Comparison of Gastric Cancer Risk Classifications Using Conventional and New Pepsinogen Criteria.

Background: New serum pepsinogen (PG) criteria have been shown to indicate more accurately infection with Helicobacter pylori (H. pylori). We sought to improve risk classification for gastric cancer by adopting the new PG criteria with the addition of an H. pylori antibody test. Methods: The study participants were 275 patients with gastric cancer and 275 apparently healthy controls from case-control study data. We cross-sectionally compared the results of gastric cancer risk classifications that were based on a combination of the new PG criteria (PG II ≥ 10 ng/mL or PG I/II ≤ 5) and an H. pylori antibody test with those that were based on a combination of the conventional criteria (PG I ≤ 70 ng/mL and PG I/PG II ≤ 3) and an H. pylori antibody test. Results: Applying the conventional criteria resulted in 89 controls being classified as low risk. Applying the new criteria resulted in 23 controls (bootstrapped 95% confidence intervals [CI]: 14, 32) being additionally classified as high risk. Eight patients with gastric cancer were classified as low risk using the conventional criteria; however, six of these patients were classified as high risk by the new criteria (bootstrapped 95% CI: 2, 11). Conclusions: Compared with the conventional criteria, the new PG criteria with H. pylori antibody reduced instances of gastric cancer cases being misclassified as low risk. These findings suggest that the new PG criteria may help identify individuals at high risk of developing gastric cancer.

Development of a HPLC system using a phase-separation multiphase flow as an eluent coupled to a silica-particle packed column.

The study reports the development of a high-performance liquid chromatography (HPLC) system in which a phase-separation multiphase flow as the eluent and a silica-particle based packed column as the separation column were combined to form the phase separation mode. Twenty-four types of mixed solutions of water/acetonitrile/ethyl acetate and water/acetonitrile were applied as eluents to the system at 20 °C. 2,6-Naphthalenedisulfonic acid (NDS) and 1-naphthol (NA) were injected as model analytes into the system. They showed separation tendency in organic solvent-rich eluents in normal-phase mode and NA was detected earlier than NDS. Subsequently, seven types of the ternary mixed solutions were examined as eluents in the HPLC system at 20 °C and 0 °C. These mixed solutions worked as a two-phase separation mixed solution, providing a phase-separation multiphase flow at 0 °C in the separation column. In the organic solvent-rich eluent, the mixture of analytes was separated at both 20 °C (normal-phase mode) and 0 °C (phase-separation mode), with NA being detected earlier than NDS. The separation at 0 °C was more efficient than at 20 °C. In the water-rich eluent, the mixture of NDS and NA was not separated at 20 °C but was separated at 0 °C (phase-separation mode), with NDS being detected earlier than NA. We also discussed the separation mechanism of phase-separation mode in HPLC together with the computer simulation for the multiphase flow in the cylindrical tube having sub-µm inner diameter.

Relative risk of gastric cancer between those with and without Helicobacter pylori infection history in Japan.

Background and Aim: The causal relationship between Helicobacter pylori (H. pylori) infection and gastric cancer has been established. Although the magnitude of the carcinogenic effect of H. pylori is the next concern, it has not been sufficiently evaluated in Japan. Spontaneous disappearance of H. pylori infection may have provoked underestimation of the carcinogenic effect of the infection. To reduce the influence, a comparison should be carried out between subjects with and without the infection history. Cutoff values of H. pylori antibody lower than the manufacturer's recommendation are known to be more appropriate to diagnose history of H. pylori infection. The aim was to evaluate the carcinogenic effect of H. pylori. Methods: A case-control study consisting of 275 gastric cancer patients and 275 age- and sex-matched controls was performed. Serum H. pylori antibody was measured using the "JHM-Cap" kit with a domestic antigen (cut value of the manufacturer's recommendation was 2.3 EV: ELISA value). Using a conditional logistic model, the odds ratios (ORs) for five cutoff values adjusted for smoking and drinking doses were calculated. Results: For cutoff values of 1.25, 1.5, 1.75, 2.0, and 2.3 EV, the ORs (95% confidence intervals) were 67.7 (9.1, 502), 37.2 (8.8, 157), 21.3 (9.0, 60.2), 25.5 (9.0, 72.7), and 25.9 (9.2, 73.2), respectively. Conclusions: These results suggest that the risk ratio of gastric cancer between subjects with and without history of H. pylori infection in Japan may exceed 20.

