Blue light imaging and linked color imaging as a screening mode for esophageal squamous cell carcinoma in high-risk patients: Multicenter randomized trial.

OBJECTIVES: Blue light imaging (BLI) and linked color imaging (LCI) are superior to conventional white light imaging for detecting esophageal squamous cell carcinoma (ESCC). Hence, we compared their diagnostic performances in ESCC screening. METHODS: This open-labeled, randomized controlled trial was performed at seven hospitals. Patients with a high risk of ESCC were randomly assigned to the BLI group (BLI followed by LCI) and LCI group (LCI followed by BLI). The primary end-point was the detection rate of ESCC in the primary mode. The main secondary end-point was its miss rate in the primary mode. RESULTS: In total, 699 patients were enrolled. The detection rate of ESCC did not significantly differ between the BLI and LCI groups (4.0% [14/351] vs. 4.9% [17/348]; P = 0.565); however, the number of patients with ESCC tended to be smaller in the BLI group (19 vs. 30). Notably, the miss rate of ESCC was lower in the BLI group (26.3% [5/19] vs. 63.3% [19/30]; P = 0.012) and LCI detected no ESCCs missed by BLI. The sensitivity was higher in BLI (75.0% vs. 47.6%; P = 0.042); on the other hand, the positive predictive value in BLI tended to be lower (28.8% vs. 45.5%; P = 0.092). CONCLUSIONS: The detection rates of ESCC did not significantly differ between BLI and LCI. Although BLI may have the potential to be advantageous over LCI for the diagnosis of ESCC, it is still unclear whether BLI is superior to LCI, and a further large-scale study is needed. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCT1022190018-1).

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.

Prognostic Benefit of Additional Treatment After Endoscopic Submucosal Dissection for Esophageal Squamous Cell Carcinoma.

BACKGROUND: Although additional treatment is considered for patients with esophageal squamous cell carcinoma (ESCC) invading into the muscularis mucosa (pT1a-MM) or submucosa (pT1b-SM) after endoscopic submucosal dissection (ESD), the actual benefits of this method remain to be elucidated. AIMS: We aimed to evaluate the prognostic benefits of additional treatment in such patients. METHODS: Between 2006 and 2017, we enrolled patients with pT1a-MM/pT1b-SM ESCC after ESD at 21 institutions in Japan. Overall survival (OS) and disease-specific survival (DSS) were compared between the additional treatment and follow-up groups after propensity score matching, to reduce the bias of baseline characteristics. A subgroup analysis was performed according to the pathological findings: category A, pT1a-MM but negative for lymphovascular invasion (LVI) and vertical margin (VM); category B, tumor invasion into the submucosa ≤ 200 µm but negative for LVI and VM; category C, others. RESULTS: Of 593 patients with pT1a-MM/pT1b-SM ESCC after ESD, 101 matched pairs were extracted after propensity score matching. The OSs were similar between the additional treatment and follow-up groups (80.6% vs. 78.6% in 5 years; P = 0.972). In a subgroup analysis, the OS in the additional treatment group was significantly lower than that in the follow-up group (65.7% vs. 95.2% in 5 years; P = 0.037) in category A, whereas OS did not significantly differ in category C (76.8% vs. 69.5% in 5 years; P = 0.360). CONCLUSIONS: Additional treatment after ESD in patients with pT1a-MM/pT1b-SM ESCC was not associated with an improved prognosis.

[A case of anaplastic pancreatic cancer with osteoclast-like giant cells during follow-up of a branch-duct pancreatic intraductal papillary mucinous tumor].

In this study, a 76-year-old man initially diagnosed with branch-duct pancreatic intraductal papillary mucinous tumor is presented. During follow-up, stenosis was discovered in the main pancreatic duct of the tail. A nodular lesion was found in the pancreatic duct consistent with the stenosis. Distal pancreatectomy was performed since it was suspected to be malignant. Histopathology revealed polymorphic mononuclear cells proliferated with osteoclast-like giant cells in the nodule. The patient was finally diagnosed with anaplastic pancreatic cancer with osteoclast-like giant cells, a relatively rare tumor. It is reported herein with a review of the literature.

Combined assessment of clinical and pathological prognostic factors for deciding treatment strategies for esophageal squamous cell carcinoma invading into the muscularis mucosa or submucosa after endoscopic submucosal dissection.

