Endoscopic diagnosis and treatment of early cancer in the alimentary tract

Image Quality Analysis of Various Gastrointestinal Endoscopes: Why Image Quality Is a Prerequisite for Proper Diagnostic and Therapeutic Endoscopy

Arising from human curiosity in terms of the desire to look within the human body, endoscopy has undergone significant advances in modern medicine. Direct visualization of the gastrointestinal (GI) tract by traditional endoscopy was first introduced over 50 years ago, after which fairly rapid advancement from rigid esophagogastric scopes to flexible scopes and high definition videoscopes has occurred. In an effort towards early detection of precancerous lesions in the GI tract, several high-technology imaging scopes have been developed, including narrow band imaging, autofocus imaging, magnified endoscopy, and confocal microendoscopy. However, these modern developments have resulted in fundamental imaging technology being skewed towards red-green-blue and this technology has obscured the advantages of other endoscope techniques. In this review article, we have described the importance of image quality analysis using a survey to consider the diversity of endoscope system selection in order to better achieve diagnostic and therapeutic goals. The ultimate aims can be achieved through the adoption of modern endoscopy systems that obtain high image quality.

Feasibility of endoscopic submucosal dissection for gastric and colorectal lesions: Initial experience from the Gastrocentro--UNICAMP

OBJECTIVE

Endoscopic submucosal dissection is a technique developed in Japan for en bloc resection with a lower rate of recurrence. It is considered technically difficult and performed only in specialized centers. This study sought to report the initial experience from the Gastrocentro--Campinas State University for the treatment of gastric and colorectal lesions by endoscopic submucosal dissection.

MATERIALS AND METHODS

The guidelines of the Japanese Association of Gastric Cancer were used as evaluative criteria. For colorectal lesions, the recommended standards proposed by Uraoka et al. and Saito et al. were employed. The practicability of the method, the development of complications and histological analysis of the specimens were evaluated.

RESULTS

Sixteen patients underwent endoscopic submucosal dissection from June 2010 to April 2011; nine patients were treated for gastric lesions, and seven were treated for colorectal lesions. The average diameter of the gastric lesions was 28.6 mm, and the duration of resection was 103 min without complications. All lesions presented lesion-free margins. Of the seven colorectal tumors, four were located in the rectum and three were located in the colon. The average size was 26 mm, and the average procedure time was 163 min. Two complications occurred during the rectal resection procedures: perforation, which was treated with an endoscopic clip, and controlled bleeding. One of the lesions presented a compromised lateral margin without relapse after 90 days. Depth margins were all free of lesions.

CONCLUSION

Endoscopic submucosal dissection at our institution achieved high success rates, with few complications in preliminary procedures. The procedure also made appropriate lesion staging possible.

Endoscopic submucosal dissection for the treatment of early esophageal and gastric cancer--initial experience of a western center

BACKGROUND

Endoscopic submucosal dissection is a new Japanese technique characterized by en-bloc resection of the entire lesion irrespective of size, with lower local recurrence when compared to endoscopic mucosal resection.

OBJECTIVE

To evaluate the feasibility, early results and complications of the endoscopic submucosal dissection technique for treating early gastric and esophageal cancer at the Endoscopic Unit of Clinics Hospital and Cancer Institute of the São Paulo University.

MATERIALS AND METHODS

Twenty patients underwent endoscopic resection using the endoscopic submucosal dissection technique for early gastric or esophageal cancer. The patients were evaluated prospectively as to the executability of the technique, the short-term results of the procedure and complications.

