Cancer incidence among members of the Norwegian trade union of insulation workers

Insulation work has been described as an occupation with high exposure to asbestos. A cohort of members of the Norwegian Trade Union of Insulation Workers (n = 1116), hired between 1930 and 1975, was established. During 2002, the cohort was linked to the Cancer Registry of Norway. The standardized incidence ratio (SIR) of pleural mesothelioma was 12.9 (95% confidence interval [CI] = 6.0-24.6). Two cases with peritoneal mesotheliomas were found (SIR, 14.8; 95% CI = 1.8-53.4). The SIR of lung cancer was 3.0 (95% CI = 2.3-3.8). Four cases of lung cancer were observed among cork workers without any exposure to asbestos, but to cork dust and tar smoke (SIR, 5.3; 95% CI = 1.5-13.6). Our study showed a high risk of mesothelioma and an elevated risk of lung cancer among members of the Trade Union of Insulation Workers.     

Incidence of cancer among anthophyllite asbestos miners in Finland.

A cohort of 736 male and 167 female workers of two anthophyllite mines in Finland was followed up through the Finnish Cancer Registry for cancer in 1953-91. Compared with the total cancer incidence of the east Finnish population, the men had a raised risk of total cancer (standardised incidence ratio (SIR) 1.7; 95% confidence interval (95% CI) 1.4-1.9), mainly attributable to an excess in lung cancer (SIR 2.8; 95% CI 2.2-3.6). The risk of lung cancer was somewhat higher among workers classified as heavily exposed (SIR 3.2; 95% CI 2.4-4.1) than among those moderately exposed (SIR 2.3; 95% CI 1.5-3.6) and the risk increased with increasing smoking and with increasing time of work with exposure. There were four cases of mesothelioma v 0.1 expected, all in men who smoked and had had a long and heavy asbestos exposure. Among women, a non-significant excess in total cancer (SIR 1.5; 95% CI 0.9-2.4) was found in the subgroup with heavy exposure to asbestos. Anthophyllite asbestos seems to have high potency in the carcinogenesis of lung cancer and low potency in carcinogenesis of mesothelioma in comparison with the other types of asbestos.     

Asbestos, cement, and cancer in the right part of the colon.

OBJECTIVE--The aim was to investigate associations between exposure to mineral fibres and dust, and cancer in subsites within the large bowel. DESIGN--Pooled retrospective cohort studies. SUBJECTS AND SETTINGS--Blue collar workers, employed for at least one year in different trades; asbestos cement or cement workers (n = 2507), other industrial workers (n = 3965), and fishermen (n = 8092). MAIN OUTCOME MEASURES--Standardised incidence ratios (SIRs, national reference rates) were calculated for cause specific cancer morbidity between 1958 and 1989. The observation period began 15 years after first employment. RESULTS--The asbestos cement and cement workers had a slightly increased risk of colorectal cancer (SIR 1.5; 95% confidence interval (95% CI) 1.1-2.0). This was due to an increase only in the right part of the colon (SIR 2.5; 95% CI 1.6-3.8). The ratio of right (7th revision of the International Classification of Diseases ICD-7) 1530-1531)/left (ICD-7 1532-1533) colon cancer among the asbestos cement and cement workers of 4.8 differed significantly from the ratio both among the other blue collar workers (0.4) and among the fishermen (1.5). As the sensitivity and accuracy was insufficient, mortality data did not show the excess of cancers in the right part of the colon. CONCLUSIONS--An increased incidence of cancer in the right part of the colon was evident in the asbestos cement and cement workers. The distribution of cancers within the colon was noticeably different from that in other blue collar workers, indicating that our findings cannot be explained by socioeconomic confounding factors. A detailed and appropriate disease classification, based on incidence data, is necessary in order not to obscure or underestimate effects of exposure in epidemiological studies on colorectal cancer.     

