Mini-probe ultrasonography for the staging of colon cancer: a systematic review and meta-analysis

Harnessing the oloid shape in magnetically driven robots to enable high-resolution ultrasound imaging

Magnetic fields enable remote manipulation of objects and are ideal for medical applications because they pass through human tissue harmlessly. This capability is promising for surgical robots, allowing navigation deeper into the human anatomy and accessing organs beyond the reach of current technologies. However, magnetic manipulation is typically limited to a maximum two-degrees-of-freedom orientation, restricting complex motions, especially those including rolling around the main axis of the magnetic robot. To address this challenge, we introduce a robot design inspired by embodied intelligence and the unique geometry of developable rollers, leveraging the oloid shape. The oloid, with its axial asymmetry and sinusoidal motion, facilitates rolling when precisely controlled by an external magnetic field. We present a versatile closed-loop control model to ensure precise magnetic manipulation of an oloid-shaped robot. This capability was validated in endoluminal applications through the integration of a 28-megahertz micro-ultrasound array to perform virtual biopsies, noninvasive real-time histological imaging. Extensive in vitro and in vivo tests using a porcine model showed the robot's ability to execute sweeping motions, identify lesions, and generate detailed three-dimensional scans of gastrointestinal subsurface tissue. This research not only restores a critical movement capability to magnetic medical robots but also enables additional clinical applications deep within the human body.

Substratifying the risk of covert malignancy in significant rectal polyps: Outcomes from a specialist multidisciplinary team (MDT)

AIM

A treatment strategy for patients with a significant polyp or early colon cancer (SPECC) of the rectum presents a challenge due to the significant rate of covert malignancy and lack of standardized assessment. For this reason, NICE recommends multidisciplinary meetings to improve outcomes. The primary aim of the present study was to report the performance of our specialist early rectal cancer (SERC) multidisciplinary team (MDT) in correctly substratifying the risk of cancer and to discuss the limitations of staging investigations in those patients with "poor outcomes".

METHOD

This was a retrospective review of patients referred to our SERC MDT from 2014 to 2019. Lesions were assigned by the MDT to three pre-resection categories (low, intermediate, high) according to the risk of covert malignancy. Resection method and final histology were compared to the pre-resection categories.

RESULTS

Of 350 SPECC lesions, 174 were assessed as low-risk, 108 intermediate-risk and 68 high-risk. The cancer incidence was 4.8%, 8.3% and 53%, respectively (15.5% overall). Eight lesions were categorized as low-risk but following piecemeal resection were found to be malignant. Five lesions, three of which were categorized as high-risk, were ultimately benign following conventional surgery. One pT1sm1 cancer, removed by anterior resection, may have been treated by local excision.

CONCLUSION

A total of 83% of malignant polyps were triaged to an en bloc resection technique and surgical resection avoided for nearly all benign lesions. However, 12 patients from this cohort were deemed to have a poor outcome because of miscategorization. Further comparative research is needed to establish the optimum strategy for rectal SPECC lesion assessment.

ORIGINALITY STATEMENT

There is currently no consensus for staging significant polyps of the rectum. This paper reports the effectiveness of a specialist early rectal cancer MDT to correctly risk-stratify significant rectal polyps. It underscores the importance of accurate categorization for treatment decision-making, while acknowledging the limitations of current staging modalities.

[Endoscopic ultrasonography in diagnosis of chemical esophageal burn and prediction of cicatricial stenosis]

OBJECTIVE

To analyze the role of endoscopic ultrasonography (EUS) in predicting the risk of cicatricial stenosis after chemical esophageal burn.

MATERIAL AND METHODS

A retrospective study included 56 patients with chemical esophageal burn grade III/IV. Primary endoscopy was performed upon admission. To estimate lesion of muscular layer of esophageal wall, we performed EUS using mini-sensor 20 MHz in 3-5 days after injury. To assess severity of chemical esophageal burn, we used the classification proposed by Volkov S.V. (1997) and supplemented by Pesnya-Prasolova E.A. (2006): grade I - catarrhal damage, grade II - erosive, grade III - ulcerative, grade IV - ulcerative-necrotic damage.

RESULTS

To predict the risk of cicatricial esophageal stenosis, we identified 4 grades (a, b, c, d) of damage to muscular layer of esophageal wall considering EUS data. There was no esophageal stenosis in chemical esophageal burn grade III/IVa and acetic essence poisoning with esophageal burn grade IVb. Cicatricial stenosis occurred in 22 (78.6%) out of 28 patients with chemical esophageal burn grade IV (chemical burn grade IVb following alkalis poisoning and in all patients with chemical burn grade IVc/IVd). The risk of cicatricial stenosis was 9.4 times higher after alkalis burn compared to acetic acid burn.

CONCLUSION

EUS in chemical esophageal burn grade IV made it possible to identify additional grades (a, b, c, d) of damage to muscular layer of esophageal wall. This increased the effectiveness of endoscopic diagnostics and assessment of the risk of cicatricial esophageal stenosis.

Endoscopic Ultrasound in Cancer Staging

The authors review the role of endoscopic ultrasound (EUS) in the staging of cancers throughout the gastrointestinal tract. EUS offers an advantage over cross-sectional imaging in locoregional tumor staging but is less sensitive in identifying distant metastasis. The addition of FNA increases diagnostic accuracy and provides a tissue diagnosis. EUS combined with cross-sectional imaging is important in accurately staging GI tumors and thereby reducing unnecessary procedures and health care costs.

Impact of the preoperative clinical N stage on the prognosis of patients with colon cancer

AIM

Although preoperative clinical staging (cStage) is performed for most cancer patients, limited information is currently available on the relationship with postoperative prognosis. We herein investigated the relationship between cStage and prognosis of colon cancer (CC) patients, particularly focusing on the presence or absence of clinical lymph node (LN) metastasis.

