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).

Altered Sex Ratio at Birth with Maternal Exposure to Dioxins in Vietnamese Infants

Excess female births (lower sex ratio at birth) associated with paternal exposure to 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) have been reported in Italy. However, no significant effects of maternal TCDD exposure on the sex ratio were reported. We investigated the effects of maternal TCDD exposure and the toxic equivalent quantity of polychlorinated dibenzo-p-dioxins/dibenzofurans (TEQ-PCDD/Fs) on the sex ratio at birth in 576 Vietnamese infants from three birth cohorts. TCDD and TEQ-PCDD/Fs in breast milk were stratified (low, mild, moderate, and high) as maternal exposure markers. Logistic regression analysis was used to investigate associations between female birth and dioxin exposure groups after adjusting for confounders. In sprayed and unsprayed areas, adjusted odds ratios (ORs) of female birth (reference: low-TCDD group) were 2.11 in the moderate-TCDD group and 2.77 in the high-TCDD group, which were significantly associated with increased TCDD exposure. In sprayed areas, a significantly increased OR in the high-TCDD group was observed. No significant associations, however, were found between having a girl and TEQ-PCDD/F levels. These results suggest that maternal TCDD exposure may alter the sex ratio at birth among Vietnamese residents of areas with high dioxin contamination.

Subsite-specific trends in mid- and long-term survival for head and neck cancer patients in Japan: A population-based study

Advances in diagnostic techniques and treatment modalities have impacted head and neck cancer (HNC) prognosis, but their effects on subsite-specific prognosis remain unclear. This study aimed to assess subsite-specific trends in mid- and long-term survival for HNC patients diagnosed from 1993 to 2011 using data from population-based cancer registries in Japan. We estimated the net survival (NS) for HNC by subsite using data from 13 prefectural population-based cancer registries in Japan. Changes in survival over time were assessed by multivariate excess hazard model of mortality. In total, 68,312 HNC patients were included in this analysis. We observed an overall improvement in 5-year NS for HNC patients in Japan. However, survival varied among subsites of HNC, with some, such as naso-, oro- and hypopharyngeal cancers, showing significant improvement in both 5- and 10-year NS, whereas others such as laryngeal cancer showed only a slight improvement in 5-year NS and no significant change in 10-year NS after adjustment for age, sex and stage. In conclusion, the study provides insights into changing HNC survival by site at the population level in Japan. Although advances in diagnostic techniques and treatment modalities have improved survival, these improvements are not shared equally among subsites.

The Effects of Neighborhood Trust and Support on Parenting Stress of Mothers With Young Children in Japan

INTRODUCTION

While childrearing can enhance mothers' psychological well-being, parenting can also increase mental stress for mothers with young children, which is considered a risk factor for child maltreatment. A lack of social capital reportedly influences mothers' parenting, but few studies have investigated the effects of social capital on the perception of mental stress and well-being associated with childrearing among mothers with young children. Therefore, we investigated the effects of lower perceived neighborhood trust and support on higher mental stress and/or lower well-being associated with childrearing among Japanese mothers with children aged 2 to 3 years.

METHODS

A total of 570 mothers with children (aged 2-3 years) in nursery school were invited to join the survey. The childrearing perspective scale for mothers (CPS-M97) was used to evaluate mothers' perceptions of mental stress and well-being associated with childrearing. Odds ratios (ORs) reflecting lower satisfaction/fulfillment scores (ie, well-being) and/or higher burdened/anxious scores (ie, mental stress) associated with perceived social capital levels were analyzed, after adjusting for confounding factors.

RESULTS

The OR for lower satisfaction/fulfillment scores was significantly higher (OR = 1.77) for mothers with lower neighborhood trust. Significantly increased ORs for higher burdened/anxious scores were found in mothers with lower neighborhood trust (OR = 1.50) and support (OR = 1.49). The ORs for poor mental status, with lower satisfaction/fulfillment scores and higher burdened/anxious scores, were significantly increased in mothers with lower neighborhood trust (OR = 1.96) and lower neighborhood support (OR = 2.10).

CONCLUSIONS

Higher social capital was associated with higher psychological well-being and/or lower mental stress in Japanese childrearing mothers. These results suggest that enhancing social capital is necessary to facilitate successful parenting that contributes to the prevention of child maltreatment.

Impacts of perinatal dioxin exposure on gaze behavior in 2-year-old children in the largest dioxin-contaminated area in Vietnam

Fifty-five children aged 2 years from a birth cohort in the largest dioxin-contaminated area in Bien Hoa city, Vietnam participated in this survey to examine gaze behavior. Exposure levels were indicated by 2,3,7,8-tetrachlorodibenzo-p-dibenzodioxin (TCDD) and toxic equivalent of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (TEQ-PCDD/Fs) levels in maternal breast milk. The percentage of the total fixation duration on the face (% Face), mouth (% Mouth), and eye areas (% Eyes) when viewing silent and conversation scenes was used as gaze behavior indices. When they reached 3-year-old, autistic behavior was assessed using the Autism Spectrum Rating Scale (ASRS). A general linear model adjusted for confounding factors was used to compare gaze indices and ASRS scores between high and low dioxin exposure groups. Effects of perinatal dioxin exposure on gaze behavior were found only when viewing conversation scenes indicated by lower % Face for boys in high TCDD exposure group and lower % Eyes for girls in high TEQ-PCDD/Fs group. Increased autistic traits showed by higher ASRS scores at 3-year-old were found in both gender in the high TCDD exposure group. These findings indicate that perinatal TCDD and TEQ-PCDD/Fs exposure may reduce gaze behavior in 2-year-old children, predicting increased autistic traits at 3-year-old.

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.

Impact of dioxin exposure on brain morphometry and social anxiety in men living in the most dioxin-contaminated area in Vietnam

BACKGROUND

Previously, we reported that the global brain volume was significantly higher in men with estimated perinatal dioxin exposure in Vietnam. In this study, we aimed to clarify which brain lobes, consisting of several gyri, contributed to the increased global brain volume. We then analyzed associations between changes in brain volume and social anxiety symptoms to investigate the role of structural changes of the brain on social anxiety following perinatal dioxin exposure.

METHODS

Thirty-three men living near the dioxin-contaminated Bien Hoa airbase, underwent MRI examination. The regional gray matter volumes were extracted using the SPM12 in a MATLAB environment, and compared between subgroups with and without perinatal dioxin exposure estimated from their maternal residency in Bien Hoa during pregnancy. The social anxiety questionnaire for adults (SAQ-A30) was used to assess social anxiety.

RESULTS

In both hemispheres, higher gray matter volume in the frontal and temporal lobes, particularly in the superior frontal gyrus, superior temporal gyrus, and temporal pole were found in men with perinatal dioxin exposure. Superior temporal gyrus volume was significantly higher in men with perinatal exposure also after adjusting for reduction of its volume associated with increasing 1,2,3,7,8-PentaCDD levels in blood. Increased volume of these gyri, which showed higher volume in men with perinatal exposure, was associated with increased SAQ-A30 scores.

CONCLUSION

Perinatal dioxin exposure may increase the brain volume of gyri involved in social behavior, which was associated with increased social anxiety symptoms, suggesting functional effects accompanied the morphological effects of dioxin exposure.

Epidemiological and therapeutic profiles of lung cancer patients in the Hokushin Region Japan: a retrospective hospital administrative database study

OBJECTIVE

This study was performed to validate the epidemiology, initial treatment, and clinical practice of lung cancer patients in the Hokushin region, Japan.

METHODS

We retrospectively surveyed data of 5503 newly diagnosed and registered lung cancer patients in 22 principal hospital-based cancer registries in Hokushin region linked with health insurance claims data for registered patients between 2016 and 2017.

