Endoscopic therapy of early gastric cancer

Risk assessment of lymph node metastases in early gastric adenocarcinoma fulfilling expanded endoscopic resection criteria

BACKGROUND AND AIMS

Early gastric cancer (EGC) is known to present a low rate of lymph node metastases (LNMs). Gastrectomy with D2 lymphadenectomy is usually curative for EGC. Endoscopic submucosal dissection (ESD) is a well-accepted treatment modality for lesions that meet the classic criteria: those mucosal differentiated adenocarcinoma measuring 20 mm or less, without ulceration. Expanded criteria for ESD have been proposed based on a null LNM rate from large gastrectomy series from Japan. Patients with LNM have been reported in Western centers, heightening the need for validation of expanded criteria. Our aim was to assess the risk of LNM in gastrectomy specimens of patients with EGC who met the expanded criteria for ESD.

METHODS

We conducted an evaluation of gastrectomy specimens including LNM staging of patients submitted to gastrectomy for EGC in a 39-year retrospective cohort.

RESULTS

A total of 389 surgical specimens were included. From them, 135 fulfilled criteria for endoscopic resection. None of the 31 patients with classic criteria had LNM. From the 104 patients with expanded criteria, 3 had LNM (n = 104 [2.9%], 95% confidence interval, .7%-8.6%), all of them with undifferentiated tumors without ulceration, measuring less than 20 mm.

CONCLUSIONS

There is a small risk of LNM in EGC when expanded criteria for ESD are met. Refinement of the expanded criteria for the risk of LNM may be desirable in a Brazilian cohort. Meanwhile, the decision to complement the endoscopic treatment with gastrectomy will have to take into consideration the individual risk of perioperative morbidity and mortality.

In situ gelation properties of a collagen-genipin sol with a potential for the treatment of gastrointestinal ulcers

We investigated the potential of collagen-genipin sols as biomaterials for treating artificial ulcers following endoscopic submucosal dissection. Collagen sol viscosity increased with condensation, allowing retention on tilted ulcers before gelation and resulting in collagen gel deposition on whole ulcers. The 1.44% collagen sols containing genipin as a crosslinker retained sol fluidity at 23°C for >20 min, facilitating endoscopic use. Collagen sols formed gel depositions on artificial ulcers in response to body temperature, and high temperature responsiveness of gelation because of increased neutral phosphate buffer concentration allowed for thick gel deposition on tilted ulcers. Finally, histological observations showed infiltration of gels into submucosal layers. Taken together, the present data show that genipin-induced crosslinking significantly improves the mechanical properties of collagen gels even at low genipin concentrations of 0.2-1 mM, warranting the use of in situ gelling collagen-genipin sols for endoscopic treatments of gastrointestinal ulcers.

Pretreatment Gastric Lavage Reduces Postoperative Bleeding after Endoscopic Submucosal Dissection for Gastric Neoplasms

Aim

For patients receiving endoscopic submucosal dissection (ESD), there is urgent need pertaining to the prevention of postoperative bleeding. We conducted a retrospective propensity score-matched study that evaluated whether pre-ESD gastric lavage prevents postoperative bleeding after ESD for gastric neoplasms.

Methods

From September 2002 to October 2015, the 760 consecutive patients receiving ESD for gastric neoplasm were enrolled and data regarding them were retrospectively analyzed. All patients received conventional preventive treatment against delayed bleeding after ESD, including the administration of proton pump inhibitor and preventive coagulation of visible vessels, at the end of the ESD procedure.

Results

Pre-ESD risk factors for postoperative bleeding included tumor size and no gastric lavage. Using multivariate analysis tumor size >2.0 cm (HR 2.90, 95% CI 1.65–5.10, p = 0.0002) and no gastric lavage (HR 3.20, 95% CI 1.13–9.11, p = 0.029) were found to be independent risk factors. Next, we evaluated the effect of gastric lavage on the prevention of post-ESD bleeding using a propensity score-matching method. A total of 284 subjects (142 per group) were selected. Adjusted odds ratio of gastric lavage for post-ESD bleeding was 0.25 (95% CI 0.071–0.886, p = 0.032).

Conclusion

Pretreatment gastric lavage reduced postoperative bleeding in patients receiving ESD for gastric neoplasm.

