Risk factors for gastric cancer in Japan in the 2010s: a large, long-term observational study.

BACKGROUND: The numbers of Helicobacter pylori (HP)-infected individuals and deaths due to gastric cancer are decreasing in Japan. We aimed to determine whether the serological test for chronic gastritis (the ABC method) is still useful for gastric cancer risk stratification in the 2010s and to analyze risk factors for developing gastric cancer in Japan. METHODS: In this prospective study, we monitored 20773 individuals for the incidence of gastric cancer from 2010 to 2019. The relationships between blood sampling results, physical examination, and lifestyle in 2010 and the cumulative incidence of gastric cancer were analyzed. RESULTS: A total of 19343 participants who met the study criteria were analyzed. Overall, 0.08% of participants in group A (9/11717), 0.63% in group B (28/4452), 2.05% in group C (43/2098), 1.52% in group D (1/66), and 0.30% in group E (3/1010) developed gastric cancer. Cox hazard analysis showed that age ≥ 50 years; groups B, C, and D according to the ABC method; and current smoking habits were independent risk factors for gastric cancer. The hazard ratios (HRs) of the incidence of gastric cancer were 6.7 in group B and 21.7 in groups C and D, while the HRs of group E was 2.8, which was not significantly different from that of group A. The incidence of gastric cancer was not statistically significantly different between those with and without successful HP eradication in groups B, C, and D during follow-up. CONCLUSIONS: The ABC method was still useful for gastric cancer risk stratification in the 2010s.

TET1 upregulation drives cancer cell growth through aberrant enhancer hydroxymethylation of HMGA2 in hepatocellular carcinoma.

Ten-eleven translocation 1 (TET1) is an essential methylcytosine dioxygenase of the DNA demethylation pathway. Despite its dysregulation being known to occur in human cancer, the role of TET1 remains poorly understood. In this study, we report that TET1 promotes cell growth in human liver cancer. The transcriptome analysis of 68 clinical liver samples revealed a subgroup of TET1-upregulated hepatocellular carcinoma (HCC), demonstrating hepatoblast-like gene expression signatures. We performed comprehensive cytosine methylation and hydroxymethylation (5-hmC) profiling and found that 5-hmC was aberrantly deposited preferentially in active enhancers. TET1 knockdown in hepatoma cell lines decreased hmC deposition with cell growth suppression. HMGA2 was highly expressed in a TET1high subgroup of HCC, associated with the hyperhydroxymethylation of its intronic region, marked as histone H3K4-monomethylated, where the H3K27-acetylated active enhancer chromatin state induced interactions with its promoter. Collectively, our findings point to a novel type of epigenetic dysregulation, methylcytosine dioxygenase TET1, which promotes cell proliferation via the ectopic enhancer of its oncogenic targets, HMGA2, in hepatoblast-like HCC.

Expression of Gastric Markers Is Associated with Malignant Potential of Nonampullary Duodenal Adenocarcinoma.

BACKGROUND: Sporadic nonampullary duodenal epithelial tumors (NADETs) are uncommon, and thus their clinicopathological features have not been fully assessed. AIMS: In this study, we have analyzed a series of early sporadic NADETs, focusing on various immunohistological features. METHODS: We conducted a multicenter retrospective analysis of 68 patients with endoscopically resected sporadic NADETs. Associations between immunohistological features and clinicopathological features were statistically analyzed. RESULTS: The 68 patients consisted of 46 men (68%) and 22 women (32%) with a mean age of 60.7 ± 12.2 years (range 37-85 years). The 68 tumors were composed of 39 adenomas (57%) and 29 early-stage adenocarcinomas (43%). Duodenal adenocarcinomas were larger in size than adenomas and had papillary architecture in their pathological diagnosis with statistical significance. Duodenal adenocarcinomas also demonstrated a significantly higher expression of gastric markers (MUC5AC and MUC6) and a higher MIB-1 index. Duodenal adenomas were contrastively apt to express intestinal markers (MUC2, CDX1 and CDX2). Of the 68 cases analyzed, there were only 3 tumors positive for p53 staining, all of which were adenocarcinoma. When 7 submucosal invasive cancers and 21 intramucosal cancers were compared, submucosal invasion was positively associated with expression of MUC5AC. Also, submucosal invasion showed strong association with double-positivity of MUC5AC and MUC6. CONCLUSIONS: Our results indicate that immunohistochemical evaluation is useful for predicting malignant potential of NADETs, especially focusing on the expression of gastrointestinal markers.