RESULTS

The patients consisted of 3677 (66.8%) men and 1826 (33.2%) women with a mean (range) age of 72.2 (27-103) years). Diagnoses were small cell lung cancer (n = 512, 9.4%), squamous cell carcinoma (n = 1083, 19.7%), and non-squamous non-small cell lung cancer (NSCLC; n = 3906, 70.9%). The population with stage I disease in Toyama prefecture (41.1%) was smaller than in the other three prefectures associated with reduced selection of initial surgical therapy and increased frequencies of stage IV disease (33.2%) and best supportive care (18.6%). Initial chemotherapy for stage IV non-squamous NSCLC consisted of tyrosine kinase inhibitors in 39.3% of cases for EGFR and 4% of cases for ALK-positive non-squamous NSCLC, followed by platinum compounds (25.9%) non-platinum compounds (12.9%), and immune checkpoint inhibitors (10.2%). Carboplatin was the commonly prescribed first-line cytotoxic chemotherapeutic agent (65.4% of patients under 75 years and in 96.7% of patients over 75 years).

CONCLUSION

This study revealed real-world data on epidemiological and treatment status in lung cancer in four prefectures in Hokushin region, Japan. Simultaneous analysis of nationwide registry and insurance data could provide valuable insights for the development of lung cancer screening and medical treatment strategies. In addition, the comparative data analysis with other lesions or countries will be useful for evaluating the differences in clinical practice of cancer managements.

Multi-institutional survey of antiemetic therapy in lung cancer patients treated with carboplatin in Hokushin region

OBJECTIVE

Appropriate monitoring and management of chemotherapy-induced nausea and vomiting (CINV) with prophylactic antiemetics is important for cancer patients. This study was performed to validate the clinical practice of antiemetic use with carboplatin-based chemotherapy in lung cancer patients in the Hokushin region (Toyama, Ishikawa, Fukui, and Nagano prefectures), Japan.

METHODS

We surveyed retrospective data of newly diagnosed and registered lung cancer patients initially treated with carboplatin-based chemotherapy in 21 principal hospitals in the Hokushin region linked with health insurance claims data between 2016 and 2017.

RESULTS

A total of 1082 lung cancer patients (861 [79.6%] men, 221 [20.4%] women; median age 69.4 years [range, 33-89 years]). All patients received antiemetic therapy, with 613 (56.7%) and 469 patients (43.3%) receiving 5-hydroxytryptamine-3 receptor antagonist/dexamethasone double regimen and 5-hydroxytryptamine-3 receptor antagonist/dexamethasone/neurokinin-1 receptor antagonist triple regimen, respectively. However, the rates of double regimen and use of palonosetron were higher in Toyama and Fukui prefectures. Thirty-nine patients (3.6%) changed from double to triple regimen, while 41 patients (3.8%) changed from triple to double regimen after the second cycle, but six of these returned to triple antiemetics in subsequent cycles.

CONCLUSION

Adherence to antiemetic guidelines in clinical practice was high in Hokushin region. However, rates of double and triple antiemetic regimens differed between the four prefectures. Simultaneous analysis of nationwide registry and insurance data was valuable for evaluating and comparing the differences in the status of antiemesis and management.

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in blood samples from historically herbicide-sprayed areas and rural and industrialized unsprayed areas in Vietnam

We investigated dioxin concentrations in the blood of residents living in areas with different sources of dioxin pollution in Vietnam. A total of 823 individual blood samples were collected in 2014-2015 from residents of 16 provinces in Vietnam who were born between 1972 and 1976, and who lived in rural unsprayed areas (the control area), industrialized unsprayed areas (the industrialized area), and areas in which herbicides were sprayed during the Vietnam War (the sprayed area). After blood collection, pooled samples were obtained by combining 10-25 individual samples by age and sex for each area. A total of 6, 10, and 26 pooled blood samples were obtained for the control area, industrialized area, and sprayed area, respectively. The concentrations of 17 polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans were quantified in each pooled blood sample. The concentrations of TCDD, 1,2,3,7,8,9-HxCDD, 1,2,3,7,8-PeCDF, and OCDF were significantly higher in the sprayed area than in the unsprayed area, which comprised the control and industrialized areas. The toxic equivalents of PCDDs, TCDD, 1,2,3,7,8-PeCDF, and 1,2,3,6,7,8-HxCDF were significantly higher in the sprayed area than in the control area. No significant difference in dioxin concentration was found between the sprayed and industrialized areas after adjusting for sex. The 1,2,3,6,7,8-HxCDF concentration was significantly higher in the industrialized area than in the control area. The findings indicate that there are different dioxin congener blood profiles in residents of industrialized areas and areas in which herbicides were historically sprayed during the Vietnam War.

Foods and Nutrients at Risk for Insufficient Intake by Community-Dwelling Healthy Older Women Eating Alone and Together in Japan-A Preliminary Finding

Eating alone and poor dental status have been reported to influence dietary intake in older adults. First, we compared nutrient and food intake and dental markers between women eating alone and together, who participated in a home health management program conducted by Kanazawa Medical University. The results showed the significantly higher intake of fresh fruit and some micro-nutrients and a lower decayed, missing, and filled teeth (DMFT) index (better dental status) in women eating alone after adjusting for age, suggesting that dental status may mediate the association between commensality and dietary intake. Then, we investigated nutrients and foods at risk for insufficient intake and associated with increasing dental markers. The risks for the insufficient intake of protein and n-3 and n-6 polyunsaturated fatty acids (PUFAs) were significantly increased with an increasing DMFT index. The risk for n-3 PUFA intake also increased with increasing numbers of missing teeth in women. Foods at risk for insufficient consumption included beans for women with an increasing DMFT index and green and yellow vegetables, fresh fruits, and meat and fish for women with increasing numbers of missing teeth. These findings suggest that good health management, including the treatment of decayed teeth, is important for the prevention of malnutrition in community-dwelling healthy older women.

[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.

Epidemiological and Therapeutic Analyses in Lung Cancer Patients Over 80 Years Old in the Hokushin Region: A Retrospective Hospital Administrative Database Study

OBJECTIVE

This study was performed to validate the epidemiology, initial treatment, and clinical practice in lung cancer patients < 80 and ≥ 80 years in Hokushin region, Japan.

METHODS

We retrospectively surveyed data of 5481 newly diagnosed and registered lung cancer patients (4311 [78.7%] < 80 years; 1170 [21.3%] ≥ 80 years ) in 22 principal hospitals in Hokushin region linked with health insurance claims data between 2016 and 2017. Stage, initial treatment, and clinical practice were compared between the 2 groups.

RESULTS

The distributions of clinical stage I/II/III/IV/unknown were 2535/387/654/1371/111 in non-small cell lung cancer (NSCLC) and 37/32/114/237/3 in SCLC. Initial surgery for stage I NSCLC was performed in 90.0% and 60.2% of cases in the < 80 and ≥ 80 years groups, respectively. Rates of treatment with best supportive care (BSC) for stage IV disease were significantly higher in the ≥ 80 than the < 80 years group (NSCLC:58.9% vs. 18.7%; SCLC: 42.3% vs. 6.8%, respectively), regardless of the presence/absence of comorbidities. Propensity score matching showed that age ≥ 80 years itself was significantly related to choice of BSC in patients with lung cancer. The ratio of initial cytotoxic chemotherapy for NSCLC was low (49.9%) but that of biomarker-based therapy including tyrosine kinase inhibitors and immune checkpoint inhibitors (50.0%) was significantly higher in the ≥ 80 than < 80 years group (70.2% vs. 29.8%, respectively).

CONCLUSION

There are several differences in treatment pattern between patients < 80 and ≥ 80 years. Age ≥ 80 years may be related to BSC choice in patients with lung cancer.

[Associations between Maternal Postpartum Depression and Psychosocial Factors Including Marital Relationship and Social Support]

OBJECTIVES

We aimed to investigate the psychosocial factors for postpartum depression as indicated by a high score of the Edinburgh Postnatal Depression Scale (EPDS), including marital relationship and social support. Relevant factors for antenatal depression were also analyzed.