RESULTS

Sixteen gastric adenocarcinoma lesions and six esophageal squamous carcinoma lesions were resected. In the stomach, the mean diameter of the lesions was 16.2 mm (0.6-3.5 mm). Eight lesions were type IIa + IIc, four were type IIa and four IIc, with thirteen being well differentiated and three undifferentiated. Regarding the degree of invasion, five were M2, seven were M3, two were Sm1 and one was Sm2. The mean duration of the procedures was 85 min (20-160 min). In the esophagus, all of the lesions were type IIb, with a mean diameter of 17.8 mm (6-30 mm). Regarding the degree of invasion, three were M1, one was M2, one was M3 and one was Sm1. All had free lateral and deep margins. The mean time of the procedure was 78 min (20-150 min)

CONCLUSION

The endoscopic submucosal dissection technique was feasible in our service with a high success rate.

Predictive factors for local recurrence and incomplete resection of early gastric cancer treated by endoscopic resection: a Western experience

BACKGROUND

Early gastric cancer (EGC) is defined as adenocarcinoma limited to the mucosa or submucosa regardless of lymph node involvement. Local EGC recurrence rates have been described in up to 6% of cases.

OBJECTIVES

To evaluate predictive factors for incomplete resection and local recurrence of EGC treated by endoscopic mucosal resection (EMR) that was followed up for at least one year.

METHODS

From June 1994 to December 2005, 46 patients with EGC underwent EMR. Possible predictive factors for incomplete endoscopic resection and local recurrence were identified by medical chart analysis. Demographic, endoscopic and histopathological data were retrospectively evaluated. EMR was considered complete or incomplete. Patients from the complete resection group were divided into subgroups (with and without local EGC recurrence).

RESULTS

Complete resection was possible in 36 cases (76.6%). Predictive factors for incomplete resection were tumour location (P=0.035), histological type (P=0.021), lesion size (P=0.022) and number of resected fragments (P=0.013). On multivariate analysis, undifferentiated histological type (OR 0.8; 95% CI 0.036 to 0.897) and number of resected fragments (OR 7.34; 95% CI 1.266 to 42.629) were independent predictive factors for incomplete resection. In the complete resection group, a larger lesion size was associated with a higher the number of resected fragments (P=0.018). Local recurrence occurred in nine cases (25%). Use of the cap technique was the only predictive factor for local recurrence in five of seven cases (71.4%) (P=0.006).

CONCLUSIONS

A larger lesion size was associated with a higher number of resected fragments. Undifferentiated adenocarcinoma and piecemeal resection were predictive factors for incomplete resection. Technique type was a predictive factor for local EGC recurrence.

Comparison of chromoendoscopy and conventional endoscopy in the detection of premalignant gastric lesions

BACKGROUND

Diagnosis and localization of intestinal metaplasia and early gastric cancer is problematic because of the lack of any telltale gross endoscopic signs.

OBJECTIVE

To compare the efficacy of chromoendoscopy with conventional endoscopy for the detection of gastric premalignant lesions (intestinal metaplasia).

METHOD

Thirty-three patients in whom previous routine endoscopic biopsies showed intestinal metaplasia were enrolled in a prospective study. Each patient underwent a two-step endoscopy procedure: conventional endoscopy and chromoendoscopy using methylene blue. Biopsies were taken during each step and were studied by an expert pathologist. Presence of intestinal metaplasia was considered a positive result.

RESULTS

Considering the presence of intestinal metaplasia anywhere in the stomach as a positive result, 13 patients were diagnosed with intestinal metaplasia using both endoscopic methods, while eight patients had positive results using chromoendoscopy without any metaplastic changes detected with the conventional method (P=0.003). One patient showed positive biopsies with the conventional method while the pathology report showed no positive biopsies using the chromoendoscopy method. The number of positive biopsies from the antrum, body and fundus were 18, 15 and seven, respectively, using chromoendoscopy, and 10, four and two, respectively, from the same sites using conventional endoscopy.

CONCLUSION

The present study demonstrated that chromoendoscopy is superior to conventional endoscopy for the detection of metaplastic changes and its use can be suggested for the screening of early malignancies of the stomach.

