and, possibly, inform treatment decision-making, its value in the context of lower-intensity regimens is unclear. As such regimens have gained in popularity and can be associated with higher response rates, the need to better define the role of MRD assessment and the appropriate time points and assays used for this purpose has increased. This report outlines a roadmap for MRD testing in patients with AML treated with lower-intensity regimens. Experts from the European LeukemiaNet (ELN)-DAVID AML MRD working group reviewed all available data to propose a framework for MRD testing in future trials and clinical practice. A Delphi poll served to optimize consensus. Establishment of uniform standards for MRD assessments in lower-intensity regimens used in treating patients with AML is clinically relevant and important for optimizing testing and, ultimately, improving treatment outcomes of these patients.

An Optical Sensory System for Assessment of Residual Cancer Burden in Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy.

Breast cancer patients undergoing neoadjuvant chemotherapy (NAC) require precise and accurate evaluation of treatment response. Residual cancer burden (RCB) is a prognostic tool widely used to estimate survival outcomes in breast cancer. In this study, we introduced a machine-learning-based optical biosensor called the Opti-scan probe to assess residual cancer burden in breast cancer patients undergoing NAC. The Opti-scan probe data were acquired from 15 patients (mean age: 61.8 years) before and after each cycle of NAC. Using regression analysis with k-fold cross-validation, we calculated the optical properties of healthy and unhealthy breast tissues. The ML predictive model was trained on the optical parameter values and breast cancer imaging features obtained from the Opti-scan probe data to calculate RCB values. The results show that the ML model achieved a high accuracy of 0.98 in predicting RCB number/class based on the changes in optical properties measured by the Opti-scan probe. These findings suggest that our ML-based Opti-scan probe has considerable potential as a valuable tool for the assessment of breast cancer response after NAC and to guide treatment decisions. Therefore, it could be a promising, non-invasive, and accurate method for monitoring breast cancer patient's response to NAC.

Treatment Efficacy Score-continuous residual cancer burden-based metric to compare neoadjuvant chemotherapy efficacy between randomized trial arms in breast cancer trials.

BACKGROUND: Difference in pathologic complete response (pCR) rate after neoadjuvant chemotherapy does not capture the impact of treatment on downstaging of residual cancer in the experimental arm. We developed a method to compare the entire distribution of residual cancer burden (RCB) values between clinical trial arms to better quantify the differences in cytotoxic efficacy of treatments. PATIENTS AND METHODS: The Treatment Efficacy Score (TES) reflects the area between the weighted cumulative distribution functions of RCB values from two trial arms. TES is based on a modified Kolmogorov-Smirnov test with added weight function to capture the importance of high RCB values and uses the area under the difference between two distribution functions as a statistical metric. The higher the TES the greater the shift to lower RCB values in the experimental arm. We developed TES from the durvalumab + olaparib arm (n = 72) and corresponding controls (n = 282) of the I-SPY2 trial. The 11 other experimental arms and control cohorts (n = 947) were used as validation sets to assess the performance of TES. We compared TES to Kolmogorov-Smirnov, Mann-Whitney, and Fisher's exact tests to identify trial arms with higher cytotoxic efficacy and assessed associations with trial arm level survival differences. Significance was assessed with a permutation test. RESULTS: In the validation set, TES identified arms with a higher pCR rate but was more accurate to identify regimens as less effective if treatment did not reduce the frequency of high RCB values, even if the pCR rate improved. The correlation between TES and survival was higher than the correlation between the pCR rate difference and survival. CONCLUSIONS: TES quantifies the difference between the entire distribution of pathologic responses observed in trial arms and could serve as a better early surrogate to predict trial arm level survival differences than pCR rate difference alone.

The Landmark Series: Neoadjuvant Chemotherapy for Triple-Negative and HER2-Positive Breast Cancer.