METHODS

Thirty-five wife-and-husband pairs who visited University Hospital A for the wife's antenatal health check-up participated in a questionnaire survey using the Japanese version of the EPDS. Social support from the wife's husband, kins, and others including friends at the third trimester of pregnancy and 1 month after birth was assessed. The Marital Love Scale (MLS) was also used, and two marital relationship questions were asked regarding the husband's and wife's considerate actions toward each other during pregnancy. Binary logistic regression analysis was conducted to determine adjusted associations between higher EPDS scores (≥5 for postpartum depression and ≥7 for antenatal depression) and indicators for social support and marital relationships.

RESULTS

The most relevant factor for higher postpartum EPDS scores was a higher antenatal EPDS score, followed by the couple's poor communication skills (the wife did not feel any appreciation from her husband) during pregnancy and no support from the wife's husband during the postpartum period. The wife's poor marital communication skills and the husband's low MLS scores during pregnancy were associated (borderline significance) with the wife's higher antenatal EPDS scores.

CONCLUSIONS

A good marital relationship before birth and support by the husband after birth may be important for preventing postpartum depression.

Effects of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans, and Dioxin-like PCBs on Teeth and Bones in Animals and Humans

Bone metabolism is regulated by endocrine systems, so people exposed to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) may suffer adverse effects on bones and teeth. We reviewed previous publications in which effects of PCDD/Fs and dioxin-like polychlorinated biphenyls on the teeth and bones of animals and humans were found. The aim was to identify future research directions, particularly for epidemiological studies of populations exposed to PCDD/Fs in the environment. Exposure of fetuses to PCDD/Fs may affect odontogenesis, particularly enamel formation, but the effects of PCDD/Fs on bone genesis are limited to palatine bone. Exposure to PCDD/Fs in milk may affect both teeth and bones, but the effects on bones may be reversible. Exposure to high PCDD/F concentrations even during adulthood may adversely affect teeth. Exposure to PCDD/Fs may induce osteogenesis and improve bone properties because the disrupting effects of PCDD/Fs cause bone remodeling and vitamin D activation. More studies involving humans are required to investigate previously found associations between the PCDD/F concentrations humans are exposed to and biological markers for teeth and bones, including metabolites of vitamin D.

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.

Perinatal Dioxin Exposure and Attention Deficit Hyperactivity Disorder (ADHD) Symptoms in Children Living in a Dioxin Contamination Hotspot in Vietnam

We examined children in Da Nang, a dioxin contamination hotspot in Vietnam, twice at 5 and 8 years of age, and investigated sex- and age-dependent differences in the effects of dioxin exposure on attention deficit hyperactivity disorder (ADHD) symptoms. We also studied autistic traits in children with ADHD symptoms. A total of 163 children participated in follow-up surveys at 5 and 8 years of age and were included in the present analysis. ADHD symptoms were assessed using an ADHD rating scale with inattention and hyperactivity-and-impulsivity (hyperactivity) subscales. Autistic behaviors were evaluated using the Autism Spectrum Rating Scale (ASRS). Perinatal dioxin exposure was indicated by dioxin levels in maternal breast milk. In boys, hyperactivity scores were significantly higher in the high 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) group only at 5 years of age. In girls, hyperactivity scores at 8 years of age were significantly higher in the high TCDD group, which was significantly associated with those at 5 years of age. In girls, ASRS unusual behavior scores were significantly higher with higher TCDD exposure and hyperactivity scores at 8 years of age. These results suggest that high perinatal TCDD exposure may increase ADHD likelihood and autistic traits, particularly in girls of 7–8 years of age.

Cancer among children, adolescents and young adults in the Hokushin region, Japan, between 2010 and 2015

Adolescents and young adults with cancer encounter age-related challenges. Cancer treatment and support are not always tailored to the needs of each patient due to difficulty in the collection of accurate data. The present study aimed to investigate cancer among children and adolescents and young adults in the four adjacent prefectures of Japan (Toyama, Ishikawa, Fukui and Nagano) by analyzing data from a unique regional cancer database. We retrieved and analyzed the data of pediatric and adolescent and young adult patients aged between 0 and 39 years at cancer diagnosis (including carcinoma in situ), which was registered in the Hokushin Ganpro database between 2010 and 2015. A total of 5718 cases (1571 males and 4147 females) were identified during this period. The overall male-to-female ratio was 1:2.6. There was no distinct difference in the number of cancer cases per 100 000 population between males and females until 19 years of age. The difference became more pronounced after 20 years of age. The number of cancer cases (per 100 000 population) in the 0-14-, 15-19-, 20-29- and 30-39-year age groups was estimated to be 13.4, 14.5, 44.0 and 101.5, respectively. Carcinomas were the most common type of cancer in the adolescents and young adults (15-39 years) population (74%), whereas they were not the predominant cancer type in the pediatric (0-14 years) population. Although further research is needed to understand the needs of adolescents and young adults with cancer, we believe that our findings will help guide efforts to improve the management strategy for adolescents and young adults with cancer.

540A simulation to evaluate HTLV-1 screening for pregnant women in prevention of adult T-cell leukemia

Background

In Japan, the nation-wide screening program of pregnant women for HTLV-1 infection was launched in 2010 to prevent mother-to-child transmission. It is difficult to assess the effect of the screening program on adult T-cell leukemia (ATL) prevention by observational study because ATL develops after long-term (about 50 years) latency in HTLV-1 carriers. Thus, we assessed the effect of the screening using computer simulation.

Methods

We constructed our model that simulates lifetime history of the children born to HTLV-1 carrier mothers. Lifetime risks of ATL among the children in unscreened group and screened group were estimated employing Monte Carlo simulation. We developed three scenarios for the risk estimation of ATL in screened groups, each making different assumptions for the choice of feeding methods (formula feeding, short-term breast-feeding, and long-term breast-feeding).

Results

Our simulation revealed that lifetime risk of ATL among the children born to HTLV-1 carrier mothers was 1.19 % in unscreened group and 0.21 to 0.27 % in screened groups.

Conclusions

In Japan, it is estimated that there were 1,363 pregnant women with HTLV-1 infection in 2016 (Sekizawa 2018). From this figure, the estimated annual number of ATL patients prevented by the screening is 12.6 to 13.5.

Key message

HTLV-1 screening in pregnant women for one year is estimated to reduce the number of ATL among their children by about 13 in Japan.

Multi-institutional survey of malignant pleural mesothelioma patients in the Hokushin region

BACKGROUND

Malignant pleural mesothelioma (MPM) is a major occupational and environmental neoplasm. The purpose of this study was to validate the clinical and epidemiological factors, diagnosis, and initial treatment among MPM patients in the Hokushin region.

METHODS

We surveyed retrospective data from 152,921 cancer patients in 22 principal hospitals.

RESULTS

A total of 166 MPM cases were newly diagnosed. These patients consisted of 136 men and 30 women, with a median age of 69 years. We estimated the incidence rate for MPM to be 0.55 cases per 100,000 person-years in this study. The ratio per 100,000 population-years was 0.39 in Fukui, 0.60 in Ishikawa, 1.02 in Toyama and 0.35 in Nagano. Forty-five patients were discovered when diagnosed incidentally in patients under observations for other diseases. Forty-six cases were diagnosed as localized disease, while 13 had accompanying regional lymph node metastasis. Furthermore, 44 cases showed infiltration into adjacent organs. A histo-cytological diagnosis was made in 164 cases (98.8%). A surgical approach, chemotherapy, and radiotherapy were performed for 33, 88, and 6 patients, respectively, while 44 patients (26.5%) received best supportive care. Multimodality therapy was conducted in just 3.0% of the MPM patients CONCLUSION: MPM has a tragically rapid progression if discovered under observations for other diseases. Workers in health-related fields should be on high alert for aggressive MPM. Better evaluation and multi-disciplinary approaches to MPM in these regions are needed to optimize multimodality therapy.