Early Gastric Cancer: Current Advances of Endoscopic Diagnosis and Treatment

Endoscopy is a major method for early gastric cancer screening because of its high detection rate, but its diagnostic accuracy depends heavily on the availability of endoscopic instruments. Many novel endoscopic techniques have been shown to increase the diagnostic yield of early gastric cancer. With the improved detection rate of EGC, the endoscopic treatment has become widespread due to advances in the instruments available and endoscopist's experience. The aim of this review is to summarize frequently-used endoscopic diagnosis and treatment in early gastric cancer (EGC).

Safety and efficacy of carbon dioxide insufflation during gastric endoscopic submucosal dissection

AIM: To compare the safety and efficacy of carbon dioxide (CO₂) and air insufflation during gastric endoscopic submucosal dissection (ESD).

METHODS: This study involved 116 patients who underwent gastric ESD between January and December 2009. After eliminating 29 patients who fit the exclusion criteria, 87 patients, without known pulmonary dysfunction, were randomized into the CO₂ insufflation (n = 36) or air insufflation (n = 51) groups. Standard ESD was performed with a CO₂ regulation unit (constant rate of 1.4 L/min) used for patients undergoing CO₂ insufflation. Patients received diazepam for conscious sedation and pentazocine for analgesia. Transcutaneous CO₂ tension (PtcCO₂) was recorded 15 min before, during, and after ESD with insufflation. PtcCO₂, the correlation between PtcCO₂ and procedure time, and ESD-related complications were compared between the two groups. Arterial blood gases were analyzed after ESD in the first 30 patients (12 with CO₂ and 18 with air insufflation) to assess the correlation between arterial blood CO₂ partial pressure (PaCO₂) and PtcCO₂.

RESULTS: There were no differences in respiratory functions, median sedative doses, or median procedure times between the groups. Similarly, there was no significant difference in post-ESD blood gas parameters, including PaCO₂, between the CO₂ and air groups (44.6 mmHg vs 45 mmHg). Both groups demonstrated median pH values of 7.36, and none of the patients exhibited acidemia. No significant differences were observed between the CO₂ and air groups with respect to baseline PtcCO₂ (39 mmHg vs 40 mmHg), peak PtcCO₂ during ESD (52 mmHg vs 51 mmHg), or median PtcCO₂ after ESD (50 mmHg vs 50 mmHg). There was a strong correlation between PaCO₂ and PtcCO₂ (r = 0.66; P < 0.001). The incidence of Mallory-Weiss tears was significantly lower with CO₂ insufflation than with air insufflation (0% vs 15.6%, P = 0.013). CO₂ insufflation did not cause any adverse events, such as CO₂ narcosis or gas embolisms.

CONCLUSION: CO₂ insufflation during gastric ESD results in similar blood gas levels as air insufflation, and also reduces the incidence of Mallory-Weiss tears.

Endoscopic Submucosal Dissection Using a Novel Versatile Knife: An Animal Feasibility Study (with Video)

Background/Aims

In order to reduce the procedure time and the number of accessory changes during endoscopic submucosal dissection (ESD), we developed a novel versatile knife, which has the combined advantages of several conventional knives. The aim of this study was to compare the efficacy, safety, and histological quality of ESD performed using this novel versatile knife and a combination of several conventional knives.

Methods

This was an in vivo animal study comparing two different modalities of ESD in mini-pigs. Completion time of each resection was documented, and the resected specimens were retrieved and evaluated for completeness. To assess the quality control of the procedures and adverse events, detailed histopathological examinations were performed.

Results

A total of 18 specimens were dissected by ESD safely and easily (nine specimens using the new versatile knife; nine specimens by mixing conventional knives). All resections were completed as en bloc resections. There was no significant difference in procedure time between the 2 modalities (456 seconds vs. 355 seconds, p=0.258) and cutting speed (1.983 mm²/sec vs. 1.57 mm²/sec, p=1.000). The rate of adverse events and histological quality did not statistically differ between the modalities.

Conclusions

ESD with a versatile knife appeared to be an easy, safe, and technically efficient method.

Safety of carbon dioxide insufflation during gastric endoscopic submucosal dissection in patients with pulmonary dysfunction under conscious sedation

BACKGROUND

Carbon dioxide (CO2) insufflation is effective for gastric endoscopic submucosal dissection (ESD). However, its safety is unknown in patients with pulmonary dysfunction. This study aimed to investigate the safety of CO2 insufflation during gastric ESD in patients with pulmonary dysfunction under conscious sedation.

METHODS

We analyzed 322 consecutive patients undergoing ESD using CO2 insufflation (1.4 L/min) for gastric lesions. Pulmonary dysfunction was defined as a forced expiratory volume in 1.0 s/forced vital capacity (FEV1.0%) <70% or vital capacity <80%. Transcutaneous partial pressure of CO2 (PtcCO2) was recorded before, during, and after ESD.

