Differences in the pathological diagnosis of colorectal neoplasia between the East and the West: Present status and future perspectives from Japan

White-Light Imaging and Image-Enhanced Endoscopy With Magnifying Endoscopy for the Optical Diagnosis of Superficial Nonampullary Duodenal Epithelial Tumors: A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

Optical diagnosis of superficial nonampullary duodenal epithelial tumors using white-light imaging (WLI) and/or narrow-band imaging with magnifying endoscopy (NBI-ME) is used to guide the treatment strategy and avoid biopsy-induced fibrosis. However, the effectiveness of this approach has not been elucidated. We conducted a systematic review and meta-analysis aiming to investigate the diagnostic yield between Vienna classification category 3 (VCL C3) and categories 4 or 5 (VCL C4/C5) using biopsy, WLI, NBI-ME, and WLI + NBI-ME.

METHODS

A literature search identified studies on the diagnosis of superficial nonampullary duodenal epithelial tumors using biopsy, WLI, or NBI-ME. A bivariate random-effects model was utilized to analyze the summary estimates of sensitivity and specificity, as well as the area under the summary receiver operating characteristic curves for diagnosing VCL C4/C5.

RESULTS

Ultimately, 13 studies were included in the meta-analysis. For the diagnosis of VCL C4/C5, summary estimates of sensitivity, specificity, and area under the curve were for biopsy 47% (95% confidence interval: 37-58), 86% (79-91), and 0.745; for WLI 80% (65-89), 80% (70-87), and 0.859; for NBI-ME were 72% (61-81), 76% (68-85), and 0.811; and for WLI + NBI-ME 88% (67-96), 87% (51-98), and 0.929, respectively.

CONCLUSIONS

WLI, NBI-ME, and WLI + NBI-ME showed high values for sensitivity and area under the curve. Biopsies can be replaced by WLI, NBI-ME, and WLI + NBI-ME for the preoperative diagnosis of superficial nonampullary duodenal epithelial tumors. However, further accumulation of research findings is needed.

The Long-Term Risk of Metachronous Advanced Adenoma Recurrence After Endoscopic Submucosal Dissection for Colorectal Neoplasia: A Propensity-Score Matched Longitudinal Cohort With 5-Year Follow-Up

INTRODUCTION

Long-term data on metachronous advanced adenoma (AA) recurrence after endoscopic submucosal dissection (ESD) remain scarce, leading to a lack of a standardized surveillance strategy. This study aims to evaluate the long-term risk of recurrent AA after ESD.

MATERIALS AND METHODS

A longitudinal retrospective cohort study with propensity-score matching was conducted in a tertiary hospital in Hong Kong. Subjects who underwent colorectal ESD between 2011 and 2017 were enrolled and defined as the post-ESD group. Selected subjects who underwent polypectomy in their index colonoscopy between 2011 and 2017 were enrolled and stratified into the low- intermediate- and the high-risk groups according to the US Multi-Society Task Force (USMSTF) guideline. The risks of recurrent AA were assessed by Cox proportional hazards regression in the matched cohorts.

RESULTS

A total of 1745 subjects were included, with 203 post-ESD subjects fully matched with 729 high-risk and 813 low-intermediate-risk subjects, respectively. The 5-year cumulative incidence of recurrent AA in the post-ESD group was 7.8%. After 5 years, the post-ESD group was not associated with a higher rate of recurrent AA to the low-intermediate-risk group (7.8% vs. 5.5%; adjusted HR [aHR] 1.64, 95% CI 0.77-3.48, p = 0.197) but a lower rate of recurrent AA (7.8% vs. 11.8%; aHR 0.40, 95% CI 0.19-0.85, p = 0.017) than the high-risk group.

CONCLUSION

Subjects who underwent ESD were not associated with an increased 5-year risk of metachronous AA recurrence than low-intermediate or high-risk groups in USMSTF. The findings will inform future guidelines on post-ESD surveillance colonoscopy strategies.

Is it time to acknowledge intramucosal colorectal carcinoma?