METHOD

This was a retrospective study on 840 consecutive patients with colon adenocarcinoma who underwent radical resection at our institution between January 2007 and December 2018. A Kaplan-Meier curve was used to analyse the prognosis of two groups: cN(+)pN(-); a group preoperatively diagnosed with clinical LN metastasis positive, but with no pathological LN metastasis postoperatively, and cN(-)pN(-); a group without clinical and pathological LN metastasis. We also investigated whether a clinical diagnosis is a more accurate prognostic factor than other clinical factors.

RESULTS

Among pN(-) cases, the 5-year recurrence-free survival rate was significantly lower in preoperatively diagnosed cN(+) cases than in cN(-) cases (79.4% vs. 95.6%, 3.04 years vs. 3.85 years, p < 0.01). In a multivariate analysis of various preoperative clinical factors in pStage II cases, including high risk factors for pStage II CC, cN(+) was identified as an independent prognostic factor (hazard ratio: 2.06, 95% CI: 1.02-4.27, p = 0.04).

CONCLUSION

Preoperatively over-staged cN cases had a poorer prognosis than cases without over-staging, indicating its potential as a prognostic factor. In addition to already known high risk factors in pStage II cases, the preoperative cStage may be an indication for adjuvant chemotherapy.

A Clinicopathological Feature-Based Nomogram for Predicting the Likelihood of D3 Lymph Node Metastasis in Right-Sided Colon Cancer Patients

BACKGROUND

Despite advancements in treating right-sided colon cancer patients, the ideal scope of lymphadenectomy remains controversial.

OBJECTIVE

Our objective was to investigate the likelihood of D3 lymph node metastasis in right-sided colon cancer patients and develop a clinicopathological feature-based nomogram for D3 lymphadenectomy.

DESIGN

We retrospectively analyzed 286 right-sided colon cancer patients who underwent D3 lymphadenectomy. The patients were divided into 2 groups based on whether D3 lymph node metastasis was positive. Then, univariable and multivariable logistic regression analyses were performed to obtain independent risk factors for predicting D3 lymph node metastasis. Moreover, we performed receiver operating characteristic curve analyses to evaluate the predictive power of the model.

SETTING

This study was conducted at Nanfang Hospital of Southern Medical University in China.

PATIENTS

A total of 286 consecutive patients who underwent right hemicolectomy and D3 lymphadenectomy as a primary treatment for right-sided colon cancer between January 2016 and December 2019 were enrolled in this study.

MAIN OUTCOME MEASURES

The primary measures were independent risk factors for predicting D3 lymph node metastasis in right-sided colon cancer.

RESULTS

The D3 lymph node metastasis rate in right-sided colon cancer patients was 16.1% (46/286). D3 lymphadenectasis on CT, lymphatic invasion, and T4 tumors were filtered out as independent risk factors for D3 lymph node metastasis according to the multivariable logistic regression analysis. We established a nomogram that predicted D3 lymph node metastasis of right-sided colon cancer on the combination of the 3 factors with an area under the curve of 0.717 (95% CI, 0.629-0.806).

LIMITATIONS

This was a retrospective study from a single center.

CONCLUSIONS

We developed a valuable clinicopathological feature-based nomogram to predict the incidence of D3 lymph node metastasis in right-sided colon cancer patients. Patients with D3 lymphadenectasis on CT, preoperative T4 tumors, and lymphatic invasion should undergo D3 lymphadenectomy. See Video Abstract at http://links.lww.com/DCR/B852 .

UN NOMOGRAMA BASADO EN CARACTERSTICAS CLNICOPATOLGICAS PARA PREDECIR LA PROBABILIDAD DE METSTASIS EN GANGLIOS LINFTICOS D EN PACIENTES CON CNCER DE COLON DERECHO

ANTECEDENTES:A pesar de los avances en el tratamiento de pacientes con cáncer de colon derecho, el ámbito ideal de la linfadenectomía sigue siendo controvertido.OBJETIVO:Investigar la probabilidad de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho y desarrollar un nomograma basado en características clínico-patológicas basado para la linfadenectomía D3.DISEÑO:Analizamos retrospectivamente a 286 pacientes con cáncer de colon derecho que se sometieron a linfadenectomía D3. Los pacientes se dividieron en dos grupos en función de si eran positivos para metástasis en los ganglios linfáticos D3. Luego, se realizaron análisis de regresión logística univariable y multivariable para obtener factores de riesgo independientes para predecir metástasis en los ganglios linfáticos D3. Además, realizamos análisis de las curvas de características operatorias del receptor para evaluar el poder predictivo del modelo.SEDE:Este estudio se realizó en el Hospital Nanfang de la Universidad Médica del Sur en China.PACIENTES:Un total de 286 pacientes consecutivos que se sometieron a hemicolectomía derecha y linfadenectomía D3 como tratamiento primario para el cáncer de colon derecho entre enero de 2016 y diciembre de 2019 se inscribieron en este estudio.PRINCIPALES MEDIDAS DE RESULTADO:Las medidas primarias fueron factores de riesgo independientes para predecir las metástasis en ganglios linfáticos D3 en el cáncer de colon derecho.RESULTADOS:La tasa de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon del lado derecho fue del 16,1% (46/286). El aumento de tamaño de ganglios D3 en la TC, la invasión linfática y los tumores T4 se filtraron como factores de riesgo independientes de metástasis en los ganglios linfáticos D3 de acuerdo con el análisis de regresión logística multivariable. Establecimos un nomograma que predijo metástasis en los ganglios linfáticos D3 del cáncer de colon derecho en la combinación de los tres factores con un área bajo la curva de 0,717 (IC del 95%, 0,629-0,806).LIMITACIONES:Este fue un estudio retrospectivo de un solo centro.CONCLUSIONES:Desarrollamos un valioso nomograma basado en características clínico-patológicas para predecir la incidencia de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho. Los pacientes con crecimiento de ganglios D3 en TC, tumores con clasificación preoperatoria T4 e invasión linfática, deben ser sometidos a linfadenectomía D3. Consulte Video Resumen en http://links.lww.com/DCR/B852 . (Traducción-Dr. Juan Carlos Reyes ).

