Association of mesothelioma deaths with neighborhood asbestos exposure due to a large-scale asbestos-cement plant.

A causal relationship between mesothelioma and occupational asbestos exposure is well known, while some studies have shown a relationship to non-occupational exposures. The aim of this study was to quantify the risk of mesothelioma death associated with neighborhood asbestos exposure due to a large-scale asbestos-cement (AC) plant in Amagasaki, Japan, adjusting properly risk factors including occupational exposures. We conducted a nested case-control study in which a fixed population of 143,929 residents who had been living in Amagasaki City between 1975 and 2002 were followed from 2002 to 2015. All 133 cases and 403 matched controls were interviewed about their occupational, domestic, household, and neighborhood asbestos exposures. Odds ratios (ORs) for mesothelioma death associated with the neighborhood exposure were estimated by a conditional logistic-regression model. For quantitative assessments for neighborhood exposure, we adopted cumulative indices for individuals' residential histories at each residence-specific asbestos concentration multiplied by the duration during the potential exposure period of 1957-1975 (crocidolite). We observed an increasing, dose-dependent risk of mesothelioma death associated with neighborhood exposure, demonstrating that ORs in the highest quintile category were 21.4 (95% confidence interval [CI] 5.8-79.2) for all, 23.7 (95% CI 3.8-147.2) for males, and 26.0 (95% CI 2.8-237.5) for females compared to the lowest quintile, respectively. A quantitative assessment for risk of mesothelioma deaths, adjusting for occupational and non-occupational exposures separately, showed a dose-dependent association with neighborhood exposure and no substantial gender differences in magnitude.

[Geographic information in National Cancer Registry data: Overseas examples and challenges in Japan].

Worldwide, research based on geographic information of official statistical data, including cancer registries, is utilized for cancer control and public health policies. The National Cancer Registry of Japan was launched in 2016, making it possible to use data on cancer incidence systematically. Given the nature of this comprehensive survey, the usefulness of the National Cancer Registry would be further enhanced when it is utilized at small-regional levels, such as in municipalities or even smaller geographical units. It is essential to maintain a balance between privacy protection and data usability. Currently, the national and prefectural councils determine the availability of the data from the National Cancer Registry at the small-regional level on an individual application basis. Under this framework, use of the data is often restricted or declined. This paper showcases three model countries where geographic information obtained from cancer registry data are widely utilized: the United States, Canada, and the United Kingdom. It further discusses measures to ensure that data are effectively used, without compromising data privacy. In the three countries, data-providing systems have been established to compile the necessary data from the cancer registry and other linked databases, in accordance with the purpose of use. The relationships between healthcare access and various outcomes are elaborately examined at the small-regional level. In Japan, similar utilization of data has not been fully implemented, and there remain many hurdles to the application of the data use. For the National Cancer Registry to promote research and further enhance cancer control, it is necessary to establish a system that enables effective and safe utilization of the data from the National Cancer Registry, including linkage with other data and on-site use.

Association between socioeconomic status and net survival after primary lung cancer surgery: a tertiary university hospital retrospective observational study in Japan.

BACKGROUND: Inequalities in opportunities for primary lung cancer surgery due to socioeconomic status exist. We investigated whether socioeconomic inequalities exist in net survival after curative intent surgery at a tertiary university hospital, in Japan. METHODS: Data from the hospital-based cancer registry on primary lung cancer patients who received lung resection between 2010 and 2018 were linked to the surgical dataset. An area deprivation index, calculated from small area statistics and ranked into tertiles based on Japan-wide distribution, was linked with the patient's address as a proxy measure for individual socioeconomic status. We estimated net survival of up to 5 years by deprivation tertiles. Socioeconomic inequalities in cancer survival were analyzed using an excess hazard model. RESULTS: Of the 1039 patient-sample, advanced stage (Stage IIIA+) was more prevalent in the most deprived group (28.1%) than the least deprived group (18.0%). The 5-year net survival rates (95% confidence interval) from the least to the most deprived tertiles were 82.1% (76.2-86.6), 77.6% (70.8-83.0) and 71.4% (62.7-78.4), respectively. The sex- and age-adjusted excess hazard ratio of 5-year death was significantly higher in the most deprived group than the least deprived (excess hazard ratio = 1.64, 95% confidence interval: 1.09-2.47). The hazard ratio reduced toward null after additionally accounting for disease stage, suggesting that the advanced stage may explain the poor prognosis among the deprived group. CONCLUSION: There was socioeconomic inequality in the net survival of patients who received curative intent surgery for primary lung cancer. The lower socioeconomic status group might be less likely to receive early curative surgery.

