Association of female reproductive and hormonal factors with gallbladder cancer risk in Asia: A pooled analysis of the Asia Cohort Consortium

The female predominance of gallbladder cancer (GBC) has led to a hypothesis regarding the hormone-related aetiology of GBC. We aimed to investigate the association between female reproductive factors and GBC risk, considering birth cohorts of Asian women. We conducted a pooled analysis of 331,323 women from 12 cohorts across 4 countries (China, Japan, Korea, and Singapore) in the Asia Cohort Consortium. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) to assess the association between reproductive factors (age at menarche, parity, age at first delivery, breastfeeding, and age at menopause) and GBC risk. We observed that a later age at menarche was associated with an increased risk of GBC (HR 1.4, 95% CI 1.16-1.70 for 17 years and older vs. 13-14 years), especially among the cohort born in 1940 and later (HR 2.5, 95% CI 1.50-4.35). Among the cohort born before 1940, women with a later age at first delivery showed an increased risk of GBC (HR 1.56, 95% CI 1.08-2.24 for 31 years of age and older vs. 20 years of age and younger). Other reproductive factors did not show a clear association with GBC risk. Later ages at menarche and at first delivery were associated with a higher risk of GBC, and these associations varied by birth cohort.

Association between reproductive factors with lung cancer incidence and mortality: A pooled analysis of over 308,000 females in the Asia cohort consortium

Previous studies have investigated the association between reproductive factors and lung cancer risk; however, findings have been inconsistent. In order to assess this association among Asian women, a total of 308,949 female participants from 11 prospective cohorts and four Asian countries (Japan, Korea, China, and Singapore) were included. Cox proportional hazards regression models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CIs). A total of 3,119 primary lung cancer cases and 2247 lung cancer deaths were identified with a mean follow-up of 16.4 years. Parous women had a lower risk of lung cancer incidence and mortality as compared with nulliparous women, with HRs of 0.82 (95% CI = 0.70-0.96) and 0.78 (95% CI = 0.65-0.94). The protective association of parity and lung cancer incidence was greater among ever-smokers (HR = 0.66, 95% CI = 0.49-0.87) than in never-smokers (HR = 0.90, 95% CI = 0.74-1.09) (P-interaction = 0.029). Compared with age at first delivery ≤20 years, older age at first delivery (21-25, ≥26 years) was associated with a lower risk of lung cancer incidence and mortality. Women who ever used hormone replacements had a higher likelihood of developing non-small cell lung cancer (HR = 1.31, 95% CI = 1.02-1.68), compared to those who never used hormone replacements. Future studies are needed to assess the underlying mechanisms, the relationships within these female reproductive factors, and the potential changes in smoking habits over time.

Association between being breastfed in infancy and adult colorectal cancer risk among Japanese men and women

It has been postulated that being breastfed in infancy affects not only health status in childhood but also disease risk in adulthood. To investigate the association of being breastfed with the risks of adult colorectal cancer and benign tumor, we conducted a case-control study including 1190 colorectal cancer and 1585 benign tumor cases and 5301 controls, admitted to a single hospital in Miyagi Prefecture, Japan, between 1997 and 2013. History of having been breastfed was assessed using a self-administered questionnaire, and odds ratios (ORs) were estimated using unconditional logistic regression. There was no association between being breastfed and colorectal cancer risk (breastfed versus formula-only fed, OR = 1.21; 95% CI 0.87-1.67). There was also no association with the risk of benign tumor (OR = 1.04). On the other hand, analyses stratified by sex and birth year found heterogeneous associations. Women born after 1950 who had been breastfed tended to have increased risks of colorectal cancer (OR = 1.58) and benign tumor (OR = 1.51) relative to those who had been formula-only fed, although not statistically significant. In men born after 1950, being breastfed was associated with a significantly decreased risk of benign tumor (OR = 0.57; 95% CI 0.33-0.98).

Diabetes is associated with increased liver cancer incidence and mortality in adults: A report from Asia Cohort Consortium

There has been growing evidence suggesting that diabetes may be associated with increased liver cancer risk. However, studies conducted in Asian countries are limited. This project considered data of 968,738 adults pooled from 20 cohort studies of Asia Cohort Consortium to examine the association between baseline diabetes and liver cancer incidence and mortality. Cox proportional hazard model and competing risk approach was used for pooled data. Two-stage meta-analysis across studies was also done. There were 839,194 subjects with valid data regarding liver cancer incidence (5654 liver cancer cases [48.29/100,000 person-years]), follow-up time and baseline diabetes (44,781 with diabetes [5.3%]). There were 747,198 subjects with valid data regarding liver cancer mortality (5020 liver cancer deaths [44.03/100,000 person-years]), follow-up time and baseline diabetes (43,243 with diabetes [5.8%]). Hazard ratio (HR) (95% confidence interval [95%CI]) of liver cancer diagnosis in those with vs. without baseline diabetes was 1.97 (1.79, 2.16) (p < .0001) after adjusting for baseline age, gender, body mass index, tobacco smoking, alcohol use, and heterogeneity across studies (n = 586,072; events = 4620). Baseline diabetes was associated with increased cumulative incidence of death due to liver cancer (adjusted HR (95%CI) = 1.97 (1.79, 2.18); p < .0001) (n = 595,193; events = 4110). A two-stage meta-analytic approach showed similar results. This paper adds important population-based evidence to current literature regarding the increased incidence and mortality of liver cancer in adults with diabetes. The analysis of data pooled from 20 studies of different Asian countries and the meta-analysis across studies with large number of subjects makes the results robust.

Family history and gastric cancer incidence and mortality in Asia: a pooled analysis of more than half a million participants

BACKGROUND

The family history of gastric cancer holds important implications for cancer surveillance and prevention, yet existing evidence predominantly comes from case-control studies. We aimed to investigate the association between family history of gastric cancer and gastric cancer risk overall and by various subtypes in Asians in a prospective study.

METHODS

We included 12 prospective cohorts with 550,508 participants in the Asia Cohort Consortium. Cox proportional hazard regression was used to estimate study-specific adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between family history of gastric cancer and gastric cancer incidence and mortality, then pooled using random-effects meta-analyses. Stratified analyses were performed for the anatomical subsites and histological subtypes.

RESULTS

During the mean follow-up of 15.6 years, 2258 incident gastric cancers and 5194 gastric cancer deaths occurred. The risk of incident gastric cancer was higher in individuals with a family history of gastric cancer (HR 1.44, 95% CI 1.32-1.58), similarly in males (1.44, 1.31-1.59) and females (1.45, 1.23-1.70). Family history of gastric cancer was associated with both cardia (HR 1.26, 95% CI 1.00-1.60) and non-cardia subsites (1.49, 1.35-1.65), and with intestinal- (1.48, 1.30-1.70) and diffuse-type (1.59, 1.35-1.87) gastric cancer incidence. Positive associations were also found for gastric cancer mortality (HR 1.30, 95% CI 1.19-1.41).

CONCLUSIONS

In this largest prospective study to date on family history and gastric cancer, a familial background of gastric cancer increased the risk of gastric cancer in the Asian population. Targeted education, screening, and intervention in these high-risk groups may reduce the burden of gastric cancer.

Obesity is associated with biliary tract cancer mortality and incidence: A pooled analysis of 21 cohort studies in the Asia Cohort Consortium

Body fatness is considered a probable risk factor for biliary tract cancer (BTC), whereas cholelithiasis is an established factor. Nevertheless, although obesity is an established risk factor for cholelithiasis, previous studies of the association of body mass index (BMI) and BTC did not take the effect of cholelithiasis fully into account. To better understand the effect of BMI on BTC, we conducted a pooled analysis using population-based cohort studies in Asians. In total, 905 530 subjects from 21 cohort studies participating in the Asia Cohort Consortium were included. BMI was categorized into four groups: underweight (<18.5 kg/m2 ); normal (18.5-22.9 kg/m2 ); overweight (23-24.9 kg/m2 ); and obese (25+ kg/m2 ). The association between BMI and BTC incidence and mortality was assessed using hazard ratios (HR) and 95% confidence intervals (CIs) by Cox regression models with shared frailty. Mediation analysis was used to decompose the association into a direct and an indirect (mediated) effect. Compared to normal BMI, high BMI was associated with BTC mortality (HR 1.19 [CI 1.02-1.38] for males, HR 1.30 [1.14-1.49] for females). Cholelithiasis had significant interaction with BMI on BTC risk. BMI was associated with BTC risk directly and through cholelithiasis in females, whereas the association was unclear in males. When cholelithiasis was present, BMI was not associated with BTC death in either males or females. BMI was associated with BTC death among females without cholelithiasis. This study suggests BMI is associated with BTC mortality in Asians. Cholelithiasis appears to contribute to the association; and moreover, obesity appears to increase BTC risk without cholelithiasis.

Lung Cancer Risk Prediction Models for Asian Ever-Smokers

INTRODUCTION

Although lung cancer prediction models are widely used to support risk-based screening, their performance outside Western populations remains uncertain. This study aims to evaluate the performance of 11 existing risk prediction models in multiple Asian populations and to refit prediction models for Asians.

