Evaluation of ionizing radiation as a risk factor for the incidence of breast cancer: long-term analysis after the cesium-137 accident in Goiânia, Brazil. An ecological study

ABSTRACT BACKGROUND: The largest radiological accident to occur in any urban area happened in Goiânia, Brazil, in 1987. OBJECTIVE: To evaluate the association between breast cancer incidence and ionizing radiation levels. DESIGN AND SETTING: Ecological study among residents of the city of Goiânia, Brazil. METHODS: The central region of Goiânia, with seven major sources of contamination from cesium-137, was defined as the study area. The addresses of women diagnosed with breast cancer were identified between 2001 and 2010. The data were geographically referenced and, using census data, the annual averages of crude incidence rates were estimated. The existence of clusters of new cases was ascertained by means of the Moran index. Correlations of radiometric measurements with the incidence were assessed using unconditional linear regression. RESULTS: A total of 4,105 new cases were identified, of which 2,233 were in the study area, and of these, 1,286 (57.59%) were georeferenced. The gross rates of total and referenced cases were 102.91 and 71.86/100,000 women, respectively. These were close to the average for Brazilian state capitals, which is 79.37/100,000 women. The cluster analysis showed slight correlations in three small sets of census tracts, but these were far from the sources of contamination. The scatter plot of points and the R2 value close to zero indicated that there was no association between the variables. CONCLUSION: This study reinforces the hypothesis that the ionizing radiation levels to which women living in Goiânia are now exposed to are not associated with the onset of new cases of breast cancer.

Residential radon and lung cancer: a cohort study in Galicia, Spain / Radón residencial y cáncer de pulmón: un estudio de cohorte en Galicia, España / Radônio residencial e câncer de pulmão: um estudo de coorte na Galícia, Espanha

Case-control studies show an association between residential radon and lung cancer. The aim of this paper is to investigate this association through a cohort study. We designed an ambispective cohort study using the Galician radon map, Spain, with controls drawn from a previous case-control study. Subjects were recruited between 2002 and 2009. The data were cross-checked to ascertain lung cancer incidence and then analysed using a Cox regression model. A total of 2,127 subjects participated; 24 lung cancer cases were identified; 76.6% of subjects were drawn from the radon map. The adjusted hazard ratio was 1.2 (95%CI: 0.5-2.8) for the category of subjects exposed to 50Bq/m3 or more. This risk rose when subjects from the case-control study were analyzed separately. In conclusion, we did not observe any statistically significant association between residential radon exposure and lung cancer; however, it appears that with a sample of greater median age (such as participants from the case-control study), the risk of lung cancer would have been higher.

Los estudios de casos y controles muestran una asociación entre el radón residencial y el cáncer de pulmón. El objetivo del artículo fue investigar esa asociación a través de un estudio de cohorte. Proyectamos un estudio de cohorte ambispectivo, utilizando el mapa de radón de Galicia, España, con los controles obtenidos de un estudio anterior de casos y controles. Los individuos fueron reclutados entre 2002 y 2009. Los datos fueron verificados para confirmar la incidencia de cáncer de pulmón y después analizados con un modelo de regresión de Cox. Participaron un total de 2.127 individuos; se identificaron 24 casos de cáncer de pulmón; un 76,6% de los individuos fueron obtenidos a través del mapa de radón. El hazard ratio ajustado era 1,2 (IC95%: 0,5-2,8) para la categoría de individuos expuestos a 50Bq/m3 o más. El riesgo aumentó cuando los individuos del estudio de casos y controles fueron analizados separadamente. En conclusión, no se observó una asociación estadísticamente significativa entre exposición al radón residencial y cáncer de pulmón; sin embargo, parece que con una muestra con una media de edad más elevada (tales como los participantes del estudio de casos y controles), el riesgo de cáncer de pulmón habría sido más alto.

Estudos de casos e controles mostram uma associação entre radônio residencial e câncer de pulmão. O artigo teve como objetivo investigar essa associação através de um estudo de coorte. Projetamos um estudo ambispectivo coorte, utilizando o mapa de radônio da Galícia, Espanha, com os controles obtidos de um estudo anterior de casos e controles. Os indivíduos foram recrutados entre 2002 e 2009. Os dados foram verificados para confirmar a incidência de câncer de pulmão e depois analisados com um modelo de regressão de Cox. Participaram um total de 2.127 indivíduos; foram identificados 24 casos de câncer de pulmão; 76,6% dos indivíduos foram obtidos através do mapa de radônio. O hazard ratio ajustado era 1,2 (IC95%: 0,5-2,8) para a categoria de indivíduos expostos a 50Bq/m3 ou mais. O risco aumentou quando os indivíduos do estudo de casos e controles foram analisados separadamente. Em conclusão, não foi observada associação estatisticamente significativa entre exposição ao radônio residencial e câncer de pulmão; entretanto, parece que com uma amostra com mediana de idade mais elevada (tais como os participantes do estudo de casos e controles), o risco de câncer de pulmão teria sido mais alto.