#63 Cancer incidence in the u. s. radiologic technologists health study, 1983–1998

PURPOSE: Few studies have evaluated cancer risk associated with low-dose occupational ionizing radiation exposure to women. We present data on incident cancer risks among a predominantly (77%) female cohort of 73,963 U. S. radiologic technologists followed up from 1983 through 1998.METHODS: Cancer incidence information and data on work history, selected cancer risk factors, personal radiation exposure and other health outcomes were obtained from two mailed questionnaires (administered ~1984 and ~1995). Incident cancers were ascertained from the second survey and supplemented by mortality records. Medical records, obtained for 74% of all self-reported cancers, confirmed the cancer in 85%. We computed standardized incidence ratios (SIR) using cancer incidence rates from the National Cancer Institute's Surveillance Epidemiology and End Results Program.RESULTS: The SIR for all cancers combined in both sexes was 1.04 (95% confidence interval (CI): 1.00, 1.07; n = 3292). The incidence of solid cancers was elevated in women (SIR = 1.06, 95% CI: 1.02, 1.10), but lower than expected among men (SIR = 0.92 , 95% CI 0.85, 0.98). Female technologists had an elevated incidence of breast cancer (SIR = 1.16, 95% CI: 1.09, 1.23). Among both sexes combined, elevated risks were seen for melanoma (SIR = 1.59, 95% CI: 1.38, 1.80) and thyroid cancers (SIR = 1.61, 95% CI: 1.34, 1.88), and decreased risks were observed for buccal cavity/pharynx (SIR = 0.73, 95% CI: 0.55, 0.90), rectum (SIR = 0.62, 95% CI: 0.48, 0.76), and lung (SIR = 0.77, 95% CI: 0.70, 0.85) cancers.CONCLUSION: The elevated risk for breast cancer may be related to occupational radiation exposure. The observed melanoma and thryoid cancer excesses may reflect, at least in part, increased screening among medical workers with easy access to health care.     

Cancer risk in persons with oral cleft--a population-based study of 8,093 cases

The authors conducted a nationwide study of the occurrence of cancer among 8,093 Danish oral cleft cases born in 1936 through 1998 and followed in the Danish Cancer Registry from 1968 through 1998, a total of 175,863 person-years, to assess a possible association between cancer and oral clefts. Observed and expected numbers of cancers among oral cleft cases were summarized as the overall and as 52 site-specific standardized incidence ratios. The expected overall number of all cancers was 131, but 140 incident cancers were found, corresponding to a standardized incidence ratio of 1.07 (95% confidence interval (CI): 0.90, 1.26). Analyses of the 52 sites for all oral cleft cases and analyses stratified for three cleft subgroups and the two sexes revealed only a few significant associations: an increased occurrence of breast cancer among females born with cleft lip and/or cleft palate (standardized incidence ratio (SIR) = 1.52, 95% CI: 1.05, 2.14), primary brain cancer among females born with cleft palate (SIR = 3.11, 95% CI: 1.14, 6.78), and primary lung cancer among males born with both cleft lip and cleft palate (SIR = 2.49, 95% CI: 1.00, 5.14). The results do not provide evidence for an increased overall cancer risk for individuals born with oral clefts.     

Cancer Incidence in World Trade Center Rescue and Recovery Workers, 2001–2008

Background: World Trade Center (WTC) rescue and recovery workers were exposed to a complex mix of pollutants and carcinogens.Objective: The purpose of this investigation was to evaluate cancer incidence in responders during the first 7 years after 11 September 2001.Methods: Cancers among 20,984 consented participants in the WTC Health Program were identified through linkage to state tumor registries in New York, New Jersey, Connecticut, and Pennsylvania. Standardized incidence ratios (SIRs) were calculated to compare cancers diagnosed in responders to predicted numbers for the general population. Multivariate regression models were used to estimate associations with degree of exposure.Results: A total of 575 cancers were diagnosed in 552 individuals. Increases above registry-based expectations were noted for all cancer sites combined (SIR = 1.15; 95% CI: 1.06, 1.25), thyroid cancer (SIR = 2.39; 95% CI: 1.70, 3.27), prostate cancer (SIR = 1.21; 95% CI: 1.01, 1.44), combined hematopoietic and lymphoid cancers (SIR = 1.36; 95% CI: 1.07, 1.71), and soft tissue cancers (SIR = 2.26; 95% CI: 1.13, 4.05). When restricted to 302 cancers diagnosed ≥ 6 months after enrollment, the SIR for all cancers decreased to 1.06 (95% CI: 0.94, 1.18), but thyroid and prostate cancer diagnoses remained greater than expected. All cancers combined were increased in very highly exposed responders and among those exposed to significant amounts of dust, compared with responders who reported lower levels of exposure.Conclusion: Estimates should be interpreted with caution given the short follow-up and long latency period for most cancers, the intensive medical surveillance of this cohort, and the small numbers of cancers at specific sites. However, our findings highlight the need for continued follow-up and surveillance of WTC responders.     