While historically breast cancer has been treated with primary surgery followed by adjuvant therapy, the delivery of systemic therapy in the neoadjuvant setting has become increasingly common, especially for triple-negative and HER2-positive breast cancer. The initial motivations for pursuing neoadjuvant chemotherapy (NAC) were decreasing the tumor burden in the breast and axilla to enable de-escalation of surgery, and use the strategy to advance drug development. While these remain of interest, recent trials have additionally demonstrated survival advantages from escalation of systemic treatment in patients with residual disease, and new studies are testing de-escalation of systemic therapy based on pathologic response. Thus, response information to NAC has become pivotal to guide adjuvant treatment recommendations, and has resulted in NAC being the preferred approach for most HER2-positive and triple-negative breast cancers. Herein, we review select landmark trials that have paved the way for the use of chemotherapy in the neoadjuvant setting for breast cancer.

Predictive value of endoscopic esophageal findings for residual esophageal cancer after neoadjuvant chemoradiotherapy.

BACKGROUND: Endoscopic evaluation of the esophageal mucosa may play a role in an active surveillance strategy after neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer. This study investigated the yield of endoscopic findings for detection of residual disease. METHODS: Patients from the multicenter preSANO cohort, who underwent nCRT followed by surgery for esophageal or junctional cancer, were included. Upper endoscopy was performed 6 and 12 weeks after nCRT. Patients with residual disease at 6 weeks underwent immediate surgery. Endoscopic records were reviewed for presence of stenosis, suspicion of residual tumor, scar tissue, and ulceration. Presence and type of endoscopic findings were compared with outcome of the resection specimen. RESULTS: 118 of 156 patients (76 %) had residual disease in the resection specimen. Endoscopic suspicion of residual tumor was significantly associated with presence of residual disease. At 6 weeks, 40/112 patients with residual disease and 4/33 patients with complete response had endoscopic suspicion of residual tumor (36 % vs. 12 %; P = 0.01), while this was reported in 16/73 and 0/28 patients, respectively, at 12 weeks (22 % vs. 0 %; P < 0.01). Positive predictive value of endoscopic suspicion of residual tumor was 91 % at 6 weeks and 100 % at 12 weeks. Endoscopic findings of non-passable stenosis, passable stenosis, scar tissue, or ulceration were not associated with residual disease. CONCLUSIONS: Endoscopic suspicion of residual tumor was the only endoscopic finding associated with residual disease. Based on its positive predictive value, this endoscopic finding may contribute to the diagnostic strategy used in active surveillance.

Management of Malignant Colon Polyps.

CASE SUMMARY: A 54-year-old otherwise healthy woman presented for screening colonoscopy, during which 4 pedunculated 5- to 12-mm polyps distributed throughout the colon were found (Fig. 1). The 12-mm sigmoid polyp was removed with hot snare polypectomy in a nonpiecemeal fashion. Pathology demonstrated 3 tubular adenomas and a poorly differentiated invasive carcinoma in a sigmoid polyp without tumor budding, invading 0.8 mm into the submucosa, with lymphovascular invasion and with a deep margin of 0.6 mm. The next week, she underwent repeat flexible sigmoidoscopy with tattooing of the polypectomy site. She had a normal staging CT chest/abdomen/pelvis as well as CEA level and later underwent uneventful laparoscopic sigmoid resection, which included the area of endoscopic tattoo. Final pathology confirmed the presence of the tattooed area and polypectomy scar and showed no residual primary tumor and 2/18 positive lymph nodes (Fig, 2). She was referred to medical oncology for adjuvant chemotherapy.

Suboptimal outcome for patients with biliary rhabdomyosarcoma treated on low-risk clinical trials: A report from the Children's Oncology Group.