RESULTS

In total, 127 patients (39%) had pulmonary dysfunction. There were no significant differences in baseline PtcCO2 before ESD, peak PtcCO2 during ESD, and median PtcCO2 after ESD between the pulmonary dysfunction group and normal group. There was a significant correlation between PtcCO2 elevation from baseline and ESD procedure time (r = 0.22, P < 0.05) only in the pulmonary dysfunction group. In patients with FEV1.0% <60%, the correlation was much stronger (r = 0.39, P < 0.05). Neither the complication incidences nor the hospital stay differed between the two groups. CO2 narcosis or gas embolism was not reported in either group.

CONCLUSIONS

CO2 insufflation during gastric ESD in patients with pulmonary dysfunction under conscious sedation is safe with regard to complication risk and hospital stay. However, in patients with severe obstructive lung disease, especially in those with FEV1.0% <60%, longer procedure time may induce CO2 retention, thus requiring CO2 monitoring.

Risk factors for pyrexia after endoscopic submucosal dissection of gastric lesions

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) is widely used in the resection of gastric tumors en bloc, however, complications such as pyrexia frequently occur following the procedure. The study aim was to elucidate the incidence, clinical characteristics, and risk factors of post-ESD pyrexia.

PATIENTS AND METHODS

We conducted a retrospective cohort study of 471 consecutive patients with 485 gastric lesions resected by ESD between December 2005 and 2010. Pyrexia was defined as body temperature above 37.5 °C, regardless of its duration. Blood tests and chest radiography were performed three times before and after ESD. Chest and abdominal computed tomography (CT) was taken on postoperative day 1.

RESULTS

Post-ESD pyrexia developed in 117 patients (24.8 %), including 40 patients with pneumonia as shown by computed tomography. The pyrexia was resolved in all the patients after 1 day (median; range, 1 - 36 days). A multivariate analysis identified age (P = 0.0029) and resection diameter (P = 0.0009) as risk factors for pyrexia in patients without pneumonia, and operation time (P = 0.0025) as a risk factor for pyrexia in patients with pneumonia.

CONCLUSION

The patient would be at risk for post-ESD pyrexia if a large ESD is performed in the elderly. The longer operation time would raise the risk for pneumonia-associated fever.

Endoscopic treatment for early gastric cancer

Gastric cancer remains one of the most common causes of cancer death. However the proportion of early gastric cancer (EGC) at diagnosis is increasing. Endoscopic treatment for EGC is actively performed worldwide in cases meeting specific criteria. Endoscopic mucosal resection can treat EGC with comparable results to surgery for selected cases. Endoscopic submucosal dissection (ESD) increases the en bloc and complete resection rates and reduces the local recurrence rate. ESD has been performed with expanded indication and is expected to be more widely used in the treatment of EGC through the technological advances in the near future. This review will describe the techniques, indications and outcomes of endoscopic treatment for EGC.

Endoscopic submucosal dissection for large colorectal tumor in a Japanese general hospital

Background and Aims. Endoscopic submucosal dissection (ESD) is not widely used in large colorectal lesions because of technical difficulty and possible complications. We aimed to examine the efficacy and safety of ESD for large colorectal neoplasms. Patients and Methods. During the past 5 years, 608 cases of colorectal neoplasm (≧20 mm) were treated by ESD. They were divided into Group A (20–49 mm, 511 cases) and Group B (≧50 mm, 97 cases). Results. The average age, lesion size, and procedure time were 67.4 years, 30.0 mm, and 60.0 min in Group A, and they were 67.1 years, 64.2 mm, and 119.6 min in Group B. En bloc resection rates were 99.2% and 99.0% (P = 0.80), and complication rates were 4.1% and 9.9% (P = 0.03). Complications in Group A consisted of perforation (2.7%), bleeding (1.2%), and ischemic colitis (0.2%). Those in Group B were perforation (8.2%) and bleeding (1.0%). Two cases in Group A and none in Group B required emergency surgery for perforation. Conclusions. There was no difference in efficacy between Groups A and B. Complications were more frequent in Group B, but all perforations in Group B were successfully managed conservatively. ESD can be effective and safe for large colorectal tumors.