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.

Socioeconomic disparities in cancer survival: Relation to stage at diagnosis, treatment, and centralization of patients to accredited hospitals, 2005-2014, Japan.

BACKGROUND: Cancer survival varies by socioeconomic status in Japan. We examined the extent to which survival disparities are explained by factors relevant to cancer control measures (promoting early-stage detection, standardizing treatment, and centralizing patients to government-accredited cancer hospitals [ACHs]). METHODS: From the Osaka Cancer Registry, patients diagnosed with solid malignant tumors during 2005-2014 and aged 15-84 years (N = 376,077) were classified into quartiles using the Area Deprivation Index (ADI). Trends in inequalities were assessed for potentially associated factors: early-stage detection, treatment modality, and utilization of ACH (for first contact/diagnosis/treatment). 3-year all-cause survival was computed by the ADI quartile. Multivariable Cox regression models were used to assess survival disparities and their trends through a series of adjustment for the potentially associated factors. RESULTS: During 2005-2014, the most deprived ADI quartile had lower rates than the least deprived quartile for early-stage detection (42.6% vs. 48.7%); receipt of surgery (58.1% vs. 64.1%); and utilization of ACH (83.5% vs. 88.4%). While rate differences decreased for receipt of surgery and utilization of ACH (Annual Percent Change = -3.2 and - 11.9, respectively) over time, it remained unchanged for early-stage detection. During 2012-2014, the most deprived ADI quartile had lower 3-year survival than the least deprived (59.0% vs. 69.4%) and higher mortality (Hazard Ratio [HR] = 1.32, adjusted for case-mix): this attenuated with additional adjustment for stage at diagnosis (HR = 1.23); treatment modality (HR = 1.20); and utilization of ACH (HR = 1.19) CONCLUSIONS: Despite improvements in equalizing access to quality cancer care during 2005-2014, survival disparities remained. Interventions to reduce inequalities in early-stage detection could ameliorate such gaps.

Revisiting the Geographical Distribution of Thyroid Cancer Incidence in Fukushima Prefecture: Analysis of Data From the Second- and Third-round Thyroid Ultrasound Examination.

BACKGROUND: After the first-round (Preliminary Baseline Survey) ultrasound-based examination for thyroid cancer in response to the accident at the Fukushima Daiichi Nuclear Power Plant in 2011, two rounds of surveys (Full-scale Survey) have been carried out in Fukushima Prefecture. Using the data from these surveys, the geographical distribution of thyroid cancer incidence over 6 or 7 years after the disaster was examined. METHODS: Children and adolescents who underwent the ultrasound-based examinations in the second- and/or third-round (Full-scale) survey in addition to the first-round survey were included. With a discrete survival model, we computed age, sex, and body mass index standardized incidence ratios (SIRs) for municipalities. Then, we employed spatial statistics to assess geographic clustering tendency in SIRs and Poisson regression to assess the association of SIRs with the municipal average absorbed dose to the thyroid gland at the 59-municipality level. RESULTS: Throughout the second- and third-round surveys, 99 thyroid cancer cases were diagnosed in the study population of 252,502 individuals. Both flexibly shaped spatial scan statistics and maximized excess events test did not detect statistically significant spatial clustering (P = 0.17 and 0.54, respectively). Poisson regression showed no significant dose-response relationship: the estimated relative risks of lowest, middle-low, middle-high, and highest areas were 1.16 (95% confidence interval [CI], 0.52-2.59), 0.55 (95% CI, 0.31-0.97), 1.05 (95% CI, 0.79-1.40), and 1.24 (95% CI, 0.89-1.74). CONCLUSION: There was no statistical support for geographic clustering or regional association with radiation dose measures of the thyroid cancer incidence in the cohort followed up to the third-round survey (fiscal years 2016-2017) in Fukushima Prefecture.