Practical approach to linear endoscopic ultrasound examination of the rectum and anal canal

Standard endosonographic examination of the rectal area is usually performed with radial endoscopic ultrasound (EUS). However, in recent years, widespread availability of linear EUS for assessing various anatomical regions in the gastrointestinal tract has facilitated its use in the assessment of anorectal disorders. Currently, many rectal and anal diseases, including perianal abscesses, fistulae, polyps, and neoplastic lesions, can be well-visualized and evaluated with linear EUS. The aim of this review is to shed light on the anatomy and systematic examination of the anorectal region with linear EUS and clinical implications for different anorectal pathologies.

Clinical application of endoscopic ultrasonography in evaluation of colorectal and peri-colorectal lesions

BACKGROUND

Endoscopic ultrasonography (EUS) has the functions of both endoscopy and ultrasound. Due to the complex anatomical structure of the intestine, there are few studies on EUS in colorectal lesions.

AIM

To explore the clinical application value of EUS in the diagnosis of colorectal and peri-colorectal lesions.

METHODS

We retrospectively analyzed the examination results of 95 patients detected by endoscopic miniprobe sonography (MPS) and linear EUS from September 2018 to July 2021, which were then compared to postoperative pathology. The kappa test was used in statistical analysis.

RESULTS

Using postoperative pathology as the golden standard, the accuracy of linear EUS in diagnosing the depth of rectal cancer invasion (T stage) was 73.9% (17/23 cases), including T1 (2/4 cases), T2 (4/6 cases), T3 (6/7 cases) , and T4 (5/ 5 cases) stages. The accuracy of linear EUS in diagnosing regional lymph node metastasis (N stage) was 91.3% (21/23 cases), including N0 (14/15 cases) and N1 (7/8 cases) stages. The consistency was high (kappa value = 0.782, P < 0.01). During preoperative evaluation of colorectal adenoma or early cancer before endoscopic submucosal dissection (ESD), the accuracy of MPS in diagnosing the depth of tumor invasion was 87.1% (27/31 cases), and the consistency was moderate (kappa value = 0.665, P < 0.01). The accuracy of MPS in diagnosing the origin and type of colorectal submucosal lesions was 95.5% (21/22 cases), and the consistency was high (kappa value = 0.919, P < 0.01). The accuracy of endoscopic ultrasonography-guided fine-needle aspiration in determining rectal and peri-rectal lesions was 70.0% (7/10 cases), and the consistency was moderate (kappa value = 0.565, P < 0.01).

CONCLUSION

According to the specific location and size of colorectal and peri-colorectal lesions, selective use of the MPS and linear EUS is of great value with regard to T/N staging of rectal cancer, preoperative evaluation of ESD, determination of the characteristics of colorectal-submucosal bulging lesions, and acquisition of lesion tissue of rectal and peri-rectal lesions.

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

3-D Endoluminal Ultrasound Biomicroscopic Imaging and Volumetry of Mouse Colon Tumors

Currently, colonoscopy is considered the gold standard procedure for diagnosis of colorectal cancer (CRC), the third most common cancer in the United States. However, this technique fails to detect flat adenomas, serrated polyps and advanced adenomas, with miss rates of 34%, 27% and 14%, respectively. These miss rates, more frequent than previously supposed, suggest the need for new CRC screening tools. In the work described here, the potential application of a 40-MHz ultrasound system to generate a sequence of 2-D endoluminal ultrasound biomicroscopy (eUBM-2-D) images of a mouse model of colon cancer was investigated, and this image sequence was used to render eUBM-3-D images and to measure tumor volume. The technique was validated with tissue-mimicking phantoms and used in vivo with mice bearing colon polypoid tumors. Estimated volumes ranged from 0.174-7.909 mm³ for targets in validation phantoms and from 0.066-6.082 mm³ for mouse colon tumors.

Colorectal Endoscopic Submucosal Dissection: An Update on Best Practice

Endoscopic submucosal dissection (ESD) is a method of en-bloc resection of neoplastic colorectal lesions which is less invasive compared to surgical resection. Lesion stratification, architecture recognition and estimation of depth of invasion are crucial for patient selection. Expert endoscopists have integrated a variety of classification systems including Paris, lateral spreading tumor (LST), narrow band imaging (NBI), international colorectal endoscopic (NICE) and Japanese NBI expert team (JNET) in their day-to-day practice to enhance lesion detection accuracy. Major societies recommend ESD for LST-non granular (NG), Kudo-VI type, large depressed and protruded colonic lesions with shallow submucosal invasion. Chance of submucosal invasion enhances with increased depth as well as tumor location and size. In comparison to endoscopic mucosal resection (EMR), ESD has a lowerl recurrence rate and higher curative resection rate, making it superior for larger colonic lesions management. Major complications such as bleeding and perforation could be seen in up to 11% and 16% of patients, respectively. In major Western countries, performing ESD is challenging due to limited number of expert providers, lack of insurance coverage, and unique patient characteristics such as higher BMI and higher percentage of previously manipulated lesions.

Controversies in EUS: Do we need miniprobes?