Incidence of cancer among the participants of the Finnish Asbestos Screening Campaign

OBJECTIVES: Cancer risk has been estimated for asbestos production workers or other heavily exposed asbestos workers in numerous studies. The bulk of the asbestos epidemic results come, however, from past intermittent exposures during asbestos product use. This study concentrated on estimating the risk of cancer in such a population. METHODS: Altogether 23285 men and 930 women invited to a nationwide screening campaign for benign asbestos-related diseases in 1990-1992 were followed for cancer through the Finnish Cancer Register up to 1998. Standardized incidence ratios (SIR) were calculated in comparison with the total Finnish population. RESULTS: Altogether 1392 cases of cancer were found among the men. The risk was slightly, but significantly elevated for lung cancer [SIR 1.14, 95% confidence interval (95% CI) 1.01-1.26), mesothelioma (SIR 2.77, 95% CI 1.66-4.31), and prostate cancer (SIR 1.21, 95% CI 1.09-1.34). The risk of lung cancer was slightly higher among the invited nonparticipants (SIR 1.48, 95% CI 1.20-1.79) than among the participants (SIR 1.02, 95% CI 0.88-1.17). About 98% of the lung cancers occurred in current or ex-smokers. CONCLUSIONS: In a population of long-term construction workers, the risk of lung cancer and mesothelioma was increased, but considerably lower than among insulators, asbestos sprayers, or patients with asbestosis. As it was not possible to follow most of the invited nonparticipants in the original screening study, selection bias by smoking or other life-style factors possibly correlated to the individual's decision to participate in the health screening cannot be excluded.     

Cohort study of cancer risk among male and female shift workers

OBJECTIVES: Melatonin, a hormone that inhibits experimentally induced cancers, is suppressed by nighttime exposure to light so that nighttime shift workers may be at an increased risk of cancer. Previous studies of shift workers found an increased risk of breast cancer among women and suggested a possible increased risk of colon cancer among women and prostate cancer. The present study was conducted to see whether these previous findings could be confirmed and whether shift workers are at elevated risk for cancer at additional sites. METHODS: Altogether 2 102 126 male and 1 148 661 female workers were identified who worked in both 1960 and 1970. Their jobs were classified according to the percentage of shift workers, and they were followed from 1971 through 1989 or until they were diagnosed with cancer or died. Standardized incidence ratios (SIR) were used to compare the adjusted cancer incidence rates for shift workers with those for nonshift workers. RESULTS: Cancer rates were not elevated for the male shift workers [all sites combined: N=6524 cases among shift workers, SIR 1.02, 95% confidence interval (95% CI) 1.00-1.05; prostate: N=1319, SIR 1.04, 95% CI 0.99-1.10] or for the female shift workers (all sites combined: N=268, SIR 1.00, 95% CI 0.89-1.13; breast: N=70 cases, SIR 0.94, 95% CI 0.74-1.18). CONCLUSIONS: No evidence was found for an association between shift work and breast or prostate cancer, or all cancer sites combined among shift workers.     

Cancer Incidence among Former Love Canal Residents

Background

The Love Canal was a rectangular 16-acre, 10-ft-deep chemical waste landfill situated in a residential neighborhood in Niagara Falls, New York. This seriously contaminated site came to public attention in 1978. Only one prior study examined cancer incidence in former residents of the Love Canal neighborhood (LC).

