• Asian Pacific Journal of Cancer Prevention
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• 제17권11호
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• pp.4913-4916
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• 2016

Objective: As a source of information, medical data can feature hidden relationships. However, the high volume of datasets and complexity of decision-making in medicine introduce difficulties for analysis and interpretation and processing steps may be needed before the data can be used by clinicians in their work. This study focused on the use of Bayesian models with different numbers of nodes to aid clinicians in breast cancer risk estimation. Methods: Bayesian networks (BNs) with a retrospectively collected dataset including mammographic details, risk factor exposure, and clinical findings was assessed for prediction of the probability of breast cancer in individual patients. Area under the receiver-operating characteristic curve (AUC), accuracy, sensitivity, specificity, and positive and negative predictive values were used to evaluate discriminative performance. Result: A network incorporating selected features performed better (AUC = 0.94) than that incorporating all the features (AUC = 0.93). The results revealed no significant difference among 3 models regarding performance indices at the 5% significance level. Conclusion: BNs could effectively discriminate malignant from benign abnormalities and accurately predict the risk of breast cancer in individuals. Moreover, the overall performance of the 9-node BN was better, and due to the lower number of nodes it might be more readily be applied in clinical settings.

• Asian Pacific Journal of Cancer Prevention
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• 제17권sup3호
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• pp.191-195
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• 2016

Breast cancer is the most frequent cancer in females. Its incidence is higher in developed countries than in developing ones partly due to variation in risk exposure and partly due to better detection methods. Scattered evidence in Basrah, Iraq, suggests that breast cancer has been increasing at a significant pace in recent years. This study aimed to measure the current level of risk of breast cancer among females in Basrah and to describe the time trend over almost a decade of years. Data on breast cancer cases from all sources of cancer registration in Basrah governorate were compiled for the years 2005-2012. The data for each year were first checked separately for duplicate reporting of cases among various sources. Then the eight files were pooled together and checked again for any duplicate cases among years of registration. The final set of data contained 2,284 cases of breast cancer (2,213 female cases and 71 male cases). All patients were inhabitants of Basrah governorate at the time of diagnosis. Figures on the Basrah population were obtained from various sources including the Ministry of Health, Ministry of Planning and Developmental Collaboration and local household surveys. It was possible to have total population estimates for each year and by age and sex. The data were imported into SPSS (version 17) software. Age specific and year specific incidence rates were calculated. The age standardized incidence rate was also calculated using world population as the standard population to be 34.9 per 100,000 females. Age-wise, no case was reported among children aged less than 15 years and the incidence increased with advancing age reaching a peak of 123.8/100,000 females at the age range of 50-54 years. The time trend of the crude incidence rate showed only modest increased risk with passage of years and no age shift could be documented in this study. Breast cancer in females in Basrah is a significant health problem. The current incidence rate (crude, 23.7/100,000, age-standardized, 34.9/100,000) is high and justifies intensive efforts to improve early detection of cases, provide better treatment amenities and introduce long term preventive measures. Using the age standardized incidence rate as reported in this paper, it is possible to put the risk in Basrah within a regional and international context.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6591-6593
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• 2013

Background: Environmental tobacco smoking (ETS) significantly contributes to morbidity and mortality and is a known risk factor for lung cancer development in lifelong nonsmokers. The metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides (NNAL-Glucs) have now emerged as leading biomarkers for the study of carcinogen exposure in non-smokers exposed to ETS. Materials and Methods: We carried out our study on NNAL in the urine of non-smokers exposed to ETS and the association between ETS and lung cancer. Subjects were enrolled from 2008-2010. NNAL was analyzed for 74 non-smoking lung cancer and 85 healthy controls. The main objective of this study was to provide an estimate of the risk of lung cancer from exposure to ETS in the Korean population. Results: The mean NNAL concentration in urine was significantly lower in non-smoking patient groups (n=74) than in control groups (n=85) ($4.7{\pm}15.0$ pg/mg, $6.5{\pm}17.9$ pg/mg, respectively, Mann-Whitney U test, p<0.001). Conclusions: The urine NNAL of non-smoking patients with lung cancer was not elevated with regard to the non-smoking control group. This may be due to life-style changes after diagnosis. A prospective study will be needed to evaluate the association of NNAL and non-smoking lung cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.5671-5674
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• 2013

Incidence of breast cancer shows geographical variation, even within areas of ethnic homogeneity. Saudi Arabia has witnessed an increase in occurrence of breast cancer in its unexplored ethnic populations over the past few years. We aimed at determining whether any association exists between single nucleotide polymorphisms in breast cancer associated gene 1 (BRCA1) and breast cancer associated gene 2 (BRCA2) and the risk of breast cancer. TaqMan based Real Time Polymerase chain reaction genotyping assays were used to determine the frequency of single nucleotide polymorphisms in BRCA1 (rs799917) and BRCA2 (rs144848) in a group of 100 breast cancer patients and unaffected age matched controls of Saudi Arabian origin. The present data revealed that neither BRCA1 nor the BRCA2 studied variant show any significant association with the disease. This study failed to find any role of the concerned variants in breast cancer either as risk or as prognostic factors. The small number of patients registered was one of the limitations of this study. In summary, comparison of mutation profile with other ethnic populations and regions reflected both differences and similarities indicating co-exposure to a unique set of risk factors. The differences could be due to exposure to particular environmental carcinogens; different lifestyle, reproductive pattern; dietary or cultural practices of Saudi Arabian women that need further investigations.