Epigenetic inactivation of FAT4 contributes to gastric field cancerization.

BACKGROUND: Gastric cancer (GC) is highly influenced by aberrant methylation, and accumulation of aberrant methylation in gastric mucosae produces an epigenetic field for cancerization. Nevertheless, the individual driver genes involved in such field cancerization are still unclear. Here, we aimed to demonstrate that FAT4, a novel tumor suppressor identified by exome sequencing of GC, is methylation-silenced and that such methylation is involved in epigenetic field cancerization for GC. METHODS: A transcription start site was determined by the 5' rapid amplification of complementary DNA ends method. DNA methylation was analyzed by bisulfite sequencing with use of a next-generation sequencer or quantitative methylation-specific PCR. Gene expression was analyzed by quantitative reverse transcription PCR. RESULTS: A single transcription start site was identified for FAT4 in gastric epithelial cells, and a CpG island was located in the FAT4 promoter region. FAT4 was highly methylated in two of 13 GC cell lines and was not expressed in them. Removal of FAT4 methylation by a DNA demethylating agent (5-aza-2'-deoxycytidine) restored its expression in the two cell lines. In primary GC samples, FAT4 was methylated in 12 of 82 GCs (14.6 %). FAT4 methylation was associated with the presence of the CpG island methylator phenotype but not with prognosis, tumor invasion, lymph node metastasis, or histological types. In noncancerous gastric mucosae, high FAT4 methylation levels were associated with the presence of GC and Helicobacter pylori infection. CONCLUSIONS: FAT4 was methylation-silenced in GCs. Its methylation in gastric mucosae was associated with H. pylori infection and likely contributed to epigenetic field cancerization.

Serum pepsinogen levels can quantify the risk of development of metachronous gastric cancer after endoscopic resection.

We have previously reported that serum pepsinogen (PG) can quantify the level of gastric mucosal atrophy, and that H. pylori eradication reduces cancer development in subjects with mild atrophy identified by serum PG levels. The aim of this study was to elucidate the predictive ability of serum PG levels for the development of metachronous gastric cancer (MGC) after endoscopic resection (ER) of primary cancer in association with H. pylori eradication. A retrospective chart review was performed, and 330 patients who underwent ER for initial early gastric cancer were enrolled. Presence or absence of H. pylori, serum PG levels, and endoscopic atrophy at ER were evaluated. H. pylori eradication was performed at the patient's request after ER. The incidence of MGC in these patients was analyzed. Of 330 patients, 47 developed MGC. Endoscopic extensive atrophy was observed more frequently in patients with MGC (p = 0.001). Although PG I or PG II alone did not significantly differ according to development of MGC, the proportion of PG I/II ≤ 3.0, which is one of the criteria of PG test-positive, was significantly higher in patients with MGC (83 vs. 69%, p = 0.04). H. pylori eradication after ER did not affect MGC development (p = 0.2). On multivariate analysis, serum PG I/II ratio ≤ 3.3 was significantly associated with the development of MGC (hazard ratio: 3.66, 95% confidence interval: 1.47-12.25, p = 0.004). The risk of MGC after ER could be quantitatively predicted by the PG I/II ratio regardless of H. pylori status.

Incidence of and risk factors for metachronous gastric cancer after endoscopic resection and successful Helicobacter pylori eradication: results of a large-scale, multicenter cohort study in Japan.