METHODS

In a pooled analysis of 186,458 Asian ever-smokers from 19 prospective cohorts, we assessed calibration (expected-to-observed ratio) and discrimination (area under the receiver operating characteristic curve [AUC]) for each model. In addition, we developed the "Shanghai models" to better refine risk models for Asians on the basis of two well-characterized population-based prospective cohorts and externally validated them in other Asian cohorts.

RESULTS

Among the 11 models, the Lung Cancer Death Risk Assessment Tool yielded the highest AUC (AUC [95% confidence interval (CI)] = 0.71 [0.67-0.74] for lung cancer death and 0.69 [0.67-0.72] for lung cancer incidence) and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial Model had good calibration overall (expected-to-observed ratio [95% CI] = 1.06 [0.90-1.25]). Nevertheless, these models substantially underestimated lung cancer risk among Asians who reported less than 10 smoking pack-years or stopped smoking more than or equal to 20 years ago. The Shanghai models were found to have marginal improvement overall in discrimination (AUC [95% CI] = 0.72 [0.69-0.74] for lung cancer death and 0.70 [0.67-0.72] for lung cancer incidence) but consistently outperformed the selected Western models among low-intensity smokers and long-term quitters.

CONCLUSIONS

The Shanghai models had comparable performance overall to the best existing models, but they improved much in predicting the lung cancer risk of low-intensity smokers and long-term quitters in Asia.

Differential patterns of reproductive and lifestyle risk factors for breast cancer according to birth cohorts among women in China, Japan and Korea

BACKGROUND

The birth cohort effect has been suggested to influence the rate of breast cancer incidence and the trends of associated reproductive and lifestyle factors. We conducted a cohort study to determine whether a differential pattern of associations exists between certain factors and breast cancer risk based on birth cohorts.

METHODS

This was a cohort study using pooled data from 12 cohort studies. We analysed associations between reproductive (menarche age, menopause age, parity and age at first delivery) and lifestyle (smoking and alcohol consumption) factors and breast cancer risk. We obtained hazard ratios (HRs) with 95% confidence intervals (CIs) using the Cox proportional hazard regression analysis on the 1920s, 1930s, 1940s and 1950s birth cohorts.

RESULTS

Parity was found to lower the risk of breast cancer in the older but not in the younger birth cohort, whereas lifestyle factors showed associations with breast cancer risk only among the participants born in the 1950s. In the younger birth cohort group, the effect size was lower for parous women compared to the other cohort groups (HR [95% CI] 0.86 [0.66-1.13] compared to 0.60 [0.49-0.73], 0.46 [0.38-0.56] and 0.62 [0.51-0.77]). Meanwhile, a higher effect size was found for smoking (1.45 [1.14-1.84] compared to 1.25 [0.99-1.58], 1.06 [0.85-1.32] and 0.86 [0.69-1.08]) and alcohol consumption (1.22 [1.01-1.48] compared to 1.10 [0.90-1.33], 1.15 [0.96-1.38], and 1.07 [0.91-1.26]).

CONCLUSION

We observed different associations of parity, smoking and alcohol consumption with breast cancer risk across various birth cohorts.

Association of Socioeconomic Status Assessed by Areal Deprivation With Cancer Incidence and Detection by Screening in Miyagi, Japan Between 2005 and 2010

BACKGROUND

Previous studies have shown that socioeconomic factors are associated with cancer incidence and stage at diagnosis; however, relevant findings in Japan are limited. We examined the association between socioeconomic status and cancer incidence, stage at diagnosis, and detection status by screening, as assessed using the areal deprivation index (ADI), in population-based cancer registry data.

METHODS

A total of 79,816 cases, including stomach, colorectal, lung, female breast, and cervical cancer diagnosed in Miyagi Prefecture between 2005 and 2010, were analyzed. After calculating the ADI at the place of residence in each case, we examined the association between quintiles of ADI and age-adjusted incidence rates of all stages and advanced stages by sex and site using Poisson regression analysis. The association between the ADI and the proportion of screen-detected cancers was also examined using logistic regression analysis.

RESULTS

The age-adjusted incidence rates of all sites and lung cancer in men and lung cancer and cervical cancer in women tended to increase significantly in areas with a higher ADI. The age-adjusted incidence rates of advanced-stage cancers were significantly higher for all sites and lung cancer in both sexes, and for stomach and colorectal cancer in men. The proportion of screen-detected cancer tended to be significantly lower in areas with a higher ADI for stomach and colorectal cancer in men.

CONCLUSION

Our results indicate that socioeconomic disparities may affect cancer incidence and early diagnosis in Japan. These results suggest the importance of cancer control measures targeting people with low socioeconomic status in Japan.

Sleep duration and the risk of endometrial cancer incidence among Japanese women: A pooled analysis of the Miyagi Cohort Study and the Ohsaki Cohort Study

OBJECTIVE

Endometrial cancer has been increasing worldwide, and is one of the most common female hormone-related cancers. The purpose of this study was to examine the association between sleep duration and risk of endometrial cancer among Japanese women.

METHODS

We conducted a pooled analysis of two prospective studies conducted among residents of Miyagi Prefecture in rural northern Japan. A total of 36,537 women aged 40-79 years participated in the Miyagi Cohort Study in 1990 and in the Ohsaki Cohort Study in 1994. The participants responded to a self-administered questionnaire that including sleep duration. Sleep duration was assessed at the baseline using a self-administered questionnaire. The participants entered the mean integer number representing the hours of sleep taken per day during the previous year. We divided the participants into three groups (≤6 h, 7-8 h, or ≥9 h). Cox proportional hazards regression analysis was used to estimate the multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for endometrial cancer incidence.

RESULTS

During 745,993 person-years of follow-up, we identified 146 incident cases of endometrial cancer. Compared with women who slept 7-8 h per day, the multivariate HR (95%CI) for endometrial cancer incidence was 1.07 (0.72-1.60) for those who slept 6 h or less, and 1.05 (0.57-1.93) for those who slept 9 h or longer (p-trend=0.57).

CONCLUSION

In analysis of two population -based prospective cohort studies conducted among Japanese women, we found no significant associations between sleep duration and the incidence of endometrial cancer.

Reproductive Factors and Endometrial Cancer Risk Among Women

Importance

Despite evidence of an association between reproductive factors and endometrial cancer risk, prospective studies have been conducted mainly in non-Asian countries.

Objective

To assess the association between reproductive factors, such as number of deliveries, age at menarche, or menopause, and endometrial cancer risk.

Design, Setting, and Participants

This cohort study used pooled individual data from 13 prospective cohort studies conducted between 1963 and 2014 in the Asia Cohort Consortium. Participants were Asian women. Data analysis was conducted from September 2019 to April 2023.

Exposures

Reproductive factors were assessed using a questionnaire in each cohort.

Main Outcomes and Measures

The main outcome was time to incidence of endometrial cancer. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% CIs.

Results

A total of 1005 endometrial cancer cases were detected among 332 625 women (mean [SD] age, 54.3 [10.4] years) during a mean (SD) of 16.5 (6.4) years of follow-up. Increasing number of deliveries was associated with a decreased endometrial cancer risk in a dose-response manner (≥5 deliveries vs nulliparous [reference]: HR, 0.37; 95% CI, 0.26-0.53; P for trend < .001). Compared with menarche at younger than 13 years, menarche at 17 years or older had an HR of 0.64 (95% CI, 0.48-0.86; P for trend < .001). Late menopause (age ≥55 years) showed an HR of 2.84 (95% CI, 1.78-4.55; P for trend < .001) compared with the youngest age category for menopause (<45 years). Age at first delivery, hormone therapy, and breastfeeding were not associated with endometrial cancer risk.

Conclusions and Relevance

This large pooled study of individual participant data found that late menarche, early menopause, and a higher number of deliveries were significantly associated with a lower risk of endometrial cancer. These convincing results from Asian prospective studies add to the growing body of evidence for the association between reproductive factors and endometrial cancer.

Seaweed consumption and the risk of prostate cancer: the Miyagi cohort study

Some laboratory studies have shown that fucoidan, which is contained in seaweed extract, has inhibitory effects on the invasion and angiogenesis of tumor cells; however, the association between seaweed consumption and prostate cancer incidence remains unclear. The purpose of the present study was to examine the association between seaweed consumption and the risk of prostate cancer incidence in the Japanese population. Data from 19 311 men in the Miyagi Cohort Study who were 40-64 years old at baseline in 1990 were examined. Seaweed consumption was assessed at baseline using a self-administered food frequency questionnaire. The participants were divided into three categories based on seaweed consumption at baseline. During 24.5 years of follow-up, we identified 815 incident cases of prostate cancer. Multivariate analysis showed that seaweed consumption was not associated with prostate cancer incidence. The multivariate hazard ratios and 95% confidence intervals for prostate cancer incidence in the highest tertile versus the other tertiles were 0.76 (0.60-0.96) and 0.78 (0.61-0.99) ( P -trend = 0.15). Furthermore, the null association was independent of whether their clinical stage was localized or advanced. In this population-based prospective cohort study conducted in Japan, we found no significant association between seaweed consumption and the incidence of prostate cancer.

Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

Association between personality and the risk of ischemic heart disease mortality before and after the Great East Japan Earthquake: Data from the Miyagi Cohort Study

BACKGROUND

The purpose of the present study was to investigate the association between personality and the risk of IHD mortality among Great East Japan Earthquake (GEJE) survivors, and to investigate whether personality traits affected the increase in IHD mortality observed after the GEJE.

METHODS

We analyzed data for 29,065 men and women in the Miyagi Cohort Study who were 40-64 years old at baseline. We divided the participants into quartiles based on scores for each of the four personality subscales (extraversion, neuroticism, psychoticism, and lie), using the Japanese version of the Eysenck Personality Questionnaire-Revised Short Form. We divided the eight years before and after the GEJE event (11 March 2011) into two period, and examined the relationship between personality traits and the risk of IHD mortality. Cox proportional hazards analysis was used to estimate the multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of IHD mortality according to each personality subscale category.

RESULTS

In the four years before the GEJE, neuroticism was significantly associated with an increased risk of IHD mortality. Compared with the lowest category for neuroticism, the multivariate-adjusted HR (95% CI) for IHD mortality in the highest category was 2.19 (1.03-4.67) (p-trend = 0.12). In contrast, no statistically significant association between neuroticism and IHD mortality was observed in the four years after the GEJE.

CONCLUSION

This finding suggests that the observed increase in IHD mortality after the GEJE can be attributed to risk factors other than personality.

Association between Body Mass Index and Risk of Gastric Cancer by Anatomic and Histologic Subtypes in Over 500,000 East and Southeast Asian Cohort Participants

BACKGROUND

This study was performed to investigate the association between body mass index (BMI) and gastric cancer in East and Southeast Asia where most of gastric cancer is non-cardia gastric cancer.

METHODS

On the basis of 8,997 gastric cancer cases among the Asia Cohort Consortium participants from China, Japan, Korea, and Singapore (N = 538,835), we assessed gastric cancer risk according to BMI by calculating hazard ratios (HR) and 95% confidence intervals (CI) using the Cox proportional hazard regression model.

RESULTS

A U-shaped associations between BMI and gastric cancer risk were observed. Gastric cancer risks in underweight group (&lt;18.5 kg/m2) and in obesity group (≥27.5 kg/m2) were higher than reference BMI group (23-24.9 kg/m2; HR, 1.15; 95% CI, 1.05-1.25 for underweight; HR, 1.12; 95% CI, 1.03-1.22 for obesity, respectively). The associations of underweight and obesity with gastric cancer risk were consistent in the analyses for non-cardia gastric cancer, intestinal-type gastric cancer, and late-onset gastric cancer. No significant association of underweight and obesity with the risk of cardia gastric cancer, diffuse-type gastric cancer, and early-onset gastric cancer was observed. In addition, we found that the U-shaped association between BMI and gastric cancer risk remained in nonsmokers, while only underweight was related to increased gastric cancer risk in smokers.

CONCLUSIONS

BMI has a U-shaped association with gastric cancer risk in East and Southeast Asian population, especially for the non-cardia gastric cancer, intestinal-type gastric cancer, and late-onset gastric cancer.

IMPACT

Future studies with consideration of anatomic location and histology of gastric cancer are needed to establish the association of underweight as well as obesity with gastric cancer risk.

Associations of cigarette smoking, alcohol drinking and body mass index with survival after colorectal cancer diagnosis by anatomic subsite: a prospective patient cohort study in Japan

BACKGROUND

Cigarette smoking, alcohol drinking and obesity are known to be risk factors for colorectal cancer. These factors may affect survival after diagnosis, but evidence has been inconsistent. We investigated subsite-specific associations between prediagnosis smoking, alcohol drinking and body mass index and survival in colorectal cancer.

METHODS

Subjects were 1300 patients (colon 778; rectum 502; concurrent 20) with histologically confirmed colorectal cancer diagnosed during 1997-2013 at a single institution in Japan. Histories of smoking and alcohol drinking, height and prediagnosis weight were assessed using a self-administered questionnaire. Using Cox proportional hazards model, hazard ratios and 95% confidence intervals of mortality were estimated.

RESULTS

During a median follow-up period of 6.7 years, 479 deaths were documented. Ever-smoking was associated with an increased risk of all-cause death among patients with colon cancer (hazard ratio: 1.47; 95% confidence interval: 1.07-2.02 compared with never-smoking). According to colon subsite, this increased risk was clear in patients with proximal colon cancer (hazard ratio: 2.09; 95% confidence interval: 1.28-3.40). There was no association between smoking and rectal cancer survival. Alcohol drinking was not associated with survival for either colon or rectal cancer. Among patients with rectal cancer, higher body mass index was associated with a lower risk of all-cause (Ptrend = 0.0006) and disease-specific death (Ptrend = 0.02). For colon cancer, lower body mass index tended to be associated with a higher risk of all-cause death (Ptrend = 0.05).

CONCLUSIONS

The results indicate that lifestyles identified as risk factors for colorectal cancer may impact differently on patient survival according to anatomic subsite.

Association of Marital Status With Total and Cause-Specific Mortality in Asia

IMPORTANCE

Marital status has been shown to be associated with mortality, but evidence in Asian populations is limited.

OBJECTIVE

To examine the association of marital status with total and cause-specific mortality.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included individual participant data from 16 prospective studies in the Asia Cohort Consortium conducted between 1963 and 2015. Asian participants with complete information on marital and vital status were included. Study-specific hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards model and then pooled using a random-effects meta-analysis. The analysis began in February 2021 and ended in August 2021.

EXPOSURES

Marital status.

MAIN OUTCOMES AND MEASURES

All-cause and cause-specific mortality.

RESULTS

Of 623 140 participants (326 397 women [52.4%] and 296 743 men [47.6%]; mean [SD] age, 53.7 [10.2] years; mean [SD] follow-up time, 15.5 [6.1] years), 123 264 deaths were ascertained. Compared with married individuals, those who were unmarried had pooled HRs of 1.15 (95% CI, 1.07-1.24) for total mortality, 1.12 (95% CI, 1.03-1.22) for cerebrovascular disease mortality, 1.20 (95% CI, 1.09-1.31) for coronary heart disease mortality, 1.17 (95% CI, 1.07-1.28) for circulatory system diseases mortality, 1.06 (95% CI, 1.01-1.11) for cancer mortality, 1.14 (95% CI, 1.05-1.23) for respiratory diseases mortality, and 1.19 (95% CI, 1.05-1.34) for external causes of death. Positive associations with total mortality were also observed for those who were single (HR, 1.62; 95% CI, 1.41-1.86), separated (HR, 1.35; 95% CI, 1.13-1.61), divorced (HR, 1.38; 95% CI, 1.13-1.69), and widowed (HR, 1.09; 95% CI, 1.04-1.13). In subgroup analyses, the positive association persisted across baseline health conditions, and the risk of death was more pronounced among men or people younger than 65 years.

CONCLUSIONS AND RELEVANCE

This large pooled cohort study of individual participant data provides strong evidence that being unmarried, as well as belonging to the unmarried subcategories, was positively associated with total and cause-specific mortality. Investment of targeted social support services might need to be considered in light of the mortality differences between married and unmarried individuals.

Body Mass Index and Thyroid Cancer Risk: A Pooled Analysis of Half a Million Men and Women in the Asia Cohort Consortium

Background: Although previous meta-analyses have suggested a dose-response relationship between body mass index (BMI) and thyroid cancer risk, limited evidence has been presented about Asian populations. To assess this association among Asian populations, where underweight is more prevalent than in other regions, a pooled analysis from the Asia Cohort Consortium was conducted. Methods: Baseline height and weight were measured in five cohorts and self-reported in eight cohorts. Thyroid cancer incidence was ascertained by linkage to local cancer registries. Cohorts were treated as a stratum in the Cox proportional hazard model to estimate the pooled hazard ratios (HRs) and corresponding confidence intervals (CIs) from the estimates for each cohort. All analyses were stratified by sex. Results: A total of 538,857 men and women from 13 cohorts from mainland China, Korea, Japan, and Singapore were included in the analysis. During a mean of 15.1 years of follow-up, 1132 thyroid cancer cases were ascertained. Using a BMI of 18.5-22.9 kg/m² as a reference, an elevated risk of thyroid cancer was observed for groups with a BMI between 25 and 29.9 kg/m² (HR: 1.31, [CI: 0.95-1.80]) and a BMI of 30 kg/m² and greater (HR: 1.84, [CI: 0.89-3.81]) in men. Thyroid cancer risk was elevated in women with a BMI of 23-24.9 kg/m² (HR: 1.26, [CI: 1.07-1.48]). The HRs for 5-U increment of BMI showed a linear association among men (HR: 1.25, [CI 1.10-1.55]) but not among women (HR: 1.07, [CI: 0.97-1.18]). Although the overall thyroid cancer risk was lower among underweight men and women, the papillary cancer risk may be elevated among underweight men (HR: 2.24, [CI: 0.75-6.66]). Conclusion: While higher BMI is associated with an elevated risk of thyroid cancer in both men and women, the association of underweight BMI may differ by sex and histological subtype.