AIM

The term 'intramucosal carcinoma' in the colorectum is controversial when used as a synonym for high-grade dysplasia. However, setting clear definitions for this diagnosis (i.e. unequivocal infiltrative growth in the lamina propria, which might be most easily recognized in cases with overt poor differentiation or formation of signet ring cells or tumour budding) allow us to investigate its relevance.

METHODS AND RESULTS

We reviewed cases from our archive (1990-2024) and selected 14 true intramucosal carcinomas using our strict histological criteria, excluding high-grade dysplasia and invasive carcinomas. These occur primarily in conventional adenomas and are frequently associated with microsatellite instability (50%). Our study shows a low estimated incidence of intramucosal carcinoma (0.01%) in population screening and highlights the low lymph node risk and the good outcome of patients with intramucosal carcinoma.

CONCLUSION

The rare diagnosis of intramucosal colorectal carcinoma aids in identifying patients at increased colorectal cancer risk, notably those with hereditary syndromes. Standardizing this diagnosis is critical to prevent overdiagnosis and unnecessary treatment.

Unravelling interobserver variability in gastrointestinal glandular neoplasia: a contemporary study of US and Korean pathologists

AIMS

Interobserver variability in the assessment of gastric neoplasia biopsies between most Western and Eastern (predominantly represented by Japanese in the literature) pathologists has been documented. It is unknown if such variability exists between the US and Korean pathologists in the current era.

METHODS

Ten gastrointestinal (GI) pathologists from the USA (n=5) and South Korea (n=5) evaluated 100 scanned images of gastric (n=50) and colorectal (n=50) neoplasia biopsies and answered multiple questionnaires. Consensus was defined as the answer chosen by the majority. Cohen's (κc) and Fleiss' kappa (κf) values were calculated between the consensus of the two groups and among the raters, respectively.

RESULTS

Both groups reached a consensus in the majority of cases (74%-100%) with slight to perfect intergroup (κc=0.049-1.000) and no to substantial intragroup (κf=-0.083 to 0.660) agreements. For gastric neoplasia, Korean pathologists relied heavily on cytoarchitectural atypia, whereas the US pathologists focused on stromal invasion when diagnosing adenocarcinoma. For colorectal neoplasia, the Korean pathologists identified concurrent intramucosal carcinoma when diagnosing invasive adenocarcinoma, while the presence of desmoplasia was a prerequisite for the diagnosis of invasive adenocarcinoma for the US pathologists.

CONCLUSIONS

For GI neoplasia biopsy interpretation, the diagnostic approach of Korean pathologists is similar to that of Eastern/Japanese pathologists. Consensus outperformed kappa statistics in capturing the magnitude of inter-rater and intergroup reliability, highlighting the potential benefit of consensus meetings to decrease the gap between Western and Eastern diagnostic approaches.

Proportions and characteristics of interval cancer in annual fecal immunochemical test screening and postcolonoscopy colorectal cancer: Results from a Japanese multicenter prospective study using questionnaires, the C-DETECT study

OBJECTIVES

There are several types of colorectal cancer (CRC) according to the detection methods and intervals, including interval CRC (iCRC) and postcolonoscopy CRC (PCCRC). We aimed to examine their proportions and characteristics.

METHODS

We conducted a multicenter prospective study using questionnaires in Japan ("C-DETECT study"), in which differences in CRC characteristics according to detection methods and intervals were examined from consecutive adult patients. Because the annual fecal immunochemical test (FIT) was used in population-based screening, the annual FIT-iCRC was assessed.