This is the fifth in a series of papers entitled "Controversies in EUS." In the current paper, we deal with high-resolution catheter probes, otherwise known as EUS miniprobes (EUS-MPs). The application of miniprobes for early carcinomas in the entire intestinal tract, for subepithelial lesions, and for findings in the bile duct and pancreatic duct as well as endobronchial use is critically discussed. Submucous lesions, especially in the colon, but also early carcinomas in special cases are considered the most important indications. The argument is illustrated by numerous examples.

Multimodal Endoscopic Assessment Guides Treatment Decisions for Rectal Early Neoplastic Tumors

BACKGROUND

There is a trend toward organ conservation in the management of rectal tumors. However, there is no consensus on standardized investigations to guide treatment.

OBJECTIVE

We report the value of multimodal endoscopic assessment (white light, magnification chromoendoscopy and narrow band imaging, selected colonoscopic ultrasound) for rectal early neoplastic tumors to inform treatment decisions.

DESIGN

This was a retrospective study.

SETTING

The study was conducted in a tertiary referral unit for interventional endoscopy and early colorectal cancer.

PATIENTS

A total of 296 patients referred with rectal early neoplastic tumors were assessed using standardized multimodal endoscopic assessment and classified according to risk of harboring invasive cancer.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive and negative predictive values of multimodal endoscopic assessment, and previous biopsy to predict invasive cancer were calculated and treatment outcomes reported.

RESULTS

After multimodal endoscopic assessment, lesions were classified as invasive cancer, at least deep submucosal invasion (n = 65); invasive cancer, superficial submucosal invasion or high risk of covert cancer (n = 119); or low risk of covert cancer (n = 112). Sensitivity, specificity, positive predictive values, and negative predictive values of multimodal endoscopic assessment for diagnosing invasive cancer, deep submucosal invasion, were 77%, 98%, 93%, and 93%. The combined classification of all lesions with invasive cancer or high risk of covert cancer had a negative predictive value of 96% for invasive cancer on final histopathology. Sensitivity of previous biopsy was 37%. A total of 47 patients underwent radical surgery and 33 transanal endoscopic microsurgery. No patients without invasive cancer were subjected to radical surgery; 222 patients initially underwent endoscopic resection. Of the 203 without deep submucosal invasion, 95% avoided surgery and were free from recurrence at last follow-up.

LIMITATIONS

This was a retrospective study from a tertiary referral unit.

CONCLUSIONS

Standardized multimodal endoscopic assessment guides rational treatment decisions for rectal tumors resulting in organ-conserving treatment for all patients without deep submucosal invasive cancer. See Video Abstract at http://links.lww.com/DCR/B133. LA EVALUACIÓN ENDOSCÓPICA MULTIMODAL COMO GUÍA DE DECISIONES EN EL TRATAMIENTO DE TUMORES RECTALES NEOPLÁSICOS PRECOCES: La tendencia actual es la preservación del órgano en el manejo de los tumores de rectao. Sin embargo, no hay consenso sobre las investigaciones estandar para guiar dicho tratamiento.Presentamos los valores de la evaluación endoscópica multimodal (luz blanca, cromoendoscopia de aumento, imagen de banda estrecha y ecografía colonoscópica seleccionada) para tumores rectales neoplásicos tempranos y así notificar las decisiones sobre el tratamiento.Estudio retrospectivo.El estudio se realizó en una unidad de referencia terciaria para endoscopia intervencionista y cáncer colorrectal temprano.Se evaluaron 296 pacientes referidos con tumores neoplásicos precoces de recto mediante una evaluación endoscópica multimodal estandarizada y se clasificaron de acuerdo al riesgo de albergar un cáncer invasivo.Se calcularon la sensibilidad, la especificidad, los valores predictivos positivos y negativos de la evaluación endoscópica multimodal y la biopsia previa para predecir el cáncer invasivo y se notificaron los resultados para el tratamiento.Después de la evaluación endoscópica multimodal, las lesiones se clasificaron como: cáncer invasive (al menos invasión submucosa profunda n = 65); cáncer invasive (invasión submucosa superficial o alto riesgo de cáncer encubierto n = 119) y finalmente aquellos de bajo riesgo de cáncer encubierto (n = 112). La sensibilidad, la especificidad, los valores predictivos positivos y negativos de la evaluación endoscópica multimodal para el diagnóstico de cáncer invasivo, la invasión submucosa profunda fueron 77%, 98%, 93% y 93% respectivamente. La clasificación combinada de todas las lesiones con cáncer invasivo o de alto riesgo de cáncer encubierto tuvo un VPN del 96% para el cáncer invasivo en la histopatología final. La sensibilidad fué de 37% en todas las biopsias previas. 47 pacientes fueron sometidos a cirugía radical, 33 por microcirugía endoscópica transanal. Ningún paciente sin cáncer invasivo fue sometido a cirugía radical. Inicialmente, 222 pacientes fueron sometidos a resección endoscópica. De los 203 sin invasión submucosa profunda, el 95% evitó la cirugía y no tuvieron recurrencia en el último seguimiento.Estudio retrospectivo de una unidad de referencia terciaria.La evaluación endoscópica multimodal estandarizada guía las decisiones racionales de tratamiento para los tumores rectales que resultan en un tratamiento conservador de órganos para todos los pacientes sin cáncer invasivo submucoso profundo. Consulte Video Resumen en http://links.lww.com/DCR/B133.

Estimation of invasion depth of early colorectal cancer using EUS and NBI-ME: a meta-analysis

BACKGROUND

Endoscopic ultrasonography (EUS) and narrow band imaging-magnifying endoscopy (NBI-ME) are often used as diagnostic tools to estimate the depth of invasion in early colorectal cancer (CRC). The aim of this study was to compare NBI-ME with EUS in distinguishing between slight submucosal invasion (invasion depth < 1000 μm) and massive submucosal invasion in patients with early CRC, since slight submucosal invasion is currently considered as an indication for endoscopic resection.