High expression of long non-coding RNA MALAT1 in breast cancer is associated with poor relapse-free survival.

PURPOSE: Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified as a prognostic marker for the metastasis of early-stage non-small cell lung cancer (NSCLCs). We studied MALAT1 expression in breast cancer in relation to disease features and patient survival. METHODS: Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to measure MALAT1 expression in tumor samples of 509 breast cancer patients. Hazards ratios (HRs) and 95% confidence intervals (CIs) were calculated to assess the association between MALAT1 expression and breast cancer survival using the Cox proportional hazards regression model, and the analysis was adjusted for age at surgery, tumor grade, disease stage, and hormone receptor status. Meta-analysis of multiple microarray datasets from online databases and our own study was performed to evaluate the association of MALAT1 with breast cancer survival. RESULTS: Patients with low-grade or ER-positive tumors had higher expression of MALAT1 compared to those with high-grade (p = 0.013) or ER-negative (p = 0.0002) tumors. Patients with PR-positive tumors also had higher MALAT1 expression than those with PR-negative tumors (p < 0.0001). In patients with positive hormone receptors or low tumor grade, tumors with high MALAT1 expression were more likely to recur. Survival analysis showed that patients with high expression of MALAT1 had a twofold increase in risk of relapse (p = 0.0083) compared to those with low expression. This association remained significant after adjustment for age at surgery, disease stage, tumor grade, and hormone receptor status. Meta-analysis showed that high MALAT1 expression was associated with poor relapse-free survival in patients with hormone receptor-positive tumors (HR 1.44, 95% CI 1.08-1.92). CONCLUSIONS: High expression of lncRNA MALAT1 is associated with breast cancer relapse and may play a role in tumor progression.

Helicobacter Pylori Infection and Risk of Death From Cardiovascular Disease Among the Japanese Population: a Nested Case-Control Study within the JACC Study.

AIM: An increasing number of studies have linked Helicobacter pylori (H. pylori) infection to extragastric diseases; however, the role of H. pylori in the pathogenesis of cardiovascular disease (CVD) remains controversial. We examined the association between H. pylori infection and risk of death from coronary heart disease (CHD) and stroke in a nested case-control study within a large prospective cohort study of Japanese subjects. METHODS: The cases were 627 subjects who died from CHD and stroke during the follow-up period until December 31, 2003, and 627 control subjects were selected and matched to cases on sex, age, and area. Commercial immunoassay IgG enzyme-linked immunosorbent assay kits were used for the determination of the seropositivity for H. pylori. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using a conditional logistic regression model. RESULTS: Overall, H. pylori infection was not associated with CVD (CHD and stroke) mortality risk. The multivariable OR was 0.96 (0.76-1.21) for the H. pylori positive subjects in comparison with H. pylori negative subjects. As for the subtype of CVD, H. pylori appears to be inversely associated with the risk of death from CHD, with an OR of 0.79 (0.50-1.25), but this was not statistically significant. No significant association was observed between H. pylori infection and stroke, with an OR of 1.02 (0.78-1.33). CONCLUSION: The results of this nested case-control study suggest that there is no association between H. pylori infection and CHD and stroke mortality risk in otherwise healthy, elderly Japanese individuals.

Reduced serum vascular endothelial growth factor receptor-2 (sVEGFR-2) and sVEGFR-1 levels in gastric cancer patients.