Protein expression status in mucosal and submucosal portions of early gastric cancers and their predictive value for lymph node metastasis

We aimed to find out predictive markers for lymph node (LN) metastasis of early gastric carcinoma (EGC) by separating evaluation of protein expression in mucosa and submucosa considering tumor heterogeneity. We selected 37 pN1-3 EGCs and depth- and size-matched 31 pN0 EGCs as training set and 72 EGCs including 14 pN1-3 EGCs as test set. Protein expression for β-catenin, E-cadherin, N-cadherin, galectin-3, c-MET, TrkB, and Ki-67 was assessed by immunohistochemistry in mucosal (-m) and submucosal (-sm) portions of tumor. In the training set, Ki67-m was higher than in Ki67-sm (mean ± SD: 82.67 ± 11.99% vs 61.79 ± 22.53%, p < 0.001). Altered E-cadherin-sm, high Ki67-m, and high Ki67-sm were correlated with LN metastasis (p < 0.05) and Ki67-sm was independent with lymphatic invasion and desmoplasia (p = 0.015 by multivariate logistic analysis). The test set confirmed Ki67-sm and E-cadherin-sm as predictors of LN metastasis (p < 0.05). Submucosal EGCs with ≥2 predictive factors out of high Ki67-sm, altered E-cadherin-sm, large tumor size (≥3 cm), diffuse type histology, and present lymphatic invasion yielded 100% sensitivity and 90.9% specificity for prediction of LN metastasis in 21 submucosal EGCs of test set. The proliferative activity of tumor in submucosa is suggested to be an independent predictor for LN metastasis in EGC.

Endoscopic holmium:YAG laser ablation of early gastrointestinal intramucosal cancer

Various endoscopic techniques are being increasingly used in early gastrointestinal (GI) cancer. The holmium: yttrium-aluminum-garnet (Ho:YAG) laser has precise tissue cutting ability and good hemostatic properties and has been widely applicated to soft tissue, but the use of endoscopic Ho:YAG laser ablation for early gastrointestinal cancer has not been reported. Twenty patients with biopsy-proven early GI cancer who had a high surgical risk or refused surgery were treated by endoscopic Ho:YAG laser ablation. The tumors of all patients were confined to the mucosal layer without ulceration and without lymph node metastasis. The tumor diameter was not more than 2.5 cm. Endoscopy, endoscopic ultrasound, and computed tomography scan were performed 1-3 months after the treatment, and a biopsy was performed to evaluate the effects of the therapy. Long-term endoscopic follow-up was maintained. Complete eradication was achieved in all the 20 patients, including four patients with high-grade dysplasia associated with focal canceration, seven patients with well-differentiated squamous cell cancer, and nine patients with well-differentiated adenocarcinoma, resulting in a complete response rate of 100% at 1-3 months after treatment. No recurrence was found during 36-73 months of follow-up in all 20 patients. No operative or delayed complications were observed in any of the 20 patients. Preliminary study shows that endoscopic Ho:YAG laser ablation may be an effective, safe, and minimally invasive method for selected patients with early GI intramucosal cancer. Further research is required to confirm the safety and efficacy of this technique compared to its alternative techniques in a multicenter randomized controlled trial.

Animal feasibility study of an innovated splash-needle for endoscopic submucosal dissection in the upper gastrointestinal tract

BACKGROUND AND AIM

The high frequency of complications accompanying endoscopic submucosal dissection (ESD) and its complex processes suggest that the process requires improvement. The objective of the present study was to investigate the feasibility of an innovated splash-needle for ESD.

METHODS

An animal feasibility study with a living pig was conducted. Six resections per portion (esophagus and upper, middle, and lower thirds of the stomach) in a total of 24 resections were carried out by using an original splash-needle or an innovated splash-needle. Major innovations were a thicker part in the middle of the knife and a metal plate on the tip of the sheath to obtain more coagulation ability. Injection solution in the submucosal layer was also changed due to possible influence on the outcomes. Main outcome measurements were entire procedure time, cutting speed, and frequency of bleeding during ESD.

RESULTS

All the 24 resections were completed without complications. Among the obtained data, only mean cutting speeds were significantly influenced by location of the simulated lesion, which revealed that ESD at the upper third was significantly quicker than that at the lower third (P = 0.01), and ESD at the esophagus was significantly slower than that at the three parts of the stomach (P < 0.01). There was no significant difference between the different knives in each variable.

CONCLUSIONS

The innovated splash-needle will be feasible for human use, although the safety and advantages in clinical settings must be elucidated by proper comparative studies with existing knives in humans.