RESULTS

In total, 1241 CRC patients (1064 with invasive CRC) were included. Annual FIT-iCRC (a), 3-year PCCRC (b), and CRC detected within 1 year after a positive FIT with noncompliance to colonoscopy (c) accounted for 4.5%, 7.0%, and 3.9% of all CRCs, respectively, and for 3.9%, 5.4%, and 4.3% of invasive CRCs, respectively. The comparison among these (a, b, c) and other CRCs (d) demonstrated differences in the proportions of ≥T2 invasion ([a] 58.9%, [b] 44.8%, [c] 87.5%, [d] 73.0%), metastasis ([a] 33.9%, [b] 21.8%, [c] 54.2%, [d] 43.9%), right-sided CRC ([a] 42.9%, [b] 40.2%, [c] 18.8%, [d] 28.6%), and female sex ([a] 53.6%, [b] 49.4%, [c] 27.1%, [d] 41.6%). In metastatic CRC, (a) and (b) showed a higher proportions of BRAF mutations ([a] [b] 12.0%, [c] [d] 3.1%).

CONCLUSIONS

Annual FIT-iCRC and 3-year PCCRC existed in nonnegligible proportions. They were characterized by higher proportions of right-sided tumors, female sex, and BRAF mutations. These findings suggest that annual FIT-iCRC and 3-year PCCRC may have biological features different from those of other CRCs.

Predictors of severe submucosal fibrosis during endoscopic submucosal dissection in patients with ulcerative colitis: Retrospective cohort study

OBJECTIVES

Severe submucosal fibrosis is a crucial technical difficulty encountered during endoscopic submucosal dissection (ESD) in patients with ulcerative colitis (UC). We aimed to identify predictors of severe submucosal fibrosis in patients with UC.

METHODS

We retrospectively included 55 tumors resected using ESD from 48 consecutive patients with UC. We analyzed the clinicopathological characteristics and treatment outcomes between the F0/1 (none to mild submucosal fibrosis) group (n = 28) and F2 (severe submucosal fibrosis) group (n = 27).

RESULTS

No significant difference was found between the F0/1 and F2 groups in en bloc resection rate (100% vs. 96%, P = 0.49), the R0 resection rate (100% vs. 93%, P = 0.24), and the dissection speed (0.18 vs. 0.13 cm2 /min, P = 0.07). Intraoperative perforation was more common in the F2 group (30%) than in the F0/1 group (8%; P = 0.01). Multivariable analysis showed that a longer duration of UC (≥10 years; odds ratio [OR] 6.11; 95% confidence interval [CI] 1.20-31.03; P = 0.03) and scarring of background mucosa of the tumor (OR 39.61; 95% CI 3.91-400.78; P < 0.01) were independent predictors of severe submucosal fibrosis.

CONCLUSION

Long UC duration and scarring background mucosa were predictors of severe submucosal fibrosis associated with perforation during ESD.

Association between new plasma inflammatory markers and risk of colorectal neoplasms in individuals over 50 years old

OBJECTIVE(S)

The prognostic value of systemic cytokine profiles and inflammatory markers in colorectal cancer were explored by several studies. We want to know more about inflammatory biomarkers in colorectal adenoma and early cancer.

METHOD

The level of 38 inflammatory markers in the plasma of 112 adenoma patients, 72 Tis-T1 staging of colorectal carcinoma patients, 34 T2-T4 staging of colorectal carcinoma patients and 53 normal subjects were detected and compared.

RESULT(S)

Eight inflammatory biomarkers (Eotaxin, GCSF, IL-4, IL-5, IL-17E, MCP-1, TNF-α and VEGF-A) have higher plasma concentrations in colorectal adenoma and cancer patients compared with normal participants over 50 years old.

CONCLUSION(S)

Inflammatory markers may have the prognostic value for colorectal adenoma and early-stage carcinoma.

Fibroblast Activation Protein-α (FAP) Identifies Stromal Invasion in Colorectal Neoplasia