The relationship between gastric cancer and serum vascular endothelial growth factor receptor-1 (sVEGFR-1) and sVEGFR-2, which are soluble form receptor proteins of vascular endothelial growth factor (VEGF), has not been extensively studied. VEGF, sVEGFR-1 and sVEGFR-2 were measured in the sera obtained before surgical operation from 164 gastric cancer patients and from 164 healthy controls matched for age and gender. Compared with controls, the cases showed elevated VEGF (P < 0.01) and reduced sVEGFR-1 (P = 0.07) and sVEGFR-2 (P = 0.02). The difference in VEGF levels was small among men and when the outcome was early cancer. The difference in sVEGFR-1 levels was significant or borderline significant only in men and when the outcome was diffuse type cancer. The difference in sVEGFR-2 levels was significant only in men and when the outcome was advanced or diffuse type cancer. The sensitivities and specificities of VEGF, sVEGFR-1 and sVEGFR-2 were all approximately 60%. For diffuse type cancer, sVEGFR-2 showed a sensitivity of 62.4% and a specificity of 63.4%, which was similar to serum pepsinogen. In conclusion, elevated VEGF and reduced sVEGFR-1 and sVEGFR-2 in serum are characteristic of gastric cancer patients, and the value of serum sVEGFR-2 in the diagnosis of diffuse type gastric cancer should be further evaluated.

Cancer deaths in a cohort of Japanese barbers in Aichi Prefecture.

Barbers have frequent occasion to come in contact with hair and beauty products that contain many chemical substances, which could have harmful effects on health. Subjects were barbers belonging to the Barbers' Union of Aichi Prefecture who responded to a questionnaire in 1976. Deaths from all sites of cancers in the subjects were observed over 27 years. Mortalities of several cancers in the subjects were compared with individuals in the Japanese population, calculating standardized mortality ratios (SMRs) using the general Japanese population as a standard. Subjects included 8,360 people (4,674 men). There were a total of 551 deaths (469 men) during the follow-up period, and 277 deaths (211 men) from all cancers. The male and female SMRs (95% CI) were 0.62 (0.58-0.66) and 0.25 (0.16-0.34) for all deaths, 0.46 (0.39-0.53) and 0.41 (0.35-0.53) for all cancers combined, 0.49 (0.35-0.63) and 0.40 (0.12-0.68) for stomach, 0.40 (0.24-0.56) and 0.30 (0.10-0.70) for lung, 0.56 (0.39-0.73) and 0.26 (0.02-0.76) for liver, 0.38 (0.16-0.60) and 0.30 (0.07-0.67) for colon, and 0.48 (0.08-0.88) and 0.22 (0.04-0.79) for blood cancers, respectively, with significantly fewer deaths than in the general populace. The female SMRs were 0.90 (0.74-4.06) for breast and 0.55 (0.06-1.04) for ovarian, lacking significance. Thus, no excess mortality of any cancer sites was observed compared with the general population in both Japan and Aichi Prefecture.

Lack of association between risk of biliary tract cancer and circulating IGF (Insulin-like Growth Factor) -I, IGF-II or IGFBP-3 (IGF-binding Protein-3): A nested case-control study in a large scale cohort study in Japan.

Biliary tract cancer, encompassing gallbladder and bile duct cancers, has a poor prognosis, but little is known of the etiology. A nested case-control study was here conducted to evaluate the association between serum levels of IGF-I, IGF-II and IGFBP-3 and death from biliary tract cancer. In a large scale cohort study, 35 gallbladder and 42 bile duct cancers were observed during the follow-up. For each subject in the case group, 1-3 control subjects (228 in total) were selected randomly, matched for sex, age (as near as possible) and residential area. The subjects were divided into tertiles by circulating levels of IGF-I, IGF-II or IGFBP-3. Using conditional logistic regression, risks among the tertiles were compared adjusted for defecation, smoking and drinking habits. No remarkable differences in risks of gallbladder or bile duct cancer were observed among tertiles of IGF-I or IGF-II, and no remarkable trend was observed. Circulating IGFBP-3 showed an inverse U-shape association with gallbladder cancer and a U-shaped one with bile duct cancer. Associations between IGF-I or IGF-II and gallbladder or bile duct cancer thus were lacking or very weak. The observed U- and inverse U-shaped association of IGFBP-3 with the cancers is not suggestive of any meaningful relationships.

