Elizabeth M. Allen

Mortality experience among Minnesota taconite mining industry workers

Objective To evaluate the mortality experience of Minnesota taconite mining industry workers. Methods Mortality was evaluated between 1960 and 2010 in a cohort of Minnesota taconite mining workers employed by any of the seven companies in operation in 1983. Standardised mortality ratios (SMR) were estimated by comparing observed deaths in the cohort with expected frequencies in the Minnesota population. Standardised rate ratios (SRR) were estimated using an internal analysis to compare mortality by employment duration. Results The cohort included 31 067 workers with at least 1 year of documented employment. Among those, there were 9094 deaths, of which 949 were from lung cancer, and 30 from mesothelioma. Mortality from all causes was greater than expected in the Minnesota population (SMR=1.04, 95% CI 1.02 to 1.04). Mortality from lung cancer and mesothelioma was higher than expected with SMRs of 1.16 for lung cancer (95% CI 1.09 to 1.23) and 2.77 for mesothelioma (95% CI 1.87 to 3.96). Other elevated SMRs included those for cardiovascular disease (SMR=1.10, 95% CI 1.06 to 1.14), specifically for hypertensive heart disease (SMR=1.81, 95% CI 1.39 to 2.33) and ischemic heart disease (SMR=1.11, 95% CI 1.07 to 1.16). Results of the SRR analysis did not show variation in risk by duration of employment. Conclusions This study provides evidence that taconite workers may be at increased risk for mortality from lung cancer, mesothelioma, and some cardiovascular disease. Occupational exposures during taconite mining operations may be associated with these increased risks, but non-occupational exposures may also be important contributors.

Mortality and cancer incidence in ammonium perfluorooctanoate production workers

Objective To evaluate mortality and cancer incidence in a cohort of ammonium perfluorooctanoate (APFO) exposed workers. Methods We linked a combined cohort (n=9027) of employees from APFO and non-APFO production facilities in Minnesota to the National Death Index and to cancer registries of Minnesota and Wisconsin. Industrial hygiene data and expert evaluation were used to create a task-based job exposure matrix to estimate APFO exposure. Standardised mortality ratios were estimated using Minnesota population rates. HRs and 95% CIs for time-dependent cumulative APFO exposure were estimated with an extended Cox model. A priori outcomes of interest included cancers of the liver, pancreas, testes, kidney, prostate and breast, and mortality from cardiovascular, cerebrovascular and chronic renal diseases. Results Mortality rates in the APFO-exposed cohort were at or below the expected, compared with Minnesota. The HR for dying from the cancer and non-cancer outcomes of interest did not show an association with APFO exposure. Similarly, there was little evidence that the incident cancers were associated with APFO exposure. Compared to the non-exposed population, modestly elevated, but quite imprecise HRs were observed in the higher-exposure quartiles for bladder cancer (HR=1.66, 95% CI 0.86 to 3.18) and pancreatic cancer (HR=1.36, 95% CI 0.59 to 3.11). No association was observed between APFO exposure and kidney, prostate or breast cancers. Conclusions This analysis did not support an association between occupational APFO exposure and the evaluated health endpoints, however, the study had limited power to evaluate some conditions of interest.

Occupational exposures and lung cancer risk among Minnesota taconite mining workers

Objective To examine the association between employment duration, elongate mineral particle (EMP) exposure, silica exposure and the risk of lung cancer in the taconite mining industry. Methods We conducted a nested case–control study of lung cancer within a cohort of Minnesota taconite iron mining workers employed by any of the mining companies in operation in 1983. Lung cancer cases were identified by vital records and cancer registry data through 2010. Two age-matched controls were selected from risk sets of cohort members alive and lung cancer free at the time of case diagnosis. Calendar time-specific exposure estimates were made for every job and were used to estimate workers’ cumulative exposures. ORs and 95% CIs were estimated using conditional logistic regression. We evaluated total lung cancer risk and risk of histological subtype by total work duration and by cumulative EMP, and silica exposure by quartile of the exposure distribution. Results A total of 1706 cases and 3381 controls were included in the analysis. After adjusting for work in haematite mining, asbestos exposure and sex, the OR for total duration of employment was 0.99 (95% CI 0.96 to 1.01). The ORs for quartile 4 versus 1 of EMP and silica exposure were 0.82 (95% CI 0.57 to 1.19) and 0.97 (95% CI 0.70 to 1.35), respectively. The risk of each histological subtype of lung cancer did not change with increasing exposure. Conclusions This study suggests that the estimated taconite mining exposures do not increase the risk of developing lung cancer.