Objective

In this study we aimed to describe cancer incidence in former LC residents from 1979 to 1996 and to investigate whether it differs from that of New York State (NYS) and Niagara County (NC).

Methods

From 1978 to 1982, we interviewed 6,181 former residents, and 5,052 were eligible to be included in this study. In 1996, we identified 304 cancer diagnoses in this cohort using the NYS Cancer Registry. We compared LC cancer incidence with that of NYS and NC using standardized incidence ratios (SIRs), and we compared risks within the LC group by potential exposure to the landfill using survival analysis.

Results

SIRs were elevated for cancers of the bladder [SIR_NYS = 1.44; 95% confidence interval (CI), 0.91–2.16] and kidney (SIR_NYS = 1.48; 95% CI, 0.76–2.58). Although CIs included 1.00, other studies have linked these cancers to chemicals similar to those found at Love Canal. We also found higher rates of bladder cancer among residents exposed as children, based on two cases.

Conclusions

In explaining these excess risks, the role of exposure to the landfill is unclear given such limitations as a relatively small and incomplete study cohort, imprecise exposure measurements, and the exclusion of cancers diagnosed before 1979. Given the relatively young age of the cohort, further surveillance is warranted.     

Malignant mesothelioma: attributable risk of asbestos exposure.

OBJECTIVES--To evaluate a case-control study of malignant mesothelioma through patterns of exposure to asbestos based upon information from telephone interviews with next of kin. METHODS--Potential cases, identified from medical files and death certificates, included all people diagnosed with malignant mesothelioma and registered during 1975-1980 by the Los Angeles County Cancer Surveillance Program, the New York State Cancer Registry (excluding New York City), and 39 large Veterans Administration hospitals. Cases whose diagnosis was confirmed in a special pathology review as definite or probable mesothelioma (n = 208) were included in the analysis. Controls (n = 533) had died of other causes, excluding cancer, respiratory disease, suicide, or violence. Direct exposure to asbestos was determined from responses to three types of questions: specific queries as to any exposure to asbestos; occupational or non-vocational participation in any of nine specific activities thought to entail exposure to asbestos; and analysis of life-time work histories. Indirect exposures were assessed through residential histories and reported contact with family members exposed to asbestos. RESULTS--Among men with pleural mesothelioma the attributable risk (AR) for exposure to asbestos was 88% (95% confidence interval (95% CI) 76-95%). For men, the AR of peritoneal cancer was 58% (95% CI 20-89%). For women (both sites combined), the AR was 23% (95% CI 3-72%). The large differences in AR by sex are compatible with the explanations: a lower background incidence rate in women, lower exposure to asbestos, and greater misclassification among women. CONCLUSIONS--Most of the pleural and peritoneal mesotheliomas in the men studied were attributable to exposure to asbestos. The situation in women was less definitive.     

Cancer incidence among physicians occupationally exposed to ionizing radiation in Finland

OBJECTIVES: Occupational radiation exposure was estimated, and the cancer incidence among physicians working with radiation was compared to that of unexposed physicians. METHODS: A cohort of 1312 physicians was identified from the Finnish occupational radiation exposure registry. Radiation exposure data were obtained from 1970 to 2001 on the basis of individual dosimeters. Never-monitored Finnish physicians (N=15 821) were used as a reference group, identified from census data of Statistics Finland. Incident cancer cases were identified by record linkage with the Finnish Cancer Registry. RESULTS: The cumulative radiation dose exceeded the recording level (0.3-3.0 mSv during a 3-month period for 1029 radiation-exposed physicians (59.8%). Six percent of the radiologists had received a cumulative dose of 50 mSv or more. Altogether there were 41 cancers observed among the radiation-exposed physicians and 998 cases found in the never-monitored group. Standardized incidence ratios (SIR) for all cancers were comparable with those of the general population among physicians monitored for radiation [SIR 1.0, 95% confidence interval (95% CI) 0.7-1.4] and other physicians (SIR 1.0, 95% CI 1.0-1.1). For specific cancer sites, a slightly elevated risk of female breast cancer was found among monitored physicians when compared with other physicians (rate ratio 1.7, 95% CI 1.0-3.1). No obvious dose-response relationship was found for the overall cancer incidence. CONCLUSIONS: According to the results from a nationwide cohort, occupational exposure to medical radiation is not a strong risk factor for cancer among physicians. Possible excess risk could not be reliably demonstrated even after the follow-up of a nationwide cohort for up to 30 years.     