The increasing detection of colorectal adenomas and early adenocarcinomas (ADCs) in the context of nationwide screening programs has led to a significant increase in the incidence of inconclusive diagnoses in which histopathologic analysis of endoscopic biopsies does not allow pathologists to provide a reliable diagnosis of stromal invasion. The objective of this study was to analyze the discriminative capacity of the immunohistochemical expression of fibroblast activation protein-α (FAP) in distinguishing colorectal adenomas with low-grade dysplasia (LGD) and high-grade dysplasia (HGD) from invasive intestinal-type ADCs. The study analyzed the first endoscopic biopsies from a series of patients classified as inconclusive or conclusive for stromal invasion based on the pathologic report. In total, 30 ADCs, 52 HGDs, and 15 LGDs were included in the study. FAP expression was detected in 23/30 ADCs and was negative in all adenomas with either LGD or HGD features (100% specificity and 76.7% sensitivity, area under the curve=0.883, CI=0.79-0.98). Considering these findings, we conclude that FAP is a potentially useful tool for helping pathologists identify invasive lesions in colorectal endoscopic biopsies, avoiding unnecessary biopsy repetitions.

Endoscopic resection is feasible for high-grade dysplasia in patients with ulcerative colitis

BACKGROUND

Endoscopic resection (ER) is feasible for treating well-circumscribed dysplasia in patients with ulcerative colitis (UC). However, long-term prognosis of ER for high-grade dysplasia (HGD) in patients with UC remains unclear. We aimed to evaluate the long-term prognoses of ER for HGD compared with low-grade dysplasia (LGD) and verify the feasibility of ER and follow-up with surveillance colonoscopy for HGD.

METHODS

An observational, single-center retrospective study included 38 and 22 patients with LGD and HGD who were followed-up with surveillance colonoscopy after ER. We evaluated the cumulative incidence rate of metachronous HGD or colorectal cancer (CRC) and identified the characteristics of metachronous dysplasia.

RESULTS

The median follow-up period was 56 months, and surveillance colonoscopies were performed 3.6 times (mean). The 5-year cumulative incidence rate of HGD/CRC was relatively high in HGD (24.6%) than in LGD (13.7%), but the difference was not significant (p = .16). In HGD cases, six metachronous dysplasia lesions (two LGD and four HGD) were detected 11.6-40.5 months after ER. However, these patients did not progress to CRC. All metachronous lesions were well-circumscribed and with no invisible dysplasia surrounding them; they were 'endoscopically resectable' lesions. Two of the four metachronous HGD lesions were treated endoscopically and two, by colectomy. No synchronous HGD or CRC was detected in the colectomy specimens.

CONCLUSIONS

Our results suggest that ER and follow-up with surveillance colonoscopy is feasible in patients with HGD when histological complete resection is achieved.

Endoscopic diagnosis and treatment of early colorectal cancer

Early colorectal cancer refers to cancer in the colorectum that is confined to the mucosa or submucosa and does not invade the muscularis propria, irrespective of lymph node or distant metastasis. As the number of persons undergoing screening colonoscopy increases, the proportion of patients diagnosed with precancerous colorectal lesions and early colorectal cancer also increases. In the last decade, innovative optical technologies for endoscopic diagnosis have been introduced and endoscopic treatment techniques such as endoscopic submucosal dissection have provided major breakthroughs in the management of early colorectal cancer. With these remarkable developments, endoscopic treatment has established itself as an alternative to surgical resection in the treatment of early colorectal cancer. This review will discuss the endoscopic diagnosis and treatment of early colorectal cancer. Furthermore, the unmet needs in this field and the latest research addressing those issues will be summarized.

Application of artificial intelligence in a real-world research for predicting the risk of liver metastasis in T1 colorectal cancer

Background

Liver is the most common metastatic site of colorectal cancer (CRC) and liver metastasis (LM) determines subsequent treatment as well as prognosis of patients, especially in T1 patients. T1 CRC patients with LM are recommended to adopt surgery and systematic treatments rather than endoscopic therapy alone. Nevertheless, there is still no effective model to predict the risk of LM in T1 CRC patients. Hence, we aim to construct an accurate predictive model and an easy-to-use tool clinically.

Methods

We integrated two independent CRC cohorts from Surveillance Epidemiology and End Results database (SEER, training dataset) and Xijing hospital (testing dataset). Artificial intelligence (AI) and machine learning (ML) methods were adopted to establish the predictive model.

