Dataset Information

Breast cancer risk in residents of Belarus exposed to Chernobyl fallout while pregnant or lactating: standardized incidence ratio analysis, 1997 to 2016.

ABSTRACT:

Background

Pregnancy and lactation may constitute radiation-sensitive reproductive periods due to rapid cell proliferation and concentration of radioiodine in the lactating breast. However, there are limited epidemiological data among women exposed to radiation during these periods.

Methods

We examined incidence of breast cancer in a cohort of 3214 women who were pregnant and/or lactating within 2 months (26 April to 30 June 1986) of the Chernobyl accident and residing in contaminated regions of Belarus. There were 33 breast cancers identified through linkage with the Belarusian National Cancer Registry. Breast cancer rates among women who were either pregnant and/or lactating were compared with population rates by calculating standardized incidence ratios (SIR) and 95% confidence intervals (CI) adjusting for attained age, oblast, urban/rural residence and calendar year.

Results

Among women who were lactating, we found a greater than 2-fold increased risk of breast cancer compared with the general population, SIR = 2.49 (95% CI: 1.55, 3.75). In contrast, women who were pregnant were not at increased risk (SIR = 0.84 95% CI: 0.46, 1.38). The SIR was highest in women who were exposed at a younger age and at the earliest time period since the accident, though stratified analyses had limited sample sizes.

Conclusions

We found a significantly increased risk of breast cancer among women residing in contaminated areas of Belarus who were lactating at the time of the accident and may have had elevated exposure to radioiodine, when compared with the general population. Studies of breast cancer with individual radiation dose estimates among women exposed during lactation are warranted.

SUBMITTER: Cahoon EK

PROVIDER: S-EPMC9082790 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Breast cancer risk in residents of Belarus exposed to Chernobyl fallout while pregnant or lactating: standardized incidence ratio analysis, 1997 to 2016.

Cahoon Elizabeth K EK Preston Dale D Zhang Rui R Vij Vibha V Little Mark P MP Mabuchi Kiyohiko K Drozdovitch Vladimir V Chizhov Konstantin K Yauseyenka Vasilina V VV Rozhko Alexander V AV Velalkin Ilya V IV

International journal of epidemiology 20220501 2

<h4>Background</h4>Pregnancy and lactation may constitute radiation-sensitive reproductive periods due to rapid cell proliferation and concentration of radioiodine in the lactating breast. However, there are limited epidemiological data among women exposed to radiation during these periods.<h4>Methods</h4>We examined incidence of breast cancer in a cohort of 3214 women who were pregnant and/or lactating within 2 months (26 April to 30 June 1986) of the Chernobyl accident and residing in contamin ...[more]

PMID: 34687542

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Project description:In the last three decades, an increase in thyroid cancer incidence has been observed worldwide, as well as in Lithuania. Although the rise was linked to overdiagnosis, the role of lifestyle and environmental factors, including exposure to ionizing radiation, cannot be excluded. In our retrospective study, we aimed to assess the association between the average age-specific thyroid dose due to the radioactive iodine uptake during childhood and adolescence from the Chernobyl fallout in Lithuania, and the trends of incidence of thyroid cancer from 1991 to 2015 in different regions. Averaged age-dependent thyroid doses were estimated for every municipality based on radioiodine activity in milk, reconstructed from available 131I activity measurements in the grass. Thyroid cancer incidence rates were calculated for the entire population and for two age at the time of exposure groups: 0-19 years and 0-9 years. Thyroid cancer relative risk (RR) was estimated for three municipality-specific thyroid dose (for 0-year-old babies) categories: less than 100 mGy (reference group), 100-199 mGy, and ≥200 mGy. Over the study period (1991-2015), a total of 5664 cases of thyroid cancer were registered in the entire Lithuanian population; 817 cases in the age group from 0 to 19 years at the time of the Chernobyl accident, and 266 cases in the age group from 0 to 9 years. Age-standardized thyroid cancer incidence rates have notably increased since 2000, peaked in 2009 (especially in females), and then slightly decreased and stabilized. The estimated average municipality-specific age-dependent thyroid doses ranged from 270 mGy in western Lithuania to 1.5 mGy in central and northern Lithuania. For the age group of 0-19 years at the time of the accident, in the period 1991-1995, the thyroid cancer relative risk was significantly increased (RR 3.91; 95 % CI: 1.27-10.29, p=0.01) in the highest dose category, compared to the lowest (although based on a small number of cases). For the age group 0-9 years at the time of the accident, a tendency of increased RR in the highest dose category appeared in the most recent period, 2011-2015. Our observations need to be confirmed by further following trends of thyroid cancer incidence in the cohort of 0-19-year-old Lithuanians at the time of the Chernobyl accident.

Project description:Prenatal exposure to external radiation has been linked to growth retardation among atomic bomb survivors in adolescence. It is unclear from previous studies whether in utero exposure to internal radiation such as iodine-131 (I-131), which concentrates in the thyroid gland, has an effect on physical growth. We examined the associations between estimated thyroid gland dose from prenatal exposure to I-131 and self-reported height and weight in a cohort of 2,460 individuals exposed to radioactive fallout from the 1986 Chernobyl nuclear accident [mean I-131 dose = 72 (mGy)] and screened for thyroid diseases in adolescence. Using multivariable linear regression models, we estimated the mean differences in height, weight and body mass index (BMI) per unit increase in dose (100 mGy) in models adjusted for gender, age at examination, type of residence (rural/urban) and presence of thyroid disease diagnosed at screening. All of the adjustment factors as well as the trimester of exposure were evaluated as potential modifiers of the dose response. Overall, no significant dose response was found for height (P = 0.29), weight (P = 0.14) or BMI (P = 0.16). We found significant modification of the dose response for weight and BMI by presence/absence of thyroid disease (P = 0.02 and P = 0.03, respectively), but not for other factors. In individuals without thyroid disease (n = 1,856), there was a weak, significant association between I-131 thyroid dose and higher weight (210 g per 100 mGy, P = 0.02) or BMI (70 g/m² per 100 mGy, P = 0.02) that depended on individuals (n = 52) exposed to ≥500 mGy. In individuals with thyroid disease (n = 579, 67.4% with simple diffuse goiter) no significant association with I-131 for weight (P = 0.14) or BMI (P = 0.14) was found. These results do not support the hypothesis that in utero exposure to I-131 at levels experienced by a majority of study subjects may be associated with meaningful differences in adolescent anthropometry. However, additional studies are needed to clarify whether in utero exposure to I-131 at levels > = 500 mGy may be associated with increases in weight/BMI and to evaluate the confounding or modifying role of thyroid disease, past iodine deficiency, maternal and prenatal/postnatal factors.