Role of narrow band imaging in endoscopic submucosal dissection

Narrow band imaging (NBI) is a new image enhancement system employing optic digital methods to enhance images of blood vessels on mucosal surfaces, allowing improved visualization of mucosal surface structures. Studies have progressed over the last several years, and the clinical usefulness has been demonstrated. NBI has become frequently applied for preoperative diagnosis before endoscopic submucosal dissection (ESD) of digestive tract cancers, as well as for assessment of the range of ESD for en-bloc resection of large lesions. Consensus has been reached with regard to the usefulness of NBI for detecting micro-lesions of esophageal squamous cell carcinoma indicated for ESD, for the diagnosis of the range and depth. NBI has also been attracting attention for diagnosing gastric cancer based on the observation of micro blood vessels on the mucosal surface and mucosal surface microstructures. The usefulness of NBI has been reported in relation to various aspects of colon cancer, including diagnoses of the presence, quality, range, and depth of lesions. However, as NBI has not surpassed diagnostic methods based on magnifying observation combined with the established and widely employed dye method, its role in ESD is limited at present. Although NBI is very useful for the diagnosis of digestive tract cancers, comprehensive endoscopic diagnosis employing the combination of conventional endoscopy including dye spraying, EUS, and NBI may be important and essential for ESD.

Precancerous lesions of gastric cancer: Research progress and preventive strategies

The development of precancerous lesions of gastric cancer is a critical stage of the evolution of gastric cancer. Early detection and intervention for these lesions are of considerable significance in reducing the morbidity of gastric cancer. The development of precancerous lesions of gastric cancer is controlled by multiple factors such as Helicobacter priori infection, DNA methylation, microsatellite instability, and p53 status. Because of high malignancy and unclear etiology of gastric cancer, there are certain difficulties in carrying out successful primary prevention. This review aims to review the recent advances in understanding the pathogenesis of and preventive strategies for gastric precancerous lesions.

Diagnosis of depressed-type early gastric cancer using small-caliber endoscopy with flexible spectral imaging color enhancement

BACKGROUND AND AIM

Small-caliber endoscopy has lower resolution than normal-caliber endoscopy, limiting its use in routine outpatient practice. Flexible spectral imaging color enhancement (FICE) strengthens the color contrast of depressed-type early gastric cancer without magnification. The aim of the present study was to evaluate the detection of depressed-type early gastric cancer using small-caliber endoscopy with the FICE system.

METHODS

Eighty-two patients diagnosed with depressed-type early gastric cancer by standard endoscopy and biopsy were evaluated by small-caliber endoscopy. FICE images and conventional images were compared. Color differences in all 82 lesions were measured between malignant lesions and the surrounding mucosa using the Commission Internationale de L'Eclairage (CIE) 1976 color space.

RESULTS

Most cancers were readily detected as reddish lesions on FICE images. Lines of demarcation between the malignant lesion and the surrounding mucosa were easily identified with FICE images, as such cancers could be clearly distinguished from the surrounding atrophic mucosa. Greater median color differences between malignant lesions and the surrounding mucosa were present in FICE images compared with conventional images, resulting in images with better contrast (27.2 vs 18.7, P<0.0001).

CONCLUSIONS

Small-caliber endoscopy with the FICE system provides better color contrast of depressed-type early gastric cancers than conventional small-caliber endoscopy, and the FICE system may facilitate the diagnosis of this type of cancer as a new endoscopic modality.

Magnifying endoscopy in upper gastroenterology for assessing lesions before completing endoscopic removal

Any prognosis of gastrointestinal (GI) cancer is closely related to the stage of the disease at diagnosis. Endoscopic submucosal dissection (ESD) and en bloc endoscopic mucosal resection (EMR) have been performed as curative treatments for many early-stage GI lesions in recent years. The technologies have been widely accepted in many Asian countries because they are minimally invasive and supply thorough histopathologic evaluation of the specimens. However, before engaging in endoscopic therapy, an accurate diagnosis is a precondition to effecting the complete cure of the underlying malignancy or carcinoma in situ. For the past few years, many new types of endoscopic techniques, including magnifying endoscopy with narrow-band imaging (ME-NBI), have emerged in many countries because these methods provide a strong indication of early lesions and are very useful in determining treatment options before ESD or EMR. However, to date, there is no comparable classification equivalent to “Kudo’s Pit Pattern Classification in the colon”, for the upper GI, there is still no clear internationally accepted classification system of magnifying endoscopy. Therefore, in order to help unify some viewpoints, here we will review the defining optical imaging characteristics and the current representative classifications of microvascular and microsurface patterns in the upper GI tract under ME-NBI, describe the accurate relationship between them and the pathological diagnosis, and their clinical applications prior to ESD or en bloc EMR. We will also discuss assessing the differentiation and depth of invasion, defying the lateral spread of involvement and targeting biopsy in real time.