Multi-institutional survey of thymic carcinoma patients in Hokushin region

BACKGROUND

Thymic carcinoma is a rare neoplasm, and its prognosis is very poor. The purpose of this study was to validate the clinical and epidemiological factors, diagnosis and initial treatment of thymic carcinoma among all patients diagnosed in the registered hospital group.

METHODS

We surveyed retrospective data from 152,921 cancer patients in 22 principal hospitals.

RESULTS

A total of 88 thymic carcinoma cases were newly diagnosed. These patients were 50 men and 38 women, with a median age of 66 years old. Eight patients were discovered in cancer screening, 9 in a voluntary setting, 14 at health checkups, 25 at follow-up of other diseases, and 32 cases by introduction from another hospital. Only 14 cases had been diagnosed with localized disease, but 5 cases were accompanied by regional lymph node metastasis. Furthermore, 12 cases showed infiltration into adjacent organs, and 24 cases had distant metastasis. Eighty-three cases were diagnosed by a pathological diagnosis. A surgical approach, chemotherapy, and radiotherapy were performed for 29, 35 patients, and 31 patients, respectively, while 17 patients received best supportive care.

CONCLUSION

The diagnosis of thymic carcinoma is still difficult, and this disease has a tragically rapid progression if when discovered during follow-up of other diseases. An innovative modality for the early detection of thymic carcinoma is needed in modern medical society.

Nutritional Intervention with Dried Bonito Broth for the Amelioration of Aggressive Behaviors in Children with Prenatal Exposure to Dioxins in Vietnam: A Pilot Study

Dioxins have been suggested to induce inflammation in the intestine and brain and to induce neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), partly due to deficits in parvalbumin-positive neurons in the brain that are sensitive to inflammatory stress. Previously, we reported ADHD traits with increased aggressiveness in children with prenatal exposure to dioxins in Vietnam, whereas dried bonito broth (DBB) has been reported to suppress inflammation and inhibit aggressive behavior in animal and human studies. In the present study, we investigated the association between dioxin exposure and the prevalence of children with highly aggressive behaviors (Study 1), as well as the effects of DBB on the prevalence of children with highly aggressive behaviors (Study 2). Methods: In Study 1, we investigated the effects of dioxin exposure on the prevalence of children with high aggression scores, which were assessed using the Children’s Scale of Hostility and Aggression: Reactive/Proactive (C-SHARP) in dioxin-contaminated areas. The data were analyzed using a logistic regression model after adjusting for confounding factors. In Study 2, we performed nutritional intervention by administering DBB for 60 days to ameliorate the aggressiveness of children with high scores on the C-SHARP aggression scale. The effects of DBB were assessed by comparing the prevalence of children with high C-SHARP scores between the pre- and post-intervention examinations. Results: In Study 1, only the prevalence of children with high covert aggression was significantly increased with an increase in dioxin exposure. In Study 2, in the full ingestion (>80% of goal ingestion volume) group, the prevalence of children with high covert aggression associated with dioxin exposure was significantly lower in the post-ingestion examination compared with in the pre-ingestion examination. However, in other ingestion (<20% and 20–79%) groups and a reference (no intervention) group, no difference in the prevalence of children with high covert aggression was found between the examinations before and after the same experimental period. Conclusions: The findings suggest that DBB ingestion may ameliorate children’s aggressive behavior, which is associated with perinatal dioxin exposure.

Multi-institutional survey of cancer disparities in disabled patients in the region of northwestern Japan

BACKGROUND

Potential disparities between cancer patients with and without disabilities remained to be validate in Japan.

METHODS

We surveyed retrospective data on hospital cancer registration as well as information on disability certificates obtained through the Hokushin Ganpro database. In total, 93,545 cancer patients in 10 principal hospitals covering the region of northwestern Japan were registered with the Hokushin Ganpro database between 2010 and 2015. The database included the following data: diagnosis date, cancer type, staging, treatment, cancer detection process, and possession of a disability certificate.

RESULTS

We found that 2983 patients, which accounted for 3.2% of the total patients, had disabilities. No significant differences in gender, age at diagnosis, cancer stage distribution, and cancer incidence rates were observed between the disabled and non-disabled patients. Even though the proportion of early-stage cancer among disabled patients differed only slightly from that in non-disabled patients, early-stage cancer was more frequently diagnosed in patients with disabilities during their regular hospital visits than in those without disabilities, who had more opportunity for early cancer detection during cancer screening. According to in-house data reflecting treatment period and process from a single hospital, all 16 disabled patients treated with chemotherapy completed the treatment until disease progression or end of predetermined cycles.

CONCLUSION

These results indicate that deep disparities between cancer patients with and without disabilities are not apparent and that the disabled patients in the region of northwestern Japan receive appropriate hospital follow-up.

Dioxin exposure and sexual dimorphism of gaze behavior in prepubertal Vietnamese children living in Da Nang, a hot spot for dioxin contamination

Previous studies have reported that dioxin exposure alters sexual dimorphism of play behavior in pre-pubertal children. We aimed to investigate the effects of perinatal dioxin exposure, indicated by dioxins in breast milk, on sexual dimorphism of gaze behavior after adjusting for salivary testosterone (T). Participants were pre-pubertal children in a hot spot for dioxin contamination originating from herbicide spraying in Vietnam. We used eye tracking to assess gaze behavior in 172 children (100 boys and 72 girls) aged 8-9 years. Two sets of 15 pairs of pictures, one oriented towards boys and one oriented towards girls, containing 5 pairs of toy photos (non-biological stimuli) and 10 pairs of human line drawings (biological stimuli) were shown to all children. The total fixation duration for each picture was extracted using Tobii studio software and a feminine index of gaze behavior was defined as the ratio of the summed fixation duration for the girl- vs boy-oriented versions of each stimuli. When viewing non-biological stimuli, feminine index scores significantly increased with TCDD (β = 0.294) in girls only. For biological stimuli, however, feminine index scores significantly increased with TEQ-PCDD/Fs (β = 0.269) in boys and with TCDD in girls (β = 0.286). These associations were significant even after adjusting for salivary T levels, which were inversely associated with some dioxin congeners in girls. In addition, increased feminine index scores for biological stimuli were associated with lower cognitive scores for hand-movement and word-order tests in boys and for face-recognition tests in girls examined at 5 years of age. In conclusion, these results suggest that perinatal dioxin exposure may increase visual interest in girl-oriented objects through impairment of cognitive abilities in pre-pubertal Vietnamese children. PCDD congeners were associated with gaze behavior independently of T levels in boys, while this was only the case for TCDD levels in girls.

Effects of perinatal dioxin exposure on neonatal electroencephalography (EEG) activity of the quiet sleep stage in the most contaminated area from Agent Orange in Vietnam

OBJECTIVE

To investigate the effects of perinatal dioxin exposure indicated by dioxins in breast milk on neonatal electroencephalography (EEG) power in the quiet sleep stage, and associations with neurodevelopmental outcomes at 2 years of age.

STUDY DESIGN

Fifty-one mother-newborn pairs were enrolled for neonatal EEG analysis in the quiet sleep stage from a birth cohort recruited at a prefecture hospital in Bien Hoa city, Vietnam. Relative EEG power in intra-burst-intervals and high-voltage-bursts in the trace alternant pattern were computed from EEG data during the quiet sleep stage. Forty-three mother-child pairs participated in a 2-year follow-up survey to examine neurodevelopment using the Bayley-III scale and gaze behavior exhibited by fixation duration on the face of a child talking in videos. The general linear model and regression linear model were used for data analysis after adjusting for confounding factors.

RESULTS

Perinatal dioxin exposure, particularly 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure, influenced relative EEG power values mainly in the intra-burst-interval part of the trace alternant pattern in the quiet sleep stage. In intra-burst-intervals, decreased frontal delta power and increased frontal and parietal alpha power values in the left hemisphere and temporal beta power values in the right hemisphere were associated with increased TCDD exposure, with significant dose-response relationships. Almost none of the relative power values in these brain regions were associated with Bayley III scores, but relative delta power values were significantly associated with face fixation duration in left frontal and parietal regions at 2 years of age.

