Excess mortality in Glasgow: further evidence of 'political effects' on population health

OBJECTIVES

The aim of the study was to update previous analyses of 'excess mortality' in Glasgow (Scotland) relative to the similar postindustrial cities of Liverpool and Manchester (England). The excess is defined as mortality after adjustment for socio-economic deprivation; thus, we sought to compare changes over time in both the deprivation profiles of the cities and the levels of deprivation-adjusted mortality in Glasgow relative to the other cities. This is important not only because the original analyses are now increasingly out of date but also because since publication, important (prepandemic) changes to mortality trends have been observed across all parts of the United Kingdom.

STUDY DESIGN AND METHODS

Replicating as far as possible the methods of the original study, we developed a three-city deprivation index based on the creation of spatial units in Glasgow that were of similar size to those in Liverpool and Manchester (average population sizes of approximately 1600, 1500 and 1700 respectively) and an area-based measure of 'employment deprivation'. Mortality and matching population data by age, sex and small area were obtained from national agencies for two periods: 2003-2007 (the period covered by the original study) and 2014-2018. The rates of employment deprivation for each city's small areas were calculated for both periods. Indirectly standardised mortality ratios (SMRs) were calculated for Glasgow relative to Liverpool and Manchester, standardised by age and three-city deprivation decile. For context, city-level trends in age-standardised mortality rates by year, sex and city were also calculated.

RESULTS

There was evidence of a stalling of improvement in mortality rates in all three cities from the early 2010s. After adjustment for area deprivation, all-cause mortality in Glasgow in 2014-2018 was c.12% higher than in Liverpool and Manchester for all ages (SMR 112.4, 95% CI 111.1-113.6) and c.17% higher for deaths under 65 years (SMR 117.1, 95% CI 114.5-119.7). The excess was higher for males (17% compared with 9% for deaths at all ages; 25% compared with 5% for 0-64 years) and for particular causes of death such as suicide and drug-related and alcohol-related causes. The results were broadly similar to those previously described for 2003-2007, although the excess for premature mortality was notably lower. In part, this was explained by changes in levels of employment deprivation, which had decreased to a greater degree in the English cities: this was particularly true of Manchester (a reduction of -43%, compared with -38% in Liverpool and -31% in Glasgow) where the overall population size had also increased to a much greater extent than in the other cities.

CONCLUSIONS

High levels of excess mortality persist in Glasgow. With the political causes recently established - the excess is a 'political effect', not a 'Glasgow effect' - political solutions are required. Thus, previously published recommendations aimed at addressing poverty, inequality and vulnerability in the city are still highly relevant. However, given the evidence of more recent, UK-wide, political effects on mortality - widening mortality inequalities resulting from UK Government 'austerity' measures - additional policies at UK Government level to protect, and restore, the income of the poorest in society are also urgently needed.

Lynch syndrome associated endometrial carcinomas in Western Australia: an analysis of universal screening by mismatch repair protein immunohistochemistry

BACKGROUND

In 2016 universal screening with mismatch repair protein immunohistochemistry in all newly diagnosed endometrial carcinomas was introduced in Western Australia.

OBJECTIVE

To compare the prevalence of Lynch syndrome associated endometrial carcinomas between 2016 and 2019 with a historical control (2015). Additionally, to compare the number of cases appropriately referred for genetic assessment.

METHODS

A cross-sectional study of cases presented at the Western Australia gynecologic oncology tumor board was carried out. The primary outcome was the prevalence of Lynch syndrome associated endometrial carcinomas. A secondary outcome was the number of cases appropriately referred for genetic assessment. The following variables were extracted: date of birth; age at diagnosis; vital status; tumor mismatch repair protein expression status (retained or lost) and if lost, the specific mismatch repair protein deficiency; patients who were referred to a genetic clinic; and family history, if recorded. Data were collected from the clinical databases of the Familial Cancer Program at Genetic Services of Western Australia and WOMEN Center, to determine whether patients were appropriately referred for genetic evaluation and to ascertain the results of genetic testing.

RESULTS

Between 2016 and 2019, there were 1040 new endometrial carcinomas. Tumors of 883 (85%) patients underwent mismatch repair protein immunohistochemistry compared with 117 of 199 patients (59%) in 2015 (χ² 73.14, p<0.001). Of 883 tumors tested, 242 (27%) showed loss of mismatch repair protein expression. In 2015, 30 (26%) tumors of 117 tested showed loss of mismatch repair protein expression. During the 4 years of universal screening, 13 (1.5%) of 883 patients screened were diagnosed with Lynch syndrome compared with 2 (1.7%) of 117 in 2015 (Fisher's exact test 0.04, p=0.69). In 2015, 11 (37%) of 30 patients with loss of mismatch repair protein expression were not referred for genetic assessment compared with 36 (17%) of 209 patients in the universal screening group (χ² 6.28, p=0.02). No cases of Lynch syndrome were diagnosed in patients aged over 70 years.

CONCLUSIONS

Universal immunohistochemical screening did not increase the proportion of Lynch syndrome associated endometrial carcinomas identified, although the study was underpowered to detect small differences. There was an improvement in appropriate referrals for genetic assessment.

Incidence of germline BRCA1/2 mutations in women with tubo-ovarian high-grade serous carcinomas with and without serous tubal intra-epithelial carcinomas

OBJECTIVE

To compare the germline BRCA1 and BRCA2 mutation (gBRCA) status in women with high-grade serous tubo-ovarian and primary peritoneal carcinoma with and without serous tubal intra-epithelial carcinomas (serous tubal intra-epithelial carcinoma-positive vs serous tubal intra-epithelial carcinoma-negative).

MATERIALS AND METHODS

A retrospective study was performed of patients in Western Australia diagnosed with high-grade serous tubo-ovarian and primary peritoneal carcinoma and referred for genetic counseling and gBRCA testing from July 1, 2014 to June 30, 2017. Histopathology reports were reviewed to ascertain whether serous tubal intra-epithelial carcinoma was present. Personal or family gBRCA status, family history, age at diagnosis, mode of treatment (neoadjuvant chemotherapy vs primary surgery), and stage were also recorded.