Long-term exposure to fine particle matter and all-cause mortality and cause-specific mortality in Japan: the JPHC Study.

BACKGROUND: Many epidemiological studies have reported the association between exposure to particulate matter and mortality, but long-term prospective studies from Asian populations are sparse. Furthermore, associations at low levels of air pollution are not well clarified. Here, we evaluated associations between long-term exposure to particulate matter <2.5 µg/m3 (PM2.5) and mortality in a Japanese cohort with a relatively low exposure level. METHODS: The Japan Public Health Center-based Prospective Study (JPHC Study) is a prospective cohort study of men and women aged 40-69 years in 1990 who were followed up through 2013 for mortality. In this cohort of 87,385 subjects who did not move residence during follow-up, average PM2.5 levels from 1998 to 2013 by linkage with 1-km2 grids of PM2.5 concentration were assigned to the residential addresses of all participants. To avoid exposure misclassification, we additionally evaluated the association between 5-year (1998-2002) cumulative exposure level and mortality during the follow-up period from 2003 to 2013 in 79,078 subjects. Cox proportional hazards models were used to calculate the association of long-term exposure to PM2.5 on mortality, with adjustment for several individual confounding factors. RESULTS: Average PM2.5 was 11.6 µg/m3. Average PM2.5 exposure was not associated with all-cause mortality or cancer and respiratory disease mortality. However, average PM2.5 was positively associated with mortality from cardiovascular disease (hazard ratio (HR) of 1.23 (95%CI=1.08-1.40) per 1-µg/m3 increase; in particular, HR in mortality from cerebrovascular disease was 1.34 (95%CI=1.11-1.61) per 1-µg/m3 increase. Additionally, these results using cumulative 5-year PM2.5 data were similar to those using average PM2.5 over 15 years. CONCLUSIONS: We found evidence for a positive association between PM2.5 exposure and mortality from cardiovascular disease in a Japanese population, even in an area with relatively low-level air pollution.

Associations of neighborhood socioeconomic conditions with self-rated health, mental distress, and health behaviors: A nationwide cross-sectional study in Japan.

Although associations between neighborhood socioeconomic conditions and health have been well established, their geographical scope is mostly limited to Western societies, while multilevel studies in the non-Western context (e.g., Japan) are limited to specific cities/regions within countries. This consequently limits the external validity of the findings. To fill the gap, this study examined the associations between neighborhood socioeconomic conditions and health-related indicators by using nationwide cross-sectional data in Japan. Individual data was collected from a nationwide online survey conducted in 2015 (n = 4593). Self-rated health, mental distress (Kessler Psychological Distress Scale: K6), smoking, and physical activity were analyzed in relation to neighborhood conditions. Analyses of multilevel logistic regression models were done using the Areal Deprivation Index (ADI) with population density as the neighborhood-level independent variable. After adjusting for individual covariates, ADI showed significant positive associations with poor self-rated health (odds ratio for one standard deviation increase and 95% confidence interval: 1.09, 1.00-1.19), mental distress (1.09, 1.02-1.16), current smoking (1.11, 1.03-1.19), and physical inactivity (1.11, 1.04-1.18). Population density was not associated with the four dependent variables. Analyses of the nationwide survey data in Japan showed that neighborhood socioeconomic conditions were independently associated with multiple health statuses and behaviors. These analyses may contribute to generalizing existing findings. Lastly, the results indicate the importance of neighborhood socioeconomic conditions in reducing health disparities in Japan.

Factors Influencing the Proportion of Non-examinees in the Fukushima Health Management Survey for Childhood and Adolescent Thyroid Cancer: Results From the Baseline Survey.