OBJECTIVES: We aimed to clarify the prognostic factors for patients with esophageal squamous cell carcinoma (ESCC) invading into the muscularis mucosa (pT1a-MM) or submucosa (pT1b-SM) after endoscopic submucosal dissection (ESD). METHODS: This retrospective study enrolled such patients at 21 institutions in Japan between 2006 and 2017. We evaluated 15 factors, including pathological risk categories for ESCC-specific mortality, six non-cancer-related indices, and treatment strategies. RESULTS: In the analysis of 593 patients, the 5-year overall and disease-specific survival rates were 83.0% and 97.6%, respectively. In a multivariate Cox analysis, male sex (hazard ratio [HR] 3.56), Charlson comorbidity index (CCI) ≥3 (HR 2.53), ages of 75-79 (HR 1.61) and ≥80 years (HR 2.04), prognostic nutrition index (PNI) <45 (HR 1.69), and pathological intermediate-risk (HR 1.63) and high-risk (HR 1.89) were prognostic factors. Subsequently, we developed a clinical risk classification for non-ESCC-related mortality based on the number of prognostic factors (age ≥75 years, male sex, CCI ≥3, PNI <45): low-risk, 0; intermediate-risk, 1-2; and high-risk, 3-4. The 5-year non-ESCC-related mortality rates for patients without additional treatment were 0.0%, 10.2%, and 45.8% in the low-, intermediate-, and high-risk groups, respectively. Meanwhile, the 5-year ESCC-specific mortality rates for the pathological low-, intermediate-, and high-risk groups were 0.3%, 5.3%, and 18.2%, respectively. CONCLUSIONS: We clarified prognostic factors for patients with pT1a-MM/pT1b-SM ESCC after ESD. The combined assessment of non-ESCC- and ESCC-related mortalities by the two risk classifications might help clinicians in deciding treatment strategies for such patients.

Kyoto classification risk scoring system and endoscopic grading of gastric intestinal metaplasia for gastric cancer: Multicenter observation study in Japan.

OBJECTIVES: The usefulness of endoscopic and histological risk assessment for gastric cancer (GC) has not been fully investigated in Japanese clinical practice. METHODS: In this multicenter observation study, GC and non-GC patients were prospectively enrolled in 10 Japanese facilities. The Kyoto classification risk scoring system, the Kimura-Takemoto endoscopic atrophy classification, the endoscopic grading of gastric intestinal metaplasia (EGGIM), the operative link on gastritis assessment (OLGA) and the operative link on gastric intestinal metaplasia assessment (OLGIM) were applied to all patients. The strength of an association with GC risk was compared. In addition, important endoscopic findings in the Kyoto classification were identified. RESULTS: Overall, 115 GC and 265 non-GC patients were analyzed. Each risk stratification method had a significant association with GC risk in univariate analysis. In multivariate analysis, OLGIM stage III/IV (odds ratio [OR] 2.8 [95% CI 1.5-5.3]), high EGGIM score (OR 1.8 [1.0-3.1]) and opened-type Kimura-Takemoto (OR 2.5 [1.4-4.5]) had significant associations with GC risk. In the Kyoto classification, opened-type endoscopic atrophy, invisible regular arrangement of collecting venules (RAC), extensive (>30%) intestinal metaplasia in the corpus in image-enhanced endoscopy, and map-like redness in the corpus were independent high-risk endoscopic findings. The modified Kyoto classification risk scoring system using these four findings demonstrated a better area under the receiver operating characteristic curve value (0.750, P = 0.052) than that of the original Kyoto classification (0.706). CONCLUSIONS: The OLGIM stage III/IV, high EGGIM score and open-typed Kimura-Takemoto had strong association with GC risk in Japanese patients. The modified Kyoto classification risk scoring system may be useful for GC risk assessment, which warrants further validation. (UMIN000027023).

Risk of metastatic recurrence after endoscopic resection for esophageal squamous cell carcinoma invading into the muscularis mucosa or submucosa: a multicenter retrospective study.