• 환경생물
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• 제34권4호
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• pp.353-360
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• 2016

중금속 Cd, Cu 및 Zn이 해산로티퍼(Brachionus plicatilis)의 생존율 및 개체군 성장률에 미치는 영향을 알아보기 위하여 중금속 3종에 대한 독성평가를 수행하였다. 중금속에 24시간 노출하였을 때 Cd, Cu 및 Zn에 대한 생존율은 40.00, 0.13 및 $10.00mg\;L^{-1}$ 농도에서 급격한 감소가 시작되어 농도의존적으로 감소하였고, 중금속에 72시간 노출한 개체군 성장률도 Cd, Cu 및 Zn의 12.50, 0.06 및 $1.00mg\;L^{-1}$ 농도에서 급격한 감소가 시작되어, 중금속 3종에서 모두 농도의존적으로 감소하였다. Cd, Cu 및 Zn에 노출된 개체군 성장률의 $EC_{50}$ 값은 각각 21.41, 0.12 및 $6.15mg\;L^{-1}$이며, 독성의 세기는 Cu>Zn>Cd로 생존율과 개체군 성장률이 동일하였다. 또한 Cd, Cu 및 Zn에 대한 개체군 성장률의 LOEC는 각각 6.25, 0.03 및 $0.10mg\;L^{-1}$, NOEC는 각각 12.50, 0.06 및 $1.00mg\;L^{-1}$로 나타났다. 해양환경에서 개체군 성장률의 LOEC를 초과하는 농도가 B. plicatilis에게 독성영향을 미칠 수 있다고 판단되며, NOEC와 $EC_{50}$ 값은 혼합독성을 판단하기 위한 WET test와 해양생태계 내 생물에게 영향을 미치는 중금속 독성에 대한 가이드라인으로 활용될 수 있을 것이다.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.44.1-44.11
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• 2023

Background: A series of breast cancer cases were recently reported in a tertiary university hospital in South Korea. Nurses are generally exposed to risk factors for breast cancer such as night shift work, antineoplastic agents, and job strain. However, the epidemiological evidence of excess incidence among nurses remains lacking. This study aims to investigate the excess incidence of breast cancer among nurses in a tertiary university hospital and provide epidemiological evidence of occupational risk factors. Methods: A retrospective cohort was developed using personnel records of female workers in the nursing department who worked from January 2011 to June 2021 in a tertiary university hospital in South Korea. Sick leave records were used to identify cases of breast cancer. The standardized incidence ratio of breast cancer among nurses was compared to the general population. Results: A total of 5,509 nurses were followed up for 30,404 person-years, and 26 breast cancer cases were identified. This study revealed a significantly increased breast cancer incidence among all included nurses, with a standardized incidence ratio of 1.65 (95% confidence interval [CI]: 1.08-2.41), compared to the general population. Workers, who handle antineoplastic agents in their representative department and current and/or former department, had significantly elevated breast cancer standardized incidence ratios of 2.73 (95% CI: 1.008-5.94) and 3.39 (95% CI: 1.46-6.68), respectively. Conclusions: This study provides significant evidence of increased breast cancer risk among nursing staff in a hospital setting, particularly those who handle antineoplastic drugs. Measures that reduce exposure to risk factors should be implemented, especially anticancer drugs, to protect healthcare professionals. Further research at a national level that focuses on healthcare workers is necessary to validate breast cancer incidence and its contributing factors.

• Safety and Health at Work
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• 제7권3호
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• pp.208-212
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• 2016

Background: Outdoor workers are at risk of high ultraviolet radiation exposure, and may have difficulty using sun protection. The objectives were to determine the prevalence of sun protection behaviors in a sample of outdoor construction workers, and to assess which factors predict better sun protection practices. Methods: Participants were recruited via construction unions. Workers answered a questionnaire on demographics, skin cancer risk, sun protection behaviors, and job. Sun protection behavior scores (from questions on sunscreen use, sleeved shirt, hat, shade seeking, sunglasses) were calculated by converting Likert-scale answers to scores from 0 to 4, and taking the mean (separately for work and leisure). Determinants of sun protection behavior scores were examined for work and leisure using generalized linear models. Results: Seventy-seven workers had complete questionnaire data (participation 98%). Sun protection behaviors used most often were hats (79% often/always) and sleeved shirts (82% often/always); least prevalent were shade-seeking (8% often/always) and sunscreen (29% often/always). For both work and leisure scores, the strongest predictor was skin type, with fairer-skinned individuals having higher sun protection behavior scores. Workers had higher scores at work than on weekends. Workplaces that required hats and sleeved shirts for safety purposes had higher protection behavior scores. Conclusion: This high-participation rate cohort helps characterize sun protection behaviors among outdoor workers. Workers practiced better sun protection at work than on weekends, suggesting that workplace policies supportive of sun protection could be useful for skin cancer prevention in the construction industry.

