Risk stratification of synchronous gastric cancers including alcohol-related genetic polymorphisms.

BACKGROUND AND AIM: We previously identified that ever-smoking and severe gastric atrophy in pepsinogen are risk factors for synchronous gastric cancers (SGCs). This study aimed to determine the association of alcohol drinking status or alcohol-related genetic polymorphism with SGCs and also stratify their risk. METHODS: This multi-center prospective cohort study included patients who underwent endoscopic submucosal dissection for the initial early gastric cancers at 22 institutions in Japan. We evaluated the association of alcohol drinking status or alcohol dehydrogenase 1B (ADH1B) and acetaldehyde dehydrogenase 2 (ALDH2) genotypes with SGCs. We then stratified the risk of SGCs by combining prespecified two factors and risk factors identified in this study. RESULTS: Among 802 patients, 130 had SGCs. Both the ADH1B Arg and ALDH2 Lys alleles demonstrated a significant association with SGCs on multivariate analysis (odds ratio, 1.77), although alcohol drinking status showed no association. The rates of SGCs in 0-3 risk factors in the combined evaluation of three risk factors (ever-smoking, severe gastric atrophy in pepsinogen, and both the ADH1B Arg and ALDH2 Lys alleles) were 7.6%, 15.0%, 22.0%, and 32.1%, respectively. The risk significantly increased from 0 to 3 risk factors on multivariate analysis (P for trend <0.001). CONCLUSIONS: Both the ADH1B Arg and ALDH2 Lys alleles were at high risk for SGCs. The risk stratification by these three factors may be a less invasive and promising tool for predicting their risk.

Smoking history and severe atrophic gastritis assessed by pepsinogen are risk factors for the prevalence of synchronous gastric cancers in patients with gastric endoscopic submucosal dissection: a multicenter prospective cohort study.

BACKGROUND: No studies have evaluated the relationship between lifestyle and synchronous gastric cancers (SGCs) in patients with endoscopic submucosal dissection (ESD) for early gastric cancers (EGCs). Using data from the Tohoku gastrointestinal (GI) study, we aimed to identify factors associated with SGCs. METHODS: Tohoku GI study is a multicenter prospective cohort study investigating the relationship between lifestyle and metachronous gastric cancers. Patients who had a schedule to undergo ESD for primary EGCs were enrolled. We used logistic regression analysis to examine the relationship of 15 candidate factors, including lifestyle, with the prevalence of SGCs in this study. RESULTS: Of 850 patients between 2016 and 2019, 16.0% (136 patients) had SGCs. In multivariate analysis, smoking history (odds ratio [OR], 1.93; p = 0.048) and severe atrophic gastritis assessed by pepsinogen (OR, 1.92; p = 0.004) were risk factors for the prevalence of SGCs. Regarding smoking, current smoking (OR, 2.33; p = 0.021), but not former smoking (OR, 1.76; p = 0.098), was a significant risk factor for its prevalence. In the stratified analysis, severe atrophic gastritis assessed by pepsinogen was a risk factor in patients without Helicobacter pylori (H. pylori) eradication (OR, 2.10; p = 0.002), but not a risk factor in those with H. pylori eradication (OR, 0.75; p = 0.737). CONCLUSION: Smoking history was a risk factor for the prevalence of SGCs in patients with ESD for EGCs, and severe atrophic gastritis assessed by pepsinogen was also a risk factor when H. pylori was not eradicated.

Enhanced expression of the M2 isoform of pyruvate kinase is involved in gastric cancer development by regulating cancer-specific metabolism.

Recent studies have indicated that increased expression of the M2 isoform of pyruvate kinase (PKM2) is involved in glycolysis and tumor development. However, little is known about the role of PKM2 in gastric cancer (GC). Therefore, we examined the expression and function of PKM2 in human GC. We evaluated PKM1 and PKM2 expression by quantitative RT-PCR in gastric tissues from 10 patients who underwent gastric endoscopic submucosal dissection, 80 patients who underwent gastrectomy, and seven healthy volunteers, and analyzed the correlation with clinicopathological variables. To assess the function of PKM2, we generated PKM2-knockdown GC cells, and investigated the phenotypic changes. Furthermore, we examined the induction of PKM2 expression by cytotoxin-associated gene A (CagA), a pathogenic factor of Helicobacter pylori, using CagA-inducible GC cells. We found that PKM2 was predominantly expressed not only in GC lesions but also in the normal gastric regions of GC patients and in the gastric mucosa of healthy volunteers. The PKM2 expression was significantly higher in carcinoma compared to non-cancerous tissue and was associated with venous invasion. Knockdown of PKM2 in GC cells caused significant decreases in cellular proliferation, migration, anchorage-independent growth, and sphere formation in vitro, and in tumor growth and liver metastasis in vivo. The serine concentration-dependent cell proliferation was also inhibited by PKM2 silencing. Furthermore, we found that PKM2 expression was upregulated by CagA by way of the Erk pathway. These results suggested that enhanced PKM2 expression plays a pivotal role in the carcinogenesis and development of GC in part by regulating cancer-specific metabolism.

