Screening Value Research Articles

A failure analysis of invasive breast cancer: Most deaths from disease occur in women not regularly screened

Mortality reduction from mammographic screening is controversial. Individual randomized trials and meta-analyses demonstrate statistically significant mortality reductions in all age groups invited to screening. In women actually screened, mortality reductions are greater. Individual trials and meta-analyses show varying rates of mortality reduction, leading to questions about screening's value and whether treatment advances have diminished the importance of early detection. This study hypothesized that breast cancer deaths predominantly occurred in unscreened women. Invasive breast cancers diagnosed between 1990 and 1999 were followed through 2007. Data included demographics, mammography use, surgical and pathology reports, and recurrence and death dates. Mammograms were categorized as screening or diagnostic based on absence or presence of breast signs or symptoms, and were substantiated by medical records. Breast cancer deaths were defined after documentation of prior distant metastases. Absence of recurrent cancer and lethal other diseases defined death from other causes. Invasive breast cancer failure analysis defined 7301 patients between 1990 and 1999, with 1705 documented deaths from breast cancer (n = 609) or other causes (n = 905). Among 609 confirmed breast cancer deaths, 29% were among women who had been screened (19% screen-detected and 10% interval cancers), whereas 71% were among unscreened women, including > 2 years since last mammogram (6%), or never screened (65%). Overall, 29% of cancer deaths were screened, whereas 71% were unscreened. Median age at diagnosis of fatal cancers was 49 years; in deaths not from breast cancer, median age at diagnosis was 72 years. Most deaths from breast cancer occur in unscreened women. To maximize mortality reduction and life-years gained, initiation of regular screening before age 50 years should be encouraged.

Largemouth bass ( Micropterus salmoides) and striped mullet ( Mugil cephalus) as vectors of contaminants to human consumers in northwest Florida

The health benefits of regular consumption of fish and seafood have been espoused for many years. However, fish are also a potential source of environmental contaminants that have well known adverse effects on human health. We investigated the consumption risks for largemouth bass ( Micropterus salmoides; n = 104) and striped mullet ( Mugil cephalus; n = 170), two commonly harvested and consumed fish species inhabiting fresh and estuarine waters in northwest Florida. Skinless fillets were analyzed for total mercury, inorganic arsenic, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F), polychlorinated biphenyls (PCBs), and organochlorine pesticides. Contaminant levels were compared to screening values (SV) calculated using U.S. Environmental Protection Agency (EPA) recommendations for establishing consumption advisories. Largemouth bass were found to contain high levels of total mercury at all sampling locations (0.37–0.89 ug/g) and one location exhibited elevated total PCBs (39.4 ng/g). All of the samples exceeded Florida fish consumption advisory trigger levels for total mercury and one location exceeded the U.S. EPA SV for total PCBs. As a result of the high mercury levels, the non-cancer health risks (hazard index–HI) for bass were above 1 for all locations. Striped mullet from several locations with known point sources contained elevated levels of PCBs (overall range 3.4–59.3 ng/g). However, total mercury levels in mullet were low. Eight of the 16 mullet sampling locations exceeded the U.S. EPA SV for total PCBs and two locations exceeded an HI of 1 due to elevated PCBs. Despite the elevated levels of total PCBs in some samples, only two locations exceeded the acceptable cancer risk range and therefore cancer health risks from consumption of bass and mullet were determined to be low at most sampling locations.

Occurrence of priority hazardous PAHs in water, suspended particulate matter, sediment and common eels ( Anguilla anguilla) in the urban stretch of the River Tiber (Italy)

This study investigated the occurrence of polycyclic aromatic hydrocarbons (PAHs) in water, suspended particulate matter (SPM), bed sediment and common eels ( Anguilla anguilla) in the urban stretch of the River Tiber (Italy). The selected PAHs, fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, benzo(g,h,i)perylene, indeno(1,2,3-cd)pyrene, belong to the EC priority list of dangerous substances. SPM was found to be the most polluted compartment, with values ranging from 1663.1 to 15472.9 ng g −1 (Σ 6PAHs), followed by sediment samples, from 157.8 to 271.6 ng g −1 and by aqueous samples, from 23.9 to 72.0 ng L −1. The distribution coefficient ( K d) showed a good correlation with particle organic carbon (OC) content, while K oc values experimentally measured for sediment/SPM deviated from those predicted by K ow, implying that for very hydrophobic compounds, K ow alone may not be an appropriate descriptor of all the thermodynamic forces involved in their sorption to aquatic particles. Some selected PAH ratios indicated that PAHs in the River Tiber come mainly from pyrolitic sources and vehicular traffic. Concentrations of individual PAHs in muscles of common eels varied from 0.8 to 7.0 ng g −1 wet wt. and the calculated toxicity equivalent concentration (TEQ, 1.8 ng g −1 wet wt.) of total PAHs fell below the recommended screening value (SV) in US EPA guidelines, suggesting no concern for human consumption.