BACKGROUND: After the Fukushima Daiichi Nuclear Power Plant accident, a preliminary ultrasound-based screening for thyroid cancer was conducted to establish a baseline for subsequent evaluations. In this survey, we assessed the relationship between the proportion of non-examinees and characteristics of the target populations. METHODS: After summarizing a regional difference of non-examinees among the population of 359,200 (primary evaluation) and 2,246 (confirmatory testing) individuals who were living in Fukushima Prefecture on March 11, 2011, we estimated odds ratios (ORs) for each characteristic, including age, sex, area of residence, and moving after the accident, based on the proportion of non-examinees for the primary examination and the confirmatory testing, using a multivariate logistic regression model. RESULTS: The dataset included 64,117 non-examinees (primary evaluation) and 194 (confirmatory testing). The logistic regression result indicated that girls were not likely to be non-examinees compared to boys, with adjusted OR of 0.80 (95% confidence interval [CI], 0.78-0.81) for the primary evaluation. Odds were lowest for children 6-10 years old (OR 0.26; 95% CI, 0.25-0.27), and higher for those 11-15 years old (OR 1.28; 95% CI, 1.25-1.32) and over 16 years old (OR 5.30; 95% CI, 5.16-5.43) when compared to children 0-5 years old. Individuals residing in the western part of the prefecture showed higher ORs. There was a higher proportion of non-examinees among those who moved after the accident compared to those who did not in the primary evaluation (OR 1.72; 95% CI, 1.64-1.79). CONCLUSIONS: In addition to demographic characteristics, a change of residence could be a potential factor that influenced the proportion of non-examinees. Our results will help proper interpretation of reports and prospective management of the survey.

Equality of Treatment for Hip Fracture Irrespective of Regional Differences in Socioeconomic Status: Analysis of Nationwide Hospital Claims Data in Japan.

Despite the wide variety of international evidence on the relationship between the socioeconomic status (SES) and health outcomes, less is known about the association between SES and healthcare provider practices. We assessed whether patients with a closed hip fracture were treated differently by hospital physicians according to the SES of their residential areas in Japan. Hip fracture is a common cause of hospitalization among the elderly, but the relationship between SES and hip fracture treatment remains unknown in Japan. We employed the Diagnosis Procedure Combination (DPC) database from April 2011 to March 2014. SES of the patient's residential area was estimated using Census-derived areal deprivation index (ADI). We performed a cross-sectional study of national claims data and analyzed it using cross-classified multilevel models. We used two outcome measures: (i) whether the patient received an operation or was treated by watchful waiting; and (ii) number of waiting days until operation following admission. We identified 95,011 patients admitted to 1,050 hospitals. Of these, 85,480 patients underwent surgery. Low SES of residential areas was not correlated with the chance of undergoing surgery (P = 0.15) but was weakly correlated with longer waiting days (coefficient, 0.03; 95% confidence interval, -0.01 to 0.06; P = 0.08). The difference of waiting days between maximum (10.4) and minimum ADI (-4.0) was marginal (0.39 days). The results indicate the SES of patient's residential area does not affect the decision of surgical treatment for hip fracture and has ignorable impact on waiting days from hospital admission to surgery.

Population-based cohort study on health effects of asbestos exposure in Japan.

Occupational asbestos exposure occurs in many workplaces and is a well-known cause of mesothelioma and lung cancer. However, the association between nonoccupational asbestos exposure and those diseases is not clearly described. The aim of this study was to investigate cause-specific mortality among the residents of Amagasaki, a city in Japan with many asbestos factories, and evaluate the potential excess mortality due to established and suspected asbestos-related diseases. The study population consisted of 143 929 residents in Amagasaki City before 1975 until 2002, aged 40 years or older on January 1, 2002. Follow-up was carried out from 2002 to 2015. Standardized mortality ratio (SMR) with its 95% confidence interval (CI) was calculated by sex, using the mortality rate of the Japanese population as reference. A total of 38 546 deaths (including 303 from mesothelioma and 2683 from lung cancer) were observed. The SMRs in the long-term residents' cohort were as follows: death due to all causes, 1.12 (95% CI, 1.10-1.13) in men and 1.07 (95% CI, 1.06-1.09) in women; lung cancer, 1.28 (95% CI, 1.23-1.34) in men and 1.23 (95% CI, 1.14-1.32) in women; and mesothelioma, 6.75 (95% CI, 5.83-7.78) in men and 14.99 (95% CI, 12.34-18.06) in women. These SMRs were significantly higher than expected. The increased SMR of mesothelioma suggests the impact of occupational asbestos exposure among men and nonoccupational asbestos exposure among women in the long-term residents' cohort. In addition, the high level of excess mortality from mesothelioma has persisted, despite the mixture of crocidolite and chrysotile no longer being used for three or four decades.