Radiation-related neoplasms, circulatory diseases, and cataracts among radiological technologists

Background: In response to the need for diagnosis and treatment, medical radiation has been increasingly used worldwide. This study investigated the medical utilization of radiation-related diseases among radiological technologists [RTs] and factors that influence such diseases

Materials and Methods: Data were collected from the Taiwan National Health Insurance Research Database. A panel study was conducted with a sample of 3,432 RTs obtained in 2007 and followed up until 2011. Logistic regression applying generalized estimating equations was used for investigating the relationship between RTs and radiation-related diseases

Results: Among the RTs, the annual medical utilization rate of hospitalization for radiation-related neoplasms was 1.17%o-4.43%0, that for circulatory diseases was 4.68%o-11.50%o, and the annual medical utilization rate of outpatient visits for cataracts was 2.91%o-7.38%0. After sex, age, hospital accreditation level, and hospital ownership were controlled, the odds of hospitalization for neoplasms and circulatory diseases among the RTs were nonsignificantly higher than those of pharmacists, and the odds of outpatient visits for cataracts among the RTs were nonsignificantly lower than those of pharmacists

Conclusion: No sufficient evidence exists to substantiate the argument that the exposure of RTs to current doses of radiation could increase the risk of neoplasms, circulatory diseases, and cataracts. Considering the increased use of radiation treatment in current medical facilities, all speculation on occupational radiation-induced diseases must be further investigated and verified

Is the Linear No-Threshold Dose-Response Paradigm Still Necessary for the Assessment of Health Effects of Low Dose Radiation?

Inevitable human exposure to ionizing radiation from man-made sources has been increased with the proceeding of human civilization and consequently public concerns focus on the possible risk to human health. Moreover, Fukushima nuclear power plant accidents after the 2011 East-Japan earthquake and tsunami has brought the great fear and anxiety for the exposure of radiation at low levels, even much lower levels similar to natural background. Health effects of low dose radiation less than 100 mSv have been debated whether they are beneficial or detrimental because sample sizes were not large enough to allow epidemiological detection of excess effects and there was lack of consistency among the available experimental data. We have reviewed an extensive literature on the low dose radiation effects in both radiation biology and epidemiology, and highlighted some of the controversies therein. This article could provide a reasonable view of utilizing radiation for human life and responding to the public questions about radiation risk. In addition, it suggests the necessity of integrated studies of radiobiology and epidemiology at the national level in order to collect more systematic and profound information about health effects of low dose radiation.

Rebuttal to Authors' Reply, Re: Cancer Risk in Adult Residents Near Nuclear Power Plants in Korea: A Cohort Study of 1992-2010

No abstract available.

Cancer Risk among Population near Nuclear Power Plants in Korea

No abstract available.

Risks of Lung Cancer due to Radon Exposure among the Regions of Korea

Radon is likely the second most common cause of lung cancer after smoking. We estimated the lung cancer risk due to radon using common risk models. Based on national radon survey data, we estimated the population-attributable fraction (PAF) and the number of lung cancer deaths attributable to radon. The exposure-age duration (EAD) and exposure-age concentration (EAC) models were used. The regional average indoor radon concentration was 37.5 95 Bq/m3. The PAF for lung cancer was 8.3% (European Pooling Study model), 13.5% in males and 20.4% in females by EAD model, and 19.5% in males and 28.2% in females by EAC model. Due to differences in smoking by gender, the PAF of radon-induced lung cancer deaths was higher in females. In the Republic of Korea, the risk of radon is not widely recognized. Thus, information about radon health risks is important and efforts are needed to decrease the associated health problems.

Thyroid Cancer: We Need a Carcinogen-specific Genome Study

No abstract available.

Re: Cancer Risk in Adult Residents Near Nuclear Power Plants in Korea: A Cohort Study of 1992-2010

No abstract available.