Sodium alginate as an ideal submucosal injection material for endoscopic submucosal resection: preliminary experimental and clinical study

BACKGROUND

Sodium alginate is used clinically in the treatment of peptic ulcer disease. Because of its viscosity, sodium alginate could possibly become a new submucosal injection material for use in endoscopic resection.

OBJECTIVE

We evaluated the feasibility of endoscopic submucosal dissection (ESD) using sodium alginate.

SETTING AND INTERVENTIONS

The lesion-lifting properties of sodium alginate were examined in porcine stomachs and were compared with those of normal saline solution and sodium hyaluronate solution. After confirming the proper concentration of sodium alginate, ESD using sodium alginate was performed in 11 patients with gastric mucosal cancer or adenoma.

MAIN OUTCOME MEASUREMENT

The lesion-lifting properties of sodium alginate and clinical outcomes were assessed.

RESULTS

The thickness of the submucosal elevation created by 3% sodium alginate in porcine stomach was equivalent to that of sodium hyaluronate. ESD using sodium alginate was completed successfully in all patients without adverse effects except in 1 patient in whom transient shrinkage of the gastric wall disappeared spontaneously after approximately 30 minutes. The mean tumor size was 15.3 mm. En bloc resection and a negative resection margin were obtained in all. Histopathologic examination revealed that all tumors were confined to the mucosal layer except for 1 that was confined to the submucosal layer without lymphovascular invasion, and there were no adverse effects such as tissue damage. No patient required additional treatment, and none showed recurrence during a median follow-up period of 28 months.

LIMITATIONS

Small sample size.

CONCLUSION

This preliminary study suggests that sodium alginate might be a novel, safe submucosal injection material for use in endoscopic resection. Further investigation of the properties of sodium alginate is warranted.

Intestinal metaplasia, intraepithelial neoplasia and gastric carcinogenesis

Gastric cancer is a common disease that greatly endangers people's health. The mechanism of gastric carcinogenesis is still unknown. Gastric carcinogenesis is a long-term multistep process, during which a series of precancerous lesions develop sequentially. Intraepithelial dysplasia and intestinal metaplasia are two types of gastric precancerous lesions. Because of high malignancy and unclear etiology of gastric cancer, there are some difficulties in carrying out successful primary prevention. Here, we give an overview of the definitions and classification of gastric intraepithelial neoplasia and intestinal metaplasia, and elaborate the relationship among Helicobacter pylori infection, atrophic gastritis, intestinal metaplasia and gastric carcinoma.

A genomic approach to investigate expression profiles in Slovenian patients with gastric cancer

Despite its decreasing frequency in developed countries, gastric cancer remains a significant health burden. The aim of the present study was to construct cDNA libraries and analyze differentially expressed genes related to this disease. Gene expression profiles were generated with suppressive subtraction hybridization (SSH). We constructed eight SSH libraries, four representing up-regulated genes and four representing down-regulated genes in tumor tissues. Our approach revealed that several genes are abnormally expressed in gastric cancer. We also identified global deregulation of several pathways involved in the maintenance of normal gastric homeostasis. The results of this study support the view that, as a result of complex pathogenesis, diversity of genomic aberrations and multiplicity of carcinogenic causes, gastric cancer cannot be reduced to a single molecule. Our results may contribute new insight into molecular aspects of the disease and may prove advantageous for future development of therapeutic targets and diagnostic molecular markers.

Endoscopic submucosal dissection for premalignant lesions and noninvasive early gastrointestinal cancers

AIM: To investigate the indication, feasibility, safety, and clinical utility of endoscopic submucosal dissection (ESD) in the management of various gastrointestinal pathologies.

METHODS: The medical records of 60 consecutive patients (34 female, 26 male) who underwent ESD at the gastroenterology department of Kocaeli University from 2006-2010 were examined. Patients selected for ESD had premalignant lesions or non-invasive early cancers of the gastrointestinal tract and had endoscopic and histological diagnoses. Early cancers were considered to be confined to the submucosa, with no lymph node involvement by means of computed tomography and endosonography.