Results

A total of 16,785 and 326 T1 CRC patients from SEER database and Xijing hospital were incorporated respectively into the study. Every single ML model demonstrated great predictive capability, with an area under the curve (AUC) close to 0.95 and a stacking bagging model displaying the best performance (AUC = 0.9631). Expectedly, the stacking model exhibited a favorable discriminative ability and precisely screened out all eight LM cases from 326 T1 patients in the outer validation cohort. In the subgroup analysis, the stacking model also demonstrated a splendid predictive ability for patients with tumor size ranging from one to50mm (AUC = 0.956).

Conclusion

We successfully established an innovative and convenient AI model for predicting LM in T1 CRC patients, which was further verified in the external dataset. Ultimately, we designed a novel and easy-to-use decision tree, which only incorporated four fundamental parameters and could be successfully applied in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02424-7.

Optimizing the colorectal cancer screening programme using faecal immunochemical test (FIT) in Flanders, Belgium from the “interval cancer” perspective

Background

Interval cancer (IC) is a critical issue in colorectal cancer (CRC) screening. We identified factors associated with ICs after faecal immunochemical test (FIT) screening and explored the impact of lowering FIT cut-off or shortening screening interval on FIT-ICs in Flanders.

Methods

FIT participants diagnosed with a CRC during 2013–2018 were included. Factors associated with FIT-ICs were identified using logistic regression. Distributions of FIT results among FIT-ICs were examined.

Results

In total, 10,122 screen-detected CRCs and 1534 FIT-ICs were included (FIT-IC proportion of 13%). FIT-ICs occurred more frequently in women (OR 1.58 [95% CI 1.41–1.76]) and ages 70–74 (OR 1.35 [1.14–1.59]). FIT-ICs were more often right-sided (OR 3.53 [2.98–4.20]), advanced stage (stage IV: OR 7.15 [5.76–8.88]), and high grade (poorly/undifferentiated: OR 2.57 [2.08–3.18]). The majority (83–92%) of FIT-ICs would still be missed if FIT cut-off was lowered from 15 to 10 µg Hb/g or screening interval was shortened from 2 to 1 year.

Conclusions

FIT-ICs were more common in women, older age, right-sided location, advanced stage and high grade. In Flanders, lowering FIT cut-off (to 10 µg Hb/g) or shortening screening interval (to 1 year) would have a minimal impact on FIT-ICs.

Medical costs according to the stages of colorectal cancer: an analysis of health insurance claims in Hachioji, Japan

BACKGROUND

Although the effect of the early detection of colorectal cancer (CRC) on medical costs needs to be clarified, there are few reports on the actual medical costs of CRC patients in Japan. We aimed to identify medical costs according to CRC stage, using health insurance claims.

METHODS

This observational study included CRC patients who had received specific treatment for CRC, which was defined by the procedure code and the claim computer processing system code associated with the treatment of CRC. CRC patients who underwent endoscopic or radical surgical treatment were defined as the curable group and those with palliative treatment, including palliative chemotherapy, as the non-curable group. Total medical costs and medical costs of specific treatments for CRC for 3 years were measured using the claims held by Hachioji City from May 2014 to July 2019.

RESULTS

This study included 442 patients in the curable group, including 267 patients who underwent endoscopic treatment, and 175 patients who underwent radical surgical treatment, and 161 patients in the non-curable group. The mean (standard deviation) total medical costs in the curable and non-curable groups were 2,130 (2,494) and 8,279 (5,600) thousand Japanese Yen (JPY), respectively. The mean (standard deviation) medical costs for the specific treatment of CRC in the curable and non-curable groups were 408 (352) and 3,685 (3,479) thousand JPY, respectively.

CONCLUSIONS

We clarified the actual medical costs of CRC in curable and non-curable groups. These results suggest the effect of early detection of CRC in reducing medical costs.

An endoscopic treatment strategy for superficial tumors in patients with ulcerative colitis

BACKGROUND AND AIM

Endoscopic resection is feasible for superficial tumors in patients with ulcerative colitis; however, endoscopic resection options have not been evaluated comprehensively. We evaluated the efficacy and safety of endoscopic submucosal dissection and endoscopic mucosal resection, and decision making regarding endoscopic resection options for patients with ulcerative colitis.

