Risk Of Incomplete Resection Research Articles

Geometry of cold snare polypectomy and risk of incomplete resection.

Cold snare polypectomy (CSP) is safer than and equally efficacious as hot snare polypectomy (HSP) for the removal of small (<10mm) colorectal polyps. The maximum polyp size that can be effectively managed by piecemeal CSP (p-CSP) without an excessive burden of recurrence is unknown. Resection error risks (RERs), defined as the estimated likelihood of incomplete removal of adenomatous tissue for a single snare resection pass, for CSP and HSP were calculated, based on an incomplete resection rate. Polyp area, snare size, estimated number of resections, and optimal resection defect area were modeled. Overall risk of incomplete resection (RIR) was defined as RIR=1 - (1 - p)n, where p is the RER and n the number of resections. A 40-mm polyp has a four times greater area than a 20-mm polyp (314.16mm2 vs. 1256.64mm2), and requires three times more resections (11 vs. 33, respectively, assuming 8-mm piecemeal resection pieces for p-CSP). RIRs for a 40-mm polyp by HSP and p-CSP were 15.1%-23% and 40.74%-60.60% respectively. RER is more important with p-CSP than with HSP. The number of resections, n, and consequently RIR increases with increasing polyp size. Given the overwhelming safety of CSP, specific techniques to minimize the RER should be studied and developed.

Systematic Review with Meta-analysis: Endoscopic and Surgical Resection for Ampullary Lesions

Ampullary lesions (ALs) can be treated by endoscopic (EA) or surgical ampullectomy (SA) or pancreaticoduodenectomy (PD). However, EA carries significant risk of incomplete resection while surgical interventions can lead to substantial morbidity. We performed a systematic review and meta-analysis for R0, adverse-events (AEs) and recurrence between EA, SA and PD. Electronic databases were searched from 1990 to 2018. Outcomes were calculated as pooled means using fixed and random-effects models and the Freeman-Tukey-Double-Arcsine-Proportion-model. We identified 59 independent studies. The pooled R0 rate was 76.6% (71.8–81.4%, I2 = 91.38%) for EA, 96.4% (93.6–99.2%, I2 = 37.8%) for SA and 98.9% (98.0–99.7%, I2 = 0%) for PD. AEs were 24.7% (19.8–29.6%, I2 = 86.4%), 28.3% (19.0–37.7%, I2 = 76.8%) and 44.7% (37.9–51.4%, I2 = 0%), respectively. Recurrences were registered in 13.0% (10.2–15.6%, I2 = 91.3%), 9.4% (4.8–14%, I2 = 57.3%) and 14.2% (9.5–18.9%, I2 = 0%). Differences between proportions were significant in R0 for EA compared to SA (p = 0.007) and PD (p = 0.022). AEs were statistically different only between EA and PD (p = 0.049) and recurrence showed no significance for EA/SA or EA/PD. Our data indicate an increased rate of complete resection in surgical interventions accompanied with a higher risk of complications. However, studies showed various sources of bias, limited quality of data and a significant heterogeneity, particularly in EA studies.

Arthroscopic management of intra- and juxta-articular osteoid osteoma of the upper extremity: a systematic review of the literature.

Intra- and juxta-articular osteoid osteoma (OO) is rare and can result in irreversible joint damage. Recently, arthroscopic surgery is being used more and more to avoid complications associated with other treatment modalities. On October 13, 2019, we conducted a systematic review of the literature available in PubMed and EMBASE regarding the arthroscopic management of OO involving the joints of the upper extremity. Predetermined inclusion criteria were used to include any relevant article published on and before that date for further analysis. Treatment success rate and tumor recurrence rate were considered the primary outcomes in our analysis. Out of 113 studies, 19 met our inclusion criteria. Of the 32 reported cases in these 19 articles, ten involved the shoulder joint, 19 involved the elbow joint and three involved the wrist joint. Overall treatment success rate was 93.8%. Tumor recurrence rate was 0.0%. No postoperative complications (0.0%) were reported among cases involving the shoulder joint. Two out of 24 (8.3%) patients with elbow OO failed arthroscopic treatment due to incomplete excision, and two (4%) experienced minor complications. Among the three cases of wrist OO, two (66.7%) patients had residual postoperative pain and decreased hand grip strength. Arthroscopic management of OO of the upper extremity joints is highly successful and results in no tumor recurrence; however, there is a risk of incomplete resection in areas more difficult to access by arthroscopy.