RESULTS

A total of 269 women with high-grade serous tubo-ovarian and primary peritoneal carcinoma were referred for genetic counseling and testing. 114 patients were excluded because the serous tubal intra-epithelial carcinoma status was not assessable or because patients did not attend for genetic assessment. 155 patients (55 serous tubal intra-epithelial carcinoma-positive and 100 serous tubal intra-epithelial carcinoma-negative) underwent genetic testing. gBRCA mutations were found in 27.8% of serous tubal intra-epithelial carcinoma-positive patients compared with 14.0% of serous tubal intra-epithelial carcinoma-negative patients (p=0.094). Of those found to have a gBRCA mutation, 89.7% reported a positive personal or family history of BRCA-related cancers.

CONCLUSIONS

The gBRCA mutation detection rate in serous tubal intra-epithelial carcinoma-positive patients was nearly double that of serous tubal intra-epithelial carcinoma-negative patients. Factors such as a positive family history of BRCA-related cancers were seen at a higher proportion in the mutation positive women.

Enabling Global Clinical Collaborations on Identifiable Patient Data: The Minerva Initiative

The clinical utility of computational phenotyping for both genetic and rare diseases is increasingly appreciated; however, its true potential is yet to be fully realized. Alongside the growing clinical and research availability of sequencing technologies, precise deep and scalable phenotyping is required to serve unmet need in genetic and rare diseases. To improve the lives of individuals affected with rare diseases through deep phenotyping, global big data interrogation is necessary to aid our understanding of disease biology, assist diagnosis, and develop targeted treatment strategies. This includes the application of cutting-edge machine learning methods to image data. As with most digital tools employed in health care, there are ethical and data governance challenges associated with using identifiable personal image data. There are also risks with failing to deliver on the patient benefits of these new technologies, the biggest of which is posed by data siloing. The Minerva Initiative has been designed to enable the public good of deep phenotyping while mitigating these ethical risks. Its open structure, enabling collaboration and data sharing between individuals, clinicians, researchers and private enterprise, is key for delivering precision public health.

Uptake of testing for germline BRCA mutations in patients with non-mucinous epithelial ovarian cancers in Western Australia: a comparison of different genetic counseling methods

Introduction

Patients with non-mucinous epithelial tubo-ovarian cancers should be referred for genetic testing because approximately 15% will carry an inherited mutation in the BRCA1 or BRCA2 cancer susceptibility genes. However, referral rates for genetic testing remain low. For patients who carry a BRCA mutation, failure to refer for genetic testing results in missed opportunities for therapy and prevention of future cancers in the patient and at-risk relatives. In Western Australia between July 2013 and June 2015, 40.6% of patients with non-mucinous epithelial tubo-ovarian cancers discussed at a statewide gynecologic oncology tumor board were referred for genetic testing. Our objective was to investigate the proportion of patients with non-mucinous epithelial tubo-ovarian cancers in Western Australia referred for BRCA1/2 testing from July 2015 to December 2017, following the introduction of mainstreaming and tele-counseling. A secondary aim was to compare the uptake of genetic testing between different genetic counseling modalities.

Methods

Retrospective case series. All patients with high-grade non-mucinous epithelial tubo-ovarian cancers discussed at the weekly Western Australian gynecologic oncology tumor board meeting, between July 1, 2015 and December 31, 2017, and those referred for BRCA mutation testing, were ascertained.

Results

A total of 343 women were eligible for referral; 63 patients were excluded, leaving 280 patients for analysis. 220/280 patients were referred for genetic testing (78.6%). There were no differences in uptake of genetic testing by mode of genetic counseling.

Discussion

A significant increase in referrals of eligible patients for genetic testing was observed in 2015–2017 compared with 2013–2014. Although there were no differences in uptake of genetic testing by mode of counseling, mainstreaming and tele-counseling provide alternative options for patients that may lead to higher uptake of genetic testing.

Investigating barriers to genetic counseling and germline mutation testing in women with suspected hereditary breast and ovarian cancer syndrome and Lynch syndrome

OBJECTIVE

The aim of the current study was to explore barriers to genetic counseling and testing in women with gynecological cancers deemed at significant risk of carrying a germline mutation.

METHODS

A qualitative study using semi-structured interviews and inductively analysed thematically. Eight patients with ovarian or endometrial cancer participated in individual semi-structured telephone interviews that assessed motivation for genetic counseling and testing, perceived benefits and barriers, timing of the approach, perceptions of the referral process to genetic services and locus of control in relation to cancer and health.

RESULTS

Analysis of the interview transcripts revealed five themes relating to perceptions of genetic counseling and testing: Lack of importance; Level of information received; Timing of referral processes; Fear and anxiety; Resistance to and perceptions of counseling.

CONCLUSIONS

Participants had a limited understanding of hereditary cancer syndromes and did not appreciate the benefits of genetic testing. A consistent approach at the time of referral to genetic services is needed to ensure that the level and format of information is appropriate for patients.

PRACTICE IMPLICATIONS

The rationale for genetic testing needs to be better explained to patients and the timing of referral should be based both on treatment priorities and patient preferences.

Initiating an undiagnosed diseases program in the Western Australian public health system

Background

New approaches are required to address the needs of complex undiagnosed diseases patients. These approaches include clinical genomic diagnostic pipelines, utilizing intra- and multi-disciplinary platforms, as well as specialty-specific genomic clinics. Both are advancing diagnostic rates. However, complementary cross-disciplinary approaches are also critical to address those patients with multisystem disorders who traverse the bounds of multiple specialties and remain undiagnosed despite existing intra-specialty and genomic-focused approaches. The diagnostic possibilities of undiagnosed diseases include genetic and non-genetic conditions. The focus on genetic diseases addresses some of these disorders, however a cross-disciplinary approach is needed that also simultaneously addresses other disorder types. Herein, we describe the initiation and summary outcomes of a public health system approach for complex undiagnosed patients - the Undiagnosed Diseases Program-Western Australia (UDP-WA).