METHODS

For this meta-analysis, relevant studies were identified from PubMed, Embase, Web of Science, Scopus and the Cochrane Library databases between January 1997 and September 2016. Data on the yield of tumors were extracted, pooled, and analyzed by stata12.0 software. The sensitivity, specificity, positive likelihood ratio and negative likelihood ratio in differentiating slight submucosal invasion from massive submucosal invasion were calculated for both diagnostic modalities.

RESULTS

Sixteen studies involving 2197 lesions were included: nine were studies on EUS and 7 were studies on NBI-ME. The pooled sensitivity of EUS was 0.902 (95% CI 0.863-0.930), the specificity was 0.877 (95% CI 0.810-0.922), the positive likelihood ratio was 7.314 (95% CI 4.551-11.755) and the negative likelihood ratio was 0.112 (95% CI 0.076-0.164). The pooled sensitivity and specificity of NBI-ME were 0.981 (95% CI 0.949-0.993) and 0.651 (95% CI 0.600-0.699), respectively, the positive likelihood ratio was 2.815 (95% CI 2.432-3.258) and the negative likelihood ratio was 0.029 (95% CI 0.010-0.080).

CONCLUSIONS

The sensitivity tended to be higher in ME-NBI than EUS for early CRC with slight submucosal invasion, whereas the specificity was significantly lower in NBI-ME than in EUS.

Gastrointestinal diagnosis using non-white light imaging capsule endoscopy

Capsule endoscopy (CE) has proved to be a powerful tool in the diagnosis and management of small bowel disorders since its introduction in 2001. However, white light imaging (WLI) is the principal technology used in clinical CE at present, and therefore, CE is limited to mucosal inspection, with diagnosis remaining reliant on visible manifestations of disease. The introduction of WLI CE has motivated a wide range of research to improve its diagnostic capabilities through integration with other sensing modalities. These developments have the potential to overcome the limitations of WLI through enhanced detection of subtle mucosal microlesions and submucosal and/or transmural pathology, providing novel diagnostic avenues. Other research aims to utilize a range of sensors to measure physiological parameters or to discover new biomarkers to improve the sensitivity, specificity and thus the clinical utility of CE. This multidisciplinary Review summarizes research into non-WLI CE devices by organizing them into a taxonomic structure on the basis of their sensing modality. The potential of these capsules to realize clinically useful virtual biopsy and computer-aided diagnosis (CADx) is also reported.

Tumor necrosis factor-related apoptosis-inducing ligand inhibits the growth and aggressiveness of colon carcinoma via the exogenous apoptosis signaling pathway

Colon cancer is one of the most common types of gastrointestinal tumor. Previous studies have demonstrated that tumor necrosis factor-(TNF)-related apoptosis-inducing ligand (TRAIL) reduces the aggressiveness of colon cancer tumors and promotes the apoptosis of colon carcinoma cells. In the present study, the inhibitory effects of TRAIL were investigated and the potential mechanism of TRAIL-mediated apoptosis was explored in colon cancer cells. Reverse transcription-quantitative polymerase chain reaction, western blotting, immunofluorescence, immunohistochemistry, TUNEL and flow cytometry assays were used to analyze the effects of TRAIL on the growth, migration, invasion and apoptosis of colon tumor cells. In vivo experiments were performed in mice to analyze the therapeutic effects of TRAIL. The results demonstrated that TRAIL significantly suppressed the growth of colorectal tumor cells in a dose-dependent manner (0.5–2.5 mg/ml) and also promoted colon tumor cell death. The migration and invasion of colon tumor cells were inhibited by the downregulation of fibronectin, Vimentin and E-cadherin. The apoptotic rate revealed that TRAIL (2.0 mg/ml) significantly promoted the apoptosis of colon tumor cells by regulating apoptosis-related gene expression. TRAIL administration promoted the apoptosis of colon tumor cells via the exogenous apoptosis signaling pathway due to the upregulation of caspase-3, caspase-8 and nuclear factor-κB protein expression. In vivo assays revealed that TRAIL administration significantly inhibited tumor growth and promoted apoptotic body and lymphocyte infiltration, which led to increased survival in tumor-bearing mice compared with the control group. Immunohistochemistry revealed that P53 and B-cell lymphoma-2 were downregulated in TRAIL-treated tumors. In conclusion, TRAIL treatment significantly inhibited the growth and aggressiveness of colon tumors by inducing apoptosis via the exogenous apoptosis pathway, which suggests that TRAIL may be a potential anticancer agent for colon carcinoma therapy.

Tunicamycin inhibits colon carcinoma growth and aggressiveness via modulation of the ERK-JNK-mediated AKT/mTOR signaling pathway