Video-assisted thoracoscopic thymectomy is feasible for large thymomas: a propensity-matched comparison.

Video-assisted thoracoscopic thymectomy is becoming the preferable approach for early-stage thymoma. However, large thymomas are still recognized as a relative contraindication due to the possible risk of incomplete resection or capsular disruption. Thus, the aim of this study is to evaluate the feasibility of video-assisted thoracoscopic thymectomy for large thymomas. Patients diagnosed with Masaoka stage I-IV thymoma between April 2001 and December 2018 were retrospectively reviewed. All patients were divided into 2 groups: thymoma <5.0 cm (group A) and thymoma ≥5.0 cm (group B). Propensity score matching analysis was performed to compare postoperative results. Recurrence-free survival and overall survival were compared for oncological evaluation. A total of 346 patients were included in this study. In the propensity score matching analysis, 126 patients were included both in group A and group B. There was no significant difference between these 2 groups in terms of the R0 resection rate (95.2% vs 94.4%, P = 1.000), conversion rate (1.6% vs 3.2%, P = 0.684), operation time (119.4 ± 48.4 vs 139.1 ± 46.6 min, P = 0.955), blood loss (93.2 ± 231.7 vs 100.5 ± 149.3 ml, P = 0.649), duration of chest drainage (2.7 ± 1.6 vs 2.8 ± 2.0 days, P = 0.184), length of hospitalization (5.0 ± 3.9 vs 5.2 ± 2.9 days, P = 0.628) or postoperative complications (5.9% vs 8.5%, P = 0.068). There was no significant difference between these 2 groups in terms of the overall survival (P = 0.271) and recurrence-free survival (P = 0.288). Video-assisted thoracoscopic thymectomy is a safe and effective approach for large thymomas (≥5 cm) with comparable surgical and oncological results.

Management and risk factors for incomplete resection associated with jumbo forceps polypectomy for diminutive colorectal polyps: a single-institution retrospective study.

Cold forceps polypectomy is simple and widely used in clinical practice. However, there are concerns about the risk of incomplete resection using this technique. In recent years, it has been reported that polypectomy with jumbo forceps (JF) is an effective treatment modality for diminutive polyps (DPs) because JF are able to remove large tissue samples with the combined advantage of a higher complete histological resection rate for DPs than standard forceps. To our knowledge, no studies have evaluated the risk factors for incomplete resection when polypectomy with JF is performed for DPs. From among 1129 DPs resected using JF at Hiroshima City Asa Citizens Hospital between November 2015 and December 2016, we retrospectively evaluated the clinical outcomes of 999 tumors with known histopathology and investigated the relationship between incomplete resection and clinicopathological factors. Most lesions [985 (87%)] were low-grade dysplasia and 14 (1%) were high-grade dysplasia. The en bloc resection rate was 92% (918/999) and the histological en bloc resection rate was 78% (777/999). Multivariate analysis showed that the significant independent predictors of incomplete resection were tumor size ≥ 4mm [odds ratio (OR) 3.8; 95% confidence interval (CI) 2.65-5.37; p < 0.01], non-tangential direction of forceps in relation to the tumor (OR 1.73; 95% CI 1.21-2.45; p < 0.01), and lack of muscularis mucosae in the pathological specimen (OR 15.7; 95% CI 9.16-27.7; p < 0.01). This study identified significant independent predictors of incomplete resection of DPs which may be helpful when planning polypectomy with JF.

