OBJECTIVES: We conducted a meta-analysis to investigate the relationship between low external doses of ionizing radiation exposure and the risk of cancer mortality among nuclear power plant workers. METHODS: We searched MEDLINE using key words related to low dose and cancer risk. The selected articles were restricted to those written in English from 1990 to January 2009. We excluded those studies with no fit to the selection criteria and we included the cited references in published articles to minimize publication bias. Through this process, a total of 11 epidemiologic studies were finally included. RESULTS: We found significant decreased deaths from all cancers (SMR = 0.75, 95% CI = 0.62 - 0.90), all cancers excluding leukemia, solid cancer, mouth and pharynx, esophagus, stomach, rectum, liver and gallbladder, pancreas, lung, prostate, lymphopoietic and hematopoitic cancer. The findings of this meta-analysis were similar with those of the 15 Country Collaborative Study conducted by the International Agency for Research on Cancer. A publication bias was found only for liver and gallbladder cancer (p = 0.015). Heterogeneity was observed for all cancers, all cancers excluding leukemia, solid cancer, esophagus, colon and lung cancer. CONCLUSIONS: Our findings of low mortality for stomach, rectum, liver and gallbladder cancers may explained by the health worker effect. Yet further studies are needed to clarify the low SMR of cancers, for which there is no useful screening tool, in nuclear power plant workers.
Humans ; Neoplasms, Radiation-Induced/*mortality ; *Nuclear Power Plants ; Occupational Diseases/*mortality ; Occupational Exposure/adverse effects ; Radiation Monitoring

Chernobyl Nuclear Accident ; Humans ; Japan ; epidemiology ; Neoplasms, Radiation-Induced ; etiology ; mortality ; Nuclear Warfare ; Radiation Dosage ; Radiation Injuries ; etiology ; mortality ; Radioactive Hazard Release ; Risk ; Ukraine ; epidemiology

The risk of radiation-induced cancer adds to anxiety in low-dose exposed populations. Safe and effective lifestyle changes which can help mitigate excess cancer risk might provide exposed individuals the opportunity to pro-actively reduce their cancer risk, and improve mental health and well-being. Here, we applied a mathematical multi-stage carcinogenesis model to the mouse lifespan data using adult-onset caloric restriction following irradiation in early life. We re-evaluated autopsy records with a veterinary pathologist to determine which tumors were the probable causes of death in order to calculate age-specific mortality. The model revealed that in both irradiated and unirradiated mice, caloric restriction reduced the age-specific mortality of all solid tumors and hepatocellular carcinomas across most of the lifespan, with the mortality rate dependent more on age owing to an increase in the number of predicted rate-limiting steps. Conversely, irradiation did not significantly alter the number of steps, but did increase the overall transition rate between the steps. We show that the extent of the protective effect of caloric restriction is independent of the induction of cancer from radiation exposure, and discuss future avenues of research to explore the utility of caloric restriction as an example of a potential post-irradiation mitigation strategy.
Animals ; Anxiety ; Autopsy ; Caloric Restriction* ; Carcinogenesis* ; Carcinoma, Hepatocellular ; Cause of Death ; Life Style ; Mental Health ; Mice ; Models, Theoretical ; Mortality ; Neoplasms, Radiation-Induced ; Radiation Exposure

OBJECTIVETo study the diagnosis and treatment of a second primary malignant tumor induced by previous radiotherapy.

METHODSFrom March 1970 to March 1997, 108 nasopharyngeal cancer (NPC) patients who developed a second primary malignant tumor induced by radiotherapy were treated. There were squamous carcinoma 43 (39.8%), sarcoma 26 (24.1%), malignant fibrous histiocytoma 14 (13.0%), adenoid cystic carcinoma 12 (11.1%), thyroid papillary adenocarcinoma 8 (7.4%) and malignant melanoma 5 (4.6%). Fifty patients underwent operation, 32 received radiotherapy, 18 received chemotherapy and 8 received operation combined with chemotherapy.

RESULTSThe 3- and 5-year tumor-free survival rates were 64.0% and 36.0% in the operation group. They were 34.4% and 18.8% in the radiotherapy group.

CONCLUSIONSurgery, if not contra-indicated, is the first choice for the second primary malignant tumor induced by radiotherapy. Aggressive treatment for these patients is, hence, indicated clinically.

Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Neoplasms, Radiation-Induced ; diagnosis ; mortality ; therapy ; Neoplasms, Second Primary ; diagnosis ; mortality ; therapy ; Radiotherapy ; adverse effects ; Survival Rate

OBJECTIVETo follow up the cohort of a certain factory and analyze the death cause of the employees.

METHODSA dynamic cohort was adopted and the study population consisted of all workers stayed at the factory for more than 1 year. The cohort data was mainly from the personnel ministry in the factory,the death data provided by the personnel ministry,the labour union and the hospital. All cause of death of the all employee and the death condition of radiation group and no-radiation group were analyzed and compared.

RESULTSThe mortality of the workers in the factory was significantly lower than national population, the SMR of all cause of death in all employee, radiation group and no-radiation group were 0.41 (95% CI: 0.37-0.45), 0.24, 0.75 respectively; all cancer death in the three group was 0.59, 0.40 and 0.92. But the death order was different in radiation group and no-radiation group,the order of liver cancer was list first in radiation group, which was unlike that of the nation order and the no-radiation order.

CONCLUSIONThere have no excess death in the factory, but the order of liver cancer is precedence.

Cause of Death ; Cohort Studies ; Female ; Humans ; Male ; Middle Aged ; Neoplasms, Radiation-Induced ; mortality ; Nuclear Reactors ; Occupational Exposure ; Power Plants ; Prospective Studies ; Workplace

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.
Adult ; Demography ; *Environmental Exposure ; Female ; Humans ; Lung Neoplasms/*epidemiology/etiology/mortality ; Male ; Models, Theoretical ; Neoplasms, Radiation-Induced/*epidemiology/etiology ; Radon/*toxicity ; Republic of Korea/epidemiology ; Risk Assessment ; Smoking ; Survival Analysis