Cancer Risk in Adult Residents near Nuclear Power Plants in Korea: A Cohort Study of 1992-2010

This study evaluated cancer risk for adult residents near Nuclear Power Plants (NPPs) in Korea through a valid prospective cohort study during 1992-2010. The study cohort was composed of 11,367 adults living within a five km radius from the NPPs for the exposed and 24,809 adults for the non-exposed or reference cohort set at two different levels of proximity; 5-30 km radius and more than 30 km radius away from NPPs. In 303,542.5 person-years of follow-up, a total of 2,298 cancer cases of all sites, or 1,377 radio-inducible cancers diagnosed during 1992-2008 were ascertained. Multiple adjusted hazard ratios and 95% confidence intervals were estimated using multivariate Cox proportional hazard model. There were no epidemiological evidence for increased risk of cancer due to radiation from NPPs. Radiological study results or surveillance data of radiation doses around NPPs could be well documented for risk estimation of radio-inducible cancers, instead of epidemiological study results of the long-time required. Continuous surveillance of quantitative measures of dose levels around NPPs and radiation exposures to the residents is warranted.

Cutaneous melanoma in Latin America: the need for more data / El melanoma cutâneo en América Latina: la necesidad de mßs datos

OBJECTIVE: To identify the scientific literature on cutaneous melanoma in Latin America and compile all available epidemiologic data to demonstrate the need for reliable regional and country-specific data on incidence and mortality estimates. METHODS: Literature searches were conducted in PubMed, Embase, LILACS, and Google Scholar databases for epidemiologic studies from 1 January 2000 to 31 October 2010 related to melanoma in Argentina, Brazil, Colombia, Mexico, Puerto Rico, and Venezuela. A final search on melanoma cases was carried out using country-specific population-based cancer registries. No statistical analyses were conducted. RESULTS: For all six countries, most epidemiological research on cutaneous melanoma consists of hospital-based or case-control studies. Very few studies report incidence and mortality rates. Attempts to estimate disease rates have relied on national incidence and mortality data and information extracted from cancer registries. While predominance of European ancestry is a known risk factor for developing melanoma, the association of melanoma and ethnicity is not well-documented in some of the populations reviewed. Latin Americans are frequently exposed to ultraviolet (UV) radiation due to the tropical weather, high altitude, and thinning ozone layer in some regions. Tanned skin is viewed as healthy and beautiful. While melanoma public health campaigns have been under way in Latin America for decades, increasing melanoma awareness remains imperative. CONCLUSIONS: There is an urgent need to collect accurate epidemiologic melanoma data in Latin America. Future research in the region should include more comprehensive, countryspecific, population-based studies to allow for comparative evaluation of incidence and mortality rates.

OBJETIVO: Identificar la literatura científica sobre el melanoma cutßneo en América Latina y recopilar todos los datos epidemiológicos disponibles, con objeto de demostrar la necesidad de información fiable a escala regional y de país sobre los datos de incidencia y mortalidad. MÉTODOS: Se realizaron búsquedas bibliogrßficas en las bases de datos PubMed, Embase, LILACS y Google Scholar para encontrar estudios epidemiológicos relacionados con el melanoma llevados a cabo del 1 de enero del 2000 al 31 de octubre del 2010 en Argentina, Brasil, Colombia, México, Puerto Rico y Venezuela. Se efectuó una búsqueda final de casos de melanoma mediante la consulta de los registros poblacionales de cßncer de cada país. No se realizó ningún anßlisis estadístico. RESULTADOS: En los seis países, la mayor parte de la investigación epidemiológica sobre el melanoma cutßneo consiste en estudios hospitalarios o estudios de casos y testigos. Muy pocos estudios informan sobre las tasas de incidencia y mortalidad. Los intentos de calcular las tasas de la enfermedad se han basado en los datos nacionales de incidencia y mortalidad, y en la información extraída de los registros de cßncer. Aunque el predominio de la ascendencia europea constituye un conocido factor de riesgo de melanoma, la asociación entre el melanoma y el grupo étnico no puede demostrarse adecuadamente en algunas de las poblaciones estudiadas. Los latinoamericanos estßn frecuentemente expuestos a la radiación ultravioleta como consecuencia del clima tropical, la elevada altitud y la disminución de la capa de ozono en algunas regiones. La piel bronceada se considera como saludable y bella. Aunque hace decenios que se llevan a cabo campa±as de salud pública dedicadas al melanoma en América Latina, es indispensable incrementar la conciencia de esta enfermedad. Conclusiones: Existe la urgente necesidad de recopilar datos epidemiológicos precisos sobre el melanoma en América Latina. Las futuras actividades...