Enhanced expression of semaphorin 3E is involved in the gastric cancer development.

Semaphorins and their receptors are abnormally expressed in various cancers, but little is known about the expression and function of semaphorin 3E (SEMA3E) and its receptor, plexin D1 (PLXND1), in gastric cancer development or metastasis. We evaluated SEMA3E and PLXND1 expression by quantitative RT-PCR in gastric tissues from 62 patients who underwent gastrectomy and analyzed the correlation between their expression and clinicopathological variables. To assess the function of SEMA3E, we generated human gastric cancer cell lines with suppressed or increased SEMA3E expression. The expression level of SEMA3E, but not PLXND1, was correlated with lymph node involvement and metastatic progression in gastric cancer. A significant association was observed between a high level of SEMA3E expression and poor differentiation or poor survival in the intestinal type of gastric cancer. SEMA3E knockdown in gastric cancer cells attenuated cell proliferation and metastatic ability in vitro and in vivo. Moreover, SEMA3E caused cell proliferation and anchorage-independent cell growth in the intestinal type of gastric cancer. These results suggested that SEMA3E is likely to be involved in the development of gastric cancer and might also be a therapeutic target for its treatment.

A Japanese case of lymphocytic esophagitis.

We report the case of a 68-year-old Japanese man diagnosed with lymphocytic esophagitis (LE), a rare disease associated with refractory dysphagia. He has had severe dysphagia and heartburn since 2007. Findings of esophagogastroduodenoscopy (EGD) carried out by a local physician in 2010 showed pale mucosa with white exudate and lateral furrows in the esophagus. He was referred to Tohoku University Hospital in 2012, because the symptoms did not improve, despite regular use of a proton pump inhibitor (PPI). At that time, EGD revealed the coexistence of a slight stricture in the upper esophagus, the histopathological findings of which included a predominantly peri-papillary distribution of abundant, infiltrating CD3+ /CD4+ /CD8+ /CD20- lymphocytes without any granulocytes (CD4+  : CD8+  = 3.3:1). These were consistent with a diagnostic criteria of LE. Thereafter, severe dysphagia with food impaction occurred twice a month, despite the long-term use of a PPI, and EGD showed worsened strictures, where endoscopic ultrasonography findings showed marked circumferential thickness of the mucosal and submucosal layers. Then, one session of endoscopic balloon dilatation dramatically improved the dysphagia. Accordingly, LE should be considered an important differential diagnosis of refractory dysphagia based on the characteristic features of endoscopic and pathological findings.

Effects of ALDH2 genotype, PPI treatment and L-cysteine on carcinogenic acetaldehyde in gastric juice and saliva after intragastric alcohol administration.

Acetaldehyde (ACH) associated with alcoholic beverages is Group 1 carcinogen to humans (IARC/WHO). Aldehyde dehydrogenase (ALDH2), a major ACH eliminating enzyme, is genetically deficient in 30-50% of Eastern Asians. In alcohol drinkers, ALDH2-deficiency is a well-known risk factor for upper aerodigestive tract cancers, i.e., head and neck cancer and esophageal cancer. However, there is only a limited evidence for stomach cancer. In this study we demonstrated for the first time that ALDH2 deficiency results in markedly increased exposure of the gastric mucosa to acetaldehyde after intragastric administration of alcohol. Our finding provides concrete evidence for a causal relationship between acetaldehyde and gastric carcinogenesis. A plausible explanation is the gastric first pass metabolism of ethanol. The gastric mucosa expresses alcohol dehydrogenase (ADH) enzymes catalyzing the oxidation of ethanol to acetaldehyde, especially at the high ethanol concentrations prevailing in the stomach after the consumption of alcoholic beverages. The gastric mucosa also possesses the acetaldehyde-eliminating ALDH2 enzyme. Due to decreased mucosal ALDH2 activity, the elimination of ethanol-derived acetaldehyde is decreased, which results in its accumulation in the gastric juice. We also demonstrate that ALDH2 deficiency, proton pump inhibitor (PPI) treatment, and L-cysteine cause independent changes in gastric juice and salivary acetaldehyde levels, indicating that intragastric acetaldehyde is locally regulated by gastric mucosal ADH and ALDH2 enzymes, and by oral microbes colonizing an achlorhydric stomach. Markedly elevated acetaldehyde levels were also found at low intragastric ethanol concentrations corresponding to the ethanol levels of many foodstuffs, beverages, and dairy products produced by fermentation. A capsule that slowly releases L-cysteine effectively eliminated acetaldehyde from the gastric juice of PPI-treated ALDH2-active and ALDH2-deficient subjects. These results provide entirely novel perspectives for the prevention of gastric cancer, especially in established risk groups.