BACKGROUND: We aimed to elucidate the risk of metastatic recurrence after endoscopic resection (ER) without additional treatment for esophageal squamous cell carcinomas (ESCCs) with tumor invasion into the muscularis mucosa (pT1a-MM) or submucosa (T1b-SM). METHODS: We retrospectively enrolled patients with pT1a-MM/pT1b-SM ESCC after ER at 21 institutions in Japan between 2006 and 2017. We compared metastatic recurrence between patients with and without additional treatment, stratified into category A (pT1a-MM with negative lymphovascular invasion [LVI] and vertical margin [VM]), B (tumor invasion into the submucosa ≤ 200 µm [pT1b-SM1] with negative LVI and VM), and C (others). Subsequently, using multivariate Cox analysis, we evaluated risk factors for metastatic recurrence after ER without additional treatment. RESULTS: We enrolled 593 patients, and metastatic recurrence occurred in 38 patients. Metastatic recurrence after additional treatment was significantly lower than that after no additional treatment in category C (9.1% vs. 23.6% in 5 years, p = 0.001), whereas no significant difference was noted in categories A (0.0% vs. 2.6%) and B (0.0% vs. 4.3%). In patients without additional treatment after ER, risk factors for metastatic recurrence were lymphatic invasion (hazard ratio [HR], 5.61), positive VM (HR, 4.55), and tumor invasion into the submucosa > 200 µm (HR, 3.25), and, but near half of the patients with metastatic recurrence had no further recurrence after salvage treatment, resulting in excellent 5-year disease-specific survival in categories A (99.6%) and B (100.0%). CONCLUSIONS: Closed follow-up with no additional treatment may be an acceptable option after ER in pT1a-MM/pT1b-SM1 ESCC with negative LVI and VM.

Long-term endoscopic surveillance for Barrett's esophagus in Japan: Multicenter prospective cohort study.

OBJECTS: Although a recent study showed the cancer incidence of Barrett's esophagus (BE) to be 1.2%/year in 251 patient-years in Japan, the long-term outcomes remain unclear. The present study estimated the cancer risk of BE in Japan using our original prospective multicenter cohort. METHODS: A total of 98 patients with BE of maximum length of ≥2 cm were enrolled during the period of 2010-2012 and received at least one follow-up endoscopy over 5 years thereafter. Cancer incidence rates with 95% confidence interval for occurrence of esophageal adenocarcinoma (EAC) were calculated as the number of events divided by patient-years of follow-up and were expressed as %/year. RESULTS: Overall, the median endoscopic follow-up period was 59.9 (first and third quartiles, 48.5-60.8) months, constituting a total of 427 patient-years of observation. Since two EAC cases developed, the cancer incidence was 0.47% (0.01%-1.81%)/year. The cancer incidence was 0.39% (-0.16% to 2.44%) in 232 patient-years and 0.31% (-0.13% to 1.95%)/year in 318 patient-years for 55 cases with specialized intestinal metaplasia and 70 with BE ≥3 cm (maximum), respectively. At the end of follow-up, 12 of 92 patients (13.0%) died, but none died from EAC. CONCLUSION: This is the largest prospective follow-up study with endoscopy to investigate the incidence of EAC in unequivocal BE with the maximum length of ≥2 cm in Japan. Although a further large-scale study will be required to validate our results, the cancer risk of BE in Japan would be lower than previously reported (0.47% vs 1.2%/year).

Associations of Japanese food intake with survival of stomach and colorectal cancer: A prospective patient cohort study.

Dietary factors may affect the prognosis of digestive tract cancer, but evidence has been sparse. We investigated the association between pretreatment intake of 6 Japanese foods (including soy food, miso [soybean paste] soup and seaweed) and the risk of death among patients with histologically confirmed major digestive tract cancers (stomach, 1931; colon, 793; rectum, 510) diagnosed during 1997-2013 at a single institution in Japan. Pretreatment dietary intake was assessed using a food frequency questionnaire, and the patients were followed until December 2016. The Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Among the patients with stomach cancer, frequent intake of soy food was inversely associated with the risk of all-cause (Ptrend for four frequency groups = 0.01; HR = 0.72, 95% CI: 0.50-1.04 for highest vs lowest group) and stomach cancer (Ptrend  = 0.03; HR = 0.63, 95% CI: 0.40-0.99) death. A similar inverse association was also found for intake of miso soup. In contrast, frequent seaweed intake was inversely associated with the risk of all-cause death among the patients with colon cancer (Ptrend  = 0.03). Rectal cancer patients who had frequently consumed seaweed tended to have a lower risk of rectal cancer death (Ptrend  = 0.02). These findings indicate that pretreatment intake of Japanese foods such as soybean products and seaweed may have favorable effects on patient survival of stomach and colorectal cancer, although this needs to be confirmed by further research.