PS02.096: ENDOSCOPIC SUBMUCOSAL DISSECTION FOR ESOPHAGEAL HIGH-GRADE SQUAMOUS DYSPLASIA: A CASE REPORT

Abstract Background Endoscopic resection is a novel therapeutic technique for early esophageal cancer and it is indicated in well differentiated superficial M1 or M2 lesion. The selection criteria have been expanded to selected M3 and SM1 lesion with the advancement of endoscopic technology and detailed study of relation between depth of lesion and lymphatic spread. Methods We report a case of endoscopic submucosal dissection (ESD) for esophageal high grade dysplasia. Results Madam S, a 50-year-old lady with no known medical illness, presented with gradual dysphagia for 1 year. She had no prior history of corrosive ingestion or reflux disease. She was diagnosed with esophageal stricture and underwent esophageal dilatation twice, before she was referred to our center. Clinical examination revealed no abnormality and her BMI was 25. OGDS revealed a 1cm superficial ulcerative lesion at proximal esophagus (25cm from incisor) with abnormal capillary pattern on narrow band imaging. Biopsy revealed high grade intraepithelial neoplasia. PET-CT showed metabolically active esophageal lesion with no distant metastasis. She decided for ESD after given the option of endoscopic treatment versus esophagectomy. ESD was done (Figure 1) and she had an uneventful recovery. Histopathology revealed complete resection of high grade squamous dysplasia. Conclusion Endoscopic treatment is less invasive option for early esophageal tumour which spares patients from esophagectomy and the related morbidities. However, it carries the risk of incomplete resection, recurrence and under-staging of the disease. It also requires highly specialized center and has a steep learning curve. Careful patient selection and proper pre-operative counseling are crucial in endoscopic treatment of early esophageal cancer. Long term surveillance is needed for early detection of recurrence. Disclosure All authors have declared no conflicts of interest.

Clinical staging of NSCLC: current evidence and implications for adjuvant chemotherapy.

Survival of all non-small cell lung cancer (NSCLC) patients is disappointing, with a 5-year survival of 18%. Staging NSCLC patients is crucial because it determines the choice of treatment and prognosis. Clinical staging is a complex process that comes with many challenges and with low accuracy between the clinical and pathological stage. Treatment modalities for stage I–III NSCLC consist of surgical resection, radiotherapy and chemotherapy. This review describes the current evidence on staging and the implications on adjuvant chemotherapy. For stage I disease, staging is most accurate. Primary treatment consists of surgery or stereotactic ablative radiotherapy. When a patient has stage II disease, staging is less accurate because more diagnostic modalities are necessary to stage the mediastinal lymph nodes. Surgery remains the primary treatment modality and platinum-based adjuvant chemotherapy gives a 4% 5-year survival benefit. Staging patients with stage III disease is difficult because of the heterogeneity of the patients. It should be decided if a patient has potentially resectable disease with or without risk of incomplete resection. Induction therapy with chemo(radio)therapy followed by surgical resection or definitive chemoradiotherapy are the treatments of choice. The 5-year survival can reach 44% in selected patients. Decisions in staging and treating patients with NSCLC should be made by a multidisciplinary team with sufficient expertise in all aspects of staging and treatment.

Risk for Incomplete Resection after Macroscopic Radical Endoscopic Resection of T1 Colorectal Cancer: A Multicenter Cohort Study.

The decision to perform secondary surgery after endoscopic resection of T1 colorectal cancer (CRC) depends on the risk of lymph node metastasis and the risk of incomplete resection. We aimed to examine the incidence and risk factors for incomplete endoscopic resection of T1 CRC after a macroscopic radical endoscopic resection. Data from patients treated between 2000 and 2014 with macroscopic complete endoscopic resection of T1 CRC were collected from 13 hospitals. Incomplete resection was defined as local recurrence at the polypectomy site during follow-up or malignant tissue in the surgically resected specimen in case secondary surgery was performed. Multivariate regression analysis was performed to analyze factors associated with incomplete resection. In total, 877 patients with a median follow-up time of 36.5 months (interquartile range 16.0-68.3) were included, in whom secondary surgery was performed in 358 patients (40.8%). Incomplete resection was observed in 30 patients (3.4%; 95% confidence interval (CI) 2.3-4.6%). Incomplete resection rate was 0.7% (95% CI 0-2.1%) in low-risk T1 CRC vs. 4.4% (95% CI 2.7-6.5%) in high-risk T1 CRC (P=0.04). Overall adverse outcome rate (incomplete resection or metastasis) was 2.1% (95% CI 0-5.0%) in low-risk T1 CRC vs. 11.7% (95% CI 8.8-14.6%) in high-risk T1 CRC (P=0.001). Piecemeal resection (adjusted odds ratio 2.60; 95% CI 1.20-5.61, P=0.02) and non-pedunculated morphology (adjusted odds ratio 2.18; 95% CI 1.01-4.70, P=0.05) were independent risk factors for incomplete resection. Among patients in whom no additional surgery was performed, who developed recurrent cancer, 41.7% (95% CI 20.8-62.5%) died as a result of recurrent cancer. In the absence of histological high-risk factors, a 'wait-and-see' policy with limited follow-up is justified. Piecemeal resection and non-pedunculated morphology are independent risk factors for incomplete endoscopic resection of T1 CRC.