Abstract B65: Barriers to recommended screening among U.S. immigrants: A literature review

Purpose/Objectives: Maximizing cancer screening uptake has been a high public health priority in the United States, particularly for three prevalent and high-mortality cancers which benefit from early detection: breast, cervical, and colorectal cancers. However, screening rates for these cancers remain very low for US immigrants. Immigrants face unique barriers in accessing preventative healthcare that may or may not be specific to particular cultural and socioeconomic backgrounds. This review aims to synthesize literature on barriers to cancer screening among US immigrants in order to help design interventions that aim to increase screening in these diverse populations. Methods: We conducted a comprehensive search in Ovid Medline using Medical Subject Headings to capture articles discussing broadly defined barriers to screening for breast, cervical, or colorectal cancer in any immigrant communities in the United States. An initial 1148 articles was reduced to a final sample of 90 based on the following inclusion criteria: (1) population-based studies that were not evaluating an intervention (2) at least 80% of the study population immigrants or refugees to the United States (3) focus on uptake or receipt of any screening procedure for one or more of the three cancers of interest (4) study population did not include cancer patients or survivors (5) outcomes included factors influencing screening uptake (studies showing a disparity in screening but not seeking to explain it were excluded) and (6) publication year of 2000 or later. Results: Of the 90 studies included in the analysis, 26 (28.8%) were qualitative in design while the rest were quantitative survey studies. Men and women from most major immigrant groups in the United States were represented. Studies reported a large range but generally reported higher rates of having ever been screened (25-96%), and low rates of regular screening for all cancers (20-60%). Studies identified a wide-range of barriers including structural barriers such as insurance/cost (n=61), not having a regular provider or not receiving screening recommendation (n=47), language barriers (n=40), discrimination (n=18), navigating health systems (n=11) work/family responsibilities (n=9), and transportation (n=7). Fear and stigma of cancer and screening, concerns about pain, modesty, embarrassment, and lack of knowledge about availability or reason for screening were also identified. Some groups expressed fatalistic conceptions of health, or cultural/religious barriers, however many expressed interest in prevention. General themes important for increasing screening among US immigrants emerged: (1) It is important to disaggregate immigrant groups from racial categories and (2) it is equally important to understand communities9 unique cultural or religious concerns. (3) The effects of cultural or psychosocial barriers were less inhibitory than structural barriers. (4) Structural and language barriers, socioeconomic status, and time in the US, were most important for predicting screening uptake. Conclusions: There is no one-size-fits-all solution for increasing cancer screening among all US immigrants. Results suggest the importance of providers taking time to counsel all patients but perhaps especially those who were raised in cultures with differing conceptions of health. Community-based educational and motivational programs in conjunction with programs to increase structural access may help to increase screening uptake. For providers, identifying community members and/or friends and relatives of patients who can be motivators to screening is likely an effective method to improve screening rates. Targeted interventions that address both individual and structural barriers may be most effective in increasing cancer screening in immigrant communities. Citation Format: Elizabeth M. Allen, John O. Loftus. Barriers to recommended screening among U.S. immigrants: A literature review. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr B65.

342 Mortality and proportional cancer incidence in Minnesota taconite workers

Objective In response to public concerns about health in Minnesota taconite mining workers, we evaluated the mortality and cancer experience in this population. Methods From a cohort of 44,159 taconite workers born in 1920 or later, we selected 30,360 with at least one year of documented employment. Vital status and causes of death from death certificates were ascertained through December 31, 2007. Cancer diagnoses from 1988 through 2010 were identified by the Minnesota Cancer Surveillance System (MCSS). Standardised mortality ratios (SMRs) and proportional cancer incidence ratios (PCIR) were calculated using Minnesota as the reference population. Results We identified 9,012 deaths, of which 2,693 were cancers, including 943 lung cancers, and 30 mesotheliomas. Mortality from all causes was near unity (SMR = 1.02, 95% Confidence Interval (CI): 1.00–1.04). Mortality from lung cancer and mesothelioma were higher than expected; SMR = 1.16 (95% CI: 1.09–1.24) and 2.79 (95% CI: 1.88–3.98) respectively. SMRs were elevated for all heart diseases (SMR = 1.10, 95% CI: 1.06–1.14), hypertension with heart disease (SMR = 1.79, 95% CI: 1.37–2.30) and ischaemic heart disease (SMR = 1.11, 95% CI: 1.07–1.16). A total of 6,189 incident cancers were identified by MCSS including 1016 lung cancers, and 51 mesotheliomas. PCIRs for mesothelioma and lung cancer were 3.02 (95% CI: 2.24, 3.98) and 1.22 (95% CI: 1.15–1.30) respectively. Other proportionally elevated cancers include oral, esophageal, stomach, laryngeal, and bladder cancers. Conclusions This analysis indicates taconite workers have an increased risk for certain cancers and cardiovascular disease. Exposures from taconite operations include crystalline silica, respirable dust and elongated mineral particles, including non-asbestiform amphiboles and cleavage fragments. Exposure to commercial asbestos is also possible. The extent to which such exposures contribute to disease burden is being investigated. Lifestyle factors, such as smoking, could also contribute to disease burden.