RESULTS: Sixty ESD procedures were performed. The indications were epithelial lesions (n = 39) (33/39 adenoma with high grade dysplasia, 6/39 adenoma with low grade dysplasia), neuroendocrine tumor (n = 7), cancer (n = 7) (5/7 early colorectal cancer, 2/7 early gastric cancer), granular cell tumor (n = 3), gastrointestinal stromal tumor (n = 2), and leiomyoma (n = 2). En bloc and piecemeal resection rates were 91.6% (55/60) and 8.3% (5/60), respectively. Complete and incomplete resection rates were 96.6% (58/60) and 3.3% (2/60), respectively. Complications were major bleeding [n = 3 (5%)] and perforations [n = 5 (8.3%)] (4 colon, 1 stomach). Two patients with colonic perforations and two patients with submucosal lymphatic and microvasculature invasion (1 gastric carcinoid tumor, 1 colonic adenocarcinoma) were referred to surgery. During a mean follow-up of 12 mo, 1 patient with adenoma with high grade dysplasia underwent a second ESD procedure to resect a local recurrence.

CONCLUSION: ESD is a feasible and safe method for treatment of premalignant lesions and early malignant gastrointestinal epithelial and subepithelial lesions. Successful en bloc and complete resection of lesions yield high cure rates with low recurrence.

Submucosal injection of 0.4% hydroxypropyl methylcellulose facilitates endoscopic mucosal resection of early gastrointestinal tumors

BACKGROUND AND AIMS

Submucosal injection of a viscoelastic solution prolongs submucosal lift, thus, facilitating endoscopic mucosal resection. Our objective was to assess the safety and clinical effectiveness of 0.4% hydroxypropyl methylcellulose (HPMC) as a submucosal injectant for endoscopic mucosal resection.

PATIENTS AND METHODS

A prospective, open-label, multicenter, phase 2 study was conducted at 2 academic institutions in Brazil. Eligible participants included patients with early gastrointestinal tumors larger than 10 mm. Outcomes evaluated included complete resection rates, volume of HPMC injected, duration of the submucosal cushion as assessed visually, histology of the resected leisons, and complication rates.

RESULTS

Over a 12-month period, 36 eligible patients with superficial neoplastic lesions (stomach 14, colon 11, rectum 5, esophagus 3, duodenum 3) were prospectively enrolled in the study. The mean size of the resected specimen was 20.4 mm (10 to 60 mm). The mean volume of 0.4% HPMC injected was 10.7 mL (range 4 to 35 mL). The mean duration of the submucosal fluid cushion was 27 minutes (range 9 to 70 min). Complete resection was successfully completed in 89%. Five patients (14%) developed immediate bleeding requiring endoclip and APC application. Esophageal perforation occurred in 1 patient requiring surgical intervention. There were no local or systemic adverse events related to HPMC use over the follow-up period (mean 2.2 mo).

CONCLUSION

HPMC solution (0.4%) provides an effective submucosal fluid cushion and is safe for endoscopic resection of early gastrointestinal neoplastic lesions.

Short term results of endoscopic submucosal dissection in superficial esophageal squamous cell neoplasms

AIM: To evaluate the efficacy of endoscopic submucosal dissection for superficial esophageal squamous cell neoplasms.

METHODS: Between July 2007 and March 2009, 27 consecutive superficial esophageal squamous cell neoplasms in 25 enrolled patients were treated by endoscopic submucosal dissection. The therapeutic efficacy, complications, and follow-up results were assessed.

RESULTS: The mean size of the lesions was 21 ± 13 mm (range 2-55 mm); the mean size of the resection specimens was 32 ± 12 mm (range 10-70 mm). The en block resection rate was 100% (27/27), and en block resection with tumor-free lateral/basal margins was 88.9% (24/27). Perforation occurred in 1 patient who was managed by conservative medical treatments. None of the patients developed local recurrence or distant metastasis in the follow-up period.

CONCLUSION: Endoscopic submucosal dissection is applicable to superficial esophageal squamous cell neoplasms with promising results.

Intestinal metaplasia: a premalignant lesion involved in gastric carcinogenesis

Despite a plateau in incidence, gastric cancer remains a significant problem globally. The majority of gastric cancer is associated with histologically recognizable premalignant stages as first described by Pelayo Correa in the mid-1970s. The mortality from gastric cancer remains high especially in Western countries where, arguably, the index of suspicion of gastric cancer in patients presenting with upper abdominal symptoms is lower than in high prevalence countries. What is the evidence that intestinal metaplasia (IM) is a premalignant condition? What should the clinician know about IM and the relative risks of progression to gastric cancer? Finally, what are the current and future strategies that may help stratify patients into high risk and low risk for the development of gastric cancer? This review focuses on gastric IM and outlines some of the literature that discusses it as a premalignant condition. It also reviews the issue of surveillance of patients with IM in order to attempt to reduce the significant mortality of gastric cancer by detection of earlier stages of disease which are eminently treatable.