A Novel Neoadjuvant Therapy for Operable Locally Invasive Non–Small-Cell Lung Cancer. Phase I Study of Neoadjuvant Stereotactic Body Radiotherapy. LINNEARRE I (NCT02433574)

BackgroundDespite improved staging and surgical techniques, the rate of incomplete resection (R1) of non–small-cell lung cancer (NSCLC) has not significantly decreased. Patients with R1 resection have worse survival compared with those with complete resection (R0). Stereotactic body radiotherapy (SBRT) is a rapid and convenient radiotherapy treatment that delivers high-dose radiotherapy to tumors with high precision while sparing normal organs. Although its efficacy in treating small lung tumors is documented, its use as neoadjuvant therapy for locally advanced (LA) NSCLC has not been examined. We hypothesized that a short course of preoperative SBRT is feasible and can be delivered safely as a neoadjuvant therapy in patients at risk for incomplete resection. MethodsIn this phase I study, 20 patients with cT3 to 4, N0 to 1, M0 NSCLC at risk for incomplete resection will be treated with neoadjuvant SBRT followed by surgery and adjuvant chemotherapy. Four groups of 5 patients will be treated with escalating doses (35, 40, 45, and 50 Gy) in 10 daily fractions. The primary outcome is feasibility (ie, the ability to complete SBRT and surgery as planned; within 7 weeks). Secondary outcomes include acute and late adverse events; R0, R1, and R2 rates; and secondary surrogates of feasibility and safety. RelevanceThis study is an important first step in introducing a new therapeutic modality to patients with LA NSCLC that could improve surgical outcomes in the future. If neoadjuvant SBRT is found to be feasible and safe for LA NSCLC, its effect in achieving R0 resection could be investigated in randomized trials.

Optimiser le bilan d'extension locorégional

The initial assessment must meet four goals: assessing the clinical status, obtain a histological proof of diagnosis, set the stage cTNM, and if resectability, define whether the patient is operable. The locoregional staging modalities are based on national and international guidelines. Physical examination should be performed. Thorax CT-scan with contrast should be performed in all patients, except contraindication. CT can determine tumor size, bronchus, pleural, mediastinal and vascular invasion. The sensitivity and specificity of CT scan for identifying mediastinal lymph node metastasis is 61% and 79%, respectively. PET-CT is not indicated systematically but only for patients considered for curative intent treatment. The sensitivity and specificity of PET-CT for identifying mediastinal lymph node metastasis is 80 % and 80-90%, respectively. For patients with extensive mediastinal infiltration, CT assessment is sufficient. In patients with discrete mediastinal lymph node enlargement or PET uptake in mediastinal nodes or a centrally located tumour or a tumour > 3cm or N1 node, an invasive staging of the mediastinum is indicated. A needle technique (EBUS-TBNA or EUS-FNA or combined EBUS/EUS) is recommended over surgical staging. Stage IIIAN2 should be classified into potentially resectable N2, potentially resectable N2 but risk of incomplete resection and unresectable N2. The adherence to guidelines and organizational factors improve the management.

Clinicopathologic characteristics of patients who underwent additional gastrectomy after incomplete endoscopic resection for early gastric cancer.

