Inter-observer agreement in the endoscopic classification of colorectal laterally spreading tumors: a multicenter study between experts and trainees

Location, morphology and invasiveness of lateral spreading tumors in the colorectum differ between two large cohorts from an eastern and western country

BACKGROUND AND STUDY AIMS

Data from Japanese series show that surface morphology of laterally spreading tumors (LST) in the colon identifies lesions with different incidence and pattern of submucosal invasion. Such data from western countries are scarce. We compared clinical and histological features of LST in a western country and an eastern country, with special interest on mucosal invasiveness of LST, and investigated the effect of clinical factors on invasiveness in both countries.

PATIENTS AND METHODS

Patients with LST lesions ≥20mm were included from a multicenter prospective registry in Spain and from a retrospective registry from the National Cancer Center Hospital East, Japan. The primary outcome was the presence of submucosal invasion in LST. The secondary outcome was the presence of high-risk histology, defined as high-grade dysplasia or submucosal invasion.

RESULTS

We evaluated 1102 patients in Spain and 663 in Japan. Morphological and histological characteristics differed. The prevalence of submucosal invasion in Japan was six-fold the prevalence in Spain (Prevalence Ratio PR=5.66; 95%CI: 3.96, 8.08), and the prevalence of high-risk histology was 1.5 higher (PR=1.44; 95%CI: 1.31, 1.58). Compared to the granular homogeneous type and adjusted by clinical features, granular mixed, flat elevated, and pseudo-depressed types were associated with higher odds of submucosal invasion in Japan, whereas only the pseudo-depressed type showed higher risk in Spain. Regarding high-risk histology, both granular mixed and pseudo-depressed were associated with higher odds in Japan, compared with only the granular mixed type in Spain.

CONCLUSION

This study reveals differences in location, morphology and invasiveness of LST in an eastern and a western cohort.

Interobserver agreement of the Paris and simplified classifications of superficial colonic lesions: a Western study

Background and study aims  The Paris classification of superficial colonic lesions has been widely adopted, but a simplified description that subgroups the shape into pedunculated, sessile/flat and depressed lesions has been proposed recently. The aim of this study was to evaluate the accuracy and inter-rater agreement among 13 Western endoscopists for the two classification systems. Methods  Seventy video clips of superficial colonic lesions were classified according to the two classifications, and their size estimated. The interobserver agreement for each classification was assessed using both Cohen k and AC1 statistics. Accuracy was taken as the concordance between the standard morphology definition and that made by participants. Sensitivity analyses investigated agreement between trainees (T) and staff members (SM), simple or mixed lesions, distinct lesion phenotypes, and for laterally spreading tumors (LSTs). Results  Overall, the interobserver agreement for the Paris classification was substantial (κ = 0.61; AC1 = 0.66), with 79.3 % accuracy. Between SM and T, the values were superimposable. For size estimation, the agreement was 0.48 by the κ-value, and 0.50 by AC1. For single or mixed lesions, κ-values were 0.60 and 0.43, respectively; corresponding AC1 values were 0.68 and 0.57. Evaluating the several different polyp subtypes separately, agreement differed significantly when analyzed by the k-statistics (0.08-0.12) or the AC1 statistics (0.59-0.71). Analyses of LSTs provided a κ-value of 0.50 and an AC1 score of 0.62, with 77.6 % accuracy. The simplified classification outperformed the Paris classification: κ = 0.68, AC1 = 0.82, accuracy = 91.6 %. Conclusions  Agreement is often measured with Cohen's κ, but we documented higher levels of agreement when analyzed with the AC1 statistic. The level of agreement was substantial for the Paris classification, and almost perfect for the simplified system.

IS SUPERFICIAL COLORECTAL LESIONS WITH LOW AND HIGH GRADES INTRAEPITHELIAL NEOPLASMS MORE PREVALENT IN OLDER ABOVE 65 YEARS?

BACKGROUND

Colorectal cancer has a higher incidence in the rectum and sigmoid. However, with the expansion of the diagnosis of superficial lesions interest in the diagnosis and in the role they play in colorectal carcinogenesis has increased.

AIM

To verify the behavior of superficial lesions of the colon and rectum, comparing the pathological and endoscopic findings, below and above 65 years.

METHODS

Cross-sectional study with prospective evaluation of standard protocol, where 200 patients with colorectal superficial lesions were evaluated; they were submitted to colonoscopy and mucosectomy of these lesions. They were divided in two age groups, below and above 65 years.