Spatial analysis of the geographical distribution of thyroid cancer cases from the first-round thyroid ultrasound examination in Fukushima Prefecture.

Following the Fukushima Daiichi Nuclear Power Plant (FNPP) accident on 11 March 2011, there have been concerns regarding the health impacts of the ensuing radioactive environmental contamination, which was spatially heterogeneous. This study aimed to assess the geographical variability of thyroid cancer prevalence among children and adolescents in Fukushima Prefecture. We computed the sex- and age-standardised prevalence ratio using 115 diagnosed or suspected thyroid cancer cases among approximately 300,000 examinees at the first-round ultrasound examination during 2011-2015 from 59 municipalities in the prefecture, under the Fukushima Health Management Survey. We applied flexibly shaped spatial scan statistics and the maximised excess events test on the dataset to detect locally anomalous high-prevalence regions. We also conducted Poisson regression with selected regional indicators. Furthermore, approximately 200 examinees showed positive ultrasound examination results but did not undergo confirmatory testing; thus, we employed simulation-based sensitivity tests to evaluate the possible effect of such undiagnosed cases in the statistical analysis. In conclusion, this study found no significant spatial anomalies/clusters or geographic trends of thyroid cancer prevalence among the ultrasound examinees, indicating that the thyroid cancer cases detected are unlikely to be attributable to regional factors, including radiation exposure resulting from the FNPP accident.

Heat-not-burn tobacco product use in Japan: its prevalence, predictors and perceived symptoms from exposure to secondhand heat-not-burn tobacco aerosol.

OBJECTIVES: A heat-not-burn (HNB) tobacco product, IQOS, was first launched in Japan and Italy as test markets and is currently in commerce in 30 countries. Using two data sources, we examined interest in HNB tobacco (IQOS, Ploom and glo), its prevalence, predictors of its use and symptoms from exposure to secondhand HNB tobacco aerosol in Japan, where HNB tobacco has been sold since 2014. METHODS: Population interest in HNB tobacco was explored using Google search query data. Prevalence of HNB tobacco current use (ie, use in the previous 30 days) was calculated using a longitudinal internet survey of 8240 individuals (15-69 years old in 2015) followed up to 2017. Rates of perceived symptoms from exposure to exhaled aerosol of others' HNB tobacco were also calculated. RESULTS: The largest internet search volume for IQOS occurred in April 2016 in the week after a popular national entertainment TV show introduced IQOS. For Ploom and glo, search volumes have remained limited since their launch. Prevalence of IQOS users increased from 0.3% in January-February 2015 to 0.6% in January-February 2016 and up to 3.6% in January-February 2017, while estimated rates of use of other HNB tobacco products remained low in 2017. Respondents who had seen the TV programme in 2016 were more likely to have used IQOS than those who had not seen it (10.3% vs 2.7%). Among never-smokers who had been exposed to secondhand HNB tobacco aerosol, nearly half reported at least one acute symptom, although these symptoms were not serious. CONCLUSIONS: A popular TV programme triggered IQOS diffusion in Japan. Extrapolating from survey results to the general population, around 3.1 million people currently use IQOS in Japan. Tobacco control organisations and governments should closely monitor HNB tobacco and consider how to regulate it.

Investigation of Spatial Clustering of Biliary Tract Cancer Incidence in Osaka, Japan: Neighborhood Effect of a Printing Factory.

BACKGROUND: In 2013, an unusually high incidence of biliary tract cancer among current or former workers of the offset color proof printing department of a printing company in Osaka, Japan, was reported. The purpose of this study was to examine whether distance from the printing factory was associated with incidence of biliary tract cancer and whether incident biliary tract cancer cases clustered around the printing factory in Osaka using population-based cancer registry data. METHODS: We estimated the age-standardized incidence ratio of biliary tract cancer according to distance from this printing factory. We also searched for clusters of biliary tract cancer incidence using spatial scan statistics. RESULTS: We did not observe statistically significantly high or low standardized incidence ratios for residents in each area categorized by distance from the printing factory for the entire sample or for either sex. The scan statistics did not show any statistically significant clustering of biliary tract cancer incidence anywhere in Osaka prefecture in 2004-2007. CONCLUSIONS: There was no statistically significant clustering of biliary tract cancer incidence around the printing factory or in any other areas in Osaka, Japan, between 2004 and 2007. To date, even if some substances have diffused outside this source factory, they do not appear to have influenced the incidence of biliary tract cancer in neighboring residents.