Green tea consumption and the risk of pancreatic cancer in Japanese adults.

OBJECTIVE: Green tea polyphenols have been shown to inhibit tumor growth in animal and in vitro studies. We examined the relationship between green tea consumption and the risk of death from pancreatic cancer in a large Japanese cohort. METHODS: At baseline (1988-1990), study participants reported the frequency and amount of green tea consumption during the past year. They were followed-up for mortality until December 31, 2003. Relative risk and 95% confidence intervals were calculated from Cox proportional hazard models. RESULTS: During an average follow-up of 13 years, we observed 292 pancreatic cancer deaths. In men and women combined, the relative risk was 1.23 (95% confidence interval, 0.84-1.80) for participants who consumed 7 or more cups of green tea per day as compared with those who consumed less than 1 cup per day, after adjustment for potential confounding factors. No significant trend in risk reduction was noted, with increasing consumption of green tea. We found no inverse association between cups of green tea consumed per day and the risk of pancreatic cancer in either men or women. CONCLUSIONS: Our findings do not support the hypothesis that green tea consumption is associated with decreased risk of pancreatic cancer in humans.

Cigarette smoking, alcohol drinking and the risk of gallbladder cancer death: a prospective cohort study in Japan.

Gallbladder cancer is a rare cancer with a poor prognosis, and few risk factors have been identified to date. This prospective study was conducted to evaluate the association of cigarette smoking and alcohol consumption with the risk of gallbladder cancer death. A baseline survey in 45 areas throughout Japan was conducted from 1988 to 1990 using a self-administered questionnaire, and a total of 113,496 participants (65,740 women) aged 40-89 years at entry were followed for 15 years. During the follow-up period, 165 gallbladder cancer deaths (95 women) were observed. Among women, the hazard ratio (HR) [95 percent confidence interval: 95% CI] of current smoker was 2.00 [0.91-4.42], when adjusted for age and drinking. There was no clear association between alcohol consumption and the risk. Among men, HR of current smoker was 2.27 [1.05-4.90]. HRs of those who smoked 21 cigarettes or more per day and those with 801-1,000 cigarette-years were 3.18 [1.18-8.53] and 3.44 [1.40-8.45], respectively, and positive linear associations were observed between that risk and the number of cigarettes per day (p for trend = 0.007) or "cigarette-years" (p for trend = 0.012). The alcohol dose was linearly associated with risk (p for trend = 0.004), where the HR among those who consumed 72.0 g or more of alcohol per day was 3.60 [1.29-9.85]. Among both men and women, cigarette smoking may elevate the risk of death from gallbladder cancer. Drinking may pose an elevated risk among men, but that seems to be less true among women.

Obesity, physical activity and the risk of pancreatic cancer in a large Japanese cohort.

It is unclear whether body mass index (BMI) and physical activity are associated with the risk of pancreatic cancer in Asian populations. We examined these associations in the Japanese Collaborative Cohort Study for Evaluation of Cancer Risk. Our cohort study included 110,792 Japanese men and women at enrollment (1988-1990). Data on height, body weight (at baseline and at age 20 years) and physical activity were obtained from a questionnaire. Cox proportional hazards models were used to estimate the relative risks of pancreatic cancer mortality. We observed a total of 402 pancreatic cancer deaths during the follow-up period. Men with a BMI of 30 or more at age 20 years had a 3.5-fold greater risk compared with men with a normal BMI. Women with a BMI of 27.5-29.9 at baseline had approximately 60% increased risk compared with women with a BMI of 20.0-22.4. In men, weight loss of 5 kg or more between 20 years of age and baseline age was associated with an increased risk of pancreatic cancer death. In contrast, women with weight loss of 5 kg or more over the same period had a decreased risk. Physical activity was not associated with pancreatic cancer risk in either men or women. Obesity in young adulthood may be associated with an increased risk of death from pancreatic cancer in Japanese men. The risk of pancreatic cancer in relation to BMI seems to differ according to sex and the period over which BMI was measured.