Results

Briefly the UDP-WA is: i) one of a complementary suite of approaches that is being delivered within health service, and with community engagement, to address the needs of those with severe undiagnosed diseases; ii) delivered within a public health system to support equitable access to health care, including for those from remote and regional areas; iii) providing diagnoses and improved patient care; iv) delivering a platform for in-service and real time genomic and phenomic education for clinicians that traverses a diverse range of specialties; v) retaining and recapturing clinical expertise; vi) supporting the education of junior and more senior medical staff; vii) designed to integrate with clinical translational research; and viii) is supporting greater connectedness for patients, families and medical staff.

Conclusion

The UDP-WA has been initiated in the public health system to complement existing clinical genomic approaches; it has been targeted to those with a specific diagnostic need, and initiated by redirecting existing clinical and financial resources. The UDP-WA supports the provision of equitable and sustainable diagnostics and simultaneously supports capacity building in clinical care and translational research, for those with undiagnosed, typically rare, conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-017-0619-z) contains supplementary material, which is available to authorized users.

3-Dimensional Facial Analysis-Facing Precision Public Health

Precision public health is a new field driven by technological advances that enable more precise descriptions and analyses of individuals and population groups, with a view to improving the overall health of populations. This promises to lead to more precise clinical and public health practices, across the continuum of prevention, screening, diagnosis, and treatment. A phenotype is the set of observable characteristics of an individual resulting from the interaction of a genotype with the environment. Precision (deep) phenotyping applies innovative technologies to exhaustively and more precisely examine the discrete components of a phenotype and goes beyond the information usually included in medical charts. This form of phenotyping is a critical component of more precise diagnostic capability and 3-dimensional facial analysis (3DFA) is a key technological enabler in this domain. In this paper, we examine the potential of 3DFA as a public health tool, by viewing it against the 10 essential public health services of the “public health wheel,” developed by the US Centers for Disease Control. This provides an illustrative framework to gage current and emergent applications of genomic technologies for implementing precision public health.

The rare and undiagnosed diseases diagnostic service - application of massively parallel sequencing in a state-wide clinical service

Background

The Rare and Undiagnosed Diseases Diagnostic Service (RUDDS) refers to a genomic diagnostic platform operating within the Western Australian Government clinical services delivered through Genetic Services of Western Australia (GSWA). GSWA has provided a state-wide service for clinical genetic care for 28 years and it serves a population of 2.5 million people across a geographical area of 2.5milion Km². Within this context, GSWA has established a clinically integrated genomic diagnostic platform in partnership with other public health system managers and service providers, including but not limited to the Office of Population Health Genomics, Diagnostic Genomics (PathWest Laboratories) and with executive level support from the Department of Health. Herein we describe report presents the components of this service that are most relevant to the heterogeneity of paediatric clinical genetic care.

Results

Briefly the platform : i) offers multiple options including non-genetic testing; monogenic and genomic (targeted in silico filtered and whole exome) analysis; and matchmaking; ii) is delivered in a patient-centric manner that is resonant with the patient journey, it has multiple points for entry, exit and re-entry to allow people access to information they can use, when they want to receive it; iii) is synchronous with precision phenotyping methods; iv) captures new knowledge, including multiple expert review; v) is integrated with current translational genomic research activities and best practice; and vi) is designed for flexibility for interactive generation of, and integration with, clinical research for diagnostics, community engagement, policy and models of care.

Conclusion

The RUDDS has been established as part of routine clinical genetic services and is thus sustainable, equitably managed and seeks to translate new knowledge into efficient diagnostics and improved health for the whole community.

Point Mutations in Exon 1B of APC Reveal Gastric Adenocarcinoma and Proximal Polyposis of the Stomach as a Familial Adenomatous Polyposis Variant

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is an autosomal-dominant cancer-predisposition syndrome with a significant risk of gastric, but not colorectal, adenocarcinoma. We mapped the gene to 5q22 and found loss of the wild-type allele on 5q in fundic gland polyps from affected individuals. Whole-exome and -genome sequencing failed to find causal mutations but, through Sanger sequencing, we identified point mutations in APC promoter 1B that co-segregated with disease in all six families. The mutations reduced binding of the YY1 transcription factor and impaired activity of the APC promoter 1B in luciferase assays. Analysis of blood and saliva from carriers showed allelic imbalance of APC, suggesting that these mutations lead to decreased allele-specific expression in vivo. Similar mutations in APC promoter 1B occur in rare families with familial adenomatous polyposis (FAP). Promoter 1A is methylated in GAPPS and sporadic FGPs and in normal stomach, which suggests that 1B transcripts are more important than 1A in gastric mucosa. This might explain why all known GAPPS-affected families carry promoter 1B point mutations but only rare FAP-affected families carry similar mutations, the colonic cells usually being protected by the expression of the 1A isoform. Gastric polyposis and cancer have been previously described in some FAP-affected individuals with large deletions around promoter 1B. Our finding that GAPPS is caused by point mutations in the same promoter suggests that families with mutations affecting the promoter 1B are at risk of gastric adenocarcinoma, regardless of whether or not colorectal polyps are present.

A Toll-like receptor-1 variant and its characteristic cellular phenotype is associated with severe malaria in Papua New Guinean children

Genetic factors are likely to contribute to low severe malaria case fatality rates in Melanesian populations, but association studies can be underpowered and may not provide plausible mechanistic explanations if significant associations are detected. In preparation for a genome-wide association study, 29 candidate single-nucleotide polymorphisms (SNPs) with minor allele frequencies >5% were examined in a case-control study of 504 Papua New Guinean children with severe malaria. In parallel, an immunological substudy was performed on convalescent peripheral blood mononuclear cells (PBMCs) from cases and controls. Following stimulation with a Toll-like receptor (TLR) 1/2 agonist, effector cytokines and chemokines were assayed. The only significant genetic association observed involved a nonsynonymous SNP (TLR1rs4833095) in the TLR1 gene. A recessive (TT) genotype was associated with reduced odds of severe malaria of 0.52 (95% confidence interval (0.29-0.90), P=0.006). Concentrations of pro-inflammatory cytokines interleukin-1β and tumour necrosis factor α were significantly higher in severe malaria cases compared with healthy controls, but lower in children with the protective recessive (TT) genotype. A genetic variant in TLR1 may contribute to the low severe malaria case fatality rates in this region through a reduced pro-inflammatory cellular phenotype.