BACKGROUND: A previous multicenter prospective randomized study from Japan showed that Helicobacter pylori eradication reduced the development of metachronous gastric cancer (MGC) after endoscopic resection for early gastric cancer. MGC risk, however, is not eliminated; yet few studies have evaluated its long-term incidence and risk factors. In this study, we investigated the incidence of and risk factors for MGC in patients who underwent endoscopic resection for early gastric cancer with successful H. pylori eradication. METHODS: A total of 594 patients who underwent endoscopic resection for early gastric cancer and successful H. pylori eradication at three institutions (National Cancer Center Hospital, University of Tokyo Hospital, and Wakayama Medical University Hospital) were analyzed retrospectively. Annual endoscopic surveillance was performed after initial endoscopic resection. MGC was defined as a gastric cancer newly detected at least 1 year after successful H. pylori eradication. RESULTS: Ninety-four MGCs were detected in 79 patients during the 4.5-year median follow-up period. Kaplan-Meier analysis showed the cumulative incidence of MGC 5 years after successful H. pylori eradication was 15.0 %; the incidence of MGC calculated by use of the person-year method was 29.9 cases per 1000 person-years. Multivariate analysis using the Cox proportional hazards model revealed that male sex, severe gastric mucosal atrophy, and multiple gastric cancers before successful H. pylori eradication were independent risk factors for MGC. Eleven percent of MGCs (10 of 94) were detected more than 5 years after successful H. pylori eradication. CONCLUSION: Surveillance endoscopy for MGC in patients who have undergone endoscopic resection for early gastric cancer should be performed even after successful H. pylori eradication.

Excessive watering eyes in gastric cancer patients receiving S-1 chemotherapy.

BACKGROUND: Watering eyes is a common late adverse event associated with S-1 chemotherapy; however, the frequency and predictive factors are not known. METHODS: This study included 304 consecutive gastric cancer patients treated with adjuvant S-1 monotherapy for 1 year at Shizuoka Cancer Center. We retrospectively evaluated the frequency of watering eyes, and explored other nonhematological adverse events during the first course of S-1 monotherapy which could become predictive factors for watering eyes. RESULTS: The severest grade of watering eyes during S-1 monotherapy was grade 2 in 41 patients (13.5 %) and grade 3 in 36 patients (11.8 %). The median time to onset of grade 2 and grade 3 watering eyes was 82 days (range 6-344 days) and 249 days (range 84-653 days), respectively, and the median cumulative S-1 dose at the onset of grade 2 and grade 3 watering eyes was 4174 mg/m(2) (range 491-16,095 mg/m(2)) and 10,243 mg/m(2) (range 4943-16,341 mg/m(2)), respectively. Multivariate analysis showed that anorexia (odds ratio 2.37, P = 0.008), oral mucositis (odds ratio 3.86, P = 0.0003), skin hyperpigmentation (odds ratio 3.84, P = 0.0001), and rash (odds ratio 3.76, P = 0.01) observed during the first course were significantly associated with watering eyes. CONCLUSION: The risk of watering eyes was higher in patients who also had anorexia, oral mucositis, skin hyperpigmentation, or rash during first course of S-1 monotherapy than in those without them.

Atrophic gastritis and enlarged gastric folds diagnosed by double-contrast upper gastrointestinal barium X-ray radiography are useful to predict future gastric cancer development based on the 3-year prospective observation.

BACKGROUND: Double-contrast upper gastrointestinal barium X-ray radiography (UGI-XR) is the standard gastric cancer screening method in Japan. Atrophic gastritis and enlarged gastric folds are considered the two major features of Helicobacter pylori-induced chronic gastritis, but the clinical meaning of evaluating them by UGI-XR has not been elucidated. METHODS: We analyzed healthy UGI-XR examinees without a history of gastrectomy, previous Helicobacter pylori eradication and usage of gastric acid suppressants. RESULTS AND CONCLUSIONS: Of the 6433 subjects, 1936 (30.1 %) had atrophic gastritis and 1253 (19.5 %) had enlarged gastric folds. During the 3-year prospective observational follow-up, gastric cancer developed in seven subjects, six of whom (85.7 %) had atrophic gastritis with H. pylori infection and five of whom (71.4 %) had enlarged gastric folds with H. pylori infection. The Kaplan-Meier method with log-rank testing revealed that both UGI-XR-based atrophic gastritis (p = 0.0011) and enlarged gastric folds (p = 0.0003) are significant predictors for future gastric cancer incidence.