Association between body mass index and oesophageal cancer mortality: a pooled analysis of prospective cohort studies with >800 000 individuals in the Asia Cohort Consortium

BACKGROUND

The association between body mass index (BMI) and oesophageal cancer (OC) has been consistently negative among Asians, whereas different associations based on histological OC subtypes have been observed in Europeans and North Americans. We examined the association between BMI and OC mortality in the Asia Cohort Consortium.

METHODS

We performed a pooled analysis to evaluate the association between BMI and OC mortality among 842 630 Asians from 18 cohort studies. Cox regression models were used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

A wide J-shaped association between BMI and overall OC mortality was observed. The OC mortality risk was increased for underweight (BMI <18.5 kg/m2: HR = 2.20, 95% CI 1.80-2.70) and extreme obesity (BMI ≥35 kg/m2: HR = 4.38, 95% CI 2.25-8.52) relative to the reference BMI (23-25 kg/m2). This association pattern was confirmed by several alternative analyses based on OC incidence and meta-analysis. A similar wide J-shaped association was observed in oesophageal squamous cell carcinoma (OSCC). Smoking and alcohol synergistically increased the OC mortality risk in underweight participants (HR = 6.96, 95% CI 4.54-10.67) relative to that in reference BMI participants not exposed to smoking and alcohol.

CONCLUSION

Extreme obesity and being underweight were associated with an OC mortality risk among Asians. OC mortality and BMI formed a wide J-shaped association mirrored by OSCC mortality. Although the effect of BMI on OSCC and oesophageal adenocarcinoma mortality can be different in Asians, further research based on a large case-control study is recommended.

Coffee and tea consumption and mortality from all causes, cardiovascular disease and cancer: a pooled analysis of prospective studies from the Asia Cohort Consortium

BACKGROUND

Accumulating evidence suggests that consuming coffee may lower the risk of death, but evidence regarding tea consumption in Asians is limited. We examined the association between coffee and tea consumption and mortality in Asian populations.

METHODS

We used data from 12 prospective cohort studies including 248 050 men and 280 454 women from the Asia Cohort Consortium conducted in China, Japan, Korea and Singapore. We estimated the study-specific association of coffee, green tea and black tea consumption with mortality using Cox proportional-hazards regression models and the pooled study-specific hazard ratios (HRs) using a random-effects model.

RESULTS

In total, 94 744 deaths were identified during the follow-up, which ranged from an average of 6.5 to 22.7 years. Compared with coffee non-drinkers, men and women who drank at least five cups of coffee per day had a 24% [95% confidence interval (CI) 17%, 29%] and a 28% (95% CI 19%, 37%) lower risk of all-cause mortality, respectively. Similarly, we found inverse associations for coffee consumption with cardiovascular disease (CVD)-specific and cancer-specific mortality among both men and women. Green tea consumption was associated with lower risk of mortality from all causes, CVD and other causes but not from cancer. The association of drinking green tea with CVD-specific mortality was particularly strong, with HRs (95% CIs) of 0.79 (0.68, 0.91) for men and 0.78 (0.68, 0.90) for women who drank at least five cups per day of green tea compared with non-drinkers. The association between black tea consumption and mortality was weak, with no clear trends noted across the categories of consumption.

CONCLUSIONS

In Asian populations, coffee consumption is associated with a lower risk of death overall and with lower risks of death from CVD and cancer. Green tea consumption is associated with lower risks of death from all causes and CVD.

Association of Sleep Duration With All- and Major-Cause Mortality Among Adults in Japan, China, Singapore, and Korea

IMPORTANCE

The association between long sleep duration and mortality appears stronger in East Asian populations than in North American or European populations.

OBJECTIVES

To assess the sex-specific association between sleep duration and all-cause and major-cause mortality in a pooled longitudinal cohort and to stratify the association by age and body mass index.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of individual-level data from 9 cohorts in the Asia Cohort Consortium was performed from January 1, 1984, to December 31, 2002. The final population included participants from Japan, China, Singapore, and Korea. Mean (SD) follow-up time was 14.0 (5.0) years for men and 13.4 (5.3) years for women. Data analysis was performed from August 1, 2018, to May 31, 2021.

EXPOSURES

Self-reported sleep duration, with 7 hours as the reference category.

MAIN OUTCOMES AND MEASURES

Mortality, including deaths from all causes, cardiovascular disease, cancer, and other causes. Sex-specific hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards regression with shared frailty models adjusted for age and the key self-reported covariates of marital status, body mass index, smoking status, alcohol consumption, physical activity, history of diabetes and hypertension, and menopausal status (for women).

RESULTS

For 322 721 participants (mean [SD] age, 54.5 [9.2] years; 178 542 [55.3%] female), 19 419 deaths occurred among men (mean [SD] age of men, 53.6 [9.0] years) and 13 768 deaths among women (mean [SD] age of women, 55.3 [9.2] years). A sleep duration of 7 hours was the nadir for associations with all-cause, cardiovascular disease, and other-cause mortality in both men and women, whereas 8 hours was the mode sleep duration among men and the second most common sleep duration among women. The association between sleep duration and all-cause mortality was J-shaped for both men and women. The greatest association for all-cause mortality was with sleep durations of 10 hours or longer for both men (hazard ratio [HR], 1.34; 95% CI, 1.26-1.44) and women (HR, 1.48; 95% CI, 1.36-1.61). Sex was a significant modifier of the association between sleep duration and mortality from cardiovascular disease (χ25 = 13.47, P = .02), cancer (χ25 = 16.04, P = .007), and other causes (χ25 = 12.79, P = .03). Age was a significant modifier of the associations among men only (all-cause mortality: χ25 = 41.49, P < .001; cancer: χ25 = 27.94, P < .001; other-cause mortality: χ25 = 24.51, P < .001).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that sleep duration is a behavioral risk factor for mortality in both men and women. Age was a modifier of the association between sleep duration in men but not in women. Sleep duration recommendations in these populations may need to be considered in the context of sex and age.

Associations of coffee and tea consumption with lung cancer risk

Associations of coffee and tea consumption with lung cancer risk have been inconsistent, and most lung cancer cases investigated were smokers. Included in this study were over 1.1 million participants from 17 prospective cohorts. Cox regression analyses were conducted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Potential effect modifications by sex, smoking, race, cancer subtype and coffee type were assessed. After a median 8.6 years of follow-up, 20 280 incident lung cancer cases were identified. Compared with noncoffee and nontea consumption, HRs (95% CIs) associated with exclusive coffee drinkers (≥2 cups/d) among current, former and never smokers were 1.30 (1.15-1.47), 1.49 (1.27-1.74) and 1.35 (1.15-1.58), respectively. Corresponding HRs for exclusive tea drinkers (≥2 cups/d) were 1.16 (1.02-1.32), 1.10 (0.92-1.32) and 1.37 (1.17-1.61). In general, the coffee and tea associations did not differ significantly by sex, race or histologic subtype. Our findings suggest that higher consumption of coffee or tea is associated with increased lung cancer risk. However, these findings should not be assumed to be causal because of the likelihood of residual confounding by smoking, including passive smoking, and change of coffee and tea consumption after study enrolment.

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 (P_trend for four frequency groups = 0.01; HR = 0.72, 95% CI: 0.50‐1.04 for highest vs lowest group) and stomach cancer (P_trend = 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 (P_trend = 0.03). Rectal cancer patients who had frequently consumed seaweed tended to have a lower risk of rectal cancer death (P_trend = 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.

Quantifying the association of low-intensity and late initiation of tobacco smoking with total and cause-specific mortality in Asia

BACKGROUND

Little is known about the health harms associated with low-intensity smoking in Asians who, on average, smoke fewer cigarettes and start smoking at a later age than their Western counterparts.

METHODS

In this pooled analysis of 738 013 Asians from 16 prospective cohorts, we quantified the associations of low-intensity (<5 cigarettes/day) and late initiation (≥35 years) of smoking with mortality outcomes. HRs and 95% CIs were estimated for each cohort by Cox regression. Cohort-specific HRs were pooled using random-effects meta-analysis.

FINDINGS

During a mean follow-up of 11.3 years, 92 068 deaths were ascertained. Compared with never smokers, current smokers who consumed <5 cigarettes/day or started smoking after age 35 years had a 16%-41% increased risk of all-cause, cardiovascular disease (CVD), respiratory disease mortality and a >twofold risk of lung cancer mortality. Furthermore, current smokers who started smoking after age 35 and smoked <5 cigarettes/day had significantly elevated risks of all-cause (HRs (95% CIs)=1.14 (1.05 to 1.23)), CVD (1.27 (1.08 to 1.49)) and respiratory disease (1.54 (1.17 to 2.01)) mortality. Even smokers who smoked <5 cigarettes/day but quit smoking before the age of 45 years had a 16% elevated risk of all-cause mortality; however, the risk declined further with increasing duration of abstinence.

