sFRP-1: A functional prognostic marker for gastric cancer?

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Background: Despite being a leading cause of cancer-related death world wide, gastric adenocarcinoma (GA) lacks distinctive biomarkers and targeted therapies. Underexpression of the E-cadherin gene in GA is associated with an aggressive phenotype and a poor prognosis but the mechanisms of this difference are poorly understood. Developing effective therapies for GA requires identification of critical functional markers and deeper understanding of its pathophysiology.

Methods: Unsupervised hierarchical clustering analysis of a publicly available 230-sample GA microarray dataset identified a prominent cluster (21.7%) associated with underexpression of E-cadherin and overexpression of a Wnt-family protein: secreted frizzled-related protein 1 (sFRP-1). Archival GA specimens were then assessed for the expression of sFRP-1 by immunohistochemistry. Prognostic significance was assessed using univariate and multivariate analyses. GA cell lines transfected with sFRP-1 were used to determine the role of sFRP-1 in gastric cancer.

Results: 85 patients with GA underwent surgery with curative intent; 39 stained positive for sFRP-1 (46%). In this positive group, sFRP-1 staining was focal; was commonly found on the leading edge of the infiltrating tumor mass; and was not restricted to one histopathologic group, grade, or clinical stage. On univariate analysis T stage, nodal involvement, pathologic stage, nuclear grade, E-cadherin status and sFRP-1 status were predictive of overall survival. In a multivariate model, T stage (p < 0.001), nuclear grade (p < 0.001), E-cadherin status (p = 0.031) and sFRP-1 status (p = 0.0097) were predictive of overall survival. Overexpression of sFRP-1 in GA cell lines induced mesenchymal phenotype, enhanced growth and stem cell-like properties. sFRP-1 also attenuated Wnt signaling and E-cadherin expression, but potentiated Notch and Hedgehog signaling known to be involved in GA progression. These findings suggest a Wnt-independent mechanism mediated by sFRP-1.

Conclusions: The aggressive biological subtype of gastric cancer may be linked to overexpression of sFRP-1. Our findings identify sFRP-1 as a functional prognostic biomarker for gastric cancer, which may serve as a potential therapeutic target.

No significant financial relationships to disclose.

Occupational exposure to asbestos in New South Wales, Australia (1970-1989): development of an asbestos task exposure matrix

OBJECTIVES

To design and construct a standardised tool to provide exposure information associated with commonly used asbestos products and their related tasks in New South Wales (NSW), Australia.

METHODS

Asbestos dust exposure measurements taken during workplace inspections in the 1970s and 1980s were collected and stored in an exposure database. Measurements were assigned to specific asbestos product and task groups and divided into two sampling periods 1970-1979 and 1980-1989.

RESULTS

A total of 1578 asbestos air measurements collected from WorkCover and Dust Diseases Board company records were entered into a custom built exposure database. An asbestos-specific exposure matrix (ASTEM) was constructed in Microsoft Excel 2000, consisting of 3 axes incorporating 12 tasks, 8 asbestos products and the 2 time periods based on 872 individual measurements extracted from the exposure database. Each matrix cell contains the mean asbestos exposure levels measured in fibres/ml, 5th and 95th percentiles and number of data points in the set.

CONCLUSION

An ASTEM has been developed which provides exposure levels for different task/product combinations. When used in conjunction with a detailed occupational history, it will improve exposure estimates of a worker's cumulative asbestos exposure.

Endotoxin exposure and lung cancer risk: a systematic review and meta-analysis of the published literature on agriculture and cotton textile workers

Objective

To examine the association between exposure to endotoxins and lung cancer risk by conducting a systematic review and meta-analysis of epidemiologic studies of workers in the cotton textile and agricultural industries; industries known for high exposure levels of endotoxins.

Methods

Risk estimates were extracted from studies published before 2009 that met predefined quality criteria, including 8 cohort, 1 case–cohort, and 2 case–control studies of cotton textile industry workers, and 15 cohort and 2 case–control studies of agricultural workers. Summary risk estimates were calculated using random effects meta-analyses. Potential sources of heterogeneity were explored through subgroup analyses.