Cancer incidence and mortality in a New Zealand community potentially exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin from 2,4,5-trichlorophenoxyacetic acid manufacture

OBJECTIVE: To investigate whether the rates of all cancers and four cancers (soft tissue sarcoma, non-Hodgkin's lymphoma, Hodgkin's disease and chronic lymphocytic leukaemia) associated with dioxin exposure are higher in New Plymouth, the site of a former 2,4,5-T manufacturing plant, than for the rest of New Zealand. METHODS: Analysis of 1970-2001 cancer data from the New Zealand Cancer Registry was undertaken for New Plymouth and the rest of New Zealand. RESULTS:There is no evidence of an increased cancer risk apart from one period (1970-74), which falls partly outside the 1962-1987 manufacturing period if 10-year latency is assumed. For 1970-74, there was an elevated risk for all cancer incidence (SIR = 111, 95% CI 104-119), and for two of the four specific cancers that are associated with dioxin exposure (non-Hodgkin's lymphoma SIR = 175, 95% CI 121-246 and chronic lymphocytic leukaemia SIR = 251, 95% CI 144-408). CONCLUSIONS AND IMPLICATIONS: The results do not suggest an increased cancer risk among the New Plymouth population related to the period of 2,4,5-T manufacture, although the study's limitations mean the possibility of an undetectable small elevation in cancer risk cannot be excluded. Although TCDD exposure in the first few years of 2,4,5-T manufacture may have contributed to cancer incidence in 1970-74, unknown exposure(s) before the start of 2,4,5-T manufacture and chance are also possible explanations.     

Cancer among women textile workers in Shanghai, China: overall incidence patterns, 1989-1998

BACKGROUND: Cancer incidence in women textile workers has not been adequately studied. The aim of this study was to examine site-specific cancer incidence patterns in a cohort of 267,400 women textile workers in Shanghai, China. METHODS: Women employed by the Shanghai Textile Industry Bureau (STIB) were followed for cancer incidence from 1989 to 1998. Age-adjusted standardized incidence ratios (SIRs) and 95% confidence intervals (CI) were computed based on Shanghai Cancer Registry (SCR) rates. RESULTS: There was a decrease in cancer incidence for the cohort compared with urban Shanghai women (SIR = 0.91, 95% CI = 0.89-0.93). There were small increased risks of other endocrine tumors (SIR = 1.31, 95% CI = 1.02-1.65). There were decreased risks for esophageal (SIR = 0.54, 95% CI = 0.44-0.66), stomach (SIR = 0.79, 95% CI = 0.73-0.85), rectal (SIR = 0.88, 95% CI = 0.78-0.98), lung (SIR = 0.80, 95% CI = 0.74-0.86), cervical (SIR = 0.37, 95% CI = 0.28-0.50), ovarian (SIR = 0.85, 95% CI = 0.75-0.96), and bladder cancers (SIR = 0.63, 95% CI = 0.46-0.85). CONCLUSIONS: Women employed in the textile industry had a lower than expected cancer experience compared with urban Shanghai women. Further research on this cohort will examine associations between site-specific cancers and occupational exposures to dusts and chemicals.     