BACKGROUND: Biliary rhabdomyosarcoma (RMS) is the most common biliary tumor in children. The biliary tract is classified as a favorable primary site. Therefore, patients with localized biliary RMS were included in two consecutive low-risk studies, D9602 and ARST0331, by the Children's Oncology Group (COG). The outcome for these patients treated with low-risk therapy has not been reported. PROCEDURE: Patients with biliary RMS enrolled on COG low-risk trials D9602 or ARST0331 were analyzed. All patients received systemic chemotherapy and those with Group II (microscopic residual) or Group III (macroscopic residual) disease received 36-50.4 Gy adjuvant radiotherapy (RT). Delayed primary excision (DPE) was allowed on both studies. RESULTS: Seventeen patients with biliary RMS were treated on D9602 (n = 7) or ARST0331 (n = 10). Median age was 3.5 years (range 1.7-10.3). Ten (59%) patients had tumors >5 cm and 14 (82%) had Group III disease. Fifteen (88%) patients received RT. The 5-year event-free survival (EFS) and overall survival (OS) were 70.6% (95% confidence interval [CI]: 46.9-94.3%) and 76.5% (95% CI: 54.6-98.4%), respectively. The majority of patients (80%) who received RT did not have disease recurrence while both patients who did not receive RT had local relapse. Five (36%) of 14 patients with Group III disease underwent DPE; two experienced a local relapse. In the nine patients without DPE, two developed local relapse. CONCLUSIONS: Patients with localized biliary RMS treated on low-risk studies had suboptimal outcomes. These patients may benefit from therapy on intermediate-risk studies.

Eliminating the breast cancer surgery paradigm after neoadjuvant systemic therapy: current evidence and future challenges.

In patients with operable early breast cancer, neoadjuvant systemic treatment (NST) is a standard approach. Indications have expanded from downstaging of locally advanced breast cancer to facilitate breast conservation, to in vivo drug-sensitivity testing. The pattern of response to NST is used to tailor systemic and locoregional treatment, that is, to escalate treatment in nonresponders and de-escalate treatment in responders. Here we discuss four questions that guide our current thinking about 'response-adjusted' surgery of the breast after NST. (i) What critical diagnostic outcome measures should be used when analyzing diagnostic tools to identify patients with pathologic complete response (pCR) after NST? (ii) How can we assess response with the least morbidity and best accuracy possible? (iii) What oncological consequences may ensue if we rely on a nonsurgical-generated diagnosis of, for example, minimally invasive biopsy proven pCR, knowing that we may miss minimal residual disease in some cases? (iv) How should we design clinical trials on de-escalation of surgical treatment after NST?

Use of Minimal Residual Disease in Acute Myeloid Leukemia Therapy.

OPINION STATEMENT: The expanding availability of minimal or more precisely measurable residual disease (MRD) assessment in acute myeloid leukemia (AML) with its possible implications for therapeutic decisions is of high interest to clinicians treating AML patients. A variety of mostly retrospective studies have shown that AML patients with a positive MRD test, assessed by different techniques at defined cutoffs and time-points, are at significantly higher risk of relapse and experience shorter overall survival compared to MRD-negative patients. How this valuable information may be adapted in the daily routine of patients' treatment to distinguish individuals who need more aggressive therapy from the ones who can be spared additional therapy to avoid treatment-related toxicities is still being investigated. With the exception of MRD analyses in acute promyelocitic leukemia (APL), the clinical implications of MRD tests for the individual AML patient are still mostly unknown. We currently lack hard evidence that MRD-based therapy modulation during treatment or pre-emptive intervention in MRD-positive patients after therapy would improve outcomes in non-APL AML patients. These questions will be evaluated in prospective randomized clinical trials. Today, however, some conclusions with regard to MRD assessment in AML can be drawn from the published data and are reviewed in this article.

Pathologic evaluation of response to neoadjuvant therapy drives treatment changes and improves long-term outcomes for breast cancer patients.