CONCLUSIONS

Our study showed that smokers who smoked a small number of cigarettes or started smoking later in life also experienced significantly elevated all-cause and major cause-specific mortality but benefited from cessation. There is no safe way to smoke-not smoking is always the best choice.

Association between Adult Height and Risk of Lung Cancer Incidence among Japanese Men: The Miyagi Cohort Study

It is already known that adult height is a factor associated with an increased risk of colon cancer and postmenopausal breast cancer, pancreatic cancer, premenopausal breast cancer, and ovarian cancer. However, the association between adult height and lung cancer incidence remains unclear. The purpose of the present study was to examine the association between adult height and the risk of lung cancer incidence in the Japanese population. We analyzed data for 43,743 men and women who were 40-64 years old at the baseline in 1990. We divided the participants into quintiles based on height at the baseline. Cox proportional hazards analysis was used to estimate the multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for the incidence of lung cancer according to adult height, after adjustment for potential confounders. We identified 1,101 incident case of lung cancer during 24.5 years of follow-up. The multivariate HRs and 95% CIs for the highest category relative to the lowest were 1.48 (1.15-1.91) in men and 1.35 (0.91-1.99) in women. Furthermore, the association between adult height and the incidence of lung cancer was found the significant increased risk among ever smokers in men, but not never smokers. We also observed that adult height tend to be associated with an increased risk of small cell lung cancer and squamous cell carcinoma. This prospective cohort study has demonstrated a positive association between adult height and the risk of lung cancer incidence among men, especially those who have ever smoked.

Alcohol consumption and survival after breast cancer diagnosis in Japanese women: A prospective patient cohort study

Background

It is unclear whether alcohol consumption may impact survival after breast cancer diagnosis. To clarify the association between pretreatment alcohol consumption and survival in breast cancer patients, a prospective patient cohort study was conducted.

Methods

The cohort comprised 1,420 breast cancer patients diagnosed during 1997–2013 at a single institute in Japan. Alcohol drinking and other lifestyle factors were assessed by questionnaire survey at the initial admission. The patients were followed until December 31, 2016. The crude associations of pretreatment alcohol intake with survival were evaluated by Kaplan-Meier analysis. The Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) controlled by confounders.

Results

During a median follow-up period of 8.6 years, 261 all-cause and 193 breast cancer-specific deaths were documented. Survival curves showed that ever-drinkers tended to have better survival than never-drinkers (breast cancer-specific survival, log-rank p = 0.0381). Better survival was also observed for light drinkers with an intake of <5.0 g per day. In the Cox model, ever-drinking was associated with a decreased risk of all-cause (HR: 0.75; 95% CI: 0.54–1.05) and breast cancer-specific death (HR: 0.68; 95% CI: 0.46–0.99). Light drinkers had a lower risk of breast cancer-specific death (frequency of drinking, HR = 0.57 for occasional or 1–2 times per week and 0.72 for 3–7 times per week; amount of alcohol consumed per day, HR = 0.57 for <5.0 g and 0.68 for ≥5.0 g compared with never-drinking). In terms of hormone receptor status, a significantly decreased risk of death associated with ever-drinking was observed among women with receptor-negative cancer (ER-/PR-, HR = 0.41; 95% CI: 0.20–0.84 for breast cancer-specific death).

Conclusions

Pretreatment, i.e., pre-diagnosis alcohol consumption is unlikely to have an adverse effect on survival after breast cancer diagnosis. Light alcohol consumption may have a beneficial effect on patient survival.

Association of BMI, Smoking, and Alcohol with Multiple Myeloma Mortality in Asians: A Pooled Analysis of More than 800,000 Participants in the Asia Cohort Consortium

BACKGROUND

To date, few epidemiologic studies have been conducted to elucidate lifestyle-related risk factors for multiple myeloma in Asia. We investigated the association of body mass index (BMI), smoking, and alcohol intake with the risk of multiple myeloma mortality through a pooled analysis of more than 800,000 participants in the Asia Cohort Consortium.

METHODS

The analysis included 805,309 participants contributing 10,221,623 person-years of accumulated follow-up across Asia Cohort Consortium cohorts. HRs and 95% confidence intervals (95% CI) for the association between BMI, smoking, and alcohol at baseline and the risk of multiple myeloma mortality were assessed using a Cox proportional hazards model with shared frailty.

RESULTS

We observed a statistically significant dose-dependent association between BMI categories and the risk of multiple myeloma mortality (<18.5 kg/m2: HR = 0.80, 95% CI: 0.52-1.24; 18.5-24.9 kg/m2: reference; 25.0-29.9 kg/m2: HR = 1.17, 95% CI: 0.94-1.47; ≥30 kg/m2: HR = 1.61, 95% CI: 0.99-2.64, P trend = 0.014). By sex, this association was more apparent in women than in men (P for heterogeneity between sexes = 0.150). We observed no significant associations between smoking or alcohol consumption and risk of multiple myeloma mortality.

CONCLUSIONS

This study showed that excess body mass is associated with an increased risk of multiple myeloma mortality among Asian populations. In contrast, our results do not support an association between smoking or alcohol consumption and the risk of multiple myeloma mortality in Asian populations.

IMPACT

This study provides important evidence on the association of BMI, smoking, and alcohol with the risk of multiple myeloma mortality in Asian populations.

Association between educational level and total and cause-specific mortality: a pooled analysis of over 694 000 individuals in the Asia Cohort Consortium

OBJECTIVE

To study the association of educational level and risk of death from all causes, cardiovascular disease (CVD) and cancer among Asian populations.

DESIGN

A pooled analysis of 15 population-based cohort studies.

SETTING AND PARTICIPANTS

694 434 Asian individuals from 15 prospective cohorts within the Asia Cohort Consortium.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

HRs and 95% CIs for all-cause mortality, as well as for CVD-specific mortality and cancer-specific mortality.

RESULTS

A total of 694 434 participants (mean age at baseline=53.2 years) were included in the analysis. During a mean follow-up period of 12.5 years, 103 023 deaths were observed, among which 33 939 were due to cancer and 34 645 were due to CVD. Higher educational levels were significantly associated with lower risk of death from all causes compared with a low educational level (≤primary education); HRs and 95% CIs for secondary education, trade/technical education and ≥university education were 0.88 (0.85 to 0.92), 0.81 (0.73 to 0.90) and 0.71 (0.63 to 0.80), respectively (ptrend=0.002). Similarly, HRs (95% CIs) were 0.93 (0.89 to 0.97), 0.86 (0.78 to 0.94) and 0.81 (0.73 to 0.89) for cancer death, and 0.88 (0.83 to 0.93), 0.77 (0.66 to 0.91) and 0.67 (0.58 to 0.77) for CVD death with increasing levels of education (both ptrend <0.01). The pattern of the association among East Asians and South Asians was similar compared with ≤primary education; HR (95% CI) for all-cause mortality associated with ≥university education was 0.72 (0.63 to 0.81) among 539 724 East Asians (Chinese, Japanese and Korean) and 0.61 (0.54 to 0.69) among 154 710 South Asians (Indians and Bangladeshis).

CONCLUSION

Higher educational level was associated with substantially lower risk of death among Asian populations.

Abstract 632: Associations of coffee and tea consumption with lung cancer risk: A pooled analysis of 17 cohort studies involving over 1.2 million participants

Background

Epidemiological studies investigating the associations of coffee and tea intake with lung cancer risk have yielded inconsistent results. These previous studies included mostly lung cancer patients diagnosed among smokers. Because coffee and tea consumption are closely related to smoking behavior, these previous studies could suffer from biases due to residual confounding of smoking. To better characterize the relationship, a large study with a large number of lung cancer cases diagnosed among never smokers and detailed information on tea and coffee consumption, is needed. Using data from a large-scale pooled analysis that consists of over 1.2 million participants in the U.S. and Asia, we carried out a comprehensive evaluation on the association of coffee and tea intake with lung cancer risk.

Methods

Individual-level data from seven prospective cohort studies conducted in the U.S., and ten studies conducted in Asia, were included. Demographic, lifestyle, coffee and tea intake data were collected at the baseline survey for each study. Multivariable-adjusted Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). The first 2 years of follow-up time was excluded to minimize potential influence of reverse causality on study results. Subgroup analyses by smoking status, sex, race, histologic subtype and coffee type (caffeinated or decaffeinated) were also conducted to assess potential effect modification, as well as heterogeneity of the association.

Results

After a median follow-up of 8.6 years, 20,519 incident lung cancer cases were identified. Both coffee and tea consumption were associated with an increased risk of lung cancer. Comparing non-coffee and non-tea consumption, HRs for lung cancer associated with exclusive coffee drinkers (≥2 cups/day) among current, former and never smokers were 1.30 (95% CI, 1.15-1.47), 1.49 (1.27-1.74) and 1.41 (95% CI, 1.21-1.63), respectively. Similar positive associations were observed for caffeinated and decaffeinated coffee. The HRs associated with exclusive tea drinkers (&gt;2 cups/day) were 1.16 (95% CI, 1.02-1.32), 1.10 (0.92, 1.32) and 1.37 (95% CI, 1.17-1.60) for current, former and never smokers, respectively. These associations did not differ significantly by sex, race or histologic subtypes.