A germline MTOR mutation in Aboriginal Australian siblings with intellectual disability, dysmorphism, macrocephaly, and small thoraces

We report on three Aboriginal Australian siblings with a unique phenotype which overlaps with known megalencephaly syndromes and RASopathies, including Costello syndrome. A gain-of-function mutation in MTOR was identified and represents the first reported human condition due to a germline, familial MTOR mutation. We describe the findings in this family to highlight that (i) the path to determination of pathogenicity was confounded by the lack of genomic reference data for Australian Aboriginals and that (ii) the disease biology, functional analyses in this family, and studies on the tuberous sclerosis complex support consideration of an mTOR inhibitor as a therapeutic agent.

Vulnerability to food insecurity in urban slums: experiences from Nairobi, Kenya

Food and nutrition security is critical for economic development due to the role of nutrition in healthy growth and human capital development. Slum residents, already grossly affected by chronic poverty, are highly vulnerable to different forms of shocks, including those arising from political instability. This study describes the food security situation among slum residents in Nairobi, with specific focus on vulnerability associated with the 2007/2008 postelection crisis in Kenya. The study from which the data is drawn was nested within the Nairobi Urban Health and Demographic Surveillance System (NUHDSS), which follows about 70,000 individuals from close to 30,000 households in two slums in Nairobi, Kenya. The study triangulates data from qualitative and quantitative sources. It uses qualitative data from 10 focus group discussions with community members and 12 key-informant interviews with community opinion leaders conducted in November 2010, and quantitative data involving about 3,000 households randomly sampled from the NUHDSS database in three rounds of data collection between March 2011 and January 2012. Food security was defined using the Household Food Insecurity Access Scale (HFIAS) criteria. The study found high prevalence of food insecurity; 85% of the households were food insecure, with 50% being severely food insecure. Factors associated with food security include level of income, source of livelihood, household size, dependence ratio; illness, perceived insecurity and slum of residence. The qualitative narratives highlighted household vulnerability to food insecurity as commonplace but critical during times of crisis. Respondents indicated that residents in the slums generally eat for bare survival, with little concern for quality. The narratives described heightened vulnerability during the 2007/2008 postelection violence in Kenya in the perception of slum residents. Prices of staple foods like maize flour doubled and simultaneously household purchasing power was eroded due to worsened unemployment situation. The use of negative coping strategies to address food insecurity such as reducing the number of meals, reducing food variety and quality, scavenging, and eating street foods was prevalent. In conclusion, this study describes the deeply intertwined nature of chronic poverty and acute crisis, and the subsequent high levels of food insecurity in urban slum settings. Households are extremely vulnerable to food insecurity; the situation worsening during periods of crisis in the perception of slum residents, engendering frequent use of negative coping strategies. Effective response to addressing vulnerability to household food insecurity among the urban poor should focus on both the underlying vulnerabilities of households due to chronic poverty and added impacts of acute crises.

Malignant spinal cord compression: NICE guidance, improvements and challenges

BACKGROUND AND AIM

Malignant spinal cord compression (mSCC) is one of the most serious complications of cancer. Recent NICE guidance has aimed to improve patient pathways and outcomes for patients with mSCC. We have examined the current presentations, management and outcomes for patients with mSCC in West London following the implementation of the NICE guidance.

MATERIALS AND METHODS

The electronic records and clinical notes were reviewed for all patients assessed for confirmed or potential mSCC at Charing Cross Hospital in 2012. Details on the number of referrals, the proportion with confirmed mSCC, the cancer diagnosis, treatment and outcome were analysed.

RESULTS

191 patients were reviewed with 127 (66%) cases of confirmed mSCC. The commonest tumour types were prostate cancer (26 cases), lung cancer (26), breast cancer (21) and kidney cancer (15). 21% of the patients had no previous cancer diagnosis; mSCC was their presenting diagnostic event. Radiotherapy was the predominant management, 24% of the patients had first line surgical treatment. At presentation 62% of patients were either chair or bed bound. Treatment brought important mobility benefits to all patients groups with 20% of the initially chair or bed bound patients leaving the hospital with independent mobility.

CONCLUSION

Enhanced patients pathways with ease of access, rapid assessment and prompt treatment can improve outcomes. Despite these pathways many patients still present with gross motor impairment and over 20% have no previous diagnosis of cancer. Ongoing work to maintain awareness for patients and primary care of the diagnosis and emergency pathways is essential to optimize outcomes.

Population-based screening for Lynch syndrome in Western Australia

We showed earlier that routine screening for microsatellite instability (MSI) and loss of mismatch repair (MMR) protein expression in colorectal cancer (CRC) led to the identification of previously unrecognized cases of Lynch syndrome (LS). We report here the results of screening for LS in Western Australia (WA) during 1994-2012. Immunohistochemistry (IHC) for loss of MMR protein expression was performed in routine pathology laboratories, while MSI was detected in a reference molecular pathology laboratory. Information on germline mutations in MMR genes was obtained from the state's single familial cancer registry. Prior to the introduction of routine laboratory-based screening, an average of 2-3 cases of LS were diagnosed each year amongst WA CRC patients. Following the implementation of IHC and/or MSI screening for all younger (<60 years) CRC patients, this has increased to an average of 8 LS cases diagnosed annually. Based on our experience in WA, we propose three key elements for successful population-based screening of LS. First, for all younger CRC patients, reflex IHC testing should be carried out in accredited pathology services with ongoing quality control. Second, a state- or region-wide reference laboratory for MSI testing should be established to confirm abnormal or suspicious IHC test results and to exclude sporadic cases by carrying out BRAF mutation or MLH1 methylation testing. Finally, a state or regional LS coordinator is essential to ensure that all appropriate cases identified by laboratory testing are referred to and attend a Familial Cancer Clinic for follow-up and germline testing.