Cancer risk among 43000 Norwegian nurses

OBJECTIVES: This study evaluated the influence of occupational exposure on cancer risk among female Norwegian nurses. METHODS: A historical prospective cohort study was performed. The cohort was established from the Norwegian Board of Health's registry of nurses and included women who graduated from a nursing school before 1985. The cohort (N=43 316) was linked to the Cancer Registry of Norway. The observed number of cases was compared with the expected number on the basis of national rates. Time since first employment, period of first employment, and duration of employment were used as indicators of exposure. Poisson regression analyses were used for internal comparisons, adjusting for age, period, and fertility. RESULTS: The nurses were followed over 1473931 person-years. During the follow-up (1953-2002), 6193 cancer cases were observed. The standardized incidence ratio (SIR) for all cancers combined was close to unity. Significantly lower risks were found for cancers with a known association with alcohol and tobacco consumption and sexual activity. A significantly increased risk was found for breast cancer (SIR 1.14, 95% confidence interval (95% CI) 1.09-1.19), ovarian cancer (SIR 1.14, 95% CI 1.04-1.25), malignant melanoma (SIR 1.15, 95% CI 1.04-1.28), and borderline significant risk appeared for other skin cancer (SIR 1.12, 95% CI 0.98-1.29). A positive trend for increasing time since first exposure was found for breast cancer and malignant melanoma. CONCLUSIONS: The results indicate an association between working as a nurse and an increased risk of breast cancer and malignant melanoma. Decreased risks, found for several cancers, indicate favorable lifestyle habits among nurses.     

Cancer incidence and mortality among Finnish asbestos sprayers and in asbestosis and silicosis patients

Cohorts of Finnish asbestos sprayers and of asbestosis and silicosis patients were followed for cancer with the aid of the Finnish Cancer Registry in the period 1967–1994. Compared with the cancer incidence of the total Finnish population, asbestos sprayers had an increased risk for total cancer (standardized incidence ratio [SIR] 6.7, 95% confidence interval [95% CI] 4.2–10); lung cancer (SIR 17, 95% CI 8.2–31); and mesothelioma (SIR 263, 95% CI 85–614). The SIR of the asbestosis patients was 3.7 (95% CI 2.8–5.0) for all sites, 10 (95% CI 6.9–14) for lung cancer, and 65 (95% CI 13–188) for mesothelioma. The silicosis patients also had significantly high SIR values for all sites (1.5, 95% CI 1.0–2.1) and lung cancer (2.7, 95% CI 1.5–4.5). The values for the SIR and the standardized mortality ratio for all sites and lung cancer were very similar, and therefore it seems that both are reliable indicators of the occurrence of occupational cancer. It was concluded that pneumoconioses patients and asbestos-exposed workers have a markedly elevated risk for cancer. Asbestos-induced occupational cancers are not only diseases of the elderly, since the relative risk is high also for middle-aged people. Am. J. Ind. Med. 31:693–698, 1997. © 1997 Wiley-Liss, Inc.     

Cancer risk and parental pesticide application in children of Agricultural Health Study participants

Parental exposure to pesticides may contribute to childhood cancer risk. Through the Agricultural Health Study, a prospective study of pesticide applicators in Iowa and North Carolina, we examined childhood cancer risk and associations with parental pesticide application. Identifying information for 17,357 children of Iowa pesticide applicators was provided by parents via questionnaires (1993-1997) and matched against the Iowa Cancer Registry. Fifty incident childhood cancers were identified (1975-1998). Risk of all childhood cancers combined was increased [standardized incidence ratio (SIR) = 1.36; 95% confidence interval (CI), 1.03-1.79]. Risk of all lymphomas combined was also increased (SIR = 2.18; 95% CI, 1.13-4.19), as was risk of Hodgkin's lymphoma (SIR = 2.56; 95% CI, 1.06-6.14). We used logistic regression to explore associations between self-reported parental pesticide application practices and childhood cancer risk. No association was detected between frequency of parental pesticide application and childhood cancer risk. An increased risk of cancer was detected among children whose fathers did not use chemically resistant gloves [odds ratio (OR) = 1.98; 95% CI, 1.05-3.76] compared with children whose fathers used gloves. Of 16 specific pesticides used by fathers prenatally, ORs were increased for aldrin (OR = 2.66), dichlorvos (OR = 2.06), and ethyl dipropylthiocarbamate (OR = 1.91). However, these results were based on small numbers and not supported by prior biologic evidence. Identification of excess lymphoma risk suggests that farm exposures including pesticides may play a role in the etiology of childhood lymphoma.     