Results

The summary risk of lung cancer was 0.72 (95% CI, 0.57–0.90) for textile workers and 0.62 (0.52–0.75) for agricultural workers. The relative risk of lung cancer was below 1.0 for most subgroups defined according to sex, study design, outcome, smoking adjustment, and geographic area. Two studies provided quantitative estimates of endotoxin exposure and both studies tended to support a dose–dependent protective effect of endotoxins on lung cancer risk.

Conclusion

Despite several limitations, this meta-analysis based on high-quality studies adds weight to the hypothesis that occupational exposure to endotoxin in cotton textile production and agriculture is protective against lung cancer.

Second primary melanoma: Risk factors, histopathologic features, and survival

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Background: Melanoma incidence in the United States is expected to be 4.3% of all cancers in 2008. Cutaneous melanoma patients are at risk for second primary melanoma development. Our goal was to characterize the histopathologic features, risk factors, and patient survival for second primary melanoma. Methods: A review of the melanoma database established in 1971 at John Wayne Cancer Institute was conducted identifying patients with American Joint Committee on Cancer (AJCC) stage I and II cutaneous melanoma who later developed a second primary melanoma. Patients were grouped by Breslow thickness, Clark level, and histopathologic subtype (superficial spreading [SSM], nodular, acral lentiginous, lentigo maligna, and in situ). Multivariate analysis involving age, gender, Breslow thickness, Clark level, and ulceration status was performed to determine an effect on development of second primary. Kaplan-Meier survival curves were plotted for single primary and second primary melanoma patients. Results: Second primary melanoma was identified in 411 (3.7%) of 10,968 patients with AJCC stage I-II melanoma. The most common first primary subtype was SSM, and 93% of these patients had in situ or SSM as the second primary. Sixty-five percent of first primaries had a Breslow thickness of ≤1 mm, and 75% of second primaries had a thickness ≤1 mm. Forty-nine percent of first primaries had Clark level I or II, but 68% of second primaries had Clark level I or II. In multivariate analysis, only increasing age was significantly associated with the likelihood of second primary melanoma (p<0.0001). With increasing follow-up time the hazard ratio of second primary melanoma was 1.31 for every decade. Overall survival for second primary melanoma patients was better than for single primary patients (p<0.0001). Conclusions: Most second primary melanoma patients will have SSM or in situ, with a decreased Clark level and Breslow thickness. Contrary to expectations, patients developing second primary melanoma did not exhibit decreased overall survival. Increased follow-up time after first primary melanoma is a significant risk factor for second primary development, thus illustrating the importance of lifelong patient follow-up.

No significant financial relationships to disclose.

Harm Avoidance as an Endophenotype of Schizophrenia: Comparative Study of First-degree Relatives, Schizophrenia Probands, and Healthy Controls

Objective:

Schizophrenia is highly familial neuropsychiatric disorder with heritability estimated at 60-90%. Even unaffected first-degree relatives of schizophrenia manifested some neuropsychological abnormalities as well as neurologic soft sign and morphologic anomalies. the aim of this study was to evaluate personality profile in first-degree relatives of schizophrenia compared to their schizophrenia probands and healthy controls and whether personality profile might be endophenotype of schizophrenia.

Methods:

The subjects were 97 first-degree relatives of schizophrenia, 48 their schizophrenia probands, and 106 healthy controls, who completed Temperament and Character Inventory (TCI) scale. Relatives were further divided into presumed carriers and pesumed non-carriers by schizophrenia genetic loading. Group difference in TCI scores were compared by general linear model using age and gender as covariates.

Results:

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Conclusion:

We found that HA scores of first-degree relatives of schizophrenia is intermediate level between schizophrenia probands and healthy controls. Considering increase of HA with schizophrenia genetic loading, HA may be potential endophenotype of schizophrenia. Further research with longitudinal follow up is needed to elucidate the clinical implication of high HA observed in schizophrenia family.

