Search

Background and study aims: Conventional endoscopic resection (CER) includes polypectomy and endoscopic mucosal resection. The most common complications related to these techniques are post procedure bleeding and perforation. The aim of this study was to evaluate the outcomes of CER for colorectal neoplasms ≧20 mm and to clarify predictive factors for complications. Patients and methods: We conducted a multicenter prospective study at 18 specialized institutes. From October 2007 to December 2010, 1,029 CERs were performed at participating institutes. We collected the data prospectively and analyzed gender, age, tumor size, gross appearance, mode of resection, etc. Results: The mean size of polyps resected was 26.4 ± 8.6 mm (range 20-120 mm). The final pathology was Vienna classification category 1 or 2 in 24, category 3 in 502, and category 4 or 5 in 503 lesions. Post procedure bleeding and intra procedure perforation occurred, respectively, in 16 (1.6 %) and 8 cases (0.78 %). The overall complication rate was 2.3 %. Risk factors for bleeding in multivariate analysis were only patients under 60 years of age. Risk factors for perforation in multivariate analysis were en bloc resection and Vienna classification category 4-5. The difference of complication rate was not statistically significant regarding gender, size, tumor location, gross appearance, treatment method, and kind of insufflation. Conclusion: CER is a safe, efficient, and effective minimally invasive therapy for large colorectal lesions. However, care should be taken for post procedure bleeding in patients under 60 years of age and for perforation in cases of Vienna classification category 4-5 or when an en bloc resection is tried. [ABSTRACT FROM AUTHOR]

We previously reported that detection of desmoplastic reaction (DR) in pretreatment biopsy specimens was useful for predicting the depth of submucosal invasion (SM depth) in nonpedunculated early colorectal cancers (ECRCs) in a retrospective study. Here, we performed a prospective multicenter study for verification of our previous findings. Subjects were diagnosed with ECRC by endoscopy, and with adenocarcinoma from the biopsy specimens. Eleven institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum participated in this collaborative study. A total of 112 patients with ECRC were enrolled. For nonpedunculated ECRCs, presence of DR was significantly correlated with SM depth. The sensitivity and specificity of detection of DR for prediction of pSM2 (tumor invasion ≥1000 µm) in nonpedunculated ECRCs were 68.6% and 92.0%, respectively. Evaluation of DR in pretreatment biopsy specimens may be useful for the clinicopathological diagnosis of colorectal carcinoma with massive invasion into the submucosal layer. [ABSTRACT FROM AUTHOR]

Background: The number of patients suffering from colorectal cancer is increasing. According to Japanese guidelines, lesions with a submucosal invasive depth >1,000 μm should be treated with radical proctocolectomy. We propose and evaluate a new clinical classification for pit patterns that uses endoscopy to assess lesion depth for determination of the appropriate therapeutic approach for early colorectal cancers and adenomas. Methods: Endoscopic images of colorectal adenomas and early cancer cases with type V pit pattern, resected surgically or endoscopically from April 2002 to April 2007 at Showa University Yokohama Northern Hospital, were utilized for analysis. Each image was retrospectively analyzed for (A) pit narrowness, (B) irregular pit margins, and (C) indistinct stromal staining. Sensitivity, specificity, and predictive value were evaluated as major outcomes, using pathological results as the standard. Result: In total, 186 cases were assessed. With all features considered (A, B, and C), the sensitivity, specificity, and positive and negative predictive values were 47.8%, 86.3%, 66.0%, and 74.2%, respectively. When limited to two features (A and B), these values were 75.3%, 81.2%, 70.2%, and 84.8%, respectively. Conclusion: Our results suggest that the established criteria can, to a certain degree, distinguish between high and low irregularity in colorectal lesions with V pit pattern indicating submucosal cancer infiltration of more or less than 1,000 μm with the clinical consequence of surgery versus endoscopic mucosal resection/endoscopic mucosal dissection. [ABSTRACT FROM AUTHOR]

Background: We have previously demonstrated a relationship between the depth of submucosal invasion (SM depth) and the frequency of lymph node metastasis in resected submucosal invasive colorectal cancers (SICRCs). Here, we assessed the desmoplastic reaction (DR) in pretreatment biopsy specimens of SICRC to predict the SM depth. Methods: A total of 359 patients with SICRCs, who had undergone surgical or endoscopic mucosal resection, were enrolled. The SM depth of the SICRC lesions was evaluated according to the procedure established by the Japanese Society for Cancer of the Colon and Rectum, and the patients' corresponding pretreatment biopsy specimens were examined histologically to evaluate the prevalence of DR. Results: For pedunculated SICRCs, the prevalence of DR in pretreatment biopsy specimens was significantly higher in moderately differentiated than in well-differentiated adenocarcinomas, but was not significantly related to SM depth. For nonpedunculated SICRCs, the prevalence of DR in pretreatment biopsy specimens was significantly related to histological type, tumor size, and SM depth. When non-pedunculated SICRCs were further divided using a specific cutoff value of 1000 μm for SM depth, the DR positivity rate in pretreatment biopsy specimens was significantly higher in SICRCs with an SM depth of ≧1000 μm (termed 'SM massive CRCs') than in cases where the SM depth was <1000 μm (termed 'SM slight CRCs'). Conclusions: Detection of DR in pretreatment biopsy specimens is useful for the prediction of SM depth in nonpedunculated SICRCs, and may be useful for the selection of such cases that would be treatable by endoscopic mucosal resection and endoscopic submucosal dissection (EMR/ESD). [ABSTRACT FROM AUTHOR]