METHODS

Endoscopically treated tumors from patients with ulcerative colitis were analyzed retrospectively. We evaluated en bloc and R0 resection, adverse events, local tumor recurrence, and metachronous lesion occurrence rates.

RESULTS

We examined 102 tumors (mean size, 12 mm; non-polypoid, 55 tumors) from 74 patients with ulcerative colitis, of whom, 39 and 63 underwent endoscopic submucosal dissection and endoscopic mucosal resection, respectively. The R0 resection rate was significantly higher for endoscopic submucosal dissection (97%) than for endoscopic mucosal resection (80%) (P = 0.0015). For 11-20-mm tumors, the R0 resection rate was significantly higher for endoscopic submucosal dissection (94%) than for endoscopic mucosal resection (55%) (P = 0.0027); the endoscopic submucosal dissection and endoscopic mucosal resection R0 rates did not differ for ≤ 10-mm tumors. The non-polypoid tumor R0 resection rates were significantly higher for endoscopic submucosal dissection (100%) than for endoscopic mucosal resection (65%) (P < 0.001) and did not differ regarding the polypoid tumor R0 resection rates (75% vs 86%, P = 0.49). Four patients experienced intraoperative perforation during endoscopic submucosal dissection. No local recurrences occurred. Metachronous high-grade dysplasia occurred in three patients during surveillance.

CONCLUSIONS

In patients with ulcerative colitis, endoscopic submucosal dissection is suitable for ≥ 11-mm and non-polypoid tumors, whereas endoscopic mucosal resection is acceptable for ≤ 10-mm tumors.

Pathology definitions and resection strategies for early colorectal neoplasia: Eastern versus Western approaches in the post-Vienna era

There is a well-known discrepancy between East and West classifications of colorectal neoplasm, especially "intramucosal carcinoma," categorized as subgroup 4.4 in the Vienna classification, usually recognized as high-grade dysplasia in the United States and as carcinoma in situ in Japan. Focusing on management, in the current National Comprehensive Cancer Network algorithm, high-grade dysplasia, carcinoma in situ, and intramucosal carcinoma are managed similarly, whereas submucosal invasion by carcinoma requires en bloc resection. To bridge the differences with regard to these conceptual problems in the definition and management of carcinoma in situ and intramucosal carcinoma, endoscopists and pathologists from Japan and the United States gathered and discussed from their perspectives how to accurately assess specimens of en bloc/piecemeal resection and to effectively predict lymph node metastasis risk.

Does cold snare polypectomy completely resect the mucosal layer? A prospective single-center observational trial

BACKGROUND AND AIM

The true incidence of incomplete muscularis mucosa resection with cold snare polypectomy (CSP) is unknown. We examined the incidence of incomplete muscularis mucosa resection both with and without cold snare defect protrusion (CSDP).

METHODS

We prospectively enrolled patients undergoing polypectomy for 4 to 9mm nonpedunculated polyps. We evaluated the presence of CSDP immediately following CSP and biopsied the CSDP or the center of the mucosal defect without CSDP. The presence of the muscularis mucosa and any residual polyp in the biopsies was evaluated histologically. The primary outcome was the incidence of incomplete mucosal layer resection defined as the presence of muscularis mucosa or residual polyp in the biopsies.

RESULTS

From August 2017 to October 2018, 188 patients were screened, and 357 polyps were included. CSDP was detected in 122/355 (34%) evaluated mucosal defects. Excluding five lesions requiring hemostasis immediately following CSP, 352 mucosal defects were biopsied. After excluding 102 biopsies containing normal mucosa, we evaluated 250 biopsies. The overall incidence of incomplete mucosal layer resection was 63% (159/250), 76% (68/90) with CSDP and 57% (91/159) without CSDP (P < 0.01). Both univariate and multivariate analyses showed that size (≥ 6 mm), resection time (≥ 5 s), and serrated lesions were risk factors for CSDP.