Distinct distribution of killer-cell immunoglobulin-like receptor genes in the Mugil and Ilaita areas of Papua New Guinea

The frequency of the killer-cell immunoglobulin-like receptor (KIR) genes and transmembrane alleles of KIR2DL4 were studied in coastal (Mugil community) and inland (Ilaita community) communities in Papua New Guinea. Linkage disequilibria between KIR genes and between alleles of KIR2DL4 and the KIR genes were similar to those found in other populations suggesting conservation of the usual gene order in Papua New Guinean haplotypes. Significant differences in the frequency of KIR genes were found between the two populations despite being separated by only 300 km. Examples of individuals who lacked the KIR2DL4 gene and others whose KIR2DL4 allele appeared to have 11 adenines in the polyadenine tract in exon 6 were identified. A relatively low frequency of the KIR A haplotype was found in both populations and particularly in the inland community. The KIR gene frequencies were consistent with the inland Ilaita community being closely related to Australian Aborigines and southern Indians, whereas the KIR gene frequencies of the coastal Mugil community appeared to have been influenced either by recent or ancient admixture from populations with a higher frequency of the KIR A haplotype.

Challenges in the diagnosis and management of Lynch Syndrome in an Indigenous family living in a remote West Australian community

CONTEXT

Lynch syndrome (LS), also referred to as hereditary non-polyposis colorectal cancer, is a familial cancer syndrome characterised by young age of onset of colorectal and other extra-colonic cancers. Most studies suggest that LS accounts for approximately 1% of all colorectal cancers (CRC). The identification of persons with a mutation for this syndrome is of major clinical importance because regular and life-long surveillance has been shown to improve their survival through early cancer detection. However, the identification of LS among CRC patients is a major challenge because there are no specific distinguishing clinical features. Clinical criteria based on family history of cancer and age of cancer diagnosis have been proposed. For various reasons, these are not well utilised and clinicians often fail to refer high-risk CRC patients for genetic assessment of LS. The low rate of referrals to the single, state-wide familial cancer program in Western Australia led to calls for a more sensitive and specific means of detecting LS cases. Virtually all tumours from LS patients are characterised by the molecular features of microsatellite instability (MSI) and loss of expression of mismatch repair proteins detected by immunohistochemistry (IHC). It was recently established that routine MSI and IHC testing in CRC patients aged under 60 years was an effective screening tool to identify previously unrecognized LS cases. This approach has now become routine practice in Western Australia and has led to the identification of more than 20 new LS families, including the Indigenous family described in this report.

ISSUES

Population-based screening programs can identify individuals who may not be aware of their at-risk status, who may have little prior knowledge of their medical condition and who may have limited access to tertiary health services. This report describes some challenges met when following up a positive screening result for LS in an individual residing in a remote community more than 2000 km from the state's only Family Cancer Clinic. The challenges included finding the patient, arranging genetic counselling and testing, informing him of the result and providing advice regarding life-long surveillance. Also discussed are issues relating to management of the extended kindred in terms of cultural sensitivities, intra-familial communication and involvement of the local health providers, as well as the provision of genetic counselling, testing and surveillance services for patients living in remote regions. Prior to this study, there were no known Indigenous families with LS in Australia.

LESSONS LEARNED

The likelihood of finding hereditary cancer syndromes in Indigenous families living in remote communities is low. However, advances in modern diagnostic screening technologies will result in the identification of an increased number of at-risk individuals, some of whom will be from minority groups or from remote communities. Despite geographical isolation and cultural differences, hereditary cancer syndromes can be managed in individuals and families living in rural and remote areas. The key issues identified from this case are flexibility with standard clinical genetic protocols and the presence of a local medical practitioner who takes an active interest in delivery of the genetic testing and surveillance strategies.

Robert Koch redux: malaria immunology in Papua New Guinea

Over a century ago, the malaria expedition of the brilliant microbiologist Robert Koch to the Dutch East Indies (Indonesia) and German New Guinea (now Papua New Guinea, or PNG), resulted in profound observations that are still central to our current understanding of the epidemiology and acquisition of immunity to the malaria parasite Plasmodium. The tradition of malaria research in PNG pioneered by Koch continues to this day, with a number of recent studies still continuing to elucidate his original concepts and hypotheses. These include age and exposure-related acquisition of immunity, species-specific and cross-species immunity, correlates of protective immunity and determining the prospects for anti-malaria vaccines.

Population-based detection of Lynch syndrome in young colorectal cancer patients using microsatellite instability as the initial test

Approximately 1-2% of colorectal cancers (CRC) arise because of germline mutations in DNA mismatch repair genes, referred to as Lynch syndrome. These tumours show microsatellite instability (MSI) and loss of expression of mismatch repair proteins. Pre-symptomatic identification of mutation carriers has been demonstrated to improve survival; however, there is concern that many are not being identified using current practices. We evaluated population-based MSI screening of CRC in young patients as a means of ascertaining mutation carriers. CRC diagnosed in patients aged <60 years were identified from pathology records. No prior information was available on family history of cancer. PCR techniques were used to determine MSI in the BAT-26 mononucleotide repeat and mutation in the BRAF oncogene. Loss of MLH1, MSH2, MSH6 and PMS2 protein expression was evaluated in MSI+ tumours by immunohistochemistry. MSI+ tumours were found in 105/1,344 (7.8%) patients, of which 7 were excluded as possible Lynch syndrome because of BRAF mutation. Of the 98 "red flag" cases that were followed up, 25 were already known as mutation carriers or members of mutation carrier families. Germline test results were obtained for 35 patients and revealed that 22 showed no apparent mutation, 11 showed likely pathogenic mutations and 2 had unclassified variants. The proportion of MSI+ cases in different age groups that were estimated to be mutation carriers was 89% (<30 years), 83% (30-39), 68% (40-49) and 17% (50-59). We recommend MSI as the initial test for population-based screening of Lynch syndrome in younger CRC patients, regardless of family history.