39 Background: Endoscopic resection (ER) is widely accepted as standard treatment for early gastric cancer (EGC) without lymph node metastasis. However, surgery is sometimes needed after endoscopic mucosal resection (EMR)/endoscopic submucosal dissection (ESD) due to incomplete resection. We analyzed the clinicopathological characteristics of patients who underwent additional gastrectomy after incomplete EMR/ESD. Methods: From 2003 to 2013, 80 patients received additional gastrectomy after EMR/ESD due to incomplete resection. The patients were grouped according to the presence of histologic residual tumor in specimens obtained by gastrectomy as residual tumor (RT, n = 47) or non-residual tumor (NRT, n = 33). We analyzed reasons for gastrectomy, tumor characteristics of RT and NRT group, risk factors associated with residual tumor, retrospectively from medical records. Results: After the gastrectomy, the positive residual tumor rate and lymph node metastasis rate were 58.7% (47/80) and 7.5% (6/80). RT group showed significantly higher rate of lateral and vertical margin involvement compared to NRT group (59.5 vs. 15.1%).Multivariate analysis demonstrated that endoscopic piecemeal resection, H. pylori infection, depressed or mixed type, large tumor size (&gt; 2cm), histologic diagnosis (signet ring cell carcinoma or mixed carcinoma) were significantly independent predictive factors associated with positive residual tumor of patients who underwent additional gastrectomy after incomplete EMR/ESD (p &lt; 0.05). Conclusions: For complete and curative ER, endoscopists should try to determine the depth of invasion, histologic diagnosis accurately and to eradicate the H. pylori infection before ER. During ER, wide marking and En bloc resection could be considered to avoid the risk of incomplete resection.

Results of a Standardized Endoscopic Approach to Resection of Polyps >20 mm

Results of a Standardized Endoscopic Approach to Resection of Polyps >20 mm

Endoluminal Resection and Tissue Acquisition

Endoscopic resection as curative treatment is feasible and indicated for gastrointestinal adenomas and early cancer limited to the mucosal layer and submucosal layers, where the risk for nodal and distant metastases is minimal. The initial technique of endoscopic resection, endoscopic mucosal resection, was limited by the inability to have en bloc resections for lesions larger than 2cm. This meant that proper assessment of resection margins and depths was not possible in these cases, with the risk of incomplete resection and remnant lesions. In the last decade, the technique of endoscopic submucosal dissection was introduced, and this has allowed en bloc resection of superficial cancers of the esophagus, stomach, and colon. Cumulative data have shown high en bloc resection rates and excellent short-term and long-term outcomes when treatment inclusion criteria are adhered to. Endoscopic resection techniques were recently applied in the context of submucosal lesions. In the case of lesions located in the muscularis mucosa and submucosal layers, the gastrointestinal wall is not breached during endoscopic resection. However, in the case of submucosal lesion located in the muscularis propria layer, endoscopic mucosal resection or endoscopic submucosal dissection would result in perforation which may not be easily closed endoscopically. The technique of endoscopic submucosal tunneling was introduced in the context of peroral endoscopic myotomy for the treatment of achalasia. The principle was extended to the resection of tumors arising from the muscularis propria layer, with promising results.

Diagnostic accuracy and value of magnetic resonance imaging (MRI) in planning exenterative pelvic surgery for advanced colorectal pelvic cancer.

370 Background: Exenterative pelvic surgery is challenging and has been used in colorectal surgery to manage patients with advanced colorectal pelvic cancer. Resection of the tumor needs to be performed en-bloc and if feasible, without exposing the tumor, since this can compromise resection margins. This can only be performed through careful pre-operative staging. This study aimed to assess the diagnostic accuracy of MRI in detecting colorectal tumor invasion into seven intrapelvic compartments and its value in planning exenterative pelvic surgery. Methods: Sixty four consecutive patients underwent preoperative MRI planning for exenterative surgery, for locally advanced (n= 23) and recurrent (n= 41) pelvic colorectal cancer. Two radiologists reported tumor invasion for each of the seven anatomic surgical resection compartments and were blinded to histopathology and intraoperative reference standards. Sensitivity, specificity and predictive values were calculated for each compartments. Kaplan-Meier methodology was used to calculate survival rates. Interobserver agreement was assessed using Cohen's Kappa coefficient (k). Results: The sensitivity of MRI was ≥93.3% in all except for the lateral compartment where it was 89.3%. Its specificity for the posterior (82.2%), anterior below (86.4%) the peritoneal reflection compartments was lower compared to the rest of the compartments. MRI diagnosis of lateral (OR= 11.41, p= 0.033), anterior compartment above the peritoneal reflection (OR= 3.14, p= 0.005) and multicompartmental involvement (OR= 1.99, p&lt;0.001) was associated with higher risk of incomplete resection which was subsequently found to be significant factor in predicting overall and disease free survival (p&lt;0.05). The agreement between the two radiologists was found to be either good or very good for all the compartments (k&gt;0.72). Conclusions: MRI is highly accurate in predicting tumor invasion within the intrapelvic compartments and it should be the pre-operative staging modality of choice when considering exenterative surgery for patients with locally advanced colorectal pelvic cancer. [Table: see text]