CONCLUSIONS

Cold snare defect protrusion (CSDP), which was present with 36%, was a good indicator for incomplete mucosal layer resection. Even in nonCSDP polypectomies, 57% of the mucosal layer was not removed completely. Thus, CSP should be used for intra-epithelial lesions only, and careful pretreatment evaluation is recommended.

Cross-national analysis about the difference of histopathological management in Tis and T1 colorectal cancer between Japan and Korea

OBJECTIVES

There are differences in each country with regards to histopathological managements of colorectal cancer (CRC), such as definition of Tis and lymphatic and venous invasion. In this study, we compared Tis and T1 CRC in Japan and Korea.

METHODS

We retrospectively compared various clinical characteristics of consecutive patients who had Tis and T1 CRCs and who were newly diagnosed between 2010 and 2014 at the Kyoto Prefectural University of Medicine (Japan) and the Konkuk University (Korea).

RESULTS

Three hundred and sixty-five cases of T1 cancer and 510 cases of Tis cancer from 726 Japanese and 149 Korean patients were included. The rate of Tis in Japan was higher than in Korea (59.8% vs. 51.0%, P = 0.047), according to the difference of definition of Tis. In the analyses of 365 T1 CRCs, median age was higher in Japan than Korea (67.8 ± 10.6 vs. 62.2 ± 10.1, P < 0.001). Right-sided lesions were more frequent in Japan than they were in Korea (38.7% vs. 22.2%, P < 0.001). The rates of venous and lymphatic invasion were higher in Japan than they were in Korea (venous: 18.6% vs. 1.4%, P < 0.001, lymphatic: 25.3% vs. 13.7%, P = 0.042), according to the different methods of immunohistochemical examinations used (Japan: E-HE and D2-40, Korea: ERG).

CONCLUSIONS

Our study of T1 CRC showed that there were differences between Japan and Korea in tumor location, elderly incidence, and histopathological lymphatic and venous invasion. Additionally, rates of Tis were different between the two countries. In this international study for CRC, it is considered that we have to pay attention regarding the difference of histopathological definition and method in each country.

Intramucosal colorectal carcinoma with invasion of the lamina propria: a study by the Japanese Society for Cancer of the Colon and Rectum

Cancer invasion of the lamina propria is an important pathological finding. However, the clinicopathologic features and diagnostic accuracy of intramucosal carcinoma assessment in colorectal carcinoma (CRC) are unknown. In this study, intramucosal CRCs were reviewed in institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum, and 32 cases with invasion of the lamina propria were identified. Next, a consensus meeting was held to select cases with a high consensus about the presence of invasion, which were reviewed by one Western pathologist for confirmation. In addition to clinicopathologic evaluation, concordance was assessed for diagnosis and histologic findings. During the consensus meeting, 3 cases were found to show ambiguous features such that it was unclear whether there was intramucosal or submucosal invasion, and 7 cases were judged to have invasion of the lamina propria by more than 75% of the pathologists. A poorly differentiated adenocarcinoma and a signet ring cell carcinoma were diagnosed unanimously. Concordance in diagnosis and detection of characteristics of invasion of the lamina propria proved to be only poor to fair. Single or small clusters of cells and atypical or complex glandular arrangements that are beyond normal mucosal architecture were detected more frequently in the 7 high-consensus tumors. Desmoplasia and marked inflammation were detected more often in cases characterized as ambiguous. Intramucosal CRCs with invasion of the lamina propria constituted 5.1% of the surgically resected high-grade intramucosal epithelial dysplastic/neoplastic lesions, and stromal infiltration of single or small clusters of cells is the best objective criterion of invasion.

Endoscopic morphologic features of ulcerative colitis-associated dysplasia classified according to the SCENIC consensus statement

BACKGROUND AND AIMS

Recent advances in endoscopic equipment and diagnostic techniques have made possible the detection of early dysplasia in the inflamed mucosa of ulcerative colitis (UC). The SCENIC consensus statement recommends the use of unified terminology for the morphology of dysplasia. In this study, we investigated the endoscopic features of high-grade dysplasia (HGD) in a clinical setting.