Risk factors for cervical lymph node metastasis in endoscopically resected superficial hypopharyngeal cancers.

OBJECTIVE: Hypopharyngeal cancer is a head and neck cancer with a poor prognosis, and most cases show metastases on diagnosis. Cervical lymph node (LN) metastasis is a poor prognostic factor in hypopharyngeal cancer patients. The identification of risk factors for LN metastasis can help guide surgical treatment strategies for these patients. METHODS: This retrospective study included 93 superficial hypopharyngeal cancer patients with 109 histopathologically examined lesions treated by endoscopic resection between January 2007 and December 2017. Tumor thickness quantification, quantification of budding nests, immunostaining and other histopathological analyses in paraffin-embedded, formalin-fixed tissue sections (3-µm) of surgical specimens were performed by a certified pathologist. RESULTS: Cervical LN metastasis was positive in 18 out of 93 cases (19.3%) and 18 out of 109 lesions (16.5%). No differences were detected in patient characteristics between LN-positive and LN-negative cases, except for tumor thickness, which was significantly larger in LN-positive cases (3119.4±602.2µm vs. 1015.5±129.6µm, respectively; p<0.0001). Univariate analysis showed that tumor thickness ≥1000µm (odds ratio: 5.559, p=0.003), lesions with high budding grade (odds ratio: 5.188, p=0.01) and vascular invasion (odds ratio: 12.710, p=0.007) were significantly associated with cervical LN metastasis. Multivariate analysis revealed tumor thickness≥1000µm as the most significant risk factor for cervical LN metastasis in superficial hypopharyngeal cancer (odds ratio: 3.639, p=0.04). CONCLUSIONS: We demonstrate for the first time that high budding grade may serve as powerful predictors of LN metastasis and tumor thickness ≥1000µm is a significant risk factor for LN metastasis of superficial hypopharyngeal cancer. These results should be further examined in future larger scale studies.

Associations of cigarette smoking and alcohol drinking with stomach cancer survival: A prospective patient cohort study in Japan.

Cigarette smoking and alcohol drinking may affect the prognosis of stomach cancer, but evidence has been inconsistent. We investigated the associations between pretreatment smoking and alcohol drinking and the risk of all-cause and stomach cancer death among 1,576 patients with histologically confirmed stomach cancer diagnosed during 1997-2010 at a single hospital in Japan. Histories of smoking and alcohol drinking were assessed using a self-administered questionnaire. The patients were followed until December 31, 2013. The Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During 9,625.1 person-years, 670 all-cause and 419 stomach cancer deaths were documented. Among the patients overall, ever-drinking was significantly associated with an increased risk of all-cause death (HR: 1.25; 95% CI: 1.03-1.51), but not stomach cancer death. Positive linear associations with the frequency of drinking (ptrend = 0.02) and the amount of alcohol consumed per day (ptrend = 0.03) were observed for the risk of all-cause death. Ever-smoking was not related to either the risk of all-cause or stomach cancer death. Conversely, among the patients who underwent curative resection, a significant positive association was found between ever-smoking and the risk of stomach cancer death (HR: 2.44; 95% CI: 1.17-5.08). A positive association was also found for earlier age at start of smoking (ptrend = 0.0046). Pretreatment smoking and alcohol drinking have significant effects on stomach cancer survival. Lifestyle adjustments throughout life may improve survival.

Efficacy and safety of Helicobacter pylori eradication therapy immediately after endoscopic submucosal dissection.