Project description:Policy Points Policymakers should invest more on researching the long-term health effects of low-ionizing radiation exposure, as we are far from reaching a consensus on a topic that is of enormous importance for public health and safety. Public policies such as those limiting the import of contaminated food from areas hit by a radioactive disaster or those regulating the resident population's access to such areas should follow a precautionary approach. Neoplasm diagnosis and medical care should be designed in order to take into account the possible role of long-term, low-dose radiation exposure. Health care policies should provide effective screening and prevention strategies with a specific focus on the regions that were hit most severely by the Chernobyl nuclear fallout. Health care expenditure should be targeted, taking into account the geographical dispersion of the fallout in order to attenuate its possible effect on neoplasm incidence.ContextThis study investigates the association between the radioactive 137 Cesium fallout originated by the 1986 Chernobyl nuclear accident and dispersed over Western Europe, as a result of a combination of radioactive cloud passage days and rainy days over a 10-day period, and long-term health patterns and related costs. Since the half-life of 137 Cesium is 30.17 years, part of the radioactivity in the affected regions is still present today, and it is usually still detected in the food chain, although at lower concentration levels.MethodsWe match longitudinal data on neoplasm incidence over the time span 2000-2013 in a number of European regions not immediately adjacent to Chernobyl with the randomly distributed levels of cesium deposition after the nuclear disaster in order to assess whether we can detect an association with the long-term health effects on the European population through a random effects model.FindingsConsidering 3 levels of fallout deposition-low, medium, and high-hospital discharges after treatment for neoplasms are, respectively, 0.36, 0.44, and 0.98 discharges over 100 inhabitants higher compared to regions with no fallout, with the population average being around 1.7 hospital discharges by neoplasms over 100 inhabitants. We checked the robustness of our findings to a number of tests including a placebo simulation and different model specifications.ConclusionsRadioactive fallout is positively associated with a higher incidence of hospital discharges after treatment for neoplasms almost 30 years after its release, with larger effects in regions where the radioactivity was more intense. Our estimates are comparable to the findings of the largest-scale study on the long-term health effects of continuous low levels of radiation exposure among workers in the nuclear industry and suggest that more research is needed on this topic, given its enormous importance for public health and safety.

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Project description:IntroductionMaternal and child health, which is integral to public health, depends on maintaining a healthy diet during pregnancy and lactation to achieve optimal outcomes. This study aimed to investigate the prevalence and determinants of minimum dietary diversity (MDD) among pregnant and lactating women (PLW) in this particular context.MethodsA stratified cluster sampling approach was employed, encompassing intervention areas (Rangpur and Nilphamari in Bangladesh) as strata, with 30 clusters. The study included 631 pregnant and lactating women (PLW) aged 15 to 49 years, focusing on their consumption of a minimally diverse diet. The outcome variable was binary: MDD (1 = if they consumed ≥ 5 food items from a basket of 10 food groups, indicating they met the MDD; 0 = if they consumed < 5 items, indicating they did not meet the MDD), assessed based on ten food groups over a 24-hour period. The data were analyzed using a binary logistic regression model.ResultsThe study found that 51.19% of PLW met MDD criteria, indicating positive dietary practices. Those aged 21-49 years had significantly lower odds of meeting MDD than those aged 15-20 years. Education played a key role, with completion of primary (p = 0.029) and secondary incomplete education (p = 0.055) associated with higher odds of meeting MDD. Other identified predictors included climate-smart techniques for agriculture, women's empowerment, food security, producing legume, nut and seeds and negative impact on family expenditure due to increase in commodity prices, especially food prices. Employing climate-smart agriculture increased odds by 1.58 times (p = 0.028), empowered women had 2.31 times higher odds (p < 0.001), and food security played a crucial role (p = 0.006). Moreover, producing legumes, nuts, or seeds was significantly associated with higher odds of meeting MDD (OR = 1.55, p = 0.039), while experiencing negative economic impacts lowered the odds (OR = 0.63, p = 0.034).ConclusionThe study provides insights into factors influencing MDD among PLW in northern Bangladesh. Empowering women and promoting climate-smart techniques for agriculture emerged as pivotal determinants, alongside enhancing education levels, increasing food security, and addressing economic barriers. Implementing multifaceted interventions that consider socio-demographic diversity, economic disparities, and dietary preferences is crucial for enhancing dietary diversity and improving health outcomes in this vulnerable population.

Dataset Information

Breast cancer risk in residents of Belarus exposed to Chernobyl fallout while pregnant or lactating: standardized incidence ratio analysis, 1997 to 2016.

Background

Methods

Results

Conclusions

Publications

Breast cancer risk in residents of Belarus exposed to Chernobyl fallout while pregnant or lactating: standardized incidence ratio analysis, 1997 to 2016.

Similar Datasets

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