Conclusion

A high consumption of coffee or tea was both associated with an increased risk of lung cancer regardless of race or smoking status. Our study included a large number of never-smoker lung cancer patients, which minimized potential confounding effects due to smoking. The positive association observed for both caffeinated and decaffeinated coffee suggests that compounds other than caffeine may play a role in the etiology of lung cancer.

Citation Format: Jingjing Zhu, Wei Zheng, Rashimi Sinha, Stephanie A. Smith-Warner, Yong-Bing Xiang, Yikyung Park, Shoichiro Tsugane, Emily White, Woon-Puay Koh, Sue K. Park, Norie Sawada, Seiki Kanemura, Yumi Sugawara, Ichiro Tsuji, Kim Robien, Yasutake Tomata, Keun-Young Yoo, Jeongseon Kim, Jian-Min Yuan, Yu-Tang Gao, Yumie Takata, Eiko Saito, William Blot, Xiao-Ou Shu. Associations of coffee and tea consumption with lung cancer risk: A pooled analysis of 17 cohort studies involving over 1.2 million participants [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 632.

Reproductive history and breast cancer survival: a prospective patient cohort study in Japan

BACKGROUND

Reproductive factors may influence breast cancer progression and patient survival; however, evidence has been limited.

METHODS

The associations of reproductive factors with tumor characteristics and patient survival were analyzed among 1468 breast cancer patients diagnosed during 1997-2013 at a single institute in Japan. The patients were followed until 2016. During a median follow-up period of 8.6 years, 272 all-cause and 199 breast cancer deaths were documented.

RESULTS

In case-case comparisons, later age at menarche was inversely associated with advanced tumors. Nulliparous patients tended to have receptor-positive [estrogen receptor (ER)+ or progesterone receptor (PR)+] tumors. Conversely, the Cox proportional-hazards model including adjustment for tumor characteristics revealed U-shaped relationship between parity number and the risk of all-cause death among the patients overall [hazard ratio (HR) = 2.10 for nulliparous, 1.28 for 2, and 1.50 for ≥ 3 vs. one child]. According to hormone receptor, later age at menarche and later age at last birth were positively associated with the risk of all-cause death among patients with ER- and PR- cancer (menarche, HR = 2.18 for ≥ 15 vs. ≤ 12 years, p_trend = 0.03; last birth, HR = 3.10 for ≥ 35 vs. ≤ 29 years, p_trend = 0.01). A shorter time since last birth was associated with the risk of death among receptor-positive patients (HR = 5.72 for ≤ 4 vs. ≥ 10 years, p_trend = 0.004).

CONCLUSION

The results indicate that the timing of menarche and parity have significant effects on patient survival, providing clues for understanding the association between women's life course and breast cancer outcome.

Association of Diabetes With All-Cause and Cause-Specific Mortality in Asia: A Pooled Analysis of More Than 1 Million Participants

IMPORTANCE

Asia is home to the largest diabetic populations in the world. However, limited studies have quantified the association of diabetes with all-cause and cause-specific mortality in Asian populations.

OBJECTIVES

To evaluate the association of diabetes with all-cause and cause-specific mortality in Asia and to investigate potential effect modifications of the diabetes-mortality associations by participants' age, sex, education level, body mass index, and smoking status.

DESIGN, SETTING, AND PARTICIPANTS

This pooled analysis incorporated individual participant data from 22 prospective cohort studies of the Asia Cohort Consortium conducted between 1963 and 2006. A total of 1 002 551 Asian individuals (from mainland China, Japan, South Korea, Singapore, Taiwan, India, and Bangladesh) were followed up for more than 3 years. Cohort-specific hazard ratios and 95% confidence intervals for all-cause and cause-specific mortality were estimated using Cox regression models and then pooled using random-effects meta-analysis. Analysis was conducted between January 10, 2018, and August 31, 2018.

EXPOSURES

Doctor-diagnosed diabetes, age, sex, education level, body mass index, and smoking status.

MAIN OUTCOMES AND MEASURES

All-cause and cause-specific mortality.

RESULTS

Of 1 002 551 participants (518 537 [51.7%] female; median [range] age, 54.0 [30.0-98.0] years), 148 868 deaths were ascertained during a median (range) follow-up of 12.6 (3.0-38.9) years. The overall prevalence of diabetes reported at baseline was 4.8% for men and 3.6% for women. Patients with diabetes had a 1.89-fold risk of all-cause death compared with patients without diabetes (hazard ratio [HR], 1.89; 95% CI, 1.74-2.04), with the highest relative risk of death due to diabetes itself (HR, 22.8; 95% CI, 18.5-28.1), followed by renal disease (HR, 3.08; 95% CI, 2.50-3.78), coronary heart disease (HR, 2.57; 95% CI, 2.19-3.02), and ischemic stroke (HR, 2.15; 95% CI, 1.85-2.51). The adverse diabetes-mortality associations were more evident among women (HR, 2.09; 95% CI, 1.89-2.32) than among men (HR, 1.74; 95% CI, 1.62-1.88) (P for interaction < .001) and more evident among adults aged 30 to 49 years (HR, 2.43; 95% CI, 2.08-2.84) than among adults aged 70 years and older (HR, 1.51; 95% CI, 1.40-1.62) (P for interaction < .001). A similar pattern of association was found between diabetes and cause-specific mortality, with significant variations noted by sex and age.

CONCLUSIONS AND RELEVANCE

This study found that diabetes was associated with increased risk of death from several diseases among Asian populations. Development and implementation of diabetes management programs are urgently needed to reduce the burden of diabetes in Asia.

Association between Family History of Cancer and Lung Cancer Risk among Japanese Men and Women

Although cigarette smoking is a major risk factor for lung cancer, genetic susceptibility may also affect lung cancer risk. To explore the role of genetic risk, this case-control study investigated the association between family history of cancer at several sites and lung cancer risk. A total of 1,733 lung cancer cases and 6,643 controls were selected from patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2009. Information on family history of cancer was collected using a self-administered questionnaire and odds ratios (ORs) were estimated by unconditional logistic regression. Family history of lung cancer in first-degree relatives was associated with an increased risk of lung cancer among both sexes. According to histology and type of relatives, a parental history of lung cancer was significantly associated with an increased risk of female adenocarcinoma (OR = 1.72). Stratification by smoking status revealed that this significant positive association in women was limited to ever-smokers (OR = 4.13). In men, a history of lung cancer in siblings was significantly associated with an increased risk of small cell carcinoma (OR = 2.28) and adenocarcinoma (OR = 2.25). Otherwise, positive associations between history of breast (OR = 1.99) and total (OR = 1.71) cancers in siblings and the risk of male adenocarcinoma were observed. These results suggest that inherited genetic susceptibility may contribute to the development of lung cancer. In men, shared exposure to environmental factors among siblings may also be responsible for the increase in lung cancer risk.

Tobacco Smoking and Mortality in Asia: A Pooled Meta-analysis

IMPORTANCE

Understanding birth cohort-specific tobacco smoking patterns and their association with total and cause-specific mortality is important for projecting future deaths due to tobacco smoking across Asian populations.

OBJECTIVES

To assess secular trends of tobacco smoking by countries or regions and birth cohorts and evaluate the consequent mortality in Asian populations.

DESIGN, SETTING, AND PARTICIPANTS

This pooled meta-analysis was based on individual participant data from 20 prospective cohort studies participating in the Asia Cohort Consortium. Between September 1, 2017, and March 31, 2018, a total of 1 002 258 Asian individuals 35 years or older were analyzed using Cox proportional hazards regression analysis and random-effects meta-analysis. The pooled results were presented for mainland China; Japan; Korea, Singapore, and Taiwan; and India.

EXPOSURES

Tobacco use status, age at starting smoking, number of cigarettes smoked per day, and age at quitting smoking.

MAIN OUTCOMES AND MEASURES

Country or region and birth cohort-specific mortality and the population attributable risk for deaths from all causes and from lung cancer.

