Comparative study of Western and Japanese criteria for biopsy-based diagnosis of gastric epithelial neoplasia

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 incidence of nonampullary duodenal cancer in Japan 2016-2020: analysis of a national cancer registry

BACKGROUND AND AIM

Epidemiological research is scarce in Asian countries including Japan. We aimed to clarify the epidemiological trend of nonampullary duodenal cancer (NADC) in Japan using a national database.

METHODS

All patients with NADC diagnosed between 2016 and 2020 were identified from the Japanese national cancer registry. The crude and age-adjusted incidences were determined and temporal trends including diagnostic mode, tumor stage, and treatments were analyzed.

RESULTS

A total of 14 484 patients were included. The crude and age-adjusted incidences were 21.8-23.5 and 10.7-12.1 per 1 000 000 person-years. Male-to-female ratio was 1.7:1, and the incidence increased with age. The number of patients was highest among 70-79 year age group in both sexes. In total, 55% of patients were diagnosed during screening or surveillance for other diseases. In 54% of patients, the tumor stage was localized. The major treatment was surgery (32%), followed by endoscopic resection (27%). The trends for detection mode, tumor stage, and treatment were consistent during 2016-2020.

CONCLUSIONS

This study clarified and confirmed the high incidence of duodenal cancer in Japan. Characteristically, many NADC cases are diagnosed asymptomatically and treated by endoscopic or surgical treatment.

Long-term outcomes after endoscopic submucosal dissection for relative indication early gastric cancer in nonsurgical candidates

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is effective in treating early gastric cancer (EGC). Its role in patients with comorbidities along with more advanced disease is unknown. We sought to evaluate this in a large Western cohort.

METHODS

Consecutive patients who underwent ESD for EGC in a single tertiary Western endoscopy center over 10 years were prospectively analyzed. The primary outcomes were long-term overall survival (OS) and disease-free survival (DFS) up to 5 years. Secondary outcomes were efficacy and serious adverse events (SAEs).

RESULTS

ESD for 157 cases of EGC in 149 patients was performed in an elderly and comorbid cohort with a mean age of 73.7 years and age-adjusted Charlson Comorbidity Index of 4.2. Over a median follow-up of 51.6 months, no significant differences were found in 5-year OS (88.9% vs 77.9%, P = .290) and DFS (83.2% vs 75.1%, P = .593) between absolute indication EGC and relative indication (RI) EGC. The absolute indication EGC cohort achieved higher en bloc (96.3% vs 87.5%, P = .069) and R0 resection rates (93.6% vs 62.5%, P < .001) when compared with RI EGC. No significant differences were found in SAEs (7.3% vs 12.5%, P = .363). No mortality or surgical resection ensued from adverse events from ESD.

CONCLUSIONS

ESD safely confers DFS in poor surgical candidates with RI EGC in a large Western cohort. Patients who are elderly and/or with comorbidities or who decline surgical resection may benefit from ESD and avoid the risks of surgery and its long-term sequelae. (Clinical trial registration number: NCT02306707.).

Mucosal microbial microenvironment in early gastric neoplasia and non-neoplastic gastric disease

BACKGROUND AND AIM

The biological characterization of microbial environment in early gastric cancer (EGC), other than Helicobacter pylori, is limited. This study aimed to explore the microbial microenvironment in chronic gastritis (CG), fundic gland polyps (FGPs), low-grade intraepithelial neoplasia (LGIN), and EGC.

METHODS

16S-rRNA gene sequencing and bioinformatic analysis were performed on 63 individuals with 252 mucosal biopsies or endoscopic submucosal dissection margin samples from endoscopy.

RESULTS

The microbiota in gastric LGIN functions analogously to EGC in terms of functional prediction. Neoplastic lesions showed a significant difference to CG or FGPs in beta diversity of the microbiota. Bacteria genera including Paracoccus, Blautia, Barnesiella, Lactobacillus, Thauera, Collinsella were significantly enriched in gastric neoplastic mucosa (LGIN and EGC) compared with non-neoplastic tissues (CG and FGPs). While Pseudomonas and Kingella were depleted in neoplastic tissues. FGPs showed a distinctive microbial network system that negatively interacted with Helicobacter.

CONCLUSIONS

In terms of the mucosal microbial microenvironment, gastric LGIN and EGC showed no significant difference as early neoplastic lesions. We observed a coordinated microbial microenvironment that correlated negatively with Helicobacter.

The incidence of non-ampullary duodenal cancer in Japan: The first analysis of a national cancer registry

BACKGROUND AND AIM

Although duodenal cancer is rare, no epidemiological research on this disease has been conducted in Asian countries. We aimed to elucidate the incidence and clinical features of duodenal cancer in Japan using a large-scale national database.