Systemic therapy for breast cancer may be given before (neoadjuvant) or after (adjuvant) surgery. When neoadjuvant systemic therapy is given, response to treatment can be evaluated. However, some prognostic information (for example, pathologic tumor size pretreatment) is then lost and pathologic evaluation of breast specimens after neoadjuvant therapy is more difficult. Pathologic complete response (pCR), defined as no invasive disease in the breast (ypT0/is or ypT0) and no disease in all sampled lymph nodes (ypN0), identifies patients with a lower risk of recurrence or death compared to those with residual disease. Multidisciplinary collaboration, marking of the tumor site and any lymph node involvement pretreatment, and access to specimen imaging to facilitate correlation of gross and microscopic findings are critical for accurate determination of pCR. For HER2-positive and triple negative tumors requiring systemic therapy, giving the treatment before surgery identifies a high-risk group of patients that can receive additional adjuvant therapy after surgery if a pCR is not achieved. Recent clinical trials have demonstrated that this approach reduced recurrence risk. More than ever, pathologic evaluation of response to neoadjuvant systemic therapy directs treatment received after surgery. Using a single standardized protocol for sampling of the post-neoadjuvant surgical specimen allows pathologists to ensure accurate determination of pCR or residual disease and quantify residual disease. Residual cancer burden (RCB) and AJCC stage provide complementary quantitative information about residual disease and prognosis.

Complete polypectomy and early detection and management of residual disease to reduce the risk of interval colorectal cancers.

Advances in colorectal polyp detection and resection methods aim to reduce interval cancer rates. Complete polypectomy is essential to reduce the risk of early recurrence and the development of interval cancers. To achieve this, polyps must first be correctly identified and then completely excised. This article reviews current adenoma detection methods in use and the management of residual disease.

Effectiveness of Hysteroscopic Techniques for Endometrial Polyp Removal: The Italian Multicenter Trial.

STUDY OBJECTIVE: To compare the effectiveness and safety of different techniques of hysteroscopic polypectomy. DESIGN: Multicenter, prospective observational trial (Canadian Task Force classification II-2). SETTING: Nineteen Italian gynecologic departments (university-affiliated or public hospitals). PATIENTS: Consecutive patients suffering from endometrial polyps (EPs). INTERVENTIONS: Hysteroscopic polypectomy, as performed through different techniques. MEASUREMENTS AND MAIN RESULTS: Included in the study were 1404 patients (with 1825 EPs). The setting was an ambulatory care unit in 40.38% of the cases (567 women), of whom 97.7% (554) did not require analgesia/anesthesia. In the remaining 59.62% of women (837 women), the procedures were performed in an operating room under mild sedation, local or general anesthesia. Minor complications occurred in 32 patients (2.27%), without significant differences between the techniques used (p = ns). Uterine perforation occurred in 14 cases, all performed in the operating room with some kind of anesthesia, only 1 with a vaginoscopic technique and the remaining during blind dilatation (odds ratio [OR], 19.98; 95% confidence interval [CI], 1.19-335.79; p = .04). An incomplete removal of EPs was documented in 39 patients. Logistic regression analysis showed that a higher risk of residual EPs was associated with the use of a fiber-based 3.5-mm hysteroscope (OR, 6.78; 95% CI, 2.97-15.52; p <.001), the outpatient setting (OR, 2.17; 95% CI, 1.14-4.14; p = .019), and EPs located at the tubal corner (OR, 1.98; 95% CI, 1.03-2.79; p = .039). No association between incomplete EP removal and EP size or number was recorded (p = ns), as well as with the other variables evaluated. CONCLUSION: Outpatient polypectomy was associated with a minimal but significantly higher risk of residual EPs in comparison with inpatient polypectomy. Conversely, inpatient polypectomy was associated with a considerably higher risk of uterine perforation and penetration in comparison with office hysteroscopy. Because of lower intraoperative risks and higher cost-effectiveness, office hysteroscopy may be considered, whenever possible, as the gold standard technique for removing EPs.

Area of residual tumor is a robust prognostic marker for patients with rectal cancer undergoing preoperative therapy.