Primary cutaneous melanoma: an 18-year study

BACKGROUND: Primary cutaneous melanoma still constitutes the main cause of skin cancer death in developed countries, and its incidence in recent years has been increasing in a steady, worrisome manner. OBJECTIVES: This study evaluated the clinical, epidemiological and demographic aspects of this disease, and correlated them with patient prognosis. METHODS: Using epidemiologic and clinical data, we analyzed 84 patients with mild to severe primary cutaneous melanoma treated between 1990 and 2007. Slides containing surgical specimens were analyzed, and new slides were made from archived paraffin sections when necessary. RESULTS: The melanoma incidence was higher in areas of sun exposure, with lesions commonly observed in the trunk for males, and lower limbs for females. In addition to Breslow's thickness and ulceration (p = 0.043 and p < 0.001, respectively), the mitotic rate per mm² also correlated with worse patient outcome (p = 0.0007). The sum of ulceration (0 when absent or 1 when present), the Breslow index (1 when <1 mm, 2 when >1 mm and <4 mm, 3 when >4 mm) and the mitotic index (0 when absent or 1 when >1 per mm²) allowed the establishment of a prognostic score: if the sum was equal to or over three, nearly all (91.7 percent) patients had systemic disease. The 5-year survival was approximately seventy percent. CONCLUSION: Because American Join Committee of Cancer Staging will update the classification of malignant tumors (TNM) staging in the near future, and introduce mitosis as a prognostic factor, our results show the importance of such a feature. Additional studies are necessary to confirm the importance of a prognostic score as proposed herein.

Power Estimation and Follow-Up Period Evaluation in Korea Radiation Effect and Epidemiology Cohort Study / 예방의학회지

OBJECTIVES: The objective of this study was to calculate sample size and power in an ongoing cohort, Korea radiation effect and epidemiology cohort (KREEC). METHOD: Sample size calculation was performed using PASS 2002 based on Cox regression and Poisson regression models. Person-year was calculated by using data from '1993-1997 Total cancer incidence by sex and age, Seoul' and Korean statistical informative service. RESULTS: With the assumption of relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, sample size calculation was 405 events based on a Cox regression model. When the relative risk was assumed to be 1.5 then number of events was 170. Based on a Poisson regression model, relative risk=1.3, exposure:non-exposure=1:2 and power=0.8 rendered 385 events. Relative risk of 1.5 resulted in a total of 157 events. We calculated person-years (PY) with event numbers and cancer incidence rate in the non-exposure group. Based on a Cox regression model, with relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, 136 245PY was needed to secure the power. In a Poisson regression model, with relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, person-year needed was 129517PY. A total of 1939 cases were identified in KREEC until December 2007. CONCLUSIONS: A retrospective power calculation in an ongoing study might be biased by the data. Prospective power calculation should be carried out based on various assumptions prior to the study.

Ionizing Radiation-induced Diseases in Korea

Radiation risk has become well known through epidemiological studies of clinically or occupationally exposed populations, animal experiments, and in vitro studies; however, the study of radiation related or induced disease has been limited in Korea. This study is to find the level of occupational radiation exposure for various kinds of accidents, compensated occupational diseases, related studies, and estimations on future occupational disease risks. Research data of related institutions were additionally investigated. About 67% of 62,553 radiation workers had no exposure or less than 1.2 mSv per year. The 5 reported cases on radiation accident patients in Korea occurred during nondestructive testing. According to the recent rapid increase in the number of workers exposed to radiation, a higher social recognition of cancer, and an increasing cancer mortality rate, it is expected that occupational disease compensation will rapidly increase as well. Therefore, it is important to develop scientific and objective decision methods, such as probability of causation and screening dose in the establishment of an exposure and health surveillance system.

An epidemiological review of mobile telephones and cancer.

Mobile telecommunication technology became commercially available about 20-25 years ago in different countries around the world. The industry has grown exponentially over the years and, currently, the number of mobile phone users is estimated to be over 3.8 billion, more than half the world's population. Thus, because of such a large population-at-risk, any health hazard from these devices promises to have a large epidemiological impact. Intense speculation and investigation into the relationship between mobile phone usage and cancer has led to the publication of numerous, often contradictory, reports on this subject. This review aims to provide a large body of reported evidence to help medical professionals disseminate evidence-based information to their patients.