Diagnosis of elevated-type early gastric cancers by the optimal band imaging system

BACKGROUND

The endoscopic diagnosis of an elevated-type early gastric cancer is often difficult. The optimal band imaging (OBI) system can reconstruct the best spectral images decomposed from ordinary endoscopic images with free selection of 3 wavelengths and provide unmagnified images with high light intensity as well as magnified images.

OBJECTIVE

To evaluate whether the OBI system facilitates detection of the demarcation lines between an elevated-type early gastric cancer and surrounding tissue and thus is more helpful for performing endoscopic therapy.

DESIGN

A prospective study.

SETTING

Jichi Medical University, Japan.

PATIENTS

Seventy-five patients, 81 lesions with an elevated-type early gastric cancer.

MAIN OUTCOME MEASUREMENTS

A comparison between OBI images and conventional endoscopic images in the identification of the demarcation lines of an elevated-type early gastric cancer without magnification and the rate of success in identifying the abnormal surface structure of cancer by using low-magnified OBI images.

RESULTS

Demarcation lines were easily identified in OBI images, even without magnification, because such cancers could be clearly distinguished from the surrounding whitish atrophic mucosa. Inexperienced endoscopists could determine demarcation lines with significantly greater accuracy with unmagnified OBI images than with conventional images. With 40-fold magnification, irregular microstructural or nonstructural patterns were also found within cancer lesions in all cases studied but in none of the cases in the surrounding noncancerous mucosa.

CONCLUSIONS

The new contrast images obtained with the OBI system enable better determination of the demarcation lines of elevated-type early gastric cancers, and this system may be useful for performing endoscopic therapy of this type of cancer as a new endoscopic modality.

Technology insight: endoscopic submucosal dissection of gastrointestinal neoplasms

Gastrointestinal neoplasms can be cured by local resection as long as the lesions are in the early stage and have not metastasized. Endoscopic resection is a minimally invasive treatment for early-stage gastrointestinal neoplasms, and endoscopic submucosal dissection (ESD) is one type of endoscopic resection that has been developed in the past 10 years. For ESD to be a reliable, curative treatment for gastrointestinal neoplasms, it is necessary for the endoscopist to detect the lesion early, make a precise pretreatment diagnosis, ensure that the patient has the correct indication for endoscopic resection, and have the skill to perform ESD. For early lesion detection, endoscopists should pay attention to subtle changes in the surface structure, the color of the mucosa and the visibility of underlying submucosal vessels. Chromoendoscopy and magnifying endoscopy are useful for determining the margin of the lesions for pretreatment diagnosis, and endoscopic ultrasonography and magnifying endoscopy are useful for determining the depth of invasion. For ESD to be successful, local injection of sodium hyaluronate helps maintain mucosal elevation during dissection. Selecting the appropriate knife, using transparent hoods wisely, employing a good strategy that uses gravity, and having good control of bleeding are all needed to make ESD reliable.

Outcome of segmental gastrectomy versus distal gastrectomy for early gastric cancer

BACKGROUND

Because of the frequent occurrence of postgastrectomy disturbances after distal gastrectomy (DG), segmental gastrectomy (SG) has recently been applied to early gastric cancer (EGC). Outcomes of SG and DG in patients with EGC were compared to clarify the usefulness of SG as a treatment for EGC.

METHODS

This retrospective study involved 61 patients with EGC: 28 patients who underwent DG before March 1996 and 33 patients who underwent SG after April 1996 during the period April 1991 through March 2002. Patient and tumor characteristics, operative results, and postoperative outcomes were compared between the two groups.

RESULTS

The postoperative/preoperative body weight ratio was higher in the SG group than in the DG group. Early dumping syndrome and reflux gastritis occurred less frequently after SG than after DG. The incidence of postoperative complications was similar in the two groups. All patients remained alive without recurrence during a mean follow-up period of 54.7 months in the SG group and 99.9 months in the DG group.

CONCLUSIONS

In comparison to DG, SG is associated with improved postoperative quality of life with no decrease in operative curability of EGC. Thus, SG is a feasible treatment for EGC.