METHODS

We retrospectively identified 62 patients with UC who were diagnosed with colitis-associated cancer or HGD between 1997 and 2015. A total of 39 lesions of HGD detected by targeted biopsy sampling in 31 patients were reviewed, and the endoscopic morphology was classified according to the SCENIC guidelines.

RESULTS

In total, 0 (0%), 6 (15.4%), 19 (48.7%), 12 (30.8%), and 2 (5.1%) lesions with HGD were classified as pedunculated, sessile, superficial elevated, flat, and depressed, respectively. Nearly 80% of the lesions were located in the rectum or sigmoid colon. All flat and depressed lesions were red in color. Typically, sessile/superficial elevated lesions accompanied a flat area (Is+IIb/IIa+IIb). Ulceration was observed in 2 depressed lesions (5.1%). Although the borders were indistinct in 21 lesions (53.8%) without the use of magnifying colonoscopy, all lesions could be distinguished from the surrounding mucosa using magnifying endoscopy.

CONCLUSIONS

This is the first study to classify the morphologic features of HGD using the SCENIC guidelines in a clinical setting. Based on our findings, endoscopists should recognize that HGD is frequently associated with a flat/superficial elevated area and red discoloration and should inspect particularly carefully in the rectum and sigmoid colon. The findings of chromoendoscopy and magnifying colonoscopy may also be useful in distinguishing lesions from the surrounding mucosa.

Narrow Band Imaging, Magnifying Chromoendoscopy, and Gross Morphological Features for the Optical Diagnosis of T1 Colorectal Cancer and Deep Submucosal Invasion: A Systematic Review and Meta-Analysis

OBJECTIVES

Optical diagnosis of T1 colorectal cancer (CRC) and T1 CRC with deep submucosal invasion is important in guiding the treatment strategy. The use of advanced imaging is not standard clinical practice in Western countries. A systematic review and meta-analysis were conducted comparing the accuracy of narrow band imaging (NBI), magnifying chromoendoscopy (MCE), and gross morphological features (GMF) seen with conventional view for the optical diagnosis of T1 CRC and deep submucosal invasion.

METHODS

A literature search identified studies on the optical diagnosis of T1 CRC and deep invasion using NBI, MCE, or GMF. Pooled estimates (PE) of sensitivity and specificity across studies reporting on NBI or MCE were compared using a random effects bivariate meta-regression approach, and a paired analysis focusing on studies that performed both techniques within the same patient was performed.

RESULTS

Thirty-three studies with 31,568 polyps were included. For the optical diagnosis of T1 CRC, both NBI (4 studies; PE 0.85, 95% confidence interval (CI) 0.75-0.91) and MCE (5 studies; PE 0.90, 95% CI 0.83-0.94) yielded higher sensitivity as compared with GMF (3 studies; range 0.21-0.46). No significant preference for NBI or MCE was found (sensitivity relative risk (RR) 0.93, 95% CI 0.79-1.09, P=0.37; specificity RR 0.98, 95% CI 0.86-1.11, P=0.74). Similarly, for the optical diagnosis of deep invasion, both NBI (13 studies; PE 0.77, 95% CI 0.68-0.84) and MCE (17 studies; PE 0.81, 95% 0.75-0.87) yielded higher sensitivity as compared with GMF (6 studies; range 0.18-0.88), and no significant preference for either NBI or MCE was found (sensitivity RR 0.92, 95% CI 0.76-1.11, P=0.36; specificity RR 1.00, 95% CI 0.96-1.04, P=0.92).

CONCLUSIONS

This review supports the use of advanced imaging techniques in preference to GMF to reduce the risk of performing piecemeal resection for T1 CRCs or unnecessary surgical referral for lesions amendable to endoscopic resection. A preference for either NBI or MCE could not be observed.