BACKGROUND AND AIMS: In the treatment of patients after endoscopic submucosal dissection (ESD), there is no consensus on the optimum time to start Helicobacter pylori eradication therapy or on whether eradication therapy improves ulcer healing rate after ESD. The aim of this study was to examine the effect of immediate eradication of H. pylori on ulcer healing after ESD in patients with early gastric neoplasms. METHODS: A total of 330 patients who underwent ESD for early gastric neoplasms were enrolled. Patients were assigned to either H. pylori eradication group (Group A: H. pylori eradication + proton pump inhibitor 7 weeks) or non-eradication group (Group B: proton pump inhibitor 8 weeks). The primary end point was gastric ulcer healing rate (Group A vs Group B) determined on week 8 after ESD. RESULTS: Patients in Group A failed to meet non-inferiority criteria for ulcer scarring rate after ESD compared with that in Group B (83.0% vs 86.5%, P for non-inferiority = 0.0599, 95% confidence interval: -11.7% to 4.7%). There were, however, neither large differences between the two groups in the ulcer scarring rate nor the safety profile. CONCLUSIONS: This study failed to demonstrate the non-inferiority of immediate H. pylori eradication therapy after ESD to the non-eradication therapy in the healing rate of ESD-caused ulcers. However, because the failure is likely to attribute to small number of patients enrolled, immediate eradication therapy may be a treatment option for patients after ESD without adverse effects on eradication therapy in comparison with the standard therapy.

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.

Association between the body mass index and the risk of Barrett's esophagus in Japan.

BACKGROUND: We investigated the association between long-segment Barrett's esophagus and obesity in the Japanese population in a multicenter case-control trial. METHODS: One hundred thirteen patients with endoscopically detected Barrett's esophagus with a length of more than 2 cm and the same number of sex- and age-matched controls were prospectively enrolled. Barrett's esophagus was diagnosed based on the Prague C and M criteria. The body mass index (BMI) of the subjects was categorized into the following groups: normal, BMI <22.9; overweight, BMI 23.0-24.9, and obese, BMI >25.0. To determine the association between BMI and the risk of Barrett's esophagus, multivariate logistic regression analyses were performed. RESULTS: The basically adjusted regression model adjusted for smoking and alcohol consumption revealed that overweight and obesity were significantly associated with an elevated risk of Barrett's esophagus (OR 2.4, 95% CI 1.2-4.7, and OR 2.5, 95% CI 1.3-4.6, respectively). The intensity of the association was not attenuated even after adjustment for gastroesophageal reflux disease-related parameters. CONCLUSIONS: An increased BMI was associated with an increased risk for Barrett's esophagus through a gastroesophageal reflux-independent mechanism in the Japanese population. Further, unlike in Caucasian populations, being even slightly overweight with a BMI of 23.0-24.9 was an independent risk factor in the Japanese population.

Gene polymorphisms of NOD1 and interleukin-8 influence the susceptibility to erosive esophagitis in Helicobacter pylori infected Japanese population.

Helicobacter pylori (H. pylori) infection generally protects patients from erosive esophagitis through reduction of acid production due to gastric mucosal atrophy. However, there are H. pylori infected patients who still have erosive esophagitis. The reason for this discrepancy remains unclear. We have previously reported that polymorphisms in IL-8 promoter region influence the susceptibility of H. pylori related diseases. On the other hand, nucleotide-binding oligomerization domain 1 (NOD1) is known to play an important role in H. pylori infection. Hence, we hypothesized polymorphisms of these two molecules in H. pylori infected patients may influence the susceptibility to erosive esophagitis. Genomic DNA was extracted from 312 H. pylori infected Japanese, consisting of 110 patients with erosive esophagitis and 202 healthy controls. ND1+32656 T/GG and IL-8-251 A/T polymorphisms were genotyped by direct sequencing. ND1+32656 GG allele and IL-8-251 T/T allele increased the risk of erosive esophagitis with odds ratio (OR) of 1.9 (95% confidence interval (CI) 1.1-3.0, p=0.013) and 1.7 (95% CI 1.1-2.8, p=0.036), respectively. Combination of these two alleles increased the risk with OR of 3.2(95% CI 1.6-6.5, p=0.001). In conclusion, ND1+32656 GG and IL-8-251 T/T allele may be associated with less reactivity to H. pylori infection, and may increase the risk of erosive esophagitis even in H. pylori infected Japanese population.

Deficient aldehyde dehydrogenase 2 is associated with increased risk for esophageal squamous cell carcinoma in the presence of gastric hypochlorhydria.