Fractional polynomials and model selection in generalized estimating equations analysis, with an application to a longitudinal epidemiologic study in Australia

In epidemiologic studies, researchers often need to establish a nonlinear exposure-response relation between a continuous risk factor and a health outcome. Furthermore, periodic interviews are often conducted to take repeated measurements from an individual. The authors proposed to use fractional polynomial models to jointly analyze the effects of 2 continuous risk factors on a health outcome. This method was applied to an analysis of the effects of age and cumulative fluoride exposure on forced vital capacity in a longitudinal study of lung function carried out among aluminum workers in Australia (1995-2003). Generalized estimating equations and the quasi-likelihood under the independence model criterion were used. The authors found that the second-degree fractional polynomial models for age and fluoride fitted the data best. The best model for age was robust across different models for fluoride, and the best model for fluoride was also robust. No evidence was found to suggest that the effects of smoking and cumulative fluoride exposure on change in forced vital capacity over time were significant. The trend 1 model, which included the unexposed persons in the analysis of trend in forced vital capacity over tertiles of fluoride exposure, did not fit the data well, and caution should be exercised when this method is used.

Survey of Trainee Membership of the Intensive Care Society

In October/November 2007 we conducted a survey of the trainee membership of the Intensive Care Society in order to ascertain their views, primarily on the potential introduction of a compulsory examination in intensive care medicine (ICM). Their views on other training issues were also sought. There were 313 responses from a trainee membership of 446. A majority were supportive of a compulsory examination, but this view was heavily qualified by a large number of free text responses. The current UK diploma in ICM was not felt to be suitable as a compulsory examination. The timing of any examination would have to be flexible to avoid conflict with parent specialty training and associated examinations. Many of those training in ICM are at an advanced stage in their careers and the burden on their work and home lives presented by a further examination would be considerable. The survey also highlighted other matters important to training and employment in ICM in the UK, including the difficulties in finding employment in ICM faced by those training from parent specialties other than anaesthesia.

A randomised intervention trial to assess two arsenic mitigation options in Bangladesh

Arsenic groundwater contamination in Bangladesh warrants immediate remediation. This randomised controlled intervention trial was conducted to determine the effectiveness of two possible interventions: dug wells and three-pitcher filters. A total of 640 individuals participated with 218 randomised to the dug well group, 216 to the three-pitcher group and 206 to a control group. Data were collected at baseline and at 1, 6 and 12 months after the intervention. Self reported compliance with dug wells remained below 20% during the entire 12 months of the study. The compliance with the three-pitcher filters decreased after 6 months and became similar to the compliance of the dug well group after 12 months. A substantial decrease in urinary arsenic metabolites occurred only among those who were compliant with dug wells and three-pitcher filter systems after 1 month of intervention as opposed to control participants. However, a persistent reduction in urinary arsenic concentrations was observed only among the dug well users after 12 months of intervention. Our results show that a functional dug well could be offered as a long-term alternative to tube wells, but use of this option is likely to be low, unless appropriate behavioural change measures are taken. Our study also demonstrates that arsenic removal technologies such as three-pitcher filters are an effective option as a short-term measure. The three-pitcher filters that are not adequately maintained are not an effective option for a year. These arsenic removal technologies may be even harmful in the long term if the resultant water quality is not properly monitored.

Toxicology in Australia: a key component of environmental health

Managing public concerns relating to chemical exposures can consume substantial public health resources, particularly as the scientific basis around these issues is often contentious. Toxicology remains underrecognized as a public health discipline in Australia, although Australian toxicologists are making significant contributions from academia, government, and the commercial sector toward assessing the level of risk and protecting the community from environmental hazards. Internationally, the growth of environmental toxicology and the promotion of sound science in risk assessment as a basis for making regulatory decisions have been, to some extent, driven by the outcomes of the 1992 UNCED Conference on Sustainable Development (Rio Summit) and its Chapter 19 Agenda 21 activities. The promotion of safe chemical management practices and the need for global strengthening of capabilities in toxicology are among the initiatives of the Intergovernmental Forum on Chemical Safety (IFCS), which was formed after the Rio Summit to manage these programs. This article describes some of the initiatives in capacity building that marked the development of environmental toxicology in Australia since 1992 in response to these international environmental health initiatives.