Germ line mutations of mismatch repair genes in hereditary nonpolyposis colorectal cancer patients with small bowel cancer: International Society for Gastrointestinal Hereditary Tumours Collaborative Study

PURPOSE

The aim of study was to determine the clinical characteristics and mutational profiles of the mismatch repair genes in hereditary nonpolyposis colorectal cancer (HNPCC) patients with small bowel cancer (SBC).

EXPERIMENTAL DESIGN

A questionnaire was mailed to 55 members of the International Society for Gastrointestinal Hereditary Tumours, requesting information regarding patients with HNPCC-associated SBC and germ line mismatch repair gene mutations.

RESULTS

The study population consisted of 85 HNPCC patients with identified mismatch repair gene mutations and SBCs. SBC was the first HNPCC-associated malignancy in 14 of 41 (34.1%) patients for whom a personal history of HNPCC-associated cancers was available. The study population harbored 69 different germ line mismatch repair gene mutations, including 31 mutations in MLH1, 34 in MSH2, 3 in MSH6, and 1 in PMS2. We compared the distribution of the mismatch repair mutations in our study population with that in a control group, including all pathogenic mismatch repair mutations of the International Society for Gastrointestinal Hereditary Tumours database (excluding those in our study population). In patients with MSH2 mutations, patients with HNPCC-associated SBCs had fewer mutations in the MutL homologue interaction domain (2.9% versus 19.9%, P = 0.019) but an increased frequency of mutations in codons 626 to 733, a domain that has not previously been associated with a known function, versus the control group (26.5% versus 2.8%, P < 0.001).

CONCLUSIONS

In HNPCC patients, SBC can be the first and only cancer and may develop as soon as the early teens. The distribution of MSH2 mutations found in patients with HNPCC-associated SBCs significantly differed from that found in the control group (P < 0.001).

Heterogeneous staining for mismatch repair proteins during population-based prescreening for hereditary nonpolyposis colorectal cancer

The aim of this study was to determine the frequency of microsatellite instability (MSI(+)) in tumors from a population-based series of young colorectal cancer patients and its correlation with the loss of expression of mismatch repair (MMR) proteins. The BAT-26 mononucleotide repeat was used to screen for MSI(+) in all colorectal cancers diagnosed in Western Australia throughout a 5-year period in patients <60 years of age. MSI(+) was found in 75 of 1003 (7.5%) cases, of which six contained a concomitant mutation in BRAF and were therefore excluded from further investigations as possible hereditary nonpolyposis colorectal cancer. Immunohistochemistry was used to evaluate expression of the four major MMR proteins (MLH1, MSH2, MSH6, and PMS2) in the remaining 69 MSI(+) tumors. Complete loss of MLH1 and PMS2 expression or of MSH2 and MSH6 expression was found in 35 (51%) and 17 (25%) cases, respectively, whereas other patterns of complete loss were observed in eight cases (12%). Eight tumors (12%) were initially recorded as showing normal expression, but on review seven were reclassified as having abnormal staining because of heterogeneous patterns of MMR loss. Three of these seven cases had previously been found to have germline mutations. Because of possible misinterpretation of heterogeneous immunohistochemistry staining for MMR protein loss, MSI testing is recommended as the initial screen for population-based detection of hereditary nonpolyposis colorectal cancer.

Waiver of individual patient consent in research: when do potential benefits to the community outweigh private rights?

Health services research is important to ensure continued best quality of care, but often uses data obtained without explicit consent for this purpose. Obtaining consent may be difficult for many reasons, but excluding individuals may introduce biases that alter the significance of studies. Approval by ethics committees of a waiver of the need for consent allowed our study to proceed and provide evidence that has led to the implementation of a population-based screening policy for the prospective detection of hereditary non-polyposis colorectal cancer. This screening policy has resulted in more cases being detected routinely with better management for affected patients and their at-risk families. A need for consent would have prohibited this study, and the development of a more efficient screening policy could have been delayed for several more years. Ethics committees can effectively manage the need to uphold basic ethical principles without unnecessarily impeding socially useful research. Committees need to be familiar with the guidelines approved under sections 95 and 95A of the Privacy Act 1988 (Cwlth) in addition to the National Health and Medical Research Council National statement on ethical conduct in research involving humans.

Stimulation of innate immune responses by malarial glycosylphosphatidylinositol via pattern recognition receptors

The glycosylphosphatidylinositol (GPI) anchor of Plasmodium falciparum is thought to function as a critical toxin that contributes to severe malarial pathogenesis by eliciting the production of proinflammatory responses by the innate immune system of mammalian hosts. Analysis of the fine structure of P. falciparum GPI suggests a requirement for the presence of both core glycan and lipid moieties in the recognition and signalling of parasite glycolipids by host immune cells. It has been demonstrated that GPI anchors of various parasitic protozoa can mediate cellular immune responses via members of the Toll-like family of pattern recognition receptors (TLRs). Recent studies indicate that GPI anchors of P. falciparum and other protozoa are preferentially recognized by TLR-2, involving the MyD88-dependent activation of specific signalling pathways that mediate the production of proinflammatory cytokines and nitric oxide from host macrophages in vitro. However, the contribution of malaria GPI toxin to severe disease syndromes and the role of specific TLRs or other pattern recognition receptors in innate immunity in vivo is only just beginning to be characterized. A better understanding of the molecular mechanisms underlying severe malarial pathogenesis may yet lead to substantial new insights with important implications for the development of novel therapeutics for malaria treatment.

Successful defibrillation in water: a preliminary study

Mild hypothermia (32-34 deg C) treatment alleviates vital organ damage after cardiac arrest. A new cooling device, the Thermosuit operates by applying of a thin layer of water directly to the body surface. Hypothermic patients may experience sequential fibrillation. Therefore, we examined whether defibrillation could be administered safely and effectively in water. A 35 kg swine was anesthetized and placed inside the Thermosuit system. This consists of a water containing surround and pumping system. Conventional AED disposable defibrillation electrodes were applied to the animal's chest. Fibrillation was created by applying a 50-volt signal to a pacing wire introduced into the heart. Following a 30-second period of fibrillation, defibrillation was attempted using Medtronic AED 1000 defibrillator. Defibrillation voltage and current were measured. There were three test cases: dry in the system, wet in the functioning system, and damp. Cooling water in the system was contaminated with saline to simulate potential conditions in clinical application. In each fibrillation-defibrillation sequence, the heart was restarted successfully; this required less than 220 joules. Only a small difference was measured in the overall defibrillation voltage and current as applied to the electrodes for the different cases. Thus, underwater defibrillation is safe and can be performed effectively.