The aim of this study was to elucidate differences in the histological features of rectal cancer between patients treated with preoperative chemoradiotherapy and those treated with preoperative chemotherapy. Area of residual tumor (ART) was also evaluated for its utility as a potential prognostic marker between them. Sixty-eight patients with rectal cancer who underwent sphincter-saving surgery were enrolled in this study. Of these, 39 patients received preoperative chemoradiotherapy (CRT group) and 29 patients received preoperative (neoadjuvant) chemotherapy (NAC group). Area of residual tumor was determined by using morphometric software. Tumors in the two groups were compared for differences in their histological features and clinical outcomes. Tumors in the CRT and NAC groups varied greatly with regard to their histological features after preoperative therapy. Tumors in the CRT group showed more marked fibrosis than those in the NAC group. The total ART were significantly smaller in tumors in the CRT group than those in the NAC group. However, in circumferential resection margin-negative pathologic stage 0-III cases, clinical outcomes were not statistically different between the CRT and NAC groups. Both ART and pathologic TNM classification were associated with clinical outcome in preoperative CRT and NAC groups, but Dworak regression grade and fibrotic change were not. Tumors in those undergoing preoperative CRT and NAC were shown to differ significantly in their histological features. Area of residual tumor-based assessment may provide useful prognostic information, regardless of preoperative therapy.

Moving beyond "complete surgical resection" and "optimal": Is low-volume residual disease another option for primary debulking surgery?

OBJECTIVES: To examine the relationship between volume of residual disease and oncologic outcomes among patients with advanced-stage epithelial ovarian/fallopian tube/primary peritoneal carcinoma undergoing primary debulking surgery (PDS). For patients that did not undergo a complete surgical resection (CSR), a surrogate for volume of residual disease was used to assess oncologic outcomes. METHODS: Medical records of patients with FIGO stage IIIC and IV epithelial ovarian/fallopian tube/primary peritoneal carcinoma undergoing PDS between January 2010 and November 2014 were reviewed. Patient demographics, operative characteristics, residual disease, anatomic site of residual disease and outcome data were collected. Among patients who did not undergo CSR, but had ≤1 cm of residual disease, the number of anatomic sites (single location vs. multiple locations) with residual disease was utilized as a surrogate for volume of residual disease. The effect of residual disease volume on progression-free survival (PFS) and overall survival (OS) was evaluated. RESULTS: Of 240 patients undergoing PDS, 94 (39.2%) had CSR, 41 (17.1%) had ≤1 cm of residual disease confined to a single anatomic location (≤1 cm-SL), 67 (27.9%) had ≤1 cm of residual disease in multiple anatomic locations (≤1 cm-ML) and 38 (15.8%) were sub-optimally (SO) debulked. Median PFS for CSR, ≤1 cm-SL, ≤1 cm-ML and SO-debulked were: 23, 19, 13 and 10 months, respectively (p < 0.001). Median OS for CSR, ≤1 cm-SL, ≤1 cm-ML and SO-debulked were: Not yet reached, 64, 50 and 49 months, respectively (p = 0.001). CONCLUSIONS: Following PDS, CSR and ≤ 1 cm-SL patients have the best prognosis. In contrast, despite being considered "optimally debulked", ≤1 cm-ML patients have survival similar to those SO-debulked.

Clinical Outcomes after Pulmonary Cryoablation with the Use of a Triple Freeze Protocol.

PURPOSE: To elucidate clinical variables associated with safety and efficacy in patients after cryoablation of pulmonary tumors with the use of a triple freeze protocol. MATERIALS AND METHODS: Percutaneous cryoablation of pulmonary tumors was performed using Galil Medical cryoprobes (Arden Hills, Minnesota) with a triple freeze protocol: 67 nodules in 42 patients were treated at a single institution from 2012 to 2016. Average nodule diameter was 1.6 cm (range 0.4-5.9); 13 nodules (19.4%) were pathologically determined to be a primary lung malignancy, whereas 54 (80.6%) were metastatic nodules of extrapulmonary origin. Average patient age was 68.1 years (range 39.6-89.6), and the male-female ratio was 1.3:1. Ipsilateral thoracic surgery, intervention, or radiotherapy had been performed before the first cryoablation in 18 patients (42.9%). Mean imaging follow-up was 326 days (range 9-1,152). RESULTS: Pneumothorax occurred in 19 cases (33.9%), 7 (12.5%) requiring chest tube, the likelihood of which was significantly greater in patients with 3 or more cryoprobes (P < .01). Local tumor recurrence/residual disease occurred in 6 cases (9.0%). Local tumor recurrence was not seen after ablation of nodules measuring <1.0 cm at the time of procedure, a significant difference from the recurrence ratee of 14.3% for nodules measuring ≥1.0 cm (P < .05). Likelihood of tumor recurrence/residual disease did not correlate with tumor pathology, tumor location, or procedural factors. The estimated marginal probabilities of local recurrence were 11.4%, 11.4%, and 38.1% at 1, 2, and 3 years after ablation, respectively. CONCLUSIONS: Cryoablation of pulmonary tumors with the use of a triple freeze protocol is a viable modality with low recurrence and complication rates.