RESULTS

One hundred-and-eight were women (54%) and 92 men (46%). Most colon lesions were localized in the right colon (95%) and the remaining (5%) in the rectum. In endoscopy, 77.20% were granular lesions in patients under 65 years and 77.90% above. Colon histology showed low grade intraepithelial neoplasia, being 69.79% in patients under and 73.70% in above 65 years. In rectum, above 65 years the incidence of high-grade intraepithelial neoplasia was higher (66.70%).

CONCLUSION

The superficial colorectal lesions have been more endoscopically diagnosed today, and the highest incidence is the granular type, both in the colon and rectum, regardless of age. Regardless the age, histologically colon lesions were more as low grade intraepithelial neoplasia. In rectum, there was distinction for both age groups, being more frequent high grade intraepithelial neoplasia in patients over 65 years.

Long-term prognosis after treatment for T1 carcinoma of laterally spreading tumors: a multicenter retrospective study

PURPOSE

Long-term prognosis of T1 laterally spreading tumors (LSTs) after treatment have not been clarified. This study compared clinicopathological characteristics and long-term prognosis of T1 LSTs.

METHODS

We retrospectively assessed 169 patients with 169 T1 LSTs between January 1992 and December 2008 by ten hospitals. Patients who did not meet the Japanese Society for Cancer of the Colon and Rectum (JSCCR) 2016 guidelines for the treatment of colorectal carcinoma (CRC) criteria were defined as non-endoscopically curable. The number of non-endoscopically curable patients with LST-granular/ nodular mixed (LST-G-M) was 61, that with LST-non-granular/ flat elevated (LST-NG-FE) was 23, and that with LST-non-granular/ pseudo depressed (LST-NG-PD) was 23. Clinicopathological variables and long-term prognosis were analyzed.

RESULTS

For overall patients, tumor size, number of non-endoscopically curable cases, and rate of submucosal invasion depth ≥ 1000 μm for the LST-G-M group were significantly higher than those in the other groups. For non-endoscopically curable patients, the tumor size for those with LST-G-M was significantly larger than those in the other groups. The rate of submucosal invasion width ≥ 4000 μm and type B/C muscularis mucosae with LST-G-M was higher than that with LST-NG-FE. All recurrences occurred in non-endoscopically curable patients with LST-G-M. Five-year overall and disease-free survivals for non-endoscopically curable patients with LST-G-M were significantly shorter than those for patients with non-endoscopically curable LST-NG-FE and PD.

CONCLUSIONS

Our data supported adequacy of the JSCCR guidelines for the treatment of CRC criteria for endoscopically curable patients after T1 LSTs treatment. Patients with T1 LST-G-M should be followed up more carefully.

Laterally spreading tumors: Clinical features and curative effects of endoscopic surgery

AIM

To investigate the clinical features of laterally spreading tumors (LST) and the curative effects of endoscopic surgery.

METHODS

One hundred and twenty LST patients treated at the department of gastroenterology of Affiliated Xiang'an Hospital of Xiamen University from January 2015 to January 2016 were included, and all of then underwent endoscopic surgery. Age, gender, size of lesion, LST classification, location of lesion, pathological pattern, and pit pattern were recorded. The relations of glandular tube opening and pit pattern with pathological classification as well as curative situations were analyzed.

RESULTS

The ratio of male to female in 120 patients was 1.61:1, and the most common age groups were 60-69 and 50-59. The lesion diameter was mainly 20-29 cm. The rectum was the most frequently involved location, followed by the sigmoid colon. Villous adenoma was the most common pathological classification, followed by tubular villous adenocarcinoma. Homogeneous granular type was the most common type of lesion, followed by nodular mixed type. The pit pattern was mainly ⅢL type. The nodular mixed type and homogeneous granular type mainly had type Ⅳ openings, the pseudo-depressed type mainly had ⅤA type openings, and the flat elevated type mainly had ⅢL type openings; the difference among them was statistically significant (P < 0.05). The ⅤA type glandular tube opening was intramucosal carcinoma, Ⅳ type was mainly villous adenoma, and ⅢL type was mainly tubular adenoma; the difference among them was statistically significant (P < 0.05). There were 9(7.50%) cases who underwent endoscopic submucosal dissection (ESD), 61(50.83%) who underwent endoscopic mucosal resection (EMR), and 50(41.67%) who underwent endoscopic piecemeal mucosal resection (EPMR). The lesion locations of LST in the EMR and EPMR groups were mainly the colon and rectum, and that in the ESD group was mainly the rectum; the difference was statistically significant (P < 0.05). The LST diameter in the EMR group was mainly 10-19 cm and 20-29 cm, while that in the ESD group and EPMR group was mainly > 20-29 cm; the difference was statistically significant (P < 0.05). The postoperative recurrence rate in the EPMR group was significantly higher than those in the EMR group and ESD group (P < 0.05). There was no statistical difference in the bleeding rates among the three groups (P > 0.05).