Esomeprazole inhibits the pentagastrin-stimulated secretion of gastric acid in healthy Japanese volunteers.

Gastroesophageal reflux disease (GERD) is a common disease, in which the reflux of gastric acid causes mucosal damage of the esophagus and/or troublesome symptoms. Esomeprazole, a proton pump inhibitor, has been used for treatment of GERD in Japan since 2011; namely, only little is known about its effect on gastric acid secretion in Japanese. We, therefore, assessed the relationship between dose and timing of esomeprazole administration and gastric acid inhibition in 11 healthy male Japanese volunteers by directly examining gastric acid secretion capacity. In this randomized, open-label, three-way crossover study, the subjects were dosed with esomeprazole 10 mg or 20 mg once a day (q.d.), or 20 mg twice a day (b.i.d.) for 14 days, and pentagastrin-stimulated gastric acid secretion was measured by endoscopic gastrin test. At steady states, gastric acid inhibition rates were significantly higher in esomeprazole 20 mg b.i.d. (median 100.0%, interquartile range [IQR] 99.4-100%, P = 0.027) or 20 mg q.d. (100.0%, IQR 99.7-100%, P = 0.016), compared with 10 mg q.d. (98.4%, IQR 84.4-100%). At trough states, esomeprazole 20 mg b.i.d. showed significantly higher gastric acid inhibition (99.6%, IQR 99.0-100%) than did 20 mg q.d. (84.2%, IQR 76.4-88.8%, P = 0.002) or 10 mg q.d. (64.9%, IQR 59.1-76.7%, P = 0.001). Thus, esomeprazole 20 mg b.i.d. was sufficient to inhibit > 99% gastric acid secretion in healthy subjects. We propose that esomeprazole 20 mg b.i.d. is effective for treating Japanese patients with refractory GERD who require long-lasting gastric acid inhibition.

Prospective analysis of risk for bleeding after endoscopic biopsy without cessation of antithrombotics in Japan.

BACKGROUND AND AIM: In Japan, after the revision of the gastrointestinal endoscopic guidelines for patients taking antithrombotics, endoscopic biopsies were permitted while continuing antithrombotic treatment. However, the risk of bleeding after the biopsy with or without cessation of antithrombotics has not been fully evaluated because bleeding events are very rare. The aim of this prospective study was to evaluate the risk for bleeding after upper gastrointestinal biopsy without cessation of antithrombotics. METHODS: Consecutive patients who underwent upper gastrointestinal endoscopic biopsy from December 2011 to March 2014 were enrolled in this study. Antithrombotic medication and its cessation status was checked at enrollment. To confirm bleeding events associated with biopsy, medical examination at the hospital or direct confirmation by telephone was done within 1 month after the biopsy. RESULTS: Among the 3758 patients who underwent endoscopic biopsies, 394 patients (10.5%) were medicated with antithrombotics, and 286 of them (72.6% of the total antithrombotics users) did not undergo cessation. Bleeding after the biopsy occurred in six cases (0.15%, 95% CI; 0.09%∼0.22%), but there was only one case that had continued taking antithrombotics. The incidence of bleeding after biopsy was not significantly higher in the patients who had continued taking antithrombotics compared with the others (0.35% vs 0.14%, P = 0.38). CONCLUSION: This prospective study showed that continuation of antithrombotics did not increase the bleeding risk after upper gastrointestinal endoscopic biopsy.

Endoscopic balloon dilatation for pharyngo-upper esophageal stricture after treatment of head and neck cancer.