T4 colorectal cancer: is laparoscopic resection contraindicated?

T4 colorectal cancer remains a contraindication for laparoscopy. It is argued that the risk of incomplete resection could be higher than in open surgery. Furthermore, difficulty in dissection could lead to a very high rate of conversion. There is little information on this. The study aimed at assessing feasibility and operative and oncologic results of laparoscopic resection for T4 colorectal cancer. Between 2006 and 2009, 39 patients with colorectal cancer with suspected involvement of another organ (T4) on computed tomography scanning and/or magnetic resonance imaging were included. The cancers were in the right colon (n = 18), left colon (n =9) and rectum (n = 12). The distribution of possible organ involvement was abdominal or pelvic side-wall (n = 21), urinary bladder (n = 4), small bowel or colon (n = 6), vagina and ovary (n = 3), prostate or seminal vesicles (n = 3) and duodenum (n = 2). The overall conversion rate was 18%. Postoperative mortality and morbidity were 2.5 and 33%, respectively. Clinical anastomotic leakage rate was 15% (n = 6). Abdominal reoperation was required in three (7%) patients. Pathological invasion to other organs (pT4) was confirmed in 30 (77%) patients. The R1 resection rate was 13% (4 of 30). After a median follow up of 19 months (range 1.5-45 months), the overall survival and disease-free survival rates were 97 and 89%, respectively. This study suggests that laparoscopic surgery is feasible for colorectal T4 cancer resection. Laparoscopy cannot therefore be considered an absolute contraindication for T4 colorectal cancer.

Trapézectomie partielle arthroscopique : étude radioanatomique de 14 cas

Objectives The aim of the study was to assess the accessibility of the trapezium surface to arthroscopic resection related to the degenerative stage, to define the surgical approach and to determine the efficacy of the X-rays for evaluating the amount of resected bone. Methods Fourteen trapezectomies were performed on seven cadaveric specimens using an arthroscopic procedure. Pre- and post-procedure X-rays were used to assess the initial trapeziometacarpal osteoarthritis and the resection performed. Each subject was randomized for using two posterior portals or two posterior portals and one anterior portal. At the end of the procedure, a dissection was performed for evaluating the quality of resection and the anatomical relationship of each surgical approach. Results The stages of preprocedure osteoarthritis were comparable between the two sides of the same cadaveric specimen. On post-procedure X-rays, the resection appeared complete in only six out of 14 wrists. During dissection, no injury to neurovascular structures was observed, and the resection was visible macroscopically in 11/14 wrists. Three resections were incomplete, i.e., less than 20 % of total trapezial surface: two of them were seen in the most osteoarthritic cases of the study. Conclusions The arthroscopic approach presents an opportunity to access the entire trapezial surface, even if a high stage of osteoarthritis appears to be a risk for incomplete resection. The addition of a systematic anterior approach to the traditional dorsal approach does not increase the accessibility. Although radiography is not the most appropriate tool to assess the resected surface, it does help to locate the defects of resection and can guide the surgical procedure in situations where there is a risk of incomplete resection.

Reply to 00464-009-0844-1: Endoscopic submucosal dissection: can indications for a minimally invasive approach be expanded safely to patients with early gastric cancer?