CONCLUSION

Perinatal dioxin exposure influences neuronal activity in the quiet sleep stage, leading to poor communication ability indicated by gaze behavior in early childhood.

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.

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.

Trends in Small-Cell Lung Cancer Survival in 1993-2006 Based on Population-Based Cancer Registry Data in Japan

BACKGROUND

Lung cancers are classified into small-cell lung cancer (SCLC) and non-small-cell lung cancer due to their different treatment and prognosis. Although many studies have reported the specific survival of SCLC patients treated at cancer hospitals, survival from population-based data has rarely been reported.

METHODS

We analyzed survival of SCLC cases diagnosed from 1993 through 2006 from a population-based cancer registry of six prefectures. To assess trends in SCLC survival, we defined three periods that mirrored developments in SCLC treatment: period 1, 1993-1998; period 2, 1999-2001; and period 3, 2002-2006. Assessments were based on relative survival (RS), excess hazard, and conditional survival.

RESULTS

A total of 10,911 SCLC patients were analyzed. Five-year RS among limited disease SCLC (LD-SCLC) in periods 1 to 3 was 16.8%, 21.1%, and 21.4%, respectively. Five-year RS among extensive disease SCLC (ED-SCLC) in periods 1 to 3 was 2.3%, 2.8%, and 2.7%, respectively. Improvement in 5-year RS in periods 2 and 3 compared with period 1 was significant among both LD- and ED-SCLC patients (all P < 0.001). Conditional 5-year RS of LD-SCLC increased from 21% at year 0 to 73% at year 5, while that of ED-SCLC was 3% at year 0 and 53% at year 5.

CONCLUSIONS

The prognosis of SCLC patients improved from 1999-2001 but plateaued in 2002-2006, after which no further significant improvement was seen. Continuous survey based on population-based data is helpful in monitoring the impact of developments in treatment.

Perinatal dioxin exposure and neurodevelopment of 2-year-old Vietnamese children in the most contaminated area from Agent Orange in Vietnam

Bien Hoa airbase is the most contaminated area of dioxin contamination from Agent Orange in Vietnam, but little is known about the neurodevelopmental effects of perinatal dioxin exposure on children living nearby. We recruited 210 mother-newborn resident pairs in 2012 and 78 pairs in 2015 and followed them for 2 years to assess the children's neurodevelopment. As a control group, we used 120 mother-child pairs recruited in 2014 in the Ha Dong district of Ha Noi City, an unexposed area. Perinatal dioxin exposure levels were indicated by levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and toxic equivalency values of polychlorodibenzodioxins, polychlorodibenzofurans, and nonortho-polychlorinated biphenyls (TEQ-PCDD/Fs/noPCBs) in maternal breast milk. The Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) were used to assess neurodevelopment, and scores in each domain were compared between children with different exposure levels using general linear regression models and stratification by sex. Decreased expressive and composite language scores in boys and gross motor scores in girls were found in children exposed to TCDD ≥ 5.5 (pg/g lipid) compared with children with TCDD < 1.8. However, in matched pair analysis between children with TCDD ≥ 5.5 and <1.8 (pg/g lipid), lower expressive and composite language scores in boys exposed to TCDD ≥ 5.5 were significant, but lower gross motor scores in girls did not reach statistical significance. In addition, significant association was found between levels of PCDD congeners other than TCDD and gross motor scores in boys. These findings suggest that perinatal exposure of TCDD and other PCDD congeners affects development of language and gross motor skills, respectively, in boys at 2 years of age exposed to dioxins originating from Agent Orange in Vietnam.

Adverse effects of maternal dioxin exposure on fetal brain development before birth assessed by neonatal electroencephalography (EEG) leading to poor neurodevelopment; a 2-year follow-up study

We previously reported the adverse effects of perinatal dioxin exposure on child neurodevelopment around a former US military airbase in Vietnam. In the present study, we investigated the effects of maternal dioxin exposure on fetal brain development, which may predict neurodevelopmental outcomes in early childhood. A total of 55 newborns with mothers from dioxin-contaminated areas were recruited in the prefecture hospital in Bien Hoa, Vietnam. Dioxins in maternal breast milk collected 1 month after birth were used as a maternal exposure marker. Relative powers and coherence were computed from neonatal electroencephalogram (EEG) records during active sleep stages. Relationships between the EEG parameters and dioxin exposure markers were analyzed using linear regression and a general linear model after adjusting for gestational age, body length, and head circumference of infants at birth. Using data from 47 infants whose neurodevelopment was examined in a 2-year follow-up study, associations between EEG parameters and neurodevelopment were analyzed after adjusting for confounding factors. On the right frontal and parietal regions, relative delta powers were significantly decreased, and relative alpha and beta powers were significantly increased with increasing dioxin exposure. Increases in delta power and decreases in alpha power on the right frontal and parietal regions were associated with an increase in language scores at 2 years of age. Furthermore, intra- and inter-hemispheric coherence in theta and alpha bands were positively and inversely correlated with dioxin exposure, respectively, and increased intra-coherence in the right hemisphere was associated with lower language scores. These findings suggest that prenatal dioxin exposure affects neuronal activity and functional connectivity between brain regions, and may lead to poor language development.

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 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.

Alcohol Consumption and Breast Cancer Risk According to Hormone Receptor Status in Japanese Women: A Case-Control Study

Alcohol consumption is a risk factor for breast cancer in Western countries, but few studies have evaluated the risk for Japanese women, who have a relatively low alcohol intake. This case-control study investigated the association of alcohol consumption with breast cancer risk according to estrogen-receptor and progesterone-receptor (ER/PgR) status in Japanese women. From female patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2011, 1,256 breast cancer cases (669 ER+/PgR+, 162 ER+/PgR-, 21 ER-/PgR+, 305 ER-/PgR-, and 99 missing) and 2,933 controls were selected. Alcohol-related measures were assessed using a self-administered questionnaire. Unconditional logistic regression analysis was performed. Alcohol-related measures were not associated with breast cancer risk among the women overall. Moreover, no association was observed between ever drinking and the risk of a concordant receptor subtype (ER+/PgR+ or ER-/PgR-). Conversely, ever drinking was inversely associated with the risk of discordant subtype (ER+/PgR-, odds ratio (OR) = 0.63, 95% confidence interval (CI): 0.41-0.95; ER-/PgR+, OR = 0.44, 95% CI: 0.14-1.42). For ER+/PgR-, an inverse association with the amount of alcohol consumed per day was observed (P for trend = 0.04), and this inverse association was limited to premenopausal women. Alcohol consumption may have differential effects on concordant and discordant receptor subtypes of breast cancer. In view of the low frequency of discordant subtype in Japanese women and their relatively low alcohol intake, our findings may provide a clue for elucidating the etiology of breast cancer rather than for preventing discordant subtype.

Sex-specific effects of perinatal dioxin exposure on eating behavior in 3-year-old Vietnamese children

Background

We previously reported that perinatal dioxin exposure increased autistic traits in children living in dioxin-contaminated areas of Vietnam. In the present study, we investigated the impact of dioxin exposure on children’s eating behavior, which is often altered in those with developmental disorders.

Methods

A total of 185 mother-and-child pairs previously enrolled in a birth cohort in dioxin-contaminated areas participated in this survey, conducted when the children reached 3 years of age. Perinatal dioxin exposure levels in the children were estimated using dioxin levels in maternal breast milk after birth. Mothers were interviewed using the Children’s Eating Behaviour Questionnaire (CEBQ). A multiple linear regression model was used to analyze the association between dioxin exposure and CEBQ scores, after controlling for covariates such as location, parity, maternal age, maternal education, maternal body mass index, family income, children’s gestational age at delivery, and children’s age at the time of the survey. A general linear model was used to analyze the effects of sex and dioxin exposure on CEBQ scores.