Epidemiology and evidence have demonstrated that colon carcinoma is one of the most common gastrointestinal tumors in the clinic. Reports have suggested that Tunicamycin significantly inhibits aggressiveness of colon carcinoma cells by promotion of apoptosis. In the present study, the inhibitory effect of tunicamycin on colon cancer cells and the potential underlying molecular mechanism was investigated. Western blotting, immunohistochemistry, apoptotic assays and immunofluorescence were used to analyze the therapeutic effects of tunicamycin on apoptosis, growth, aggressiveness and cell cycle of colon tumor cells, by downregulation of fibronectin, vimentin and E‑cadherin expression levels. In vitro experiments demonstrated that tunicamycin significantly inhibited growth, migration and invasion of colon carcinoma cells. In addition, tunicamycin administration promoted apoptosis of colon carcinoma cells via upregulation of apoptotic protease activating factor 1 and cytochrome c expression levels, which are proteins that have a role in mitochondrial apoptosis signaling. Cell cycle assays revealed that tunicamycin suppressed proliferation and arrested S phase entry of colon carcinoma cells. Mechanistic analysis demonstrated that tunicamycin reduced expression and phosphorylation levels of extracellular signal‑regulated kinase (ERK), c‑JUN N‑terminal kinase (JNK) and protein kinase B (AKT), and inhibited mammalian target of rapamycin (mTOR) expression levels in colon carcinoma cells. Endogenous overexpression of ERK inhibited tunicamycin‑mediated downregulation of JNK, AKT and mTOR expression, which further blocked tunicamycin‑mediated inhibition of growth and aggressiveness of colon carcinoma. In vivo assays revealed that tunicamycin treatment significantly inhibited tumor growth and promoted apoptosis, which led to long‑term survival of tumor‑bearing mice compared with the control group. In conclusion, these results suggested that tunicamycin may inhibit growth and aggressiveness of colon cancer via the ERK‑JNK‑mediated AKT/mTOR signaling pathway, and suggested that tunicamycin may be a potential anti‑cancer agent for colon carcinoma therapy.

Colorectal endoscopic submucosal dissection: patient selection and special considerations

Endoscopic submucosal dissection (ESD) enables en bloc resection of large complex colorectal superficial neoplastic lesions, resulting in very low rates of local recurrence, high-quality pathologic specimens for accurate histopathologic diagnosis and potentially curative treatment of early adenocarcinoma without resorting to major surgical resection. The safety and efficacy of the technique, which was pioneered in the upper gastrointestinal tract, has been established by the consistently impressive outcomes from expert centers in Japan and some other eastern countries. However, ESD is challenging to perform in the colorectum and there is a significant risk of complications, particularly in the early stages of the learning curve. Early studies from western centers raised concerns about the high complication rates, and the impressive results from Japanese centers were not replicated. As a result, many western endoscopists are skeptical about the role of ESD and few centers have incorporated the technique into their practice. Nevertheless, although the distribution of expertise, referral centers and modes of practice may differ in Japan and western countries, ESD has an important role and can be safely and effectively incorporated into western practice. Key to achieving this is meticulous lesion assessment and selection, appropriate referral to centers with the necessary expertise and experience and application of the appropriate technique individualized to the patient. This review discusses the advantages, risks and benefits of ESD to treat colorectal lesions and the importance of preprocedure lesion assessment and in vivo diagnosis and outlines a pragmatic rationale for appropriate lesion selection as well as the patient, technical and institutional factors that should be considered.

Endoscopic ultrasound in oncology: An update of clinical applications in the gastrointestinal tract

An accurate staging is necessary to select the best treatment and evaluate prognosis in oncology. Staging usually begins with noninvasive imaging such as computed tomography, magnetic resonance imaging or positron emission tomography. In the absence of distant metastases, endoscopic ultrasound plays an important role in the diagnosis and staging of gastrointestinal tumors, being the most accurate modality for local-regional staging. Its use for tumor and nodal involvement in pre-surgical evaluation has proven to reduce unnecessary surgeries. The aim of this article is to review the current role of endoscopic ultrasound in the diagnosis and staging of esophageal, gastric and colorectal cancer.

Ultrasound capsule endoscopy: sounding out the future

Video capsule endoscopy (VCE) has been of immense benefit in the diagnosis and management of gastrointestinal (GI) disorders since its introduction in 2001. However, it suffers from a number of well recognized deficiencies. Amongst these is the limited capability of white light imaging, which is restricted to analysis of the mucosal surface. Current capsule endoscopes are dependent on visual manifestation of disease and limited in regards to transmural imaging and detection of deeper pathology. Ultrasound capsule endoscopy (USCE) has the potential to overcome surface only imaging and provide transmural scans of the GI tract. The integration of high frequency microultrasound (µUS) into capsule endoscopy would allow high resolution transmural images and provide a means of both qualitative and quantitative assessment of the bowel wall. Quantitative ultrasound (QUS) can provide data in an objective and measurable manner, potentially reducing lengthy interpretation times by incorporation into an automated diagnostic process. The research described here is focused on the development of USCE and other complementary diagnostic and therapeutic modalities. Presently investigations have entered a preclinical phase with laboratory investigations running concurrently.

Colon carcinoma staging by endoscopic ultrasonography miniprobes

Background and Objectives:

Due to the increasing use of endoscopic techniques for colon cancer resection, pretreatment locoregional staging may gain critical interest. The use of endoscopic ultrasonography (EUS) miniprobes in this context has been seldom reported. Our aim was to determine the accuracy of EUS miniprobes for colon cancer staging.

Materials and Methods:

Forty patients with colon cancer (2 in the cecum, 9 in the ascending colon, 5 in the transverse colon, 5 in the descending colon, and 19 in the sigmoid colon) were submitted to staging using 12 MHz EUS miniprobes. EUS and the anatomopathological results were compared with regard to the T and N stages. It was assessed if the location, longitudinal extension, or circumferential extension of the tumor had any influence on the accuracy in EUS staging.

Results:

Tumor staging was feasible in 39 (98%) patients except in one case with a stenosing tumor (out of 6). Globally, T stage was accurately determined in 88% of the cases. In the assessment of the presence or absence of lymph node metastasis, miniprobes presented an accuracy of 82% with a sensitivity of 67%. These results were neither affected by the location nor by the longitudinal or circumferential extension of the tumor.

Conclusions:

EUS miniprobes may play an important role in assessing T and N stages in colon cancer and may represent an incentive to the research of new therapeutic areas for this disease.