Very long-term molecular follow-up of minimal residual disease in patients with neuroblastoma.

In high-risk neuroblastoma (HR-NB), the clinical significance of long-term minimal residual disease (MRD) monitoring using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for neuroblastoma mRNAs has not been investigated. We report long-term MRD follow-ups of four patients with HR-NB throughout the disease (diagnosis, remission, and relapse) and treatment course (chemotherapy, autologous and allogeneic stem cell transplantation, and donor lymphocyte and natural killer cell infusions). The results showed the stability of mRNA marker expression after different treatments and demonstrated their validity to predict relapse and assess therapeutic response. This opens up the possibility of investigating the utility of long-term molecular monitoring of MRD in prospective multicenter studies.

Therapeutic digestive endoscopy I.

Digestive endoscopy today is able to examine the whole gastrointestinal tract. On the basis of the originally purely diagnostic procedures a range of therapeutic modalities has been developed over years, which in some indications have taken the place of surgical procedures and methods of invasive radiology. Of greatest importance are the methods of endoscopic resection and ablation designed for the treatment of early neoplasms of the digestive tract not accompanied by a significant risk of lymphatic and systemic dissemination. Resection methods include endoscopic polypectomy, endoscopic mucosal resection, endoscopic submucosal dissection and endoscopic transmural resection. Regarding ablation methods, commonly used in clinical practice are radiofrequency ablations in the treatment of dysplasia in Barrett's esophagus and argon plasma coagulation used in the treatment of symptomatic vascular malformations and small local residual neoplasms. Key words: digestive endoscopy - endoscopic ablation - endoscopic mucosal resection - endoscopic polyp-ectomy - endoscopic resection - endoscopic submucosal dissection - endoscopic transmural resection.

Clinical outcomes after endoscopic submucosal dissection for colorectal neoplasia: a systematic review and meta-analysis.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) is an endoscopic resection technique for lesions suspicious of superficial malignancy. It is performed using an ESD knife on its own (standard technique) or by the sequential use of a knife and a snare (hybrid technique). The experience with these techniques is different in Asian and non-Asian countries. We performed a systematic review and meta-analysis of available evidence on colorectal ESD. METHODS: Electronic databases were searched up to August 2016 for studies evaluating R0, en bloc resection, and adverse event rates of both techniques for the treatment of colorectal lesions. Proportions were pooled by a random effects model. RESULTS: Ninety-seven studies (71 performed in Asia) evaluated the standard technique and 12 studies (7 in Asia) the hybrid technique. The R0 resection rate of the standard technique was 82.9%, and it was significantly lower in non-Asian versus Asian countries: 71.3% versus 85.6%. The en bloc resection rate was 91% and was significantly lower in non-Asian versus Asian countries (81.2% vs 93%, respectively). Surgery was needed in 1.1% of the ESD-related adverse events, with a significant difference between non-Asian and Asian countries (3.1% vs 0.8%). The R0 and en bloc resection rates with the hybrid technique were significantly lower than those achieved with the standard technique: 60.6% and 68.4%, respectively, with similar adverse event rates. CONCLUSIONS: In non-Asian countries the standard ESD technique is still failing to achieve acceptable levels of performance. The hybrid technique showed low R0 resection rates and should not be considered as an adequate alternative to the standard technique.