OBJECTIVE: In Orientals, deficient aldehyde dehydrogenase 2 (ALDH2) is associated with an increased risk for esophageal squamous cell carcinoma (ESCC). The local metabolism of carcinogenic acetaldehyde in the upper gastrointestinal tract could be involved in the association, but the underlying mechanism has not been fully elucidated. Since an anacidic stomach can promote bacteria-catalyzed local acetaldehyde production, the gastric acid level could also affect acetaldehyde metabolism. This study investigated whether ALDH2-related susceptibility to ESCC differs depending on the gastric secretion level. MATERIAL AND METHODS: Sixty-two patients with ESCC and sex- and age-matched normal controls were enrolled in this study. ALDH2 polymorphism was analyzed by polymerase chain-restriction fragment length polymorphism, and those with an inactive allele (ALDH2-1/2-2 or ALDH2-2/2-2) were defined as ALDH2 deficient. Gastrin-stimulated acid output was assessed by endoscopic gastrin test and hypochlorhydria was defined as 0.6 mEq/10 min or lower. Multiple logistic regression analyses were used to adjust for other potential confounders. RESULTS: ALDH2 deficiency or hypochlorhydria was more prevalent in ESCC compared with controls and both showed increased independent associations with ESCC in multivariate analysis. Stratified analysis by the gastric acid secretion level revealed that the associations between the ALDH2 genotype and ESCC differed according to the individual gastric acid secretion levels and that ALDH2 deficiency was a significant risk factor for ESCC exclusively in individuals with hypochlorhydria with an odds ratio (95% confidence interval): 5.0 (1.2-21.2). CONCLUSION: Microbial production of carcinogen acetaldehyde in the presence of gastric hypochlorhydria is most probably involved in the mechanism of ALDH2-related susceptibility to ESCC.

Helicobacter pylori induces gastric mucosal intestinal metaplasia through the inhibition of interleukin-4-mediated HMG box protein Sox2 expression.

Helicobacter pylori is a major cause of the transdifferentiation into intestinal metaplasia that may develop gastric cancer. However, the molecular pathogenesis of this transdifferentiation is poorly understood. A SRY-related HMG box protein Sox2 is an essential transcription factor of organ development in brain, lung, and stomach. Our aim of this study was to investigate the mechanism responsible for regulation of Sox2 in host Th1-dominant response to H. pylori. Sox2 protein was immunohistochemically expressed in both human oxyntic and pyloric glands with H. pylori infection, but not in intestinal metaplasia. Western immunoblotting of gastric epithelial cell lines showed that IL-4, a Th2-related cytokine, dose dependently enhanced Sox2 expression among H. pylori infection-mediated cytokines. Small changes of Sox2 expression were observed after each treatment with IFN-gamma, IL-1beta, or TNF-alpha. IL-4-mediated Sox2 induction was suppressed by the inhibition of STAT6 activation with STAT6 RNA interference, and electrophoretic mobility shift assay indicated that activation of the Sox2 promoter by IL-4 occurred through the action of STAT6. Furthermore, H. pylori and IFN-gamma inhibited the phosphorylation of STAT6, resulting in the suppression of IL-4-mediated Sox2 expression. Immunohistochemical analyses showed significantly the suppressed STAT6 activity in H. pylori-infected human gastric mucosa. Additionally, downregulation of Sox2 by knockdown experiments led to intestinal phenotype with expressions of Cdx2 and MUC2. These results suggest that H. pylori and IFN-gamma interfere with the differentiation into oxyntic and pyloric glands by the downregulation of Sox2 on IL-4/STAT6 signaling, which may contribute to the transdifferentiation into intestinal metaplasia.

[A case of curatively resected AFP producing gastric cancer that responded remarkably to 1 course of TS-1 and showed complete loss of multiple liver metastatic tumors].

A 73-year-old woman was admitted to our hospital for evaluation of hypochondralgia, and a thorough examination revealed an AFP producing gastric cancer with multiple liver metastases. One course of TS-1 100 mg/day for 4 weeks and discontinuation for 2 weeks was started from February, 2003. After 3 months, the level of AFP reduced remarkably from 53,700 ng/ml to the normal limit. The metastatic tumors in the liver showed regression, and after 14 months, CT scanning showed that the tumors had disappeared. Since the size of the original tumor showed no change, distal gastrectomy was performed, and curability A was achieved. We consider this rare case has significant value in terms of treatment of AFP producing gastric cancer with multiple liver metastases. We think the combination of surgery and chemotherapy such as TS-1 will lead to a better prognosis in such cases.