Thyroid cancer incidence near nuclear sites in Belgium: An ecological study at small geographical level

Incidence of solid cancers among residents near nuclear facilities: a systematic review and meta-analysis

BACKGROUND

Concerns about the potential health effects of radiation exposure in communities living near nuclear facilities persist, prompting ongoing studies across various countries. However, research on solid cancers in these communities remains limited. This systematic review and meta-analysis aimed to comprehensively investigate the incidence of various solid cancers among residents near nuclear facilities, providing up-to-date scientific evidence on potential health effects in the context of energy security and net-zero emission targets.

METHODS

A comprehensive search of the databases PubMed, Excerpta Medica Database, and Web of Science was conducted. Data were extracted from 13 studies on breast, bladder, thyroid, CNS, and respiratory cancers, with the meta-analysis focusing on cancer types supported by at least five quantitative estimates to account for study heterogeneity. Study quality was assessed using the Office of Health Assessment and Translation tool. Pooled standardized incidence ratios (SIRs) were calculated using random-effects models, and publication bias was evaluated using funnel plots and Egger's test.

RESULTS

The meta-analyses included the following number of cases for each selected cancer type: breast, n = 20,701; bladder, n = 5,398; thyroid, n = 9,907; CNS, n = 3,634; and respiratory system, n = 18,033. Pooled SIRs for all cancer subtypes were statistically insignificant and ranged from 0.99 to 1.04, with substantial heterogeneity among studies (I2 range: 64%-96%). Little evidence of publication bias was revealed upon visual inspection of the funnel plots and performing Egger's test.

CONCLUSIONS

Current scientific evidence regarding the incidence of solid cancers in populations living near nuclear facilities is insufficient to draw definitive conclusions. Nonetheless, the wide range of heterogeneity among studies highlights the need for further research with refined study designs, particularly with regard to radiation exposure and individual-level confounding factors, to provide more robust evidence on the public health implications for residents near nuclear facilities.

The risk of thyroid cancer in relation to residential proximity to nuclear power plants: a systematic review and meta-analysis

INTRODUCTION

Ionizing radiation is a human carcinogen, and there is a public concern but limited evidence that it increases the incidence of cancer among those who live near nuclear power plants (NPPs). Previous analyses of thyroid cancer in these populations have been inconsistent, and the last synthesis was published nearly a decade ago. To address these gaps, we undertook a systematic review and meta-analysis.

METHODS

A search strategy was developed and applied to PubMed, Scopus, and Web of Science databases. A total of 2006 publications were identified, with 11 studies of thyroid cancer incidence that met the inclusion criteria. Study quality was assessed using the Office of Health Assessment and Translation (OHAT) tool. Summary risk estimates relating residential proximity to the NPPs and thyroid cancer were generated using a random effects model. Heterogeneity in the risk estimates was assessed for study features that included: distance to the NPP, study quality, and biological sex.

RESULTS

The 11 studies were categorized as either highly (n = 8) or plausibly (n = 3) prone to bias, primarily due to the reliance on ecological study designs. The meta-analysis summary relative risk of thyroid cancer among those who live close to NPPs (defined by ≤ 25 km distance or jurisdictional areas (e.g., community, county) relative to those who lived further away was 1.09 (95% CI: 0.93-1.29). The risk estimates were higher for studies that modelled more proximal residential distances (≤ 5 km) to NPPs than larger distances (≤ 25 km and jurisdictional areas). We found that the summary risk (RR=1.29, 95% CI: 0.77-2.16) was stronger among those studies less prone to bias. A non-significant increased risk was found among both men and women, but there was no evidence of sex differences in risk.

CONCLUSION

Overall, the findings suggest that living near a nuclear power plant increases the risk of thyroid cancer. The small number of studies on this topic, and the finding of higher risks in studies less prone to bias highlights the need for better-designed studies.

Increased Screening Rates for Thyroid Cancer Among Residents Living Near Nuclear Power Plants

Frequent screening for thyroid cancer has been suggested as a probable explanation for the observed high risk of thyroid cancer in nuclear power plant (NPP) areas. We aimed to compare thyroid cancer screening rates of residents living near NPPs to those of the general population. This study utilized data from two national survey-based studies in 2016 and in 2014, respectively, for residents (n = 1,200) living in administrative districts within 5 km of NPP sites as the interest group, and the general population (n = 228,712) including distant-living residents (n = 19,100) in administrative districts within 30 km of NPP sites as reference groups. We observed an increase in screening rates in residents near NPPs, which may lead to a higher possibility of thyroid cancer detection. Therefore, further epidemiological studies investigating radiation-induced thyroid cancer risk among residents near NPPs should be carefully designed and interpreted considering possible detection bias.

Differentiated Thyroid Cancer: A Health Economic Review

Simple Summary

This review reflects on health economic considerations associated with the increasing diagnosis and treatment of differentiated thyroid cancer. Analysis of different relevant health economic topics, such as overdiagnosis, overtreatment, surgical costs, and costs of follow-up are being addressed. Several unanswered research questions such as optimising molecular markers for diagnosis, active surveillance of primary tumours, and improved risk stratification and survivorship care all influence future healthcare expenditures.

Abstract

The incidence of differentiated thyroid cancer (DTC) is rising, mainly because of an increased detection of asymptomatic thyroid nodularity revealed by the liberal use of thyroid ultrasound. This review aims to reflect on the health economic considerations associated with the increasing diagnosis and treatment of DTC. Overdiagnosis and the resulting overtreatment have led to more surgical procedures, increasing health care and patients’ costs, and a large pool of community-dwelling thyroid cancer follow-up patients. Additionally, the cost of thyroid surgery seems to increase year on year even when inflation is taken into account. The increased healthcare costs and spending have placed significant pressure to identify potential factors associated with these increased costs. Some truly ground-breaking work in health economics has been undertaken, but more cost-effectiveness studies and micro-cost analyses are required to evaluate expenses and guide future solutions.

Childhood leukemia near nuclear sites in Belgium: An ecological study at small geographical level

BACKGROUND

A previous investigation of the occurrence of childhood acute leukemia around the Belgian nuclear sites has shown positive associations around one nuclear site (Mol-Dessel). In the following years, the Belgian Cancer Registry has made data available at the smallest administrative unit for which demographic information exists in Belgium, i.e. the statistical sector. This offers the advantage to reduce the potential misclassification due to large geographical scales.

METHODS

The current study performed for the period 2006-2016 uses Poisson models to investigate (i) the incidence of childhood acute leukemia within 20 km around the four Belgian nuclear sites, (ii) exposure-response relationships between cancer incidence and surrogate exposures from the nuclear sites (distance, wind direction frequency and exposure by hypothetical radioactive discharges taking into account historical meteorological conditions). All analyses are carried out at statistical sector level.

RESULTS

Higher incidence rate ratios were found for children <15 years (7 cases, RR = 3.01, 95% CI: 1.43;6.35) and children <5 years (< 5 cases, RR = 3.62, 95% CI: 1.35;9.74) living less than 5 km from the site of Mol-Dessel. In addition, there was an indication for positive exposure-response relationships with the different types of surrogate exposures.

CONCLUSION

Results confirm an increased incidence of acute childhood leukemia around Mol-Dessel, but the number of cases remains very small. Random variation cannot be excluded and the ecological design does not allow concluding on causality. These findings emphasize the need for more in-depth research into the risk factors of childhood leukemia, for a better understanding of the etiology of this disease.