Trends in socioeconomic inequalities in self-rated health, smoking, and physical activity of Japanese adults from 2000 to 2010.

Health disparities in Japan are attracting increasing attention. Temporal trends in health disparities should be continuously monitored using multiple indices of socioeconomic status (SES) and health-related outcomes. We explored changes in socioeconomic differences in the health of Japanese adults during 2000-2010. The data was taken from the Japanese General Social Surveys, the cross-sectional surveys for nationally representative samples of Japanese adults. We used 14,193 samples (individuals of 20-64 years of age) in our analysis. We estimated age-adjusted prevalence ratios of the lowest SES group in comparison with the highest SES group using Poisson regression models with robust error variance. Relative index of inequality (RII) and slope index of inequality (SII) were also calculated. We examined the changes in the association between health-related outcomes (self-rated health (SRH), smoking, and physical activity) and SES indices (income, education, occupation, and subjective social class identification). The results showed temporally expanding trends for the associations of current smoking with SES, especially among women, in both relative and absolute measures. In contrast, no expanding trends were seen for SRH and physical activity. Although the smoking rates declined through the first decade of the 21st century, the socioeconomic disparities in smoking prevalence among Japanese adults expanded, especially among women. Researchers and policymakers should continuously monitor the trends that may cause future disparities in smoking-related morbidity and mortality.

Neighborhood contextual factors for smoking among middle-aged Japanese: a multilevel analysis.

The purpose of this study is to explore neighborhood contextual factors in terms of smoking behaviors among middle-aged Japanese, by using a multilevel analysis. Subjects were Japanese men and women, between 40 and 59 years of age (40,961 for the cross-sectional analysis, and 9,177 for the longitudinal analysis), nested in 39 neighborhoods (Kyuson). The results showed that women in a less residentially stable neighborhood were more likely to be smokers. No associations were seen between current smoking and neighborhood deprivation; however, women in the most deprived neighborhood were more likely to quit smoking. This study is the first to demonstrate the associations between neighborhood environment and current smoking or smoking cessation, in a Japanese setting. The findings imply that policy makers should consider targeting neighborhood conditions in order to help reduce smoking prevalence, especially among women.

Neighborhood deprivation and risk of cancer incidence, mortality and survival: results from a population-based cohort study in Japan.

BACKGROUND: In many developed countries, socioeconomic status is associated with cancer incidence and survival. However, research in Japan is sparse. We examined the association between neighborhood deprivation based on the Japanese Deprivation Index and the risk of incidence, mortality and survival from total and major cancers in the Japan Public Health Center-based Prospective Study. METHODS: 86,112 participants were followed through the end of 2009. A total of 10,416 incident cases and 5,510 deaths from cancer were identified among 1,348,437 person-years of follow-up (mean follow-up: 15.7 years). The Japanese deprivation index was used to access neighborhood deprivation. Hazard ratios and 95% confidence intervals were calculated by Cox regression analysis. RESULTS: We found no associations between neighborhood deprivation index and the incidence of total and major cancers. In some cancer risks or deaths, however, we found positive or inverse associations with a higher deprivation index, such as a decreased risk of colorectal cancer incidence and an increased risk of liver cancer incidence and deaths in women. CONCLUSION: Although some positive or inverse associations were detected for specific sites, the neighborhood deprivation index has no substantial overall association with the risk of incidence, mortality and survival from cancer in the Japanese population.

Socioeconomic inequalities in cancer survival: a population-based study of adult patients diagnosed in Osaka, Japan, during the period 1993-2004.