Methodological issues in linking study participants to Australian cancer registries using different methods: lessons from a cohort study

OBJECTIVE

To compare results of concurrent linkage of records from the same occupational cohort to cancer registries at both a State and national level. Methodological issues affecting the record registry linkage process will be explored in cases of discordant results between the State and national cancer linkages.

METHODS

The number of incident invasive cancers in an occupational cohort of more than 11,000 workers was determined by linkage to the National Cancer Statistics Clearing House (NCSCH) in 2003. The results were then compared with linkages by the cancer registries of Victoria and Western Australia in 2004, and also with a previous NCSCH linkage in 1998.

RESULTS

Our analyses show an under-ascertainment of confirmed cancer cases by the NCSCH of about 13% (26/205) in Victoria and 11% (32/297) in Western Australia. In addition, 14 cases (5%) identified in a previous NCSCH record linkage in 1998 were not matched in 2003.

CONCLUSIONS

These findings strongly indicate that record linkage to the State cancer registries was essential to maximise the ascertainment of cancer cases in our cohort. We attribute the discordant linkage results to differences in the quality of the record linkage process by the cancer registries.

IMPLICATIONS

The record linkage methods of the national and State cancer registries need further standardisation. At present it is advisable to perform cancer record linkages through the State registries in addition to or instead of the NCSCH.

Challenges of recruiting farm injury study participants through hospital emergency departments

BACKGROUND

Hospital emergency departments are common recruitment sites for injury studies. Yet recruitment method details, capture rates and response fractions are not consistently reported. As privacy legislation increasingly impinges on research activity, these parameters become even more important. The authors describe their experience with recruitment via emergency departments and outline subsequent adjustments to the recruitment approach.

METHODS

The FIRM study was an Australian case-control study of serious farm work-related injury. Cases were identified prospectively by hospital staff on presentation to emergency departments. Consistent with the Victorian Health Records Act, potential cases were initially approached by hospital staff, and full recruitment was subsequently undertaken by study staff. Manual hospital record audits were conducted at five recruitment sites to determine the proportion of eligible cases approached.

RESULTS

Among 660 medical records audited, 19 eligible cases were confirmed, 9 of whom were approached by hospital staff (47%, 95% CI 25 to 70%). In response, an additional process was established to capture missed cases, who were sent a letter from the hospital providing the opportunity to opt out of telephone contact by study staff. Early indications were that 34% (41/122) of missed cases actively declined to be contacted. Among those who were contacted and eligible, 84% (21/25) agree to study participation.

CONCLUSIONS

Recruitment of injury research participants via hospital emergency departments is challenging, particularly where authorities require an intermediary to make the initial contact. Removal of some constraints imposed by privacy legislation would considerably simplify recruitment and enhance scientific rigour in conducting epidemiological research.

Working in light vehicles--a review and conceptual model for occupational health and safety

Occupational light vehicle (OLV) use is the leading cause of work related traumatic deaths in Westernised countries. Previous research has focused primarily on narrow contexts of OLV-use such as corporate fleet vehicles. We have proposed a comprehensive systems model for OLV-use to provide a framework for identifying research needs and proposing policy and practice interventions. This model presents the worker as the locus of injury at the centre of work- and road-related determinants of injury. Using this model, we reviewed existing knowledge and found most studies focused only on company car drivers, neglecting OLV-users in non-traditional employment arrangements and those using other vehicle types. Environmental exposures, work design factors and risk and protective factors for the wider OLV-user population are inadequately researched. Neither road- nor work-related policy appropriately addresses OLV-use, and population surveillance relies largely on inadequate workers compensation insurance data. This review demonstrates that there are significant gaps in understanding the problem of OLV-use and a need for further research integrating public health, insurance and road safety responses. The model provides a framework for understanding the theory of OLV-use OHS and guidance for urgently needed intervention research, policy and practice.