The potential impact of local excision for T1 colonic cancer in elderly and comorbid populations: a decision analysis

BACKGROUND

Population-based bowel cancer screening has resulted in increasing numbers of patients with T1 colonic cancer. The need for colectomy in this group is questioned due to the low risk of lymphatic spread and increased treatment morbidity, particularly for elderly, comorbid patients. This study examined the quality-of-life benefits and risks of endoscopic resection compared with results after colectomy, for low-risk and high-risk T1 colonic cancer.

METHODS

Decision analysis using a Markov simulation model was performed; patients were managed with either endoscopic resection (advanced therapeutic endoscopy) or colectomy. Lesions were considered high risk according to accepted national guidelines. Probabilities and utilities (perception of quality of life) were derived from published data. Hypothetical cohorts of 65- and 80-year-old, fit and unfit patients with low-risk or high-risk T1 colonic cancer were studied. The primary outcome was quality-adjusted life expectancy (QALE) in life-years (QALYs).

RESULTS

In low-risk T1 colonic neoplasia, endoscopic resection increases QALE by 0.09 QALYS for fit 65-year-olds and by 0.67 for unfit 80-year-olds. For high-risk T1 cancers, the QALE benefit for surgical resection is 0.24 QALYs for fit 65-year-olds and the endoscopic QALE benefit is 0.47 for unfit 80-year-olds. The model findings only favored surgery with high local recurrence rates and when quality of life under surveillance was perceived poorly.

CONCLUSIONS

Under broad assumptions, endoscopic resection is a reasonable treatment option for both low-risk and high-risk T1 colonic cancer, particularly in elderly, comorbid patients. Exploration of methods to facilitate endoscopic resection of T1 colonic neoplasia appears warranted.

Role of ultrasound in colorectal diseases

Ultrasound is an undervalued non-invasive examination in the diagnosis of colonic diseases. It has been replaced by the considerably more expensive magnetic resonance imaging and computed tomography, despite the fact that, as first examination, it can usefully supplement the diagnostic process. Transabdominal ultrasound can provide quick information about bowel status and help in the choice of adequate further examinations and treatment. Ultrasonography, as a screening imaging modality in asymptomatic patients can identify several colonic diseases such as diverticulosis, inflammatory bowel disease or cancer. In addition, it is widely available, cheap, non-invasive technique without the use of ionizing radiation, therefore it is safe to use in childhood or during pregnancy, and can be repeated at any time. New ultrasound techniques such as elastography, contrast enhanced and Doppler ultrasound, mini-probes rectal and transperineal ultrasonography have broadened the indication. It gives an overview of the methodology of various ultrasound examinations, presents the morphology of normal bowel wall and the typical changes in different colonic diseases. We will pay particular attention to rectal and transperineal ultrasound because of their outstanding significance in the diagnosis of rectal and perineal disorders. This article seeks to overview the diagnostic impact and correct indications of bowel ultrasound.

An analysis of the accuracy of computed tomography colonography when defining anatomy for novel full-thickness colonic excision techniques in early colonic neoplasia

AIM

Full-thickness laparo-endoscopic excision (FLEX) is a new technique developed for the full-thickness excision of colonic adenomas and, potentially, early cancer, avoiding the need for colectomy. FLEX requires accurate preoperative characterization of three key morphological features of the tumour, including its relation to the mesenteric border, its diameter and the circumferential extent of involvement of the bowel wall. This study evaluated the accuracy of CT colonography (CTC) for the assessment of these features in early colonic tumours.

METHOD

Consecutive patients undergoing CTC prior to colonic resection for complex benign polyps or UICC Stage 1 cancer were retrospectively analysed by two specialist gastrointestinal radiologists blinded to the subsequent histopathological findings. The location of the tumour in relation to the mesenteric border, its maximum diameter and the circumferential extent of involvement of the colonic wall were correlated with the histopathological examination of the surgical resection specimen. Pearson's correlation coefficient (r) and Kappa agreement (κ) were used to compare the maximum diameter and the circumferential extent of involvement of the colonic wall.

RESULTS

Twenty-eight patients with early colonic neoplasia were included. All had had a surgical segmental resection. Four had a benign adenoma and 24 had a TNM Stage 1 cancer. Histopathological assessment of the resected surgical specimen showed that 21 of the 28 lesions were located on the mesenteric border. The median diameter was 35 (interquartile range 28-42) mm; 13 lesions involved less than one-third of the circumference, 11 between one and two-thirds and four more than two-thirds. CTC correctly identified the location of the lesion in relation to the mesenteric border in all 28 cases. Correlation between CTC and histopathology was good for the assessment of the maximum diameter of the lesion (r = 0.81) and the circumferential extent of involvement of the colonic wall (κ = 0.76).

CONCLUSION

CTC can accurately assess the key morphological features for the selection of patients with early colonic neoplasia for full-thickness laparo-endoscopic excision.

Is endoscopic ultrasonography useful for endoscopic submucosal dissection?

Endoscopic submucosal dissection (ESD) is an innovative advance in the treatment of early gastrointestinal (GI) cancer without lymph node metastases and precancerous lesions as it is an effective and safe therapeutic method. ESD has also been a promising therapeutic option for removal of submucosal tumors (SMTs) for improving the completeness of resection of a large lesion. Endoscopic ultrasonography (EUS) can be used to detect the depth of invasion during the preoperative evaluation because of its close proximity to the lesion. EUS-guided fine-needle aspiration can be used to increase the diagnostic accuracy of EUS in determining the malignant lymph node. EUS is considered to be a useful imaging procedure to characterize early GI cancer, which is suspicious for submucosal invasion, and the most accurate procedure for detecting and diagnosing SMTs for further treatment. In the process of ESD, EUS can also be used to detect surrounding blood vessels and the degree of fibrosis; this may be helpful for predicting procedure time and decreasing the risk of bleeding and perforation. EUS-guided injection before ESD renders the endoscopic resection safe and accurate. Therefore, EUS plays an important role in the use of ESD. However, compared to conventional endoscopic staging, EUS sometimes can under or overstage the lesion, and the diagnostic accuracy is controversial. In this review, we summarize the latest research findings regarding the role of EUS in ESD.