METHODS

Data of patients with primary duodenal cancer diagnosed from January 1, 2016, to December 31, 2016, were extracted from the Japanese national cancer registry. Excluding malignant neoplasm of the Vater's ampulla, we calculated the incidence among the population as a crude number of patients with duodenal cancer divided by the total Japanese population in 2016. We performed multivariate analyses using logistic regression models to identify risk factors for advanced cancer, defined as metastatic cancer or local invasion to adjacent organs.

RESULTS

Data on 3005 patients were included. The incidence of duodenal cancer was 23.7 per 1 000 000 person-years. In total, 56.4% of cases were detected at the localized stage. In the localized cancer group, endoscopic resection was more frequently performed (48.0%), whereas in the advanced cancer group, surgery and chemotherapy were the major treatment options (39.3% and 41.5%, respectively). Multivariate analyses identified age ≥80 years (odds ratio [OR], 1.489; 95% confidence interval [CI], 1.113-1.992; P = 0.007), incidental detection (OR, 2.325; CI, 1.623-3.331; P < 0.0001), and precise examination for symptomatic patients (OR, 10.561; CI, 7.416-15.042; P < 0.0001) as independent risk factors for advanced cancer.

CONCLUSIONS

Our study revealed the incidence of duodenal cancer in Japan. However, localized cancer was the major tumor stage at detection, resulting in a high rate of endoscopic resection.

Clinicopathological characteristics of non-ampullary duodenal tumors and their phenotypic classification

The tumorigenesis of non-ampullary duodenal epithelial tumors (NADETs) might be different between the oral and anal sides of Vater's papilla. We conducted an immunohistological review to elucidate the clinicopathological features according to the tumor location and phenotypic classification. A review of an institutional database identified 121 patients with 125 superficial NADETs. NADETs were histologically evaluated and classified into the intestinal or gastric type based on immunohistochemical analysis. Clinicopathological factors were compared based on the tumor location and phenotype. Logistic regression analysis was performed to identify independent predictors for gastric-type NADETs. According to location analysis, the mucin phenotype was significantly different (oral side, intestinal-type 64.8%, gastric-type 35.3%; anal side, intestinal-type 87.3%, gastric-type 12.7%; P < 0.01). Although the incidence of adenoma was significantly predominant in the intestinal type (75.3%), most gastric-type NADETs were cancerous (64.3%). Notably, most gastric-type NADETs were adenocarcinomas even when the tumor size was ≤0 mm. In multivariate analysis, tumor location on the oral side (odds ratio [OR], 4.42), villous structure (OR, 6.44), and low tumor gland density (OR, 9.49) were independent predictors of gastric-type tumors. Gastric-type NADETs significantly differ from intestinal-type NADETs in terms of tumor location, morphology, and biology.

Natural History of Early Gastric Cancer: a Case Report and Literature Review

Early detection and treatment decrease the mortality rate associated with gastric cancer (GC). However, the natural history of GC remains unclear. An 85-year-old woman was referred to our hospital for evaluation of a gastric tumor. Esophagogastroduodenoscopy identified a 6 mm, flat-elevated lesion at the lesser curvature of the antrum. A biopsy specimen showed a well-differentiated tubular adenocarcinoma. The depth of the lesion was estimated to be intramucosal. Although the lesion met the indications for endoscopic resection, periodic endoscopic follow-up was performed due to the patient's advanced age and comorbidities. The mucosal GC invaded into the submucosa 3 years later, and finally progressed to advanced cancer 5 years after the initial examination. The patient died of tumor hemorrhage 6.4 years after the initial examination. In this case, mucosal GC progressed to advanced GC, eventually leading to the patient's death from GC. Early and appropriate treatment is required to prevent GC-related death.

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

It is well known that there are discrepancies in the diagnosis of gastrointestinal neoplasia between Western and Japanese pathologists. In the West, colorectal cancer (CRC) is defined by invasion through the muscularis mucosa into the submucosa, especially depending on the presence of desmoplasia. In Japan, however, CRC is defined based on a combination of nuclear and architectural abnormalities, regardless of invasion status. As a result, intramucosal carcinoma is diagnosed as high-grade dysplasia and even intramucosal carcinoma with poorly differentiated component is classified as 'Tis' in the West. It is logical and reasonable that the term 'T1' is used to currently describe intramucosal carcinoma. Use of the term 'high-grade dysplasia' for intramucosal CRC is outdated. In order to determine appropriate clinical treatment of CRC, the various risk factors of metastasis should be fully evaluated. With improved contributions and communication between pathologists and clinicians, overtreatment and inadequate follow up can be avoided. The discrepancies in the diagnosis of CRC between Western and Japanese pathologists may be addressed by an increase in East-West exchange. In addition, in the future, molecular analysis may also be useful for establishment of standardized diagnostic criteria of CRC.