Dietary habits and pancreatic cancer risk in a cohort of middle-aged and elderly Japanese.

Few epidemiological studies have examined associations between diet and pancreatic cancer in Japan. In the Japan Collaborative Cohort Study for Evaluation of Cancer Risk, we evaluated the relationship between dietary factors, including meat, vegetable, and fruit intake, and the risk of pancreatic cancer deaths. Among the original cohort established between 1988 and 1990, 46,465 men and 64,327 women aged 40-79 yr were followed-up through December 31,1999. During 1,042,608 person-years of follow-up, we documented 300 deaths from pancreatic cancer. A 33-item food-frequency questionnaire was used to assess dietary intake at the baseline survey. Cox proportional-hazards models were used to estimate the relative risks of pancreatic cancer death in relation to the intake frequency of food items. We did not observe an overall association between meat intake and pancreatic cancer risk. Except for a 50% decrease in risk associated with high fruit intake among men, we did not find other significant inverse relationships between vegetable and fruit intake and pancreatic cancer risk. Smoking did not modify the associations with dietary habits. Our study suggested that high consumption of pickles and wild edible plants, mainly bracken, might be related to increased pancreatic cancer risk; however, this finding should be confirmed in other epidemiological studies.

Association of menstrual and reproductive factors with pancreatic cancer risk in women: findings of the Japan Collaborative Cohort Study for Evaluation of Cancer Risk.

BACKGROUND: The etiology of pancreatic cancer remains largely unknown. We examined the association of pancreatic cancer deaths with menstrual and reproductive factors in a cohort study involving Japanese women. METHODS: A total of 63,273 women were followed up for mortality from 1988 to 1999. Information on menstrual and reproductive factors was obtained by a questionnaire survey at baseline. Cox proportional-hazards models were used to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for death from pancreatic cancer in relation to menstrual and reproductive factors. RESULTS: During 631,401 person-years of follow-up, 154 women died from pancreatic cancer. Parity was not significantly associated with the risk of death from pancreatic cancer; the RR was 0.80 (95% CI, 0.31-2.11) for women with six or more births compared with women with zero or one birth. We found no significant overall association with other reproductive factors, including pregnancy, age at first birth, and menopause. The risk appeared to increase with increasing age at menarche; the RR was 1.49 (95% CI, 0.95-2.34) for women who had menarche after 16 years of age compared to those who had menarche before they were 15 years old. CONCLUSIONS: Our prospective data indicate that menstrual and reproductive factors are not associated with the risk of death from pancreatic cancer among Japanese women.

Serum transforming growth factor-beta1 levels and pancreatic cancer risk: a nested case-control study (Japan).

OBJECTIVE: To examine the relationship of baseline levels of serum TGF-beta1 to the subsequent risk of death from pancreatic cancer in a nested case-control study. METHODS: The cases were 85 persons who had provided a blood sample at baseline and subsequently died of pancreatic cancer during the study period. For each case, three controls were randomly selected from among the cohort participants, and were matched for each case by sex, age (+/-1 year), and study area. Serum TGF-beta1 levels were measured with enzyme-linked immunosorbent assay (ELISA). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated from conditional logistic models. RESULTS: The mean of serum TGF-beta1 levels was significantly higher among cases than among controls (p = 0.01). Individuals with serum TGF-beta1 levels in the highest quartile had a 2.5-fold increase in risk as compared with those in the lowest quartile (OR, 2.5; 95% CI, 0.9-6.9), after adjustment for month of blood draw, cigarette smoking, body mass index and history of diabetes. Excluding 12 pancreatic cancer deaths that occurred within three years of follow-up did not alter the positive association. CONCLUSION: Our prospective data indicate that high serum TGF-beta1 levels may be associated with an increased risk of death from pancreatic cancer.