We thank Dr. Fatourou and Roukos for their interest and remarks in response to our article regarding endoscopic resection for undifferentiated early gastric cancer [1]. Since 1999, a national cancer screening program has recommended upper gastrointestinal endoscopy to the normal population older than 40 years for early detection of gastric cancer in Korea. The proportion of early gastric cancer indicated for endoscopic resection has increased. Although conventional endoscopic resection was limited to complete resection only for large or deep tumors confined to the mucosa without the risk of lymph node metastasis, newly developed endoscopic submucosal dissection has enabled complete resection of larger and deeper tumor without any technical barrier. With the progress of technical advances, Japan has proposed expanding the indications for endoscopic resection of early gastric cancer [2]. Although tumor of undifferentiated histology has the risk of much larger size and deeper invasion than expected, some portion of an early lesion could possibility be indicated for complete endoscopic resection as a minimally invasive treatment. In a retrospective study with postoperative pathologic review, undifferentiated early gastric cancer smaller than 2.5 cm and confined to the mucosa did not show any lymph node metastasis in a large series [3]. As expected, the complete resection rate for undifferentiated early gastric cancer was significantly lower than for differentiated histology, which explains the possibility of diffuse infiltration of tumor with undifferentiated histology and the risk of lymph node metastasis. Although endoscopic submucosal dissection has improved the complete resection of early gastric cancer more than conventional mucosal resection, expanding the indication to tumor of undifferentiated histology has the risk of incomplete resection or lymph node metastasis and should be accompanied by long-term follow-up evaluation. We think the indication for endoscopic resection of undifferentiated gastric cancer should be limited to small tumors confined to the mucosa.

Endoscopic submucosal dissection: can it safely expand indications for a minimally invasive approach to patients with early gastric cancer?

In contrast to Western countries, Asian countries such as Japan and Korea diagnose gastric cancers at an early stage, confronting the disease with screening programs and perhaps a different cancer biology. This early detection allows a minimally invasive treatment approach, substantially improving quality of life (QOL) for patients with early gastric cancer (EGC). In these Asian countries, conventional open gastrectomy and minimally invasive interventions including endoscopic mucosal resection (EMR) and laparoscopic gastrectomy have been established as standard treatment when specific criteria are met. For example, EMR is recommended by Japanese guidelines for small tumors confined to the mucosal layer of the intestinal type [1]. However, many patients do not meet these criteria. In an effort for these patients to improve both curability (by deeper gastric wall resection) and QOL (by avoiding open gastrectomy), endoscopic submucosal dissection (ESD) has been developed. To assess whether ESD is a safe procedure for undifferentiated early gastric cancer, Kang et al. [2] reported on ESD in a recent issue of Surgical Endoscopy. They performed a retrospective study of patients with early gastric cancer treated at the Seoul National University Hospital, Seoul, Korea. Of the 456 patients with early gastric cancer treated by ESD between 2005 and 2008, 60 lesions (13.2%) were diagnosed as undifferentiated gastric cancer adenocarcinoma or signet ring cell carcinoma. The complete resection (R0) rate was significantly lower for undifferentiated EGC (55%) cases than for differentiated EGC cases (84.1%; P \ 0.001). Tumor size larger than 20 mm, submucosal invasion, and ulceration were associated with increased risk of incomplete resection (R1). During a mean follow-up period of 16 months, no recurrence was experienced by any of the patients with undifferentiated EGCs thought to be completely resected by ESD. The authors conclude that ESD may be considered for carefully selected patients with undifferentiated EGC. This large series of ESD for EGC has contributed data that are very important clinically for specialized institutions performing ESD. However, these findings warn concerning the risk of an R1 resection of undifferentiated carcinoma. The incomplete resection rate in this series was very high (45%), a finding that is not surprising given the widely spread submucosal invasion of this histologic type. Indeed, this type of gastric cancer, which corresponds to the diffuse type of cancer in Lauren classification usually used in the Western world, is characterized by diffuse spread beyond the tumor. Therefore, much larger resection margins are required than with intestinal type cancer. A follow-up period longer than the 16 months in this study is required for two reasons: to assess local recurrence and to evaluate the risk of nodal recurrence. Indeed, expanding the indications for ESD to include diffuse cancers, larger tumors, and ulcerations, there is evidence of increased risk to found positive lymph nodes. These metastatic lymph nodes are left behind after ESD with substantial risk of residual nodal disease and recurrence. A recent study has demonstrated a nodal metastasis rate for EGC that may reach 23% for certain aforementioned risk groups [3]. Early gastric cancer has an excellent prognosis, with high cure rates even in the West by appropriate R0 E. Fatourou Department of Hepatology, Ippokrateio Hospital, University of Athens, Athens, Greece