Regulating immunity to malaria

The optimal outcome of a malaria infection is that parasitized cells are killed and degraded without inducing significant pathology. Since much of the pathology of malaria infection can be immune-mediated, this implies that immune responses have to be carefully regulated. The mechanisms by which anti-malarial immune responses are believed to be regulated were discussed at the recent Malaria Immunology Workshop (Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA; February 2005). Potential regulatory mechanisms include regulatory T cells, which have been shown to significantly modify cellular immune responses to various protozoan infections, including leishmania and malaria; neutralising antibodies to pro-inflammatory malarial toxins such as glycosylphosphatidylinositol and haemozoin; and self-regulating networks of effector molecules. Innate and adaptive immune responses are further moderated by the broader immunological environment, which is influenced by both the genetic background of the host and by co-infection with other pathogens. A detailed understanding of the interplay between these different immunoregulatory processes may facilitate the rationale design of vaccines and novel therapeutics.

Immediate post-dosing paralysis following severe soman and VX toxicosis in guinea pigs

There have been numerous studies of the central nervous system (CNS) involvement in organophosphate (OP) poisoning showing status epilepticus and/or 'electrographic seizures'. Brain damage has been demonstrated as 'neuronal necrosis' primarily in the cortex, thalamus and hippocampus. To the authors' knowledge there have been no reports of partial/total paralysis following close upon OP exposure although delayed paralysis has been reported. This report summarizes the immediate, OP induced paralytic events recorded in guinea pigs during development of the Canadian reactive skin decontaminant lotion (RSDL). As part of the development work, supra-lethal cutaneous doses of OP were applied to large numbers of guinea pigs followed by decontamination with the RSDL or predecessor lotions and solvents. Soman (pinacolyl methylphosphonofluoridate; GD) challenges were applied to 1277 animals and S-(2-diisopropyl-aminoethyl) methylphosphorothiolate (VX) challenges to 108. The classic sequence of clinical signs--ptyalism, tremors, fasciculations, convulsions, apnea and flaccid paralysis before death--was seen in the 658 animals that died and in many of the survivors. Eighty-four of 688 survivors of GD and 4 of 39 survivors of VX showed random paralysis of various distal regions following recovery from an insult which produced convulsions and/or flaccid paralysis. Because the experiments were designed to assess the decontamination procedures, there were no apparent relationships between the amounts of OP applied and the sequellae recorded. The observations of paralysis were also incidental to the prime focus of the experiments. Because of this, only ten animals paralysed following GD exposure were examined for histological effects. The pathologist diagnosed 'encephalomalacia' and 'focal necrotic lesions' in the cerebral cortex and 'focal necrotic lesions' in one spinal cord. Of the 84 guinea pigs paralysed after GD challenge, one was not decontaminated and the decontaminants used on the remainder were sufficiently varied that there appeared to be no relationship between the type of decontaminant and the resulting paralysis.

Drugs and syringe drivers: a survey of adult specialist palliative care practice in the United Kingdom and Eire

Subcutaneous delivery of drugs using a syringe driver is common practice within specialist palliative care units. There is, however, little documented information regarding clinical practice. A survey performed in 1992 reported that at least 28 drugs were used in combination with others in a single syringe driver. The aim of the present study was to reassess practice in this field and to enquire more specifically about newer drugs. Postal questionnaires were sent to all adult specialist palliative care in-patient units in the UK and Eire (n = 208). One hundred and sixty-five units (79%) responded. The most common syringe driver in use was the Graseby 26 (61% of responding units). Most units delivered the contents of the syringe over 24 h, and water was usually used as the diluent in 90% of cases. The maximum number of drugs that respondents were prepared to mix in a single syringe was usually three (51%) or four (35%). In the UK, all units used diamorphine in doses from 2.5 mg/24 h upwards. All respondents also used haloperidol, in doses from 0.5 to 60 mg/24 h. A total of 28 different drugs were used in syringe drivers. The most common combinations were diamorphine and midazolam (37%), diamorphine and levomepromazine (35%), diamorphine and haloperidol (33%), and diamorphine and cyclizine (31%). In conclusion, there is much in common with regard to the way in which drugs are delivered in syringe drivers. However, a wide variety of drugs and drug combinations are still in use.

Technetium-99m glucarate uptake in a swine model of limited flow plus increased demand

BACKGROUND

Glucarate is a 6-carbon dicarboxylic acid shown to be taken up by necrotic myocytes, binding to nuclear histones in animal models of coronary occlusion, resulting in infarction. This study investigated glucarate uptake in a model of severe ischemia.

METHODS AND RESULTS

Thirty-five experiments were performed, in which a catheter-mounted stenosis (reducing lumen dimensions by 80%) was placed in the left anterior descending coronary artery (LAD) of an anesthetized, instrumented domestic swine and technetium-99m glucarate (GLU) was injected during the last minute of 5 minutes of pacing. Hemodynamic and blood flow measurements were performed at control, during pacing, and during recovery. The animals were killed; their hearts were stained with fluorescein dye and triphenyl tetrazolium chloride (TTC). Electron micography (EM; n = 6) and cell centrifugation (n = 7) were also performed. On the basis of net lactate production and severe blood flow reduction in the risk region (RR), ischemia with pacing developed in 25 animals. Fifteen of 25 animals showed tracer uptake in the RR on in vivo and ex vivo imaging (scan positive), and 10 were scan negative in the RR. Endocardial blood flow in the RR during pacing was 0.28+/-0.16 mL/g/min for scan-positive and 0.30+/-0.17 mL/g/min for scan-negative experiments (P = not significant [NS]). Transmyocardial net lactate extraction during pacing was -63%+/-44% for scan-positive and -53%+/-60% for scan-negative experiments (P = NS). Control and recovery heart rates were higher in scan-positive experiments (108+/-14 vs. 92+/-17, and 125+/-24 vs. 104+/-18, P<.02). Lactate extraction was lower during control and recovery in scan-positive animals (2+/-29 vs. 30+/-19, P = .03). Scan-positive animals had a more proximal stenosis position. Minimal necrosis was documented by means of TTC negative staining in 8 of 15 scan-positive experiments (comprising 10%+/-4.3% of RR area). EM or cell fractionation was performed in 5 of the 7 remaining scan-positive and TTC-positive hearts, and in those 5 experiments, necrosis was documented by means of EM in 2 and by means of cell fractionation in 3.