Serum levels of transforming growth factor beta1 are significantly correlated with venous invasion in patients with gastric cancer.

BACKGROUND AND AIM: The significance of serum levels of transforming growth factor (TGF)-beta1 in the development of gastric cancer is unclear. The purpose of this study is to determine whether serum TGF-beta1 correlated with the clinicopathological findings of patients with gastric cancer. METHODS: Transforming growth factor-beta1 levels in the serum of 275 gastric cancer patients and 275 gender- and age-matched healthy controls were measured with enzyme-linked immunosorbent assay (ELISA) using a commercially available kit. RESULTS: The mean level of serum TGF-beta1 of gastric cancer patients (15.9 +/- 5.9 ng/mL) was significantly higher than that (13.9 +/- 7.4 ng/mL) of healthy controls (P < 0.01). The odds ratio for the subjects in the highest quartile (16.7 ng/mL or more) was 4.03 (95% confidence interval, 2.14-7.58), as compared with that for the subjects in the lowest quartile (0-9.5 ng/mL). Patients with venous invasion compared to those without venous invasion had significantly elevated serum TGF-beta1 (17.3 +/- 7.2 vs 15.0 +/- 5.1 ng/mL; P = 0.04). There were no statistically significant differences between the two groups categorized by histological type, lymph node metastasis and distant metastasis. Logistical regression analysis showed that venous invasion was significantly correlated with elevated serum TGF-beta1 levels (P = 0.02). CONCLUSIONS: The present study showed that an elevated serum TGF-beta1 level may be significantly correlated with venous invasion in gastric cancer patients.

Alcohol consumption and mortality among middle-aged and elderly Japanese men and women.

PURPOSE: We conducted a prospective cohort study to examine the association between alcohol intake and the risk of all-cause mortality among middle-aged and elderly Japanese men and women. METHODS: At baseline (1988-1990), a total of 110,792 Japanese men and women aged 40 to 79 years were asked to complete a questionnaire that included information on alcohol intake, and were followed up for all-cause mortality through December 31, 1999. Relative risks (95% confidence interval) were calculated using Cox proportional-hazards models. RESULTS: The risk of all-cause mortality was lowest among current drinkers with an alcohol intake of 0.1 to 22.9 g/d (RR, 0.80; 95% CI, 0.72-0.88 for men; and RR, 0.88; 95% CI, 0.77-1.00 for women). Excessive mortality associated with heavy drinking (> or = 69 g/d) was observed for cancer, cardiovascular disease and injuries and other external causes in men, while significantly reduced mortality with light drinking was seen for cancer in men and CVD in women. For men, the benefit associated with light alcohol consumption (< 23 g/d) was more apparent among nonsmokers than among smokers. CONCLUSION: Our prospective data show a 12% to 20% decreased risk of all-cause mortality in both Japanese men and women who consumed less than 23 g/d of alcohol (approximately 2 drinks), although heavy drinking increased that risk.

Serum pepsinogen values and Helicobacter pylori status among control subjects of a nested case-control study in the JACC study.

BACKGROUND: Helicobacter pylori infection and serum pepsinogen values are strongly related with stomach cancer. The aim of this study was to know what were these factors among general population. METHODS: Subjects were randomly selected 633 control subjects in a nested case-control study for risk of stomach cancer. Most of them were from rural areas of Japan. Using frozen sera, pepsinogen I (PG I) and II (PG II) values and H. pylori antibody were measured. Those with PG I less than 50 ng/mL and the ratio of PG I to PG II (PG I/II) was less than 2.0 were defined as severe, those with PG I less than 70 ng/ml and PG I/II less than 3.0 were defined as mild and the other subjects were defined as no serological atrophy. RESULTS: About 70% of the subjects were H. pylori seropositive and the seroprevalence did not depend on age or sex. Percentages of those with severe serological atrophy increased with age from 10% in those aged 40-49 years to 38% in 70 and more, and percentages of those with mild serological atrophy were about 30% independent of age. CONCLUSIONS: The subjects, who were expected to represent populations of rural area of Japan, had high prevalence of both H. pylori infection and serological atrophy of gastric mucosa. These facts should be considered in discussing results of the nested case-control study.