CONCLUSION

LST occurs mainly in males, and middle-aged and elderly people are susceptible to the disease. The size of lesion is mainly 20-29 cm, and the rectum is its predilection site. The lesion classification is mainly homogeneous granular type and nodular mixed type. The pit pattern is mainly ⅢL type, and the pathological pattern is mostly villous adenoma. Pathological classification and pit pattern have a significant difference. EMR and EPMR are common procedures for treatment of LST, and ESD is usually used to treat rectal lesions. EPMR is suitable for treatment of larger colon and rectum lesions, but it has a higher recurrence rate. EMR is suitable for treatment of smaller colon and rectum lesions.

A wide variation of the quality of colonoscopy reporting system in the real clinical practice in southeastern area of Korea

Background/Aims

Establishment of a colonoscopy reporting system is a prerequisite to determining and improving quality. This study aimed to investigate colonoscopists' opinions and the actual situation of a colonoscopy reporting system in a clinical practice in southeastern area of Korea and to assess the factors predictive of an inadequate reporting system.

Methods

Physicians who performed colonoscopies in the Daegu-Gyeongbuk province of Korea and were registered with the Korean Society of Gastrointestinal Endoscopy (KSGE) were interviewed via mail about colonoscopy reporting systems using a standardized questionnaire.

Results

Of 181 endoscopists invited to participate, 125 responded to the questionnaires (response rate, 69%). Most responders were internists (105/125, 84%) and worked in primary clinics (88/125, 70.4%). Seventy-one specialists (56.8%) held board certifications for endoscopy from the KSGE. A median of 20 colonoscopies (interquartile range, 10–47) was performed per month. Although 88.8% of responders agreed that a colonoscopy reporting system is necessary, only 18.4% (23/125) had achieved the optimal reporting system level recommended by the Quality Assurance Task Group of the National Colorectal Cancer Roundtable. One-third of endoscopists replied that they did not use a reporting document for the main reasons of "too busy" and "inconvenience." Non-endoscopy specialists and primary care centers were independent predictive factors for failure to use a colonoscopy reporting system.

Conclusions

The quality of colonoscopy reporting systems varies widely and is considerably suboptimal in actual clinical practice settings in southeastern Korea, indicating considerable room for quality improvements in this field.

Clinical significance and validity of the subclassification for colorectal laterally spreading tumor granular type

BACKGROUND AND AIM

Colorectal laterally spreading tumor granular type (LST-G) is generally divided into two subtypes based on morphology. Here, we retrospectively investigated the clinical significance of a concrete, objective LST-G subclassification.

METHODS

This study examined 636 consecutive cases that were resected endoscopically or surgically. LST-G was subclassified as follows: Type 1, a lesion with homogenous uniform granules with uniform (<5 mm) nodules; Type 2, a lesion with granules and small nodules (≥5 mm, <10 mm); or Type 3, a lesion accompanied by large nodules (≥10 mm). For the validation study, 194 images were compiled from 97 cases investigated using conventional colonoscopy and chromoendoscopy with indigo carmine dye spraying. Images were distributed in a randomized order to students without prior endoscopy experience, less-experienced endoscopists (LEE group), and highly experienced endoscopists (HEE group). Diagnostic accuracy and interobserver agreement were then evaluated.

RESULTS

There was no submucosal invasion in Type 1 lesions. The incidence of deep submucosal invasive carcinoma was higher for Type 3 lesions than for Type 2 lesions. Interobserver agreement was good in each group. Diagnostic accuracy was higher in the HEE group than in the student and LEE groups. Chromoendoscopy had a higher accuracy rate than conventional colonoscopy in the LEE and HEE groups (LEE, 0.74 vs 0.69, P < 0.05; HEE, 0.84 vs 0.78, P < 0.05).

CONCLUSIONS

This subclassification of LST-G according to the diameters of granules and nodules was both useful for choosing therapeutic strategies in the clinical setting and universally applicable.