Results

There was no significant association between most dioxin congeners or toxic equivalencies of polychlorinated dibenzo-p-dioxins/furans (TEQ-PCDDs/Fs) and CEBQ scores in boys, although significant associations between some eating behavior sub-scores and 1,2,3,4,6,7,8,9-octachlorodibenzofuran were observed. In girls, there was a significant inverse association between levels of TEQ-PCDFs and enjoyment of food scores and between levels of TEQ-PCDFs and TEQ-PCDDs/Fs and desire to drink scores. Two pentachlorodibenzofuran congeners and 1,2,3,6,7,8-hexachlorodibenzofuran were associated with a decreased enjoyment of food score, and seven PCDF congeners were associated with a decreased desire to drink score. The adjusted mean enjoyment of food score was significantly lower in children of both sexes exposed to high levels of TEQ-PCDFs. There was, however, a significant interaction between sex and TEQ-PCDF exposure in their effect on desire to drink scores, especially in girls.

Conclusions

Perinatal exposure to dioxin can influence eating behavior in children and particularly in girls. A longer follow-up study would be required to assess whether emotional development that affects eating styles and behaviors is related to dioxin exposure.

Electronic supplementary material

The online version of this article (10.1186/s12887-018-1171-2) contains supplementary material, which is available to authorized users.

Effects of high fat diet and perinatal dioxin exposure on development of body size and expression of platelet-derived growth factor receptor β in the rat brain

Environmental exposure to dioxins, consumption of a high fat diet, and platelet-derived growth factor receptor β signaling in the brain affect feeding behavior, which is an important determinant of body growth. In the present study, we investigated the effects of prenatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin and high fact diet after weaning on body growth and expression of platelet-derived growth factor receptor β in the brain in rat pups. Subjects from the control and dioxin exposure groups were assigned to 1 of 3 different diet groups: standard diet, high fat diet in the juvenile period, or high fat diet in adulthood. Body weight gain rate in the juvenile high fat diet group and the length gain rate in the adult high fat diet group were greater than the corresponding values in the standard diet group only in male offspring, although the effects of dioxin exposure on growth were not significant. Consumption of a high fat diet decreased platelet-derived growth factor receptor β levels in the amygdala and hippocampus in both sexes compared to control groups, while 2,3,7,8-tetrachlorodibenzo-p-dioxin decreased platelet-derived growth factor receptor platelet-derived growth factor receptor β levels in the amygdala and striatum only in females receiving an high fat diet. Furthermore, platelet-derived growth factor receptor β levels in the hippocampus and platelet-derived growth factor receptor β striatum were inversely correlated with increases in body length, while changes in platelet-derived growth factor receptor β in the amygdala and nucleus accumbens were significantly correlated to body weight gain or body mass index. In conclusion, these findings suggest that these 2,3,7,8-tetrachlorodibenzo-p-dioxin and high fat diet-induced changes in body growth and feeding behaviors might be partially mediated by changes in brain platelet-derived growth factor receptor β levels.

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.

Recent Improvement in the Long-term Survival of Breast Cancer Patients by Age and Stage in Japan

Background

Recent improvements in 5-year survival of breast cancer have been reported in Japan and other countries. Though the number of long-term breast cancer survivors has been increasing, recent improvements in 10-year survival have not been reported. Moreover, the degree of improvement according to age and disease stage remains unclear.

Methods

We calculated long-term survival using data on breast cancer diagnosed from 1993 through 2006 from six prefectural population-based cancer registries in Japan. The recent increase in 10-year relative survival was assessed by comparing the results of period analysis in 2002–2006 with the results of cohort analysis in 1993–1997. We also conducted stratified analyses by age group (15–34, 35–49, 50–69, and 70–99 years) and disease stage (localized, regional, and distant).

Results

A total of 63,348 patients were analysed. Ten-year relative survival improved by 2.4% (76.9% vs 79.3%) from 1993 through 2006. By age and stage, 10-year relative survival clearly improved in the age 35–49 years (+2.9%; 78.1% vs 81.0%), 50–69 years (+2.8%; 75.2% vs 78.0%) and regional disease (+3.4%; 64.9% vs 68.3%). In contrast, the degree of improvement was small in the age 15–34 years (+0.1%; 68.2% vs 68.3%), 70–99 years (+1.0%; 87.6% vs 88.6%), localized disease (+1.1%; 92.6% vs 93.7%) and distant metastasis (+0.9%; 13.8% vs 14.7%).

Conclusions

These population-based cancer registry data show that 10-year relative survival improved 2.4% over this period in Japan. By age and stage, improvement in the age 15–34 years and distant metastasis was very small, which suggests the need for new therapeutic strategies in these patients.

Prenatal dioxin exposure estimated from dioxins in breast milk and sex hormone levels in umbilical cord blood in Vietnamese newborn infants

Dioxin concentrations remain elevated in the environment and humans residing near the former US Air Force base in Bien Hoa city, South Vietnam. We recruited 210 mother-infant pairs for whom breast milk dioxin levels were reported in our previous study. Cord blood samples were collected from 162 mother-infant pairs. We selected 16 cord blood samples with a volume over 20mL and fat content of ≥0.03g. Toxic equivalent levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (TEQ-PCDD/Fs) and concentrations of 17 congeners, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), in cord blood were measured and compared with levels in breast milk (Study 1). Levels of 2,3,7,8-TCDD and TEQ-PCDD/Fs in cord blood samples were highly and significantly correlated with those in breast milk samples in the same pairs. This suggests dioxins in breast milk reflect prenatal dioxin exposure. Estradiol (E2) and testosterone (TS) were measured in cord blood serum from 162 samples. Associations between dioxins in breast milk and cord blood sex hormones were analyzed by infant sex, after adjusting for confounding factors (Study 2). Increased levels of TEQ-PCDD/Fs in breast milk were associated with decreased cord blood TS in girls. In boys, a significant reduction of cord blood TS was observed in those exposed to 2,3,7,8-TCDD at high levels (≥5.5pg/g lipid). There was no significant association between E2 and dioxins in breast milk in either sex. These results suggest increased prenatal dioxin exposure is associated with decreased cord TS, but in boys, only high level of 2,3,7,8-TCDD influence cord blood TS.

Improvement in 5-Year Relative Survival in Cancer of the Corpus Uteri From 1993-2000 to 2001-2006 in Japan

Background

Medical circumstances in Japanese patients with cancer of the corpus uteri have greatly changed since the late 1990s, including the introduction of concomitant therapy with taxane and platinum. We evaluated changes in survival rates for this cancer following these advances by analyzing data from population-based cancer registries in Japan.

Methods

Data were available for 8562 cases of cancer of the corpus uteri from six prefectural cancer registries. We defined the two periods of 1993–2000 (1st period) and 2001–2006 (2nd period). Relative survival (RS) in each period was calculated to assess changes using an excess mortality model, with adjustment for age group (15–54, 55–69, and 70–99 years), extent of disease (localized, regional, and distant), and histological subtype.

Results

Overall 5-year RS improved from 77.7% in the 1st period to 80.2% in the 2nd period, with an excess hazard ratio (EHR) of 0.785 (95% confidence interval [CI], 0.705–0.873). Five-year RS significantly improved in the group aged 55–69 years, in all groups by extent of disease, and in the endometrioid adenocarcinoma group. In particular, 5-year RS significantly improved in patients with endometrioid adenocarcinoma, from 84.5% to 89.7%, with an EHR of 0.698 (95% CI, 0.560–0.870).

Conclusion

Overall 5-year RS for cancer of the corpus uteri in Japan improved from the 1990s to early 2000s. These improvements might have been aided by the comprehensive medical development of management for this cancer, including the spread of concomitant therapy with taxane and platinum as a standard adjuvant chemotherapy in the early 2000s.