RESULTS

Of 1 002 258 participants (51.1% women and 48.9% men; mean [SD] age at baseline, 54.6 [10.4] years), 144 366 deaths (9158 deaths from lung cancer) were ascertained during a mean (SD) follow-up of 11.7 (5.3) years. Smoking prevalence for men steadily increased in China and India, whereas it plateaued in Japan and Korea, Singapore, and Taiwan. Among Asian male smokers, the mean age at starting smoking decreased in successive birth cohorts, while the mean number of cigarettes smoked per day increased. These changes were associated with an increasing relative risk of death in association with current smoking in successive birth cohorts of pre-1920, 1920s, and 1930 or later, with hazard ratios for all-cause mortality of 1.26 (95% CI, 1.17-1.37) for the pre-1920 birth cohort, 1.47 (95% CI, 1.35-1.61) for the 1920s birth cohort, and 1.70 (95% CI, 1.57-1.84) for the cohort born in 1930 or later. The hazard ratios for lung cancer mortality were 3.38 (95% CI, 2.25-5.07) for the pre-1920 birth cohort, 4.74 (95% CI, 3.56-6.32) for the 1920s birth cohort, and 4.80 (95% CI, 3.71-6.19) for the cohort born in 1930 or later. Tobacco smoking accounted for 12.5% (95% CI, 8.4%-16.3%) of all-cause mortality in the pre-1920 birth cohort, 21.1% (95% CI, 17.3%-24.9%) of all-cause mortality in the 1920s birth cohort, and 29.3% (95% CI, 26.0%-32.3%) of all-cause mortality for the cohort born in 1930 or later. Tobacco smoking among men accounted for 56.6% (95% CI, 44.7%-66.3%) of lung cancer mortality in the pre-1920 birth cohort, 66.6% (95% CI, 58.3%-73.5%) of lung cancer mortality in the 1920s birth cohort, and 68.4% (95% CI, 61.3%-74.4%) of lung cancer mortality for the cohort born in 1930 or later. For women, tobacco smoking patterns and lung cancer mortality varied substantially by countries and regions.

CONCLUSIONS AND RELEVANCE

In this study, mortality associated with tobacco smoking continued to increase among Asian men in recent birth cohorts, indicating that tobacco smoking will remain a major public health problem in most Asian countries in the coming decades. Implementing comprehensive tobacco-control programs is warranted to end the tobacco epidemic.

Age at First Birth and the Risk of Endometrial Cancer Incidence: A Pooled Analysis of Two Prospective Cohort Studies among Japanese Women

Background: Age at first birth has been increasing among women in developed countries. Meanwhile, endometrial cancer has also been increasing worldwide, being one of the most common female hormone-related cancers. The purpose of this study was to examine the association between age at first birth and the risk of endometrial cancer among Japanese women, and to examine the hypothesis that the recent increase in endometrial cancer incidence can be partly explained by the trend for increasing age at first birth.

Methods: We conducted a pooled analysis of two prospective studies among residents in Miyagi Prefecture in rural northern in Japan. The Miyagi Cohort Study started in 1990 and included 21,455 parous women. The Ohsaki Cohort Study started in 1994 and included 17,287 parous women. The subjects responded to a self-administrated questionnaire including reproductive factors such as age at first birth. Incident cases of cancer were identified through linkage to the Miyagi Prefectural Cancer Registry, which covers the study area.

Results: In a consortium of two prospective studies with 598,933 person-years, we identified 105 incident case of endometrial cancer. Compared with women aged 22 years or less at first birth, multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of endometrial cancer were 0.79 (0.49-1.26) for women aged 23 to 25 years at first birth, and 0.53 (0.28-1.00) for those aged 26 years and older (p-trend<0.05).

Conclusion: This pooled analysis of two prospective studies does not support the hypothesis that the recent increase in the incidence of endometrial cancer can be partly explained by the increase in the age at first birth.

Abstract 4234: Association between educational level and mortality: A pooled analysis of over 694,000 individuals in the Asia Cohort Consortium

Background: Higher educational levels have been linked to reduced risk of death in previous studies. Most of these studies, however, were conducted in the United States and Europe.

Methods: We performed a pooled analysis to evaluate the association between educational levels and risk of death among 694,434 Asian individuals from 15 prospective cohort studies that participated in the Asia Cohort Consortium. The analysis included 103,023 deaths during a mean follow-up period of 12.5 years, among which 33,945 were due to cancer and 34,645 were due to cardiovascular diseases (CVD). We employed Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association between educational level and the risk of death after adjusting for potential confounders.

Results: Higher educational levels were significantly associated with lower risk of death from all causes; compared to a low educational level (≤ primary school), HRs and 95% CIs for secondary education, trade/technical education, and ≥ university degree were 0.86 (0.83-0.90), 0.80 (0.71-0.89), and 0.68 (0.61-0.75), respectively (Ptrend &lt;0.0001). Similar associations were observed for cancer or CVD-specific mortality, with HRs of 0.93 (0.89-0.97), 0.87 (0.78-0.97), and 0.79 (0.71-0.87) for risk of cancer deaths with increasing levels of education (Ptrend = 0.003) and HRs of 0.86 (0.81-0.91), 0.75 (0.64-0.87), and 0.64 (0.57-0.73) for risk of CVD deaths with increasing levels of education (Ptrend &lt;0.0001). The pattern of the association among East Asians and South Asians was similar; compared to ≤ primary school, HR (95% CI) for all-cause mortality associated with ≥ university degree was 0.68 (0.61-0.76) among 539,724 East Asians (Chinese, Japanese, and Korean) and 0.61 (0.54-0.69) among 154,710 South Asians (Indians and Bangladeshis) included in this analysis.

Conclusions: Higher educational level was associated with substantially lower risk of death in Asian populations including both East and South Asians.

Citation Format: Keming Yang, Ying Zhang, Eiko Saito, Yu Chen, Prakash C. Gupta, Yu-Tang Gao, Akiko Tamakoshi, Yong-Bing Xiang, Woon-Puay Koh, Norie Sawada, Kemmyo Sugiyama, Yasutake Tomata, Atsuko Sadakane, Chisato Nagata, San-Lin You, Renwei Wang, Myung-Hee Shin, Habibul Ahsan, Wen-Harn Pan, Mangesh S. Pednekar, Jian-Min Yuan, Xiao-Ou Shu, Hui Cai, Shoichiro Tsugane, Ichiro Tsuji, Seiki Kanemura, Keiko Wada, Yoon-Ok Ahn, Kotaro Ozasa, John D. Potter, Wei Zheng, Hongmei Nan. Association between educational level and mortality: A pooled analysis of over 694,000 individuals in the Asia Cohort Consortium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4234.

Association of leisure-time physical activity with total and cause-specific mortality: a pooled analysis of nearly a half million adults in the Asia Cohort Consortium

BACKGROUND

Most previous studies evaluating the association between leisure-time physical activity (LTPA) and risk of death were conducted among generally healthy individuals of European ancestry. We investigated the association of LTPA with all-cause and cause-specific mortality among East Asian populations, including healthy individuals and those with existing chronic diseases, which has been less well characterized.

METHODS

We performed pooled analyses among 467 729 East Asian individuals recruited in nine prospective cohorts included in the Asia Cohort Consortium. Cox proportional hazards regressions were used to derive hazard ratios (HRs) and 95% confidence intervals (CIs) associated with LTPA after adjusting for age, sex, education and marital and smoking status.

RESULTS

During a mean follow-up period of 13.6 years, 65 858 deaths were identified. Compared with those who reported no or less than 1 h of LTPA per week, an inverse association was observed between the amount of LTPA and all-cause and cause-specific mortality (P for trend < 0.001). The strength of the inverse association was stronger for death due to cardiovascular diseases and causes other than cancer deaths. An inverse association of LTPA with total mortality was observed among individuals with a severe and often life-threatening disease: cancer, stroke or coronary heart disease [hazard ratio (HR) = 0.81, 95% CI = 0.73-0.89 for high vs low LTPA) and those with other chronic diseases such as diabetes or hypertension (HR = 0.86, 95% CI = 0.80-0.93 for high vs low LTPA). No clear modifying effects by sex, body mass index or smoking status were identified.

CONCLUSIONS

Regular participation in LTPA is associated with reduced mortality in middle-aged and elder Asians regardless pre-existing health conditions.

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 (p_trend  = 0.02) and the amount of alcohol consumed per day (p_trend  = 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 (p_trend  = 0.0046). Pretreatment smoking and alcohol drinking have significant effects on stomach cancer survival. Lifestyle adjustments throughout life may improve survival.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and [Formula: see text] credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-[Formula: see text] requires at least three detectors of sensitivity within a factor of [Formula: see text] of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Association between type 2 diabetes and risk of cancer mortality: a pooled analysis of over 771,000 individuals in the Asia Cohort Consortium

AIMS/HYPOTHESIS

The aims of the study were to evaluate the association between type 2 diabetes and the risk of death from any cancer and specific cancers in East and South Asians.

METHODS

Pooled analyses were conducted of 19 prospective population-based cohorts included in the Asia Cohort Consortium, comprising data from 658,611 East Asians and 112,686 South Asians. HRs were used to compare individuals with diabetes at baseline with those without diabetes for the risk of death from any cancer and from site-specific cancers, including cancers of the oesophagus, stomach, colorectum, colon, rectum, liver, bile duct, pancreas, lung, breast, endometrium, cervix, ovary, prostate, bladder, kidney and thyroid, as well as lymphoma and leukaemia.