Management of colorectal T1 carcinoma treated by endoscopic resection from the Western perspective

Detection of early colorectal cancer is expected to rise in light of national colorectal cancer screening programs. This The present review article delineates current endoscopic risk assessments, differentiating invasive from non-invasive neoplasia, for high likelihood of lymph node metastasis in early colorectal cancer, also termed high-risk early colorectal cancer, and endoscopic and surgical resection methods from a Western hemisphere perspective.

Endoscopic ultrasound for staging of colonic cancer proximal to the rectum: A systematic review and meta-analysis

Background and Objectives:

Treatment of colonic cancer patients is highly dependent on the depth of tumor invasion (T-stage) as well as the extension of lymph node involvement (N-stage). We aimed to systematically review the accuracy of endoscopic ultrasound (EUS) for staging of colonic cancer proximal to the rectum.

Patients and Methods:

Men and women with colonic adenocarcinomas were included in the study. EUS staging was compared to histopathology as the gold standard. Outcome measures were T- and N-staging accuracies. Articles were searched in PubMed, Web of Science, The Cochrane Library, and EMBASE.

Results:

Six studies were identified comparing EUS staging of colonic cancer to histopathology. The pooled-staging sensitivity and specificity were 0.90 and 0.98 for T1 tumors, 0.67 and 0.96 for T2 tumors, and 0.97 and 0.83 for T3/T4 tumors, respectively. Sensitivity and specificity for N + disease were 0.59 and 0.78, respectively.

Conclusions:

EUS is a feasible method for T-staging of cancers of the colon proximal to the rectum. The accuracy of lymph node staging needs to be verified by prospective multicenter studies including larger patient populations.

Role of endoscopic ultrasonography in the loco-regional staging of patients with rectal cancer

The prognosis of rectal cancer (RC) is strictly related to both T and N stage of the disease at the time of diagnosis. RC staging is crucial for choosing the best multimodal therapy: patients with high risk locally advanced RC (LARC) undergo surgery after neoadjuvant chemotherapy and radiotherapy (NAT); those with low risk LARC are operated on after a preoperative short-course radiation therapy; finally, surgery alone is recommended only for early RC. Several imaging methods are used for staging patients with RC: computerized tomography, magnetic resonance imaging, positron emission tomography, and endoscopic ultrasound (EUS). EUS is highly accurate for the loco-regional staging of RC, since it is capable to evaluate precisely the mural infiltration of the tumor (T), especially in early RC. On the other hand, EUS is less accurate in restaging RC after NAT and before surgery. Finally, EUS is indicated for follow-up of patients operated on for RC, where there is a need for the surveillance of the anastomosis. The aim of this review is to highlight the impact of EUS on the management of patients with RC, evaluating its role in both preoperative staging and follow-up of patients after surgery.

Advances, problems, and complications of polypectomy

The major role of colonoscopy with polypectomy in reducing the incidence of and mortality from colorectal cancer has been firmly established. Yet there is cause to be uneasy. One of the most striking recent findings is that there is an alarmingly high incomplete polyp removal rate. This phenomenon, together with missed polyps during screening colonoscopy, is thought to be responsible for the majority of interval cancers. Knowledge of serrated polyps needs to broaden as well, since they are quite often missed or incompletely removed. Removal of small and diminutive polyps is almost devoid of complications. Cold snare polypectomy seems to be the best approach for these lesions, with biopsy forcep removal reserved only for the tiniest of polyps. Hot snare or hot biopsy forcep removal of these lesions is no longer recommended. Endoscopic mucosal resection and endoscopic submucosal dissection have proven to be effective in the removal of large colorectal lesions, avoiding surgery in the majority of patients, with acceptably low complication rates. Variants of these approaches, as well as new hybrid techniques, are being currently tested. In this paper, we review the current status of the different approaches in removing polypoid and nonpolypoid lesions of the colon, their complications, and future directions in the prevention of colorectal cancer.

Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum

AIM: To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.

METHODS: A retrospective study with prospectively entered database. From March 2012 to February 2013, a total of 21 patients (11 men) (mean age 64.2 years) with colon cancer beyond the rectum were recruited. The novel forward-viewing radial-array echoendoscope was used for ultrasonographic staging of colon cancer beyond rectum. Ultrasonographic T and N staging were recorded when surgical pathology was used as a gold standard.

RESULTS: The mean time to reach the lesion and the mean time to complete the procedure were 3.5 and 7.1 min, respectively. The echoendoscope passed through the lesions in 13 patients (61.9%) and reached the cecum in 10 of 13 patients (76.9%). No adverse events were found. The lesions were located in the cecum (n = 2), ascending colon (n = 1), transverse colon (n = 2), descending colon (n = 2), and sigmoid colon (n = 14). The accuracy rate for T1 (n = 3), T2 (n = 4), T3 (n = 13) and T4 (n = 1) were 100%, 60.0%, 84.6% and 100%, respectively. The overall accuracy rates for the T and N staging of colon cancer were 81.0% and 52.4%, respectively. The accuracy rates among traversable lesions (n = 13) and obstructive lesions (n = 8) were 61.5% and 100%, respectively. Endoscopic ultrasound and computed tomography had overall accuracy rates of 81.0% and 68.4%, respectively.

CONCLUSION: The echoendoscope is a feasible staging tool for colon cancer beyond rectum. However, accuracy of the echoendoscope needs to be verified by larger systematic studies.