A case-control study exploring the role of serum manganese superoxide dismutase (MnSOD) levels in gastric cancer.

BACKGROUND: The role of serum manganese superoxide dismutase (MnSOD) in the development of gastric cancer has not been clearly defined. METHODS: We conducted a case-control study to address the potential relationship between serum MnSOD levels and gastric cancer. Cases were 275 gastric cancer patients and controls were 275 sex and age-matched healthy persons. Serum MnSOD levels were determined by a commercially available enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean(+/-standard deviation) of serum MnSOD levels was 177.4 +/- 87.3 ng/mL among cases and 169.4 +/- 56.7 ng/mL among controls. Gastric cancer patients had slightly higher serum MnSOD levels than the controls. After adjustment for pack-years of cigarette smoking and Helicobacter pylori infection, the odds ratio was 1.54(95% confidence interval; 0.79-3.01) for subjects in the highest quartile versus the lowest quartile. No significant differences were observed for serum MnSOD levels in gastric cancer patients according to clinicopathological factors such as disease stage, histological type, venous invasion, and lymph node metastasis. CONCLUSION: Our study suggested that serum MnSOD levels are not significantly associated with the increased risk of gastric cancer, although a weak association may exist.

Serum midkine concentrations and gastric cancer.

Midkine (MK) is one of a family of heparin-binding growth factors, and increased MK expression is reported in various types of human carcinomas. To clarify the association between serum MK (S-MK) concentrations and gastric cancer, we examined S-MK concentrations of gastric cancer patients (n=275) and healthy controls (n=275). S-MK concentrations of all subjects were measured by enzyme-linked immunosorbent assay (elisa). The medians (25th and 75th percentiles) of S-MK were 192 (123 and 314) pg/mL in the cases and 170 (81 and 273) pg/mL in the controls (P <0.01). We also compared S-MK concentrations in each group divided by the progression stage or histological type of cancer. A difference was observed in the median S-MK concentrations between early and advanced cancers [182 (105 and 301) pg/mL vs 203 (139 and 331) pg/mL, P=0.07], but not between intestinal and diffuse type cancers [185 (121 and 306) pg/mL vs 198 (127 and 323) pg/mL, P=0.51]. We found that those progression stages affect S-MK concentration more strongly than the histological types in gastric cancer patients. Because S-MK seems to reflect the progression stage of gastric cancer, it may serve as a useful marker in the clinical follow-up of gastric cancer patients.

Trends in the incidence of gastric cancer in Japan and their associations with Helicobacter pylori infection and gastric mucosal atrophy.

BACKGROUND: Although age-adjusted mortality from gastric cancer has been decreasing in Japan, the crude incidence of gastric cancer shows a slight increase. METHODS: We have observed trends in the incidence of gastric cancer by sex and 20-year age groups over the past two decades (1976-1996). Source data were obtained from the cancer statistics materials provided by the Research Group for Population-Based Cancer Registration in Japan. Simultaneously, we observed changes in the prevalence of Helicobacter pylori infection and in serological atrophy of the gastric mucosa, and compared the results with those involving changes in the incidence of gastric cancer. RESULTS: A slight decline was observed in all age groups over 40 years old, in both men and women, between 1986 and 1996. However, a marked decline in incidence was observed for those aged 20-39 years. The prevalence of H. pylori infection declined in both sexes between 1989 and 1998. The frequency of serological atrophy of the gastric mucosa significantly declined in all age groups between 1989 and 1996, with young age groups experiencing a more marked decrease. CONCLUSION: The marked decline in gastric cancer incidence observed in the young population will also begin to occur in the elderly population in the future.