Association between coffee consumption and all-sites cancer incidence and mortality

The preventive effect of coffee on cancer at different sites has been reported, but the effect on all‐sites cancer incidence has not been extensively investigated. We evaluated the association between frequency of coffee consumption and risk of all‐sites cancer incidence and mortality among 39 685 men and 43 124 women (age 40–79 years, at baseline), in the Three‐Prefecture Cohort Study. The association between frequency of coffee consumption and risk of all‐sites cancer incidence and mortality was assessed by a Cox proportional hazards regression model, adjusted for potential confounders. During 411 341 person‐years among men and 472 433 person‐years among women, a total of 4244 men and 2601 women developed cancer at different sites and a total of 3021 men and 1635 women died of cancer at different sites. We showed an inverse association between frequency of coffee consumption and all‐sites cancer incidence in both men and women. Comparing participants who consumed coffee with those who never drank coffee, the adjusted hazard ratios (95% confidential interval) for all‐sites cancer incidence was 0.74 (0.62–0.88) for coffee consumption of ≥5 cups/day in men (P for trend < 0.001) and 0.76 (0.58–1.02) in women (P for trend = 0.020). Coffee consumption frequency was inversely associated with mortality from all‐sites cancer. In this population, increasing coffee consumption resulted in a decreased risk of all‐sites cancer incidence and mortality.

Gender-Specific Impact of Cadmium Exposure on Bone Metabolism in Older People Living in a Cadmium-Polluted Area in Thailand

To elucidate the influence of cadmium exposure on bone metabolism, associations between urinary/blood cadmium and bone resorption/formation markers were investigated in older cadmium exposed men and women. Increased urinary cross-linked N-telopeptide of type I collagen (NTx), a bone resorption marker, was found to be associated with increased levels of parathyroid hormone, fractional excretion of calcium, and urinary/blood cadmium after adjusting for confounding factors in men. In women, urinary NTx was significantly associated with only urinary cadmium and a strong relationship with increased fractional excretion of calcium. Risk for bone metabolic disorders, indicated by high urinary NTx, significantly increased in men with blood cadmium ≥ 10 μg/L or urinary cadmium ≥ 10 μg/g creatinine. Increased osteocalcin level was significantly associated with increased blood cadmium in men. In conclusion, cadmium exposure appeared to have an influence on bone remodeling both bone resorption and formation in this population of older Thai men, and blood cadmium was more closely associated with bone metabolism than urinary cadmium.

Rationale, design, and profile of the Three-Prefecture Cohort in Japan: A 15-year follow-up

Background

We reutilized the existing Three-Prefecture Cohort to evaluate the relationship between lifestyle factors and the incidence or mortality from non-communicable diseases.

Methods

This study was a prospective population-based observation conducted from the 1980s to 2000 in three prefectures (Miyagi, Aichi, and Osaka) in Japan. The study subjects were residents aged ≥40 years who received a questionnaire. The follow-up period was 15 years from the baseline survey in each study area. A self-administered questionnaire, which included items on participants' demographic factors and lifestyle characteristics, was administered. Vital status and date of death were collected from residence certificates by the local government, and cause of death was identified using vital statistics. Cancer incidence and the date of diagnosis were collected from local cancer registry data.

Results

A total of 46,421 men and 54,189 women were eligible for our analysis. The person-years of follow-up for cancer incidence were 464,664 and 567,271 for men and women, respectively, and those for death were 527,940 and 648,601 for men and women, respectively. There were 8479 cancer incidences (5106 men and 3373 women) and 20,240 total deaths (11,156 men and 9084 women). The stomach was the most common cancer incidence site for both men (25.6%) and women (18.6%). The leading cause of death was cancer among men (35.0%) and cardiovascular disease among women (41.0%).

Conclusions

The Three-Prefecture Cohort Study enabled us to reveal the association of multiphasic lifestyle factors with cancer incidence and mortality. The study will also allow us to conduct a pooled analysis in combination with other large-scale cohorts.

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The Three-Prefecture Cohort had about 100,000 participants in urban and rural areas.

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This cohort collected detailed information on participants' lifestyles.

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This cohort had data on participants' cancer incidence and mortality.

Sulforaphane reduces advanced glycation end products (AGEs)-induced inflammation in endothelial cells and rat aorta

BACKGROUND AND AIMS

Advanced glycation end products (AGEs)-receptor RAGE interaction evokes oxidative stress and inflammatory reactions, thereby being involved in endothelial cell (EC) damage in diabetes. Sulforaphane is generated from glucoraphanin, a naturally occurring isothiocyanate found in widely consumed cruciferous vegetables, by myrosinase. Sulforaphane has been reported to protect against oxidative stress-mediated cell and tissue injury. However, effects of sulforaphane on AGEs-induced vascular damage remain unclear.

METHODS AND RESULTS

In this study, we investigated whether and how sulforaphane could inhibit inflammation in AGEs-exposed human umbilical vein ECs (HUVECs) and AGEs-injected rat aorta. Sulforaphane treatment for 4 or 24 h dose-dependently inhibited the AGEs-induced increase in RAGE, monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecular-1 (VCAM-1) gene expression in HUVECs. AGEs significantly stimulated MCP-1 production by, and THP-1 cell adhesion to, HUVECs, both of which were prevented by 1.6 μM sulforaphane. Sulforaphane significantly suppressed oxidative stress generation and NADPH oxidase activation evoked by AGEs in HUVECs. Furthermore, aortic RAGE, ICAM-1 and VCAM-1 expression in AGEs-injected rats were increased, which were suppressed by simultaneous infusion of sulforaphane.

CONCLUSION

The present study demonstrated for the first time that sulforaphane could inhibit inflammation in AGEs-exposed HUVECs and AGEs-infused rat aorta partly by suppressing RAGE expression through its anti-oxidative properties. Inhibition of the AGEs-RAGE axis by sulforaphane might be a novel therapeutic target for vascular injury in diabetes.

Abstract 5205: Changes in trends in colorectal cancer incidence rate by anatomic site between 1978 and 2004 in Japan

Although colorectal cancer (CRC), a major cancer worldwide, has shown a proximal or right-sided shift in subsite distribution in western countries, trends in subsite incidence in Asian countries remain unclear. Here, we evaluated subsite-specific trends in CRC incidence rate between 1978 and 2004 in Japan using large data from 10 population-based cancer registries. The colorectal sites (C18-20) were categorized into three groups, proximal colon (C18.0-18.5), distal colon (C18.6-C18.7) and rectum (C19.9 and C20.9). Trends in age-standardized incidence rates (ASRs) were characterized by Joinpoint regression analysis. A total of 474,651 colorectal cancer cases were analyzed. Overall, ASRs increased remarkably until 1993, with an annual percent change (APC) of 4.9%, and then stabilized thereafter. By subsite, however, ASRs of proximal colon significantly increased, with APCs of 7.1% (1978∼1991), 3.8% (1991∼96) and 0.9% (1996∼2004); distal colon showed an initial significant increase, with an APC of 7.6%, but stabilized from 1991 until the end of observation; and rectal cancer showed an initial significant increase, with APCs of 1.9% (1978∼88) and 5.6% (1988∼92), but then decreased abruptly in 1992, the year colorectal cancer screening was introduced nationwide, with an APC of -1.0%. Thus, we revealed that changes in incidence trends for the three anatomic sites apparently began to differ in the 1990s, and this is a first report to our knowledge. We also discuss factors that could explain these changes in Japanese. Careful monitoring is necessary to confirm whether these trends are changing in the Japanese population.

Citation Format: Hiroko Nakagawa, Hidemi Ito, Satoyo Hosono, Isao Oze, Haruo Mikami, Masakazu Hattori, Yoshikazu Nishino, Hiromi Sugiyama, Kayo Nakata, Hideo Tanaka. Changes in trends in colorectal cancer incidence rate by anatomic site between 1978 and 2004 in Japan. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5205.