Accumulation of organic and inorganic contaminants in shellfish collected in estuarine waters near Pensacola, Florida: Contamination profiles and risks to human consumers

We conducted a screening level assessment of contaminants in blue crabs ( Callinectes sapidus) and oysters ( Crassostrea virginica) from bays and bayous in the Pensacola, FL area. Tissue samples were analyzed for 17 dioxins/furans, 12 dioxin-like PCB (DL-PCBs) congeners, mercury, and various metals. Contaminant levels were compared to screening values (SV) calculated using U.S. EPA recommendations for establishing consumption advisories. All sampling locations exceeded the SV (0.098 pg g −1) for dioxins/furans/DL-PCBs, based on a Florida-specific consumption rate (46 g day −1). Arsenic (inorganic), mercury, cadmium, and zinc levels exceeded SVs in samples from select locations, and with the exception of mercury, these locations were generally downstream of known contaminated areas. We also assessed potential human health risks from consumption of these species. Risks to human health were greatest from consumption of crab hepatopancreas, suggesting that consumption of hepatopancreas, whether directly or indirectly, from crabs collected anywhere in the Pensacola Bay region should be avoided.

Colorectal Cancer Screening: Health Impact and Cost Effectiveness

Colorectal cancer is the second leading cause of cancer-related death in the United States, yet recommended screenings are not delivered to most people. This assessment of colorectal cancer screening's value to the U.S. population is part of the update to a 2001 ranking of recommended clinical preventive services found in the accompanying article. This article describes the burden of disease prevented and cost-effectiveness as a result of offering patients a choice of colorectal cancer screening tools. Methods used were designed to ensure consistent estimates across many services and are described in more detail in the companion articles. In a secondary analysis, the authors also estimated the impact of increasing offers for colorectal cancer screening above current levels among the current cross-section of adults aged 50 and older. If a birth cohort of 4 million were offered screening at recommended intervals, 31,500 deaths would be prevented and 338,000 years of life would be gained over the lifetime of the birth cohort. In the current cross-section of people aged 50 and older, 18,800 deaths could be prevented each year by offering all people in this group screening at recommended intervals. Only 58% of these deaths are currently being prevented. In year 2000 dollars, the cost effectiveness of offering patients aged 50 and older a choice of colorectal cancer screening options is $11,900 per year of life gained. Colorectal cancer screening is a high-impact, cost-effective service used by less than half of persons aged 50 and older.

Survey of methodologies for developing media screening values for ecological risk assessment

This review evaluates the methodologies of 13 screening value (SV) compilations that have been commonly used in ecological risk assessment (ERA), including compilations from state and U.S. federal agencies, the Oak Ridge National Laboratory (ORNL), Canada, The Netherlands, and Australia. The majority of surfacewater SVs were primarily derived for the protection of aquatic organisms using 2 approaches: (1) a statistical assessment of toxicity values by species groupings, such as "ambient water quality criteria," or (2) extrapolation of a lowest observed adverse effect level determined from limited toxicity data using an uncertainty factor. Sediment SVs were primarily derived for the protection of benthic invertebrates using 2 approaches: (1) statistical interpretations of databases on the incidence of biological effects and chemical concentrations in sediment, or (2) values derived from equilibrium partitioning based on a surfacewater SV. Soil SVs were derived using a diversity of approaches and were usually based on the lowest value determined from soil toxicity to terrestrial plants or invertebrates and, less frequently, from modeled, incidental soil ingestion or chemical accumulation in terrestrial organisms. The various SV compilations and methodologies had varying levels of conservatism and were not consistent in the pathways and receptors considered in the SV derivation. Many SVs were derived from other compilations and were based on outdated values, or they relied on only older toxicity data. Risk assessors involved in ERA should carefully evaluate the technical basis of SVs and consider the uncertainty in any value used to determine the presence or absence of risk and the need for further assessment.