Curability risks by endoscopic submucosal dissection for early gastric cancer

In a recent issue of Surgical Endoscopy, Ohnita and colleagues [1] reported the risk factors for incomplete tumor resection after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This identification can result in preventing pathohistologically assessed residual microscopic disease (R1) at resection margins. In 2003, the Japanese Gastric Cancer Association published recommendations for the treatment of EGC by limited surgical resection [2]. In these guidelines, strict criteria were defined to ensure the safety and efficacy of endoscopic mucosal resection (EMR) for the treatment of EGC. These criteria were: tumor size \2 cm, confined to mucosal without ulcers, and differentiated histological type. Treating patients with EMR can dramatically improve their quality of life (QOL); however, a relatively small number of patients with EGC meet these criteria. ESD was developed to expand the indications, and many patients gained substantial benefit in their QOL. However, many questions remain regarding the safety of ESD when larger undifferentiated submucosal ulcerative cancers are included for ESD. This is a very large series of ESD within a relatively short time period (2003–2008). The experience provided by these authors is valuable for institutions planning ESD, and the lessons taken from this study are important. Complications related to ESD were perforations in 21 patients (4.2%) and bleeding in 7 patients (1.4%). This morbidity rate can be considered modest and within an acceptable level. The complete tumor resection (R0) rate was high: 96%. In 476 of 495 lesions, a R0 resection was achieved. The authors exclude undifferentiated, large, submucosal cancers, and this selection may explain the high R0 rate. In another recent study, the incomplete resection rate was high: 45% [3]. However, in this report undifferentiated, ulcerative, large submucosal cancer was included, confirming the limitations of ESD. The study by Ohnita et al. [1] is limited by the absence of follow-up, which is very important to define two major risks of ESD: local recurrence and nodal recurrence. It reconfirms how carefully the EGC patients should be selected. ESD achieves a better local control than EMR regarding deeper gastric wall resection margins. However, peripheral tumor margins and nodal residual disease should be considered for achieving oncological resection quality control. Prognosis of gastric cancer with adequate open or laparoscopic surgery is excellent for early gastric cancer [4, 5]. Quality control in surgery and multimodal adjuvant treatment can substantially improve survival rates even for patients with advanced resectable stage II or III disease [6–14]. Minimally invasive approaches represent substantial progress in improving the QOL of patients. The strict selection criteria are essential for safe oncological outcomes. If there is even a modest risk of incomplete resection by ES, then laparoscopic or open gastrectomy should be considered. Despite these developments, standardized open D2 surgery is the procedure of choice for advanced gastric cancer. An improvement in oncological outcomes of advanced gastric cancer should be the first priority of biomedical sciences, whereas QOL improvement remains a secondary goal when curability has been achieved. Recent advances C. Hottenrott (&) Chirurgische Klinik St. Elisabethenkrankenhaus Ginnheimer Strase 3, Frankfurt 60487, Germany e-mail: info@gastricbreastcancer.com

Preoperative measurement of canine primary bone tumors, using radiography and bone scintigraphy

Summary Specimens of 20 canine primary bone tumors (18 osteosarcoma, 2 fibrosarcoma) were examined to compare the maximal axial length of gross tumor with the length of the lesion seen on preoperative radiographs and 99mTc methylene diphosphonate bone scintigraphic images. Radiographs defined the length of the tumor to within ± 10% of the gross measurement for 6 (30%), underestimated it for 12 (60%), and overestimated it for 2 (10%) specimens. Bone scintigraphy defined tumor length within ± 10% for 8 (40%), underestimated it for 1 (5%), and overestimated it for the remaining 11 (55%) specimens. Use of radiographic evaluation alone could result in underestimation of the diaphyseal extent of a primary bone tumor, with risk of incomplete resection. Bone scan images tend to overestimate tumor length and, therefore, may provide safer resection guidelines.