BACKGROUND AND AIM: Dysphagia caused by pharyngo-upper esophageal stricture is a complication of treatment for head and neck cancer. Endoscopic balloon dilation (EBD) is in widespread use as an effective and safe treatment for stricture in many areas of the gastrointestinal tract. In the present study, we investigated the efficacy and safety of EBD for pharyngo-upper esophageal strictures that developed after treatment for head and neck cancer. METHODS: From January 2010 to December 2013, the medical records and endoscopic findings of 19 consecutive patients with pharyngo-upper esophageal strictures occurring after surgery and/or chemoradiotherapy for head and neck cancer were retrospectively examined. RESULTS: Mean number of EBD sessions per patient was 6.6 (1-30), and mean maximum diameter of dilation was 15.8 (11-20) mm. Technical success was achieved in 16 of 19 (84.2%) patients, and only two major complications (bleeding and pha ryngeal edema) occurred in a total of 125 dilatation sessions (1.6%). Regarding the influence of chemoradiotherapy on the outcome of EBD, patients who had undergone chemoradiotherapy plus surgery experienced significantly more restenosis during the follow-up period compared to those who had undergone surgery alone (50% vs 0%, P < 0.05). CONCLUSIONS: This retrospective analysis demonstrated the efficacy and safety of exclusive EBD for pharyngo-upper esophageal strictures occurring after treatment for head and neck cancer, indicating that the therapeutic application of EBD could be extended to such strictures. Patients who underwent chemoradiotherapy and surgery experienced more restenosis; hence, such patients should be carefully followed up after EBD treatment.

Calcium carbonate breath test for non-invasive estimation of gastric acid secretion.

Gastric acid measurement is useful in assessing the effectiveness of antisecretory drugs, however, the conventional tests involve invasive nasogastric intubation. Orally administered ¹³C-labeled calcium carbonate (Ca¹³CO3) reacts with gastric acid to produce ¹³C-labeled carbon dioxide (¹³CO2), which is then excreted in the breath. The objective of this study was to evaluate the suitability of Ca¹³CO3 breath test for estimating gastric acid secretion in human noninvasively. First, the Ca¹³CO3 breath test and the measurement of pooled gastric acid under a fasting condition were performed in 6 healthy volunteers to evaluate the correlation between the two parameters. Next, endoscopic gastric acid collection and the Ca¹³CO3 breath test were performed on different days after pentagastrin injection in 20 subjects to evaluate the correlation between the tests and the reproducibility. Finally, the same studies were repeated in 4 subjects before and after 1-week rabeprazole, a proton pump inhibitor, administration. The maximum CO2 concentration (Cmax) correlated very well with the amount of pooled gastric acid (r = 0.95), suggesting that Ca¹³CO3 breath test values well reflected the fasting intragastric acidity. The ¹³CO2 concentration after pentagastrin injection correlated well with pentagastrin-stimulated maximal acid output (r = 0.79 at 20 min). The reproducibility of the Ca¹³CO3 breath test under pentagastrin-stimulation was good (coefficient of variation = 0.11). Rabeprazole administration markedly reduced the values of the Ca¹³CO3 breath test, suggesting that it can sensitively assess the efficacy of rabeprazole. The Ca¹³CO3 breath test can potentially be a useful method for non-invasive estimation for gastric acid secretion in human.

[A case of spontaneous complete necrosis of hepatocellular carcinoma sized 10cm in diameter demonstrated by the resected specimen].

A 68-year-old man with chronic hepatitis C and of a heavy drinker was admitted to our hospital because of a huge liver tumor (10cm in diameter) in segment-5 detected on CT in July 2009. One month later, the size of liver tumor was reduced to 5cm in diameter and another liver tumor of 1cm in segment-3 was detected on CT. AFP and AFP-L3 spontaneously decreased to normal range. In October, a partial hepatectomy was performed. The resected specimen demonstrated complete necrosis with thick capsule. The tumor in segment-3 became equivocal without resection. We considered this is a case of spontaneous complete necrosis of hepatocellular carcinoma.

[A case of gastric cancer accompanied by disseminated carcinomatosis of bone marrow with DIC, and subdural hematoma successfully treated with sequential methotrexate and 5-fluorouracil therapy].

A 44-year-old man visited a nearby hospital because of severe headache. Brain MRI revealed a subdural hematoma, and he was transferred to the Department of Neurosurgery of our hospital. Burr hole surgery was performed on the second day of hospitalization because of an enlargement of the hematoma. Laboratory data on admission showed the presence of a disseminated intravascular coagulation(DIC). Bone marrow aspiration revealed metastases of signet ring cell carcinoma, and abdominalCT showed gastric cancer. He was diagnosed as having DIC with bone marrow metastases of advanced gastric cancer. Despite anti-DIC therapy and blood transfusion, his systemic bleeding tendency was not improved. The neurosurgeon therefore consulted with a palliative care team. Since the patient was still young, we considered that he should be treated with anti-cancer drugs. At first, his family did not accept chemotherapy because they were pessimistic about his prognosis. However, after he regained his consciousness, we were able to perform sequential MTX and 5-FU therapy with the consent of the patient and his family. The therapy was successful, and he recovered from DIC and was discharged on the 57th hospital day.