Chromoendoscopy for early diagnosis of gastric cancer

Early diagnosis represents the most important measure to decrease gastric cancer mortality. Endoscopists should be trained to perform standardized extremely rigorous observation with a low threshold of suspicion for neoplasia. Together with recent interest in new imaging techniques such as magnification, chromoendoscopy should be considered to represent a simple, safe and inexpensive technique that may be useful in identifying premalignant conditions and minute cancerous lesions, estimating their superficial extent and determining the histological type and submucosal invasion.

Prevention and management of early esophageal cancer

Early esophageal cancer is defined by its limitation to the esophageal mucosa and submucosa. It has become a curable malignant disease, in sharp contrast to the dismal prognosis of esophageal cancer at advanced stages, which still represents the majority of patients. Understanding the risk factors, establishing surveillance programs for patients at risk, and developing preventative interventions such as dietary and lifestyle changes or pharmacologic interventions hold the potential of reducing the incidence of the disease and of shifting the stage distribution toward early cancer. Endoscopic ultrasound examination is pivotal for distinguishing early from advanced stages of the disease because it allows for accurate assessment of tumor infiltration and regional lymph node involvement. The therapeutic mainstay for early esophageal cancer remains surgery. New, less invasive surgical techniques are being tested that are associated with less morbidity and mortality than standard radical esophagectomies. For patients who are not candidates for surgery, definitive chemoradiation is a viable alternative. New endoscopic ablation techniques, such as endoscopic mucosa resection and photodynamic therapy, are potential alternatives to surgery in patients with cancers limited to the mucosa. For patients with adenocarcinoma of the gastroesophageal junction with submucosal involvement, adjuvant chemoradiation should be considered because of its potential to increase survival.

Differences in endoscopic classification of early colorectal carcinoma between China and Japan: A comparative study

AIM: To compare the differences in the endoscopic classification of early colorectal carcinoma (CRC) between Japan and China.

METHODS: Ten cases of early CRC were included in the study. After reviewing the color pictures of these cases, 5 Japanese endoscopists and 5 Chinese endoscopists made their classificatory diagnosis individually using the current Japanese classification, and indicated their findings on which the diagnosis was based.

RESULTS: Some lesions diagnosed by the Japanese endoscopists as IIa or IIa plus IIc, were classified as Is or Isp by the Chinese endoscopists. For superficial lesions consisting of elevation plus central depression, IIa plus depression, IIa plus IIc or IIc plus IIa were classified according to the ratio of elevated area/depressed area. However, international as well as interobserver difference still existed in the classification of such lesions. In addition, most Chinese endoscopists overlooked slightly depressed part on the top of a protruded lesion. Laterally spreading tumor, a special type of IIa, was identified as LST by some Japanese endoscopists.

CONCLUSION: Discrepancies on macroscopic classification for early CRC do exist between Japanese and Chinese endoscopists, which are found not only in terminology but also in recognition of some lesions. In order to develop a universal classification, it needs for international communication and cooperation.

Lessons from Japan--endoscopic management of early gastric and oesophageal cancer

A significant proportion of gastric and oesophageal cancers are diagnosed at an early stage in Japan. Early cancer is not obvious to the untrained eye as the mucosal changes are subtle. Better awareness by endoscopists of the different appearances of early cancer probably contributes significantly to this high incidence in Japan. Routine use of chromoendoscopy in high risk patients is also helpful. Survival figures after open surgery for these early cancers are excellent. Although the mortality of open surgery for carcinoma of the stomach and oesophagus is low, the morbidity is still considerable. A stage of early cancer, when the lesion is limited to the mucosa has been demonstrated to have minimal risk of metastatic spread (even to the local lymph nodes). These lesions can be reliably diagnosed with the help of endoscopic ultrasound. Once diagnosed, endoscopic mucosal resection can be performed with low morbidity. This provides tissue for histological evaluation, which is a definite advantage over other ablative methods used to treat early gastric and oesophageal cancer. Gastric cancers which are difficult to resect endoscopically, can be dealt with laparoscopically with equally satisfactory results

Endoscopic mucosal resection

Endoscopic mucosal resection (EMR), or mucosectomy technique, developed by Japanese endoscopists consists of resecting flat and polypoid neoplasms of the mucosa by longitudinal section through the submucosa. This technique is relatively simple and carries a low morbidity. It represents an important advance for endoscopists in both technical and cancer areas. Compared with the endoscopic methods of tumor destruction (laser, plasma coagulation), EMR presents the advantage of obtaining a complete specimen for histologic analysis.