Análisis de la densidad y distribución anatómica de nevos melanocíticos adquiridos, en adolescentes del estrato socioeconómico bajo de Santiago de Chile / Body distribution and density of acquired melanocytic nevi in adolescents of low socioeconomic stratus of Santiago, Chile

Background: There is an increase in the incidence of malignant melanoma in Chile. Previous studies have shown that the density and size of acquired melanocytic nevi (AMN) are a risk factor for developing malignant melanoma. Aim: To assess the number and anatomical distribution of acquired melanocytic nevi in Chilean adolescents. Material and methods: The number of AMN was counted in 30 anatomical sites in 201 Chilean school children (111 females), aged from 11 to 15 years. The number oí small AMN (2-4.9 mm) and large AMN (>5 mm ofdiameter) was determined. Results: Mean AMN number per person was 32.7 (95 percent confidence interval (CI) 30.7-42.3) in males and 29 (95 percent CI 271-38.6) in females (p =NS). Males had a higher number of AMN in the face, neck and trunk. Females had a higher number of AMN in the upper and lower limbs. Older children, adolescents with history of sunburns and with lighter skin had a higher number of total, small and large nevi. Conclusions: The average number ofAMNfound in this study is similar to that reported in the literature. The differences in site distribution between males and femalesmay be explainedby a differentsun exposurepattern.

Childhood thyroid cancer in Belarus, Russia, and Ukraine after Chernobyl and at present

Thyroid cancer in children is usually rare, but in the individuals exposed to radiation risk of disease increases considerably. After the Chernobyl accident in 1986, an over 10-fold maximal elevation in the incidence of thyroid cancer was registered about a decade later, cumulatively resulting in more than a thousand of newly diagnosed cases in children who lived in the territories of Belarus, Russia, and Ukraine affected by radioactive fallouts. Experience from the epidemic substantially promoted knowledge in clinical pediatric oncology, pathology and basic sciences. This article overviews epidemiology, clinical features, results of treatment and follow-up of childhood patients with radiation-induced Chernobyl thyroid cancer in comparison to sporadic cases diagnosed at present. In addition, we discuss general issues of pathology and molecular findings in childhood thyroid carcinomas.

O câncer de tiróide é habitualmente raro em crianças, mas em indivíduos expostos a radiação o risco da doença aumenta consideravelmente. Cerca de uma década após o acidente de Chernobil, em 1986, foi registrado um aumento de mais de 10 vezes na incidência de câncer de tiróide, resultando cumulativamente em mais de mil novos casos diagnosticados em crianças que viviam nos territórios da Bielorrússia, Russia, e Ucrânia, afetadas pela chuva radioativa. A experiência com essa epidemia resultou em conhecimento substancial de oncologia pediátrica clínica, patologia e ciências básicas. Este artigo analisa a epidemiologia, os achados clínicos, os resultados do tratamento e a evolução de pacientes pediátricos com câncer de tiróide induzido pela radiação de Chernobil, em comparação com casos esporádicos diagnosticados atualmente. Adicionalmente, serão discutidos tópicos de patologia e achados moleculares no carcinoma de tiróide infantil.

High resolution computed tomography findings on the lung of early breast-cancer patients treated by postoperative breast irradiation with a hypofractionated radiotherapy schedule.

CONTEXT: Hypofractionated breast radiotherapy (RT), although convenient for patients and health care systems, could have a negative impact on normal tissues such as lung. Aims: To evaluate radiation-induced lung toxicity in early breast-cancer patients treated by hypofractionated RT. SETTINGS AND DESIGN: We have been using the 42.5 Gy/16 fractions RT schedule since May 2003. As large fraction size is related to increased normal tissue toxicity we intended to investigate the possible radiation-induced lung toxicity to these patients, by performing high-resolution computed tomography (HRCT) 6 months after the completion of the treatment. METHODS AND MATERIAL: A group of 30 consecutive early breast cancer patients (T1-2N0M0) have been treated by the above-mentioned RT schedule, using a pair of opposing tangential fields. The impact of chemotherapy and hormonotherapy and various breast size-related parameters on HRCT lung changes were investigated. Acute skin and breast tissue reactions were also recorded. STATISTICAL ANALYSIS USED: Correlation of numerical variables was investigated by Pearson correlation coefficient. Logistic regression analysis was used to investigate correlation between HRCT findings (present vs absent) with other variables. RESULTS: Minimal HRCT findings were evident in 15/30 patients. These included small septal lines, linear and subpleural opacities and to a lesser extend, focal-ground glass opacification. The HRCT findings were positively correlated only to field separation (distance between the entrance points of the tangential beams on the breast) (H.R.=1.33, 95% CI: 1.013-1.75). CONCLUSIONS: The short 16-fraction RT schedule for early breast-cancer patients appears to have a minor effect on the underlying lung parenchyma.