Levels of Persistent Organochlorine Contaminants in Fish from Korea and Their Potential Health Risk

Organochlorine contaminants in the muscles of sport and market fish were determined to understand the potential risks to humans consuming fish originating in Korea's coastal waters. Polychlorinated biphenyls (PCBs; sum of 22 congeners) and DDTs were the dominant contaminants, and their concentrations were in the range of 2.96 to 96.6 and 0.84 to 27.0 ng/g (wet weight basis), respectively. The highest PCB concentrations were found in samples taken from an industrial complex. Hexachlorocyclohexanes, chlordane-related compounds, and hexachlorobenzene concentrations were relatively low and ranged from 0.64 to 5.6, 0.17 to 4.24, and 0.08 to 1.58, respectively. Sport fish had levels of PCBs and DDTs approximately two times higher than market fish, implying that sport fish posed high potential risk of contamination with OCs. Risk-based screening value (SV) based on U. S. Environmental Protection Agency (USEPA) method was calculated using the USEPA approach to identify the primary chemicals of concern. Total PCB concentrations in all sport and market fish exceeded the SV (5.04 ng/g based on total PCBs), but the other compounds were mostly below SV values. Based on the estimated SVs, PCB compounds were identified as potential chemicals of concern.

Survey of Methodologies for Developing Media Screening Values for Ecological Risk Assessment

This review evaluates the methodologies of 13 screening value (SV) compilations that have been commonly used in ecological risk assessment (ERA), including compilations from state and U.S. federal agencies, the Oak Ridge National Laboratory (ORNL), Canada, The Netherlands, and Australia. The majority of surfacewater SVs were primarily derived for the protection of aquatic organisms using 2 approaches: (1) a statistical assessment of toxicity values by species groupings, such as “ambient water quality criteria,” or (2) extrapolation of a lowest observed adverse effect level determined from limited toxicity data using an uncertainty factor. Sediment SVs were primarily derived for the protection of benthic invertebrates using 2 approaches: (1) statistical interpretations of databases on the incidence of biological effects and chemical concentrations in sediment, or (2) values derived from equilibrium partitioning based on a surfacewater SV. Soil SVs were derived using a diversity of approaches and were usually based on the lowest value determined from soil toxicity to terrestrial plants or invertebrates and, less frequently, from modeled, incidental soil ingestion or chemical accumulation in terrestrial organisms. The various SV compilations and methodologies had varying levels of conservatism and were not consistent in the pathways and receptors considered in the SV derivation. Many SVs were derived from other compilations and were based on outdated values, or they relied on only older toxicity data. Risk assessors involved in ERA should carefully evaluate the technical basis of SVs and consider the uncertainty in any value used to determine the presence or absence of risk and the need for further assessment.

Organochlorines and other environmental contaminants in muscle tissues of sportfish collected from San Francisco Bay

Edible fish species were collected from 13 locations throughout San Francisco Bay, during the spring of 1994, for determination of contaminant levels in muscle tissue. Species collected included white croaker, surfperch, leopard and brown smoothhound sharks, striped bass, white sturgeon and halibut. 66 composite tissue samples were analysed for the presence of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (P0CBs), pesticides, trace elements and dioxin/furans. The US EPA approach to assessing chemical contaminant data for fish tissue consumption was used for identifying the primary chemicals of concern. Six chemicals or chemical groups were found to exceed screening values (SVs) established using the US EPA approach. PCBs (as total Aroclors) exceeded the screening level of 3 ng g −1 in all 66 muscle tissue samples, with the greatest concentrations (638 ng g −1) found near San Francisco's industrial areas. Mercury was elevated (> 0.14 μg g −1) in 40 of 66 samples with the greatest concentrations (1.26 μg g −1) occurring in shark muscle tissues. Concentrations of the organochlorine pesticides dieldrin, total chlordane and total dichlorodiphenyltri-chloroethane (DDT) exceeded screening levels in a number of samples. Dioxin/furans (as toxic equivalent concentrations (TEQ's)) were elevated (> 0.15 pg g −1) in 16 of the 19 samples analysed. Fish with high lipid content (croaker and surfperch) in their muscle tissue generally exhibited higher organic contaminant levels while fish with low lipid levels (halibut and shark) exhibited lower organic contaminant levels. Tissue samples taken from North Bay stations most often exhibited high levels of chemical contamination. The California Office of Health Hazard Assessment is currently evaluating the results of this study and has issued an interim Health Advisory concerning the human consumption of fish tissue from San Francisco Bay.