RESULTS

During a mean follow-up of 12.7 years, 37,343 cancer deaths (36,667 in East Asians and 676 in South Asians) were identified. Baseline diabetes status was statistically significantly associated with an increased risk of death from any cancer (HR 1.26; 95% CI 1.21, 1.31). Significant positive associations with diabetes were observed for cancers of the colorectum (HR 1.41; 95% CI 1.26, 1.57), liver (HR 2.05; 95% CI 1.77, 2.38), bile duct (HR 1.41; 95% CI 1.04, 1.92), gallbladder (HR 1.33; 95% CI 1.10, 1.61), pancreas (HR 1.53; 95% CI 1.32, 1.77), breast (HR 1.72; 95% CI 1.34, 2.19), endometrium (HR 2.73; 95% CI 1.53, 4.85), ovary (HR 1.60; 95% CI 1.06, 2.42), prostate (HR 1.41; 95% CI 1.09, 1.82), kidney (HR 1.84; 95% CI 1.28, 2.64) and thyroid (HR 1.99; 95% CI 1.03, 3.86), as well as lymphoma (HR 1.39; 95% CI 1.04, 1.86). Diabetes was not statistically significantly associated with the risk of death from leukaemia and cancers of the bladder, cervix, oesophagus, stomach and lung.

CONCLUSIONS/INTERPRETATION

Diabetes was associated with a 26% increased risk of death from any cancer in Asians. The pattern of associations with specific cancers suggests the need for better control (prevention, detection, management) of the growing epidemic of diabetes (as well as obesity), in order to reduce cancer mortality.

Physics at the [Formula: see text] linear collider

A comprehensive review of physics at an [Formula: see text] linear collider in the energy range of [Formula: see text] GeV-3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focusses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.

Passive smoking at home and cancer risk: a population-based prospective study in Japanese nonsmoking women

OBJECTIVES

To investigate the relationship between passive smoking at home and the incidence of various cancers in a population-based prospective study.

METHODS

The subjects were 9675 Japanese lifelong nonsmoking women aged over 40 years who lived in three municipalities of Miyagi Prefecture, and completed a self-administration questionnaire in 1984. During 9 years of follow-up, 426 cancers were identified by record linkage to the population-based cancer registry. The data were analyzed using the Cox proportional hazards model.

RESULTS

The age-adjusted relative risks (RR) and 95% confidence intervals (CI) of smoking-related cancers and lung cancer for women who had smoking husbands, compared with women whose husbands did not smoke, were 1.7 (0.94 2.9, p = 0.079) and 1.9 (0.81-4.4, p = 0.14), respectively. In contrast, a significant inverse association was observed for breast cancer, the RR (95% CI) was 0.58 (0.34-0.99, p = 0.047). After multivariate adjustment for confounding factors, the risks of smoking-related cancers and breast cancer were materially unchanged.

CONCLUSIONS

These results show that passive smoking may affect the risk of cancers other than lung cancer.

Passive smoking at home and cancer risk: a population-based prospective study in Japanese nonsmoking women

OBJECTIVES

To investigate the relationship between passive smoking at home and the incidence of various cancers in a population-based prospective study.

METHODS

The subjects were 9675 Japanese lifelong nonsmoking women aged over 40 years who lived in three municipalities of Miyagi Prefecture, and completed a self-administration questionnaire in 1984. During 9 years of follow-up, 426 cancers were identified by record linkage to the population-based cancer registry. The data were analyzed using the Cox proportional hazards model.

RESULTS

The age-adjusted relative risks (RR) and 95% confidence intervals (CI) of smoking-related cancers and lung cancer for women who had smoking husbands, compared with women whose husbands did not smoke, were 1.7 (0.94 2.9, p = 0.079) and 1.9 (0.81-4.4, p = 0.14), respectively. In contrast, a significant inverse association was observed for breast cancer, the RR (95% CI) was 0.58 (0.34-0.99, p = 0.047). After multivariate adjustment for confounding factors, the risks of smoking-related cancers and breast cancer were materially unchanged.

CONCLUSIONS

These results show that passive smoking may affect the risk of cancers other than lung cancer.

Noise-tolerant stimulus discrimination by synchronization with depressing synapses

Some synapses between cortical pyramidal neurons exhibit a rapid depression of excitatory postsynaptic potentials for successive presynaptic spikes. Since depressing synapses do not transmit information on sustained presynaptic firing rates, it has been speculated that they are favorable for temporal coding. In this paper. we study the dynamical effects of depressing synapses on stimulus-induced transient synchronization in a simple network of inhibitory interneurons and excitatory neurons, assuming that the recurrent excitation is mediated by depressing synapses. This synchronization occurs in a temporal pattern which depends on a given stimulus. Since the presence of noise is always a potential hazard in temporal coding, we investigate the extent to which noise in stimuli influences the synchronization phenomena. It is demonstrated that depressing synapses greatly contribute to suppressing the influences of noise on the stimulus-specific temporal patterns of synchronous firing. The timing-based Hebbian learning revealed by physiological experiments is shown to stabilize the temporal patterns in cooperation with synaptic depression. Thus, the times at which synchronous firing occurs provides a reliable information representation in the presence of synaptic depression.

Green tea and the risk of gastric cancer in Japan

BACKGROUND

Although laboratory experiments and case-control studies have suggested that the consumption of green tea provides protection against gastric cancer, few prospective studies have been performed.

METHODS

In January 1984, a total of 26,311 residents in three municipalities of Miyagi Prefecture, in northern Japan (11,902 men and 14,409 women 40 years of age or older), completed a self-administered questionnaire that included questions about the frequency of consumption of green tea. During 199,748 person-years of follow-up, through December 1992, we identified 419 cases of gastric cancer (in 296 men and 123 women). We used Cox regression to estimate the relative risk of gastric cancer according to the consumption of green tea.

RESULTS

Green-tea consumption was not associated with the risk of gastric cancer. After adjustment for sex, age, presence or absence of a history of peptic ulcer smoking status, alcohol consumption, other dietary elements, and type of health insurance, the relative risks associated with drinking one or two, three or four, and five or more cups of green tea per day, as compared with less than one cup per day, were 1.1 (95 percent confidence interval, 0.8 to 1.6), 1.0 (95 percent confidence interval, 0.7 to 1.4), and 1.2 (95 percent confidence interval, 0.9 to 1.6), respectively (P for trend=0.13). The results were similar after the 117 cases of gastric cancer that were diagnosed in the first three years of follow-up had been excluded, with respective relative risks of 1.2 (95 percent confidence interval, 0.8 to 1.8) 1.0 (95 percent confidence interval, 0.7 to 1.5), and 1.4 (95 percent confidence interval, 1.0 to 1.9) (P for trend=0.07).

CONCLUSIONS

In a population-based, prospective cohort study in Japan, we found no association between green-tea consumption and the risk of gastric cancer.

A case control study on the effectiveness of breast cancer screening by clinical breast examination in Japan

A case-control study was conducted in Miyagi and Gunma prefectures, Japan, to evaluate the effectiveness of breast cancer screening by clinical breast examination (CBE) alone in reducing breast cancer mortality. Case subjects, who were female and had died of breast cancer, were collected from residential registry files and medical records. Control subjects matched in sex, age and residence were randomly selected from residential registry files. The screening histories during 5 years prior to the cases having been diagnosed as breast cancer were surveyed using the examinee files of the screening facilities. Finally, the data of 93 cases and 375 controls were analyzed. The odds ratio (OR) of breast cancer death for participating in screening at least once during 5 years was 0.93 (95% confidence interval (95% CI) 0.48-1.79). The cases were more symptomatic than the controls when screened. If the participants who had had symptoms in their breasts were classified as not screened, the OR decreased to 0.56 (95% CI 0.27-1.18). The case control study suggests that the current screening modality (CBE) lacks effectiveness (OR = 0.93), although it might be effective for an asymptomatic population (OR = 0.56). The number of cases was small, and a larger case-control study is desirable to define whether CBE is effective or not. However, it is necessary to consider the introduction of mammographic screening to reduce breast cancer mortality in Japan.

A prospective cohort study on National Health Insurance beneficiaries in Ohsaki, Miyagi Prefecture, Japan: study design, profiles of the subjects and medical cost during the first year

To examine the impact of health-related lifestyle upon medical care utilization and its costs, we conducted a cohort study among all National Health Insurance beneficiaries aged from 40 to 79 years living in the catchment area of Ohsaki Public Health Center, Miyagi, Japan. The baseline survey, using self-completed questionnaire regarding health-related lifestyle, was conducted between October and December 1994. Out of 54,996 eligible subjects, 52,029 (94.6%) responded and formed the cohort under study. Medical care utilization (number of outpatient visits and days of inpatient care) and the costs for each subject have been obtained from National Health Insurance Claim History files since January 1995. The baseline characteristics of health-related lifestyle and medical history at the study subjects were consistent with those at our another cohort subjects (so-called Miyagi cohort study; N = 47,605), which included all the residents aged from 40 to 64 years at 14 municipalities in Miyagi Prefecture, Japan conducted in 1990. The medical costs per capita in this cohort was quite compatible with the national average. This prospective cohort study would quantitatively demonstrate the economic impact of health-related lifestyle, thus would lead us to better provision of cost-effective preventive health services.