Cancer incidence among Australian nuclear industry workers

To assess whether workers at Lucas Heights Science and Technology Centre (LHSTC) had different levels of cancer incidence from the New South Wales (NSW) population in Australia. A retrospective cohort study was undertaken at LHSTC. Data on 7,076 workers employed between 1957-98 were abstracted from personnel, dosimetry, and medical files. An inception cohort was defined which included 4,523 workers in employment between 1972-96 to examine cancer incidence. Cancer registrations in the inception cohort were identified to 1996 through electronic linkage of records with the NSW and the Australian national registers of cancer incidence. All-cancer incidence in workers at LHSTC was 15% below the NSW rates [SIR=0.85; 95% CI=(0.75, 0.95)]. Of 37 specific cancers and groups of cancers examined, statistically significant excesses relative to NSW rates were observed only for pleural cancer incidence [SIR=17.71; 95%=(7.96, 39.43)], and for incidence of cancer of the small intestine [SIR=4.34; 95% CI=(1.40, 13.46)]. This study gives little evidence of an increased risk of cancers associated with radiation exposure in a cohort of nuclear workers in Australia. The observed increase in the risk of cancer of the pleura was probably due to unmeasured exposures, given the lack of an established association with radiation exposure, and the strong link to asbestos exposure. Findings for cancers of the small intestine were based on small numbers and were likely to be due to chance.     

Asbestos exposure, manganese superoxide dismutase (MnSOD) genotype, and lung cancer risk

To assess whether differences in genetic susceptibility to oxidative stress modify asbestos-related lung cancer risk (caused by lung inflammation, free radical production), we examined possible interactions between manganese superoxide dismutase (MnSOD) genotypes and asbestos in a hospital-based case-control study of 811 white lung cancer cases and 957 friend/spouse controls. Cumulative lifetime asbestos exposure score (AES) was calculated from self-reported duration and intensity of occupational and nonoccupational exposures. A total of 13.5% of cases and 10% of controls had "high" AES (determined by a priori cut point). The homozygous variant MnSOD genotype was associated with increased lung cancer risk among individuals with zero or "low" AES (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.52-3.01) and no association (OR = 1.00; 95% CI = 0.36-2.73) among the "high" AES group. We observed no statistically significant interaction between MnSOD genotype and asbestos exposure for lung cancer risk.     

Cancer morbidity in iron and steel workers in Korea

BACKGROUND: In the iron and steel industry, workers are potentially exposed to a number of carcinogens and are involved in a number of processes of a hazardous nature. The cancer morbidity of iron and steel workers from modern plants in a developing country is described. METHODS: Cancer morbidity at two Korean iron and steel complexes was analyzed using Poisson regression methods. Work histories were merged with the national cancer registry for 44,974 workers who were followed from 1988-2001. RESULTS: Four hundred sixty-four cancers, in 1% of the population, were diagnosed over 14 years. Based on national cancer rates, the cohort exhibited a healthy worker effect for all cancer (SIR = 0.87, 95% CI = 0.79-0.95) reflecting relative good health, particularly for lung cancer (SIR = 0.58, 95% CI = 0. 04-0.82), stomach cancer (SIR = 0.78, 95% CI = 0.64-0.93), and liver cancer (SIR = 0.83, 95% CI = 0.68-1.01). Lung cancer morbidity was significantly elevated at the affiliated plants versus the parent plants (SRR = 2.35, 95% CI = 1.07-4.92), and all-cancer morbidity was significantly elevated for maintenance workers compared to office and production workers (SRR = 1.27, 95% CI = 1.00-1.60). Lymphohematopoietic cancer incidence was higher in the coke plants (SRR = 3.46, 95% CI = 1.02-8.91) and stomach cancer incidence was higher in the maintenance departments (SRR = 1.66, 95% CI = 1.05-2.56). CONCLUSIONS: This recent steelworker cohort exhibits possible excess cancer morbidity in some processing areas. Further follow-up of this cohort and alternate study designs such as case-control study will be needed to elucidate the relationship of exposure and health risks of iron and steel workers.