CONCLUSIONS

Uptake of Tc-99m glucarate was seen in the RR in a swine model of ischemia severe enough to produce myocyte injury and early cell death.

Pathogenesis of malaria

As the mortality rate of 20-30% for severe falciparum malaria under even the best clinical conditions testifies, access to antimalarial drugs is not sufficient to prevent an appreciable mortality from this disease. Understanding the cause of death at a cellular level is essential if additional rational treatments are to be developed. Here, Ian Clark and Louis Schofield discuss recent work presented at the Molecular Approaches to Malaria conference, Lorne, Australia, 2-5 February 2000, that updates the cytokine-based concept of malarial disease.

Myocardial uptake of a (99m)Tc-nitroheterocycle in a swine model of occlusion and reperfusion

The purpose of this study was to evaluate the window for scan positivity of the radiolabeled nitroheterocycle (99m)Tc-BRU-59-21 in the peri-ischemic period using a swine model of occlusion and reperfusion.

METHODS

A balloon catheter was placed in the left anterior descending coronary artery in each of 19 domestic swine. Blood flow and hemodynamic measurements were made at baseline, during occlusion, and at 15 and 180 min after reperfusion. A dose of approximately 925 MBq (99m)Tc-BRU-59-21 was injected before a brief (6 min) period of coronary occlusion at the following times: 15 min (n = 2), 5 min (n = 2), and 2.2 min (n = 5). In 5 experiments the dose was injected 15 min after reperfusion. Animals underwent SPECT imaging 3 h later. Animals were then killed, and hearts were removed, sliced, stained with triphenyl tetrazolium chloride, and imaged on the detector.

RESULTS

The risk region became ischemic during occlusion on the basis of severe reduction in blood flow and lactate production, but necrosis occurred in only 3 experiments. Focal tracer uptake was seen in the risk region in animals injected 5 and 2.2 min before occlusion but not in animals injected 15 min before occlusion and 15 min after reperfusion.

CONCLUSION

The window for scan positivity for (99m)Tc-BRU-59-21 injected in the peri-ischemic period is short using this model of balloon occlusion and reperfusion in swine.

Preconditioning myocardium with demand ischemia in the presence of a critical coronary artery stenosis

The relative importance of adrenergic stimulation and demand ischemia as important preconditioning stimuli remains unclarified. The purpose of this investigation was to use a partial coronary stenosis to define the preconditioning role of demand ischemia. Dobutamine was infused intravenously before coronary occlusion in closed-chest swine with and without an artificial coronary stenosis in the mid-left anterior descending coronary artery. Control animals had no stenosis and did not receive dobutamine before occlusion. All three groups underwent 45 minutes of occlusion followed by 120 minutes of reperfusion. At baseline, regional myocardial blood flow in the area at risk was reduced in animals with a stenosis, but global left ventricular systolic function, measured by gated blood pool scan, was equivalent in all three groups. Animals with and without a stenosis received equivalent catecholamine stress with dobutamine, but only animals with a stenosis manifested ischemia during the infusion. At 2 hours after reperfusion, infarct size as a percentage of the area at risk was smaller in animals with a stenosis given dobutamine. Demand ischemia preconditions myocardium in closed-chest swine. Increased demand alone without ischemia had marginal preconditioning effects. This may have clinical relevance to patients with severe stenoses exposed to stressful stimuli before the development of myocardial infarction.

Specificity in signal transduction among glycosylphosphatidylinositols of Plasmodium falciparum, Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp

Glycosylphosphatidylinositols (GPIs) and related glycoconjugates of parasite origin have been shown to regulate both the innate and acquired immune systems of the host. This is achieved through the activation of novel GPI-dependent signalling pathways in macrophages, lymphocytes and other cell types. Parasite GPIs impart at least two distinct signals to host cells through the structurally distinct inositolphosphoglycan (IPG) and fatty acid domains. Binding of IPG to as yet uncharacterized cell surface receptor(s) leads to activation of src-family protein tyrosine kinases: depending upon structure, GPI-derived fatty acids can either activate or antagonize protein kinase C, and may enter the sphingomyelinase pathway. The degree of fatty acid saturation may also contribute to signalling activity. Thus, variation in structure of parasite GPIs imparts different properties of signal transduction upon this class of glycolipid. The divergent activities of GPIs from various protozoal taxa reflect global aspects of the host/parasite relationship, suggesting that GPI signalling is a central determinant of disease in malaria, leishmaniasis and both American and African trypanosomiases.

CD1d-restricted immunoglobulin G formation to GPI-anchored antigens mediated by NKT cells

Immunoglobulin G (IgG) responses require major histocompatibility complex (MHC)-restricted recognition of peptide fragments by conventional CD4(+) helper T cells. Immunoglobulin G responses to glycosylphosphatidylinositol (GPI)- anchored protein antigens, however, were found to be regulated in part through CD1d-restricted recognition of the GPI moiety by thymus-dependent, interleukin-4-producing CD4(+), natural killer cell antigen 1.1 [(NK1.1)+] helper T cells. The CD1-NKT cell pathway regulated immunogobulin G responses to the GPI-anchored surface antigens of Plasmodium and Trypanosoma and may be a general mechanism for rapid, MHC-unrestricted antibody responses to diverse pathogens.