Background: The aim of this prospective study is to compare the usefulness of magnifying narrow band imaging (NBI) and magnifying chromoendoscopy in the diagnosis of colorectal lesions. Methods: The subjects were 1185 patients who underwent a complete colonoscopic examination and endoscopic or surgical treatment, from January 2006 to February 2008. A total of 1473 lesions were evaluated (53 hyperplastic polyps, 1317 adenomas, 103 submucosally invasive cancers). The digital images with NBI or chromoendoscopy were recorded and diagnosed independently from each other by two endoscopists who were blinded to the final pathological diagnosis. Results: We could differentiate between neoplastic and non-neoplastic lesions with sensitivity of 88.9%, specificity of 98.5% and accuracy of 98.2% according to the vascular pattern. By recognizing an irregular or sparse pattern with NBI, massively invasive submucosal cancer could be diagnosed with the sensitivity and specificity of 94.9% and 76.0%. Using chromoendoscopy, we could differentiate between neoplastic and non-neoplastic lesions with sensitivity of 86.8% and specificity of 99.2%. We were able to differentiate between massively invasive cancers and slightly invasive cancers using the pit patterns with sensitivity of 89.7% and specificity of 88.0%. The specificity was superior to that of NBI colonoscopy. Conclusion: Both NBI and chromoendoscopy can be useful for distinguishing between neoplastic and non-neoplastic lesions. In the diagnosis of submucosal cancer, pit pattern diagnosis was slightly superior to vascular pattern diagnosis. It is desirable to perform chromoendoscopy in addition to NBI for distinguishing between slightly and massively invasive submucosal cancer lesions and determining the treatment. [ABSTRACT FROM AUTHOR]

In colorectal cancers, although flat and depressed-type lesions are found by regular endoscopic view, magnification and pit-pattern observation are vital parts of the precise diagnosis of the lesion. The depressed-type lesions appear to have a prominent tendency to show malignant characteristics, and the recognition and timely treatment of such lesions is important for improving the morbidity and mortality of colorectal cancer. Chromoscopy is mandatory for an accurate diagnosis of these lesions. The pit-pattern classification correlates well with actual histological findings and can provide important additional information prior to endoscopic treatment of the lesion. [ABSTRACT FROM AUTHOR]

Discusses the precancerous lesions of the colorectum. Theories associated with the development of colorectal carcinoma; Classifications of colorectal tumors; Pathohistological findings and differential diagnosis of early colorectal cancers and borderline lesions.

Background: To clarify the similarities and dissimilarities in the macroscopic classification criteria for early colorectal carcinoma (CRC) between Japan and China. Methods: Six early CRC cases were included in this study. Eleven Japanese and Chinese endoscopists were asked to review the colonoscopic pictures of these cases, including before and after indigocarmine spraying. After viewing the pictures, all the endoscopists individually made their classificatory diagnoses of these cases and indicated the findings on which they based each diagnosis. Results: Some lesions diagnosed by Japanese endoscopists as IIa or IIa + IIc, might be classified as Is or Isp by Chinese endoscopists. For superficial lesions consisting of elevation with central depression, IIa + depression, IIa + IIc or IIc + IIa were classified according to the ratio of elevated area/depressed area. However, international as well as interobserver differences still existed in the classification of such lesions. In addition, most Chinese endoscopists overlooked the slightly depressed part on the top of a protruded lesion. Conclusion: Discrepancies on macroscopic classification for early CRC do exist between Japanese and Chinese endoscopists, which were found not only in terminology, but also in recognition of some lesions. In order to develop a universal macroscopic classification, there is a great need for international communication and cooperation. [ABSTRACT FROM AUTHOR]

Abstract The present review describes the changes in views about the early forms of colorectal cancers. In 1985, a concept of ‘flat adenoma’ was born in Japan. At around the same time, depressed type early colorectal cancers started to be reported by Japanese colonoscopists. Neither flat adenomas nor depressed lesions have been frequently reported in Western countries, but increasing numbers of such cases are now described. The problem is that flat adenomas and depressed lesions seem to have been confused by many researchers. The biological aggressiveness of these lesions is quite different. The rate of submucosal invasion is very high in depressed lesions, but fairly low in small flat adenomas. Some adenomas may even look depressed at first, but such lesions should not be mistaken for truly depressed lesions. Ignorance or resistance to the concept may inhibit the detection of flat or depressed lesions. Differences of diagnostic criteria between Japanese and Western pathologists may influence the apparent frequency of mucosal cancers, but not that of invasive carcinomas. Many small adenomas do not grow if followed, but depressed lesions grow rapidly and invade the deeper layers and, as a result, may look elevated as a whole. Many cases in previously published papers suggest that small depressed carcinomas of the large intestine may develop without a precursory stage of an adenomatous polyp. At least two carcinogenic pathways, one through adenomatous polyps and one de novo, should be recognized. In addition, the importance of small depressed cancers should be emphasized. [ABSTRACT FROM AUTHOR]

The author reflects on a study about non-polypoid colorectal neoplasms. The endoscopic classification of early colorectal cancer and adenoma is tackled. The differences between flat lesions and depressed lesions are discussed. Also explored are the adenoma-carcinoma sequence theory and the de novo pathway.

Although flat and depressed-type lesions are found by regular endoscopic view, magnification and pit pattern observation are vital parts of a precise diagnosis of the lesion. The depressed-type lesions have a prominent tendency to show malignant character, and the recognition and timely treatment of this lesion is inevitable in improving the morbidity and mortality from colorectal cancer. A magnifying colonoscope has the capability of a regular colonoscope with an additional feature: magnification. With chromoscopic techniques, the surface pattern of the mucosal pits can be observed. The pit-pattern classification correlates well with actual histologic findings and provides important additional information before endoscopic treatment of the lesion. [Copyright &y& Elsevier]