Endoscopic mucosal resection. Current concepts

Recent advances in endoscopic mucosal resection of superficial early digestive tract cancers are truly remarkable. The extraordinary long-term outcomes of patients who have been treated with endoscopic mucosal resection have encouraged the widespread practice of endoscopic mucosal resection in Japan. These minimally invasive techniques allow safe and effective treatment of diseases that would otherwise require major surgery. This article provides an overview of endoscopic mucosal resection techniques, their associated outcomes, and other potential applications of endoscopic mucosal resection.

Differences in diagnostic criteria for esophageal squamous cell carcinoma between Japanese and Western pathologists

BACKGROUND

Large discrepancies have been found between Western and Japanese pathologists in the diagnosis of adenoma/dysplasia versus carcinoma for gastric and colorectal glandular lesions. It is important to determine whether similar differences exist in the diagnosis of esophageal squamous lesions.

METHODS

Eleven expert gastrointestinal pathologists from Japan, North America, and Europe individually reviewed a set of microscopic slides containing 21 sections of biopsies and corresponding endoscopic mucosal resection specimens from Japanese patients with superficial esophageal squamous neoplastic lesions. The pathologists indicated the pathologic findings on which they based each diagnosis.

RESULTS

Invasion was the most important diagnostic criterion of carcinoma for the Western pathologists whereas nuclear and structural features were more important for the Japanese pathologists. For two sections showing low grade dysplasia according to most Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in one case and definite carcinoma in the other. For nine sections with high grade dysplasia according to the Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in two cases and definite carcinoma in seven cases. For six sections with suspected carcinoma according to most Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in one case and definite carcinoma in five cases. Four sections showed definite carcinoma according to both the Western and Japanese pathologists. Thus, there was agreement among the Western and Japanese pathologists for only 5 of the 21 sections (kappa value, 0.04). However, when high grade dysplasia, noninvasive carcinoma, and suspected carcinoma were grouped together, the agreement was excellent (19 of the 21 sections; kappa value, 0.75).

CONCLUSIONS

In Japan, esophageal squamous cell carcinoma is diagnosed mainly based on nuclear criteria, even in cases judged to be noninvasive low grade dysplasia in the West. This difference in diagnostic practice may contribute to the relatively high incidence rate and good prognosis of superficial esophageal carcinoma in Japan. To improve the comparability of research data, the authors recommend that high grade dysplasia, noninvasive carcinoma, and suspected carcinoma be grouped together into one category of "noninvasive high grade neoplasia." [See editorial on pages 969-70, this issue.]

Endosonographic Staging of Esophageal Cancer

BACKGROUND: Endosonography (ES) is an important tool for staging malignant esophageal cancer with the TNM staging classification. ES is a safe procedure and an accurate method of staging tumor invasion (T) and lymph node involvement (N). METHODS: The author reviewed the literature on the comparative roles of computed tomography and ES as complementary staging procedures. RESULTS: Advantages of ES in staging esophageal cancer include the ability to accurately determine the layer depth of mural infiltration and to detect metastatic involvement of regional lymph nodes. Its disadvantages include its inability to identify distant metastases, to differentiate inflammation from malignant infiltration of wall layers or in lymph nodes, and to examine beyond obstructing tumors unless esophageal dilation is performed. A recent review indicates the accuracy for T staging to be 84% and N staging to be 77%. CONCLUSIONS: ES is a valuable tool in staging esophageal cancer and should be used in combination with computed tomography for highest accuracy.