Abstract 5209: Trends in a survival of cancer of the coupus uteri in Japan 1993-2006 (J-CANSIS)

The incidence of cancer of the corpus uteri (CC) in Japan is continuously increasing. To explore the trend in a survival of Japanese CC, we analyzed the population-based cancer registry data.

We obtained data on 8,562 CC cases from six prefectural cancer registries. We defined two periods as 1993-2001 (1st period) and 2002-2006 (2nd period). Relative survival (RS) of each period was calculated using cohort analysis, and we compared them using excess mortality model adjusted for age categories and extent of disease. We also estimated RS by age group, extent of disease and histological subtype. For age groups, patients were classified into those aged 15-54, 55-69 and 70-99. For extent of disease, patients were classified into those staged localized, regional and distant group. For histological subgroups, patients were divided into eight histological categories according to ‘Cancer Incidence in Five Continents Vol.10’ partially modified.

The 5-year RS was 78.1% in the 1st period and 80.1% in the 2nd period. Compared with the RS in the 1st period, RS in the 2nd period was significantly high [Excess Hazard Ratio (EHR): 0.805, 95%Confidence Interval (95%CI): 0.723-0.896, P&lt;0.001]. In the stratified analysis by age group, the 5-year RS of age group 55-69 significantly improved from 74.4% to 79.8% (EHR: 0.751, 95%CI: 0.643-0.877, P&lt;0.001). The 5-year RS in the other age group did not improved dramatically, but the 1-year RS of age group 70 years or older had a trend towards improvement from 81.2% to 83.4% (EHR: 0.777, 95%CI: 0.586-1.029, P = 0.079). The stratified analysis by extent of disease indicated that the 5-year RS improved significantly in local disease from 93.0% to 95.2% (EHR: 0.717, 95%CI: 0.554-0.927, P = 0.011) and regional disease from 57.3% to 64.2% (EHR: 0.813, 95%CI: 0.692-0.955, P = 0.012). Among distant cases, only 1-year RS improved significantly from 46.1% to 57.1% (EHR: 0.715, 95%CI: 0.572-0.895, P = 0.003). According to the analysis by histological subgroup, the 5-year RS of endometrioid adenocarcinoma significantly improved from 85.2% in the 1st period to 90.0% in the 2nd period (EHR: 0.700, 95%CI: 0.564-0.870, P = 0.001). In the cases of other specified adenocarcinoma and carcinoma, 1-year RS improved significantly from 84.6% in the 1st period to 89.2% in the 2nd period, but 5-year RS did not.

In conclusion, we could reveal the improved prognosis of Japanese CC from the period of 1993-2001 to the period of 2002-2006, using population-based cancer registry data. The improvement of short-term RS was observed among elderly, distant or non-endometriod cases, whereas their long-term prognosis did not change during the study period. Improved prognosis might be attributed to the progress of treatment, especially due to chemotherapy or formulation of treatment guidelines in early 2000’s.

Citation Format: Shusaku Inoue, Satoyo Hosono, Hidemi Ito, Isao Oze, Yoshikazu Nishino, Masakazu Hattori, Akiko Ioka, Tomio Nakayama, Keitato Matsuo, Mika Mizuno, Kiyoko Kato, Hideo Tanaka, Yuri Ito. Trends in a survival of cancer of the coupus uteri in Japan 1993-2006 (J-CANSIS). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5209.

Challenges in breast and cervical cancer control in Japan

Since the mid-1990s, there has been an increasing incidence of, and mortality from, cervical and breast cancers in Japan. Such an increase has raised concerns over the efficiency of Japan's screening programmes for these cancers. Although citizens benefit from universal health coverage, the Japanese health insurance system mostly focuses on tertiary prevention and disease treatment, while secondary prevention (screening) is low priority. Citizens have multiple opportunities to be screened for cancer-either through programmes organised by municipalities, or individual or collective, opportunistic and comprehensive health check-ups on a voluntary basis. Despite this, however, participation is as low as 35% of the target population for both cancers. In this Policy Review, we discuss the challenges in the prevention of breast and cervical cancers in Japan, particularly focusing on the structure of the National Health Insurance system and the National Cancer Control Plan, reasons for low participation as a result of social and political attitudes, as well as providing recommendations to overcome these challenges. Japanese women would benefit from new measures to increase participation, a national data surveillance programme to monitor screening activities, and the implementation of a quality assurance system among all providers.

Cigarette smoking and the risk of head and neck cancer in the Japanese population: a systematic review and meta-analysis

OBJECTIVE

Although cigarette smoking is a well-established risk factor for head and neck cancer, the impact of smoking on head and neck cancer might vary among geographic areas. To date, however, no systematic review of cigarette smoking and head and neck cancer in the Japanese population has yet appeared.

METHODS

We conducted a systematic review of previous epidemiological studies for cigarette smoking and head and neck cancer among Japanese. Evaluation of associations was based on the strength of evidence ('convincing', 'probable', 'possible' or 'insufficient') and the magnitude of association ('strong', 'moderate', 'weak' or 'no association'), together with biological plausibility as previously evaluated by the International Agency for Research on Cancer. A meta-analysis was conducted to obtain summary estimates for the overall magnitude of association.

RESULTS

We identified five cohort studies and 12 case-control studies. Four of five cohort studies and 11 of 12 case-control studies showed a strong positive association between cigarette smoking and head and neck cancer. Nine of 12 studies indicated a dose-response relationship between cigarette smoking and the risk of head and neck cancer. Meta-analysis of 12 studies indicated that the summary relative risk for ever smokers relative to never smokers was 2.43 (95% confidence interval: 2.09-2.83). Summary relative risks for current and former smokers relative to never smokers were 2.68 (2.08-3.44) and 1.49 (1.05-2.11), respectively.

CONCLUSIONS

Cigarette smoking is a convincing risk factor for head and neck cancer in the Japanese population.

Impacts of Perinatal Dioxin Exposure on Motor Coordination and Higher Cognitive Development in Vietnamese Preschool Children: A Five-Year Follow-Up

Dioxin concentrations remain elevated in the environment and in humans residing near former US Air Force bases in South Vietnam. Our previous epidemiological studies showed adverse effects of dioxin exposure on neurodevelopment for the first 3 years of life. Subsequently, we extended the follow-up period and investigated the influence of perinatal dioxin exposure on neurodevelopment, including motor coordination and higher cognitive ability, in preschool children. Presently, we investigated 176 children in a hot spot of dioxin contamination who were followed up from birth until 5 years old. Perinatal dioxin exposure levels were estimated by measuring dioxin levels in maternal breast milk. Dioxin toxicity was evaluated using two indices; toxic equivalent (TEQ)-polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs) and concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Coordinated movements, including manual dexterity, aiming and catching, and balance, were assessed using the Movement Assessment Battery for Children, Second Edition (Movement ABC-2). Cognitive ability was assessed using the nonverbal index (NVI) of the Kaufman Assessment Battery for Children, Second Edition (KABC-II). In boys, total test and balance scores of Movement ABC-2 were significantly lower in the high TEQ- PCDDs/Fs group compared with the moderate and low exposure groups. NVI scores and the pattern reasoning subscale of the KABC-II indicating planning ability were also significantly lower in the high TCDD exposure group compared with the low exposure group of boys. However, in girls, no significant differences in Movement ABC-2 and KABC-II scores were found among the different TEQ-PCDDs/Fs and TCDD exposure groups. Furthermore, in high risk cases, five boys and one girl highly exposed to TEQ-PCDDs/Fs and TCDD had double the risk for difficulties in both neurodevelopmental skills. These results suggest differential impacts of TEQ-PCDDs/Fs and TCDD exposure on motor coordination and higher cognitive ability, respectively. Moreover, high TEQ-PCDDs/Fs exposure combined with high TCDD exposure may increase autistic traits combined with developmental coordination disorder.