• 한국환경보건학회지
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• 제47권5호
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• pp.486-495
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• 2021

Background: Particulate matter (PM) is one of the leading causes of premature death worldwide. Previous studies in South Korea have applied a relative risk calculated from Western populations when estimating the disease burden attributable to PM. However, the relative risk of PM on health outcomes may not be the same across different countries or regions. Objectives: This study aimed to estimate the premature deaths and socioeconomic costs attributable to long-term exposure to PM in South Korea. We considered not only the difference in PM concentration between regions, but also the difference in relative risk. Methods: National monitoring data of PM concentrations was obtained, and missing values were imputed using the AERMOD model and linear regression model. As a surrogate for relative risk, hazard ratios (HRs) of PM for cardiovascular and respiratory mortality were estimated using the National Health Insurance Service-National Sample Cohort. The nation was divided into five areas (metropolitan, central, southern, south-eastern, and Gangwon-do Province regions). The number of PM attributable deaths in 2018 was calculated at the district level. The socioeconomic cost was derived by multiplying the number of deaths and the statistical value of life. Results: The average PM₁₀ concentration for 2014~2018 was 45.2 ㎍/m³. The association between long-term exposure to PM₁₀ and mortality was heterogeneous between areas. When applying area-specific HRs, 23,811 premature deaths from cardiovascular and respiratory disease in 2018 were attributable to PM₁₀ (reference level 20 ㎍/m³). The corresponding socioeconomic cost was about 31 trillion won. These estimated values were higher than that when applying nationwide HRs. Conclusions: This study is the first research to estimate the premature mortality caused by long-term exposure to PM using relative risks derived from the national population. This study will help precisely identify the national and regional health burden attributed to PM and establish the priorities of air quality policy.

• 환경생물
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• 제36권3호
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• pp.392-399
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• 2018

해산로티퍼(Brachionus plicatilis)의 생존 및 개체군 성장률(r)을 사용하여 Zinc undecylenate (ZU)에 대한 독성평가를 실시하였다. 24 h 동안 ZU에 노출된 B. plicatilis의 생존율은 실험 최고농도 $100mg\;L^{-1}$에서도 영향이 나타나지 않았으나, ZU에 72 h 노출된 개체군 성장률(r)은 농도 의존적으로 감소하는 경향을 나타내, $12.5mg\;L^{-1}$에서 유의적인 감소를 나타냈고 최고농도 $50.0mg\;L^{-1}$에서 개체군 성장률이 90% 이상 감소되었다. ZU에 노출된 B. plicatilis의 개체군 성장률의 반수영향농도($EC_{50}$)값은 $26.4mg\;L^{-1}$, 무영향농도(NOEC)는 $6.3mg\;L^{-1}$, 최소영향농도(LOEC)는 $12.5mg\;L^{-1}$로 나타났다. 자연생태계 내에서 ZU 물질이 해수 중에서 $12.5mg\;L^{-1}$ 이상을 초과하여 나타낼 때 B. plicatilis와 같은 동물성플랑크톤의 개체군 성장률이 영향을 받을 것으로 판단되며, 이러한 연구결과는 신방오도료물질의 생태안정성 평가를 위한 기준치 설정 및 다른 방오도료물질과의 독성치를 비교할 수 있는 유용한 자료로 활용될 것으로 판단된다.

• Safety and Health at Work
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• 제8권3호
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• pp.258-266
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• 2017

Background: Welders are exposed to many known and suspected carcinogens. An excess lung cancer risk among welders is well established, but whether this is attributable to welding fumes is unclear. Excess risks of other cancers have been suggested, but not established. We investigated welding cancer risks in the population-based Canadian Census Health and Environmental Cohort. Methods: Among 1.1 million male workers, 12,845 welders were identified using Standard Occupational Classification codes and followed through retrospective linkage of 1991 Canadian Long Form Census and Canadian Cancer Registry (1992-2010) records. Hazard ratios (HRs) were calculated using Cox proportional hazards models based on estimated risks of lung cancer, mesothelioma, and nasal, brain, stomach, kidney, and bladder cancers, and ocular melanoma. Lung cancer histological subtypes and risks by industry group and for occasional welders were examined. Some analyses restricted comparisons to blue-collar workers to minimize effects of potential confounders. Results: Among welders, elevated risks were observed for lung cancer [HR: 1.16, 95% confidence interval (CI): 1.03-1.31], mesothelioma (HR: 1.78, 95% CI: 1.01-3.18), bladder cancer (HR: 1.40, 95% CI: 1.15-1.70), and kidney cancer (HR: 1.30, 95% CI: 1.01-1.67). When restricted to blue-collar workers, lung cancer and mesothelioma risks were attenuated, while bladder and kidney cancer risks increased. Conclusion: Excess risks of lung cancer and mesothelioma may be partly attributable to factors including smoking and asbestos. Welding-specific exposures may increase bladder and kidney cancer risks, and particular sources of exposure should be investigated. Studies that are able to disentangle welding effects from smoking and asbestos exposure are needed.