Hypointense hepatocellular carcinomas on apparent diffusion coefficient mapping: Pathological features and metastatic recurrence after hepatectomy.

AIM: The present study aimed to evaluate pathological features of hepatocellular carcinomas (HCC) appearing hypointense on the apparent diffusion coefficient (ADC) map, and to elucidate the association between the signal intensity on the ADC map and metastatic recurrences after hepatectomy. METHODS: In total, 52 consecutive patients with initial hypervascular HCC (solitary lesion ≤5 cm in diameter) without vascular invasion on imaging were examined by diffusion-weighted magnetic resonance imaging before hepatectomy. The signal intensities of HCC on the ADC map were visually compared with the surrounding liver and categorized as hypointense or non-hypointense. Intrahepatic metastatic recurrence was defined as more than three intrahepatic recurrences. RESULTS: The 52 HCC were evaluated as 26 hypointense and 26 non-hypointense tumors. No significant differences between the hypointense and non-hypointense groups were seen for age, sex, etiology, tumor size and tumor marker levels. However, in resected specimens, significant differences between the two groups were noted for histological grade and microscopic portal invasion. The percentages of poorly differentiated HCC and microscopic portal invasion in the hypointense group were significantly higher than those in the non-hypointense group. The cumulative 3-year metastatic recurrence rates of the hypointense and non-hypointense groups on the ADC map were 56% and 13% (P = 0.001), respectively. Multivariate analyses indicated that hypointensity on the ADC map was the only independent factor related to metastatic recurrence. CONCLUSION: Hypointense HCC on ADC mapping are characterized by poor histological differentiation and more frequent microscopic portal invasion, and are significantly associated with metastatic recurrences after hepatectomy.

Contribution of Contrast-Enhanced Sonography With Perfluorobutane Microbubbles for Diagnosis of Recurrent Hepatocellular Carcinoma.

OBJECTIVES: The role of contrast-enhanced sonography in the diagnosis of recurrent hepatocellular carcinoma is still unclear. This study aimed to clarify the usefulness and limitations of contrast-enhanced sonography with a perfluorobutane microbubble contrast agent (Sonazoid; Daiichi-Sankyo, Tokyo, Japan) after contrast-enhanced computed tomography (CT) for diagnosis of recurrent hepatocellular carcinoma and to establish its optimal use. METHODS: A total of 514 patients, who were suspected to have recurrent hepatocellular carcinoma on contrast-enhanced CT, underwent contrast-enhanced sonography. Of 514 suspicious lesions, 484 were diagnosed as recurrent hepatocellular carcinomas, including 142 recurrent hepatocellular carcinomas measuring 1 cm or smaller in diameter. The largest lesion was evaluated in each patient. A final diagnosis of recurrent hepatocellular carcinoma after contrast-enhanced CT was reached on the basis of the typical hallmarks of hepatocellular carcinoma on any of the other contrast imaging modalities or by resected tissue or tumor enlargement during follow-up. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of contrast-enhanced CT were 68%, 93%, 99%, 15%, and 70%, respectively, and the values of contrast-enhanced sonography were 91%, 100%, 100%, 31%, and 91%, excluding 60 unassessable lesions on contrast-enhanced sonography. The diagnostic rate for recurrent hepatocellular carcinoma on contrast-enhanced sonography for lesions with an atypical enhancement pattern on contrast-enhanced CT was 71%. On multivariate analysis of factors contributing to the unassessability of contrast-enhanced sonography, lesion size, location, and abdominal wall thickness were independent factors. CONCLUSIONS: Although the assessability of contrast-enhanced sonography depends on lesion size, location, and abdominal wall thickness, contrast-enhanced sonography after contrast-enhanced CT is useful for confirmative diagnosis of small recurrent hepatocellular carcinoma with an atypical enhancement pattern on contrast-enhanced CT, even for lesions measuring 1 cm or smaller in diameter.