BACKGROUND: Long-term recession of the Japanese economy during the 1990s led to growing social inequalities whilst health inequalities also appeared. The 2007 National Cancer Control Program of Japan targeted "equalisation of cancer medical services", but the system to monitor health inequalities was still inadequate. We aimed to measure socioeconomic inequalities in cancer survival in Japan. MATERIAL AND METHODS: We analysed 13 common invasive, primary, malignant tumours diagnosed from 1993 to 2004 and registered by the population-based Cancer Registry of Osaka Prefecture. An ecological socioeconomic deprivation index based on small area statistics, divided into quintile groups, was linked to patients according to their area of residence at the time of diagnosis. We estimated one-, five-year and conditional five-year net survival by sex, period of diagnosis (1993-1996/1997-2000/2001-2004) and deprivation group. Changes in survival over time, deprivation gap in survival, and change in deprivation gap were estimated at one and five years after diagnosis using variance-weighted least square regression. RESULTS: The deprivation gap in one-year net survival was narrower than in five-year net survival and conditional five-year survival. During the study period, there was no change in deprivation gap, except for reductions for pancreas (men) and stomach (women), and an increase for lung (men) in one-year survival. We observed a linear association between level of survival and deprivation gap at five years and conditional five years, but no association at one-year survival. CONCLUSION: A wide deprivation gap in survival was observed in most of the adult, solid, malignant tumours, within the universal healthcare system in Japan. Overall, cancer survival improved in Osaka without any widening of inequalities in cancer survival in 1993-2004, shortly after the long-term economic recession and deep modifications in the social and work environments in Japan. The longer term impact of the recession on inequalities in cancer survival needs to be monitored using population-based cancer registry data.

Influence of municipal- and individual-level socioeconomic conditions on mortality in Japan.

BACKGROUND: The health effect of area socioeconomic conditions has been evident especially in Western countries; however, limited research has focused on the effect of municipal-level socioeconomic conditions, especially in Asia. PURPOSE: Multilevel research using data from the Japan Collaborative Cohort Study, a large cohort study followed from 1990 to 2006, was conducted to examine individual as well as municipal socioeconomic conditions on risk of death, adjusting for each other. METHOD: We included 24,460 men and 32,649 women aged 40 to 65 years at baseline in 35 municipalities as our study population. Primary predictors were municipal socioeconomic conditions (proportion of college graduates, per capita income, unemployment rate, and proportion of households receiving public assistance) and individual socioeconomic conditions (education level and occupation). RESULTS: Among men, the multilevel logistic estimate (standard errors) of proportion of college graduates and unemployment rate for mortality from cardiovascular disease were -0.399 (0.094) and -0.343 (0.122), respectively. Among women, the multilevel logistic estimate (standard errors) of proportion of college graduates and per capita annual income for mortality from injuries were -0.386 (0.171) and -1.069 (0.407). Individual education level and occupation were associated with all-cause mortality, in particular, mortality from cardiovascular disease or injuries. Interactions between individual education level and indicators of municipal socioeconomic conditions were observed for mortality from cancer and cardiovascular disease among men and mortality from injuries among women. CONCLUSION: Municipal and individual socioeconomic conditions were independently and interactively associated with premature death; this suggests that reducing social inequalities in health demands a focus on municipal conditions in addition to those of individuals.

Multilevel analysis of solar radiation and cancer mortality using ecological data in Japan.

A preventive effect of solar radiation on cancer has been suspected. This study aimed to compare the statistical relationship between solar radiation and cancer mortality according to hierarchical models and adjustment for confounding factors, and then to demonstrate the relationship with main site-specific cancer mortalities in Japan. We examined the relationship between all-site and main site-specific cancer mortalities and global solar radiation using Poisson regression with municipal data around 2000. The models included single-level (municipality) and multilevel (municipality and prefecture) with/without potential confounding factors (lifestyle and socioeconomic variables). For all-site cancer, single-level analysis showed a significant, strong negative association with solar radiation. However, multilevel analysis showed a moderate or no association. In multilevel analysis with potential confounding factors, solar radiation was significantly negatively associated with most site-specific cancers, but not with gallbladder and liver cancer in men and stomach and breast cancer in women. Our findings support the preventive effective of solar radiation on several types of cancer. However, to show a concrete relationship, a statistical model with an appropriate hierarchy and adjustment for potential confounding factors is required.