Validation of DNA methylation biomarkers for diagnosis of acute lymphoblastic leukemia

DNA methylation biomarkers capable of diagnosis and subtyping have been found for many cancers. Fifteen such markers have previously been identified for pediatric acute lymphoblastic leukemia (ALL). Validation of these markers is necessary to assess their clinical utility for molecular diagnostics. Substantial efficiencies could be achieved with these DNA methylation markers for disease tracking with potential to replace patient-specific genetic testing.

Stat5 as a diagnostic marker for leukemia

The Jak-Stat-Socs pathway is an important component of cytokine receptor signaling. Not surprisingly, perturbation of this pathway is implicated in diseases of hematopoietic and immune origin, including leukemia, lymphoma and immune deficiencies. This review examines the role of a key component of this pathway, Stat5. This has been shown to be activated in a variety of leukemias and myeloproliferative disorders, including downstream of a range of key oncogenes where it has been shown to play an important role in mediating their effects. Therefore, Stat5 represents a useful pan-leukemia/myeloproliferative disorder diagnostic marker and key therapeutic end point, as well as representing an attractive therapeutic target for these disorders.

A distinct DNA methylation signature defines pediatric pre-B cell acute lymphoblastic leukemia

Pre-B cell acute lymphoblastic leukemia (ALL) is the most prevalent childhood malignancy and remains one of the highest causes of childhood mortality. Despite this, the mechanisms leading to disease remain poorly understood. We asked if recurrent aberrant DNA methylation plays a role in childhood ALL and have defined a genome-scale DNA methylation profile associated with the ETV6-RUNX1 subtype of pediatric ALL. Archival bone marrow smears from 19 children collected at diagnosis and remission were used to derive a disease specific DNA methylation profile. The gene signature was confirmed in an independent cohort of 86 patients. A further 163 patients were analyzed for DNA methylation of a three gene signature. We found that the DNA methylation signature at diagnosis was unique from remission. Fifteen loci were sufficient to discriminate leukemia from disease-free samples and purified CD34+ cells. DNA methylation of these loci was recurrent irrespective of cytogenetic subtype of pre-B cell ALL. We show that recurrent aberrant genomic methylation is a common feature of pre-B ALL, suggesting a shared pathway for disease development. By revealing new DNA methylation markers associated with disease, this study has identified putative targets for development of novel epigenetic-based therapies.

The psychological impact of a cancer diagnosis on families: the influence of family functioning and patients' illness characteristics on depression and anxiety

A diagnosis of cancer is a very stressful event for the patients and their families. Patients, partners and other family members can suffer from clinical levels of depression and severe levels of anxiety and stress reactions. The similarity in levels of distress between patients and partners and patients and offspring suggests that there are common factors that impact on families' distress levels. The current study examined levels of depression and anxiety in newly diagnosed adult patients (n = 48) and their adult relatives (n = 99). Family functioning and patients' illness characteristics were identified as factors that might impact on families' depression and anxiety. Results from multilevel models indicated that family functioning was important. Families that were able to act openly, express feelings directly, and solve problems effectively had lower levels of depression. Direct communication of information within the family was associated with lower levels of anxiety. Aside from differences anxiety due to cancer type, patients' illness characteristics appear to be risk factors in patients' but not relatives' depression and anxiety. The results from the current study suggest that researchers and clinicians need to be family-focused as cancer affects the whole family, not just the patient.

Leukemia risk associated with low-level benzene exposure

Background: Men who were part of an Australian petroleum industry cohort had previously been found to have an excess of lympho-hematopoietic cancer. Occupational benzene exposure is a possible cause of this excess.

Methods: We conducted a case-control study of lympho-hematopoietic cancer nested within the existing cohort study to examine the role of benzene exposure. Cases identified between 1981 and 1999 (N = 79) were age-matched to 5 control subjects from the cohort. We estimated each subject's benzene exposure using occupational histories, local site-specific information, and an algorithm using Australian petroleum industry monitoring data.

Results: Matched analyses showed that the risk of leukemia was increased at cumulative exposures above 2 ppm-years and with intensity of exposure of highest exposed job over 0.8 ppm. Risk increased with higher exposures; for the 13 case-sets with greater than 8 ppm-years cumulative exposure, the odds ratio was 11.3 (95% confidence interval = 2.85-45.1). The risk of leukemia was not associated with start date or duration of employment. The association with type of workplace was explained by cumulative exposure. There is limited evidence that short-term high exposures carry more risk than the same amount of exposure spread over a longer period. The risks for acute nonlymphocytic leukemia and chronic lymphocytic leukemia were raised for the highest exposed workers. No association was found between non-Hodgkin lymphoma or multiple myeloma and benzene exposure, nor between tobacco or alcohol consumption and any of the cancers.

Conclusions: We found an excess risk of leukemia associated with cumulative benzene exposures and benzene exposure intensities that were considerably lower than reported in previous studies. No evidence was found of a threshold cumulative exposure below which there was no risk.

The performance of solarscan : an automated dermoscopy image analysis instrument for the diagnosis of primary melanoma

Objective To describe the diagnostic performance of SolarScan (Polartechnics Ltd, Sydney, Australia), an automated instrument for the diagnosis of primary melanoma.

Design Images from a data set of 2430 lesions (382 were melanomas; median Breslow thickness, 0.36 mm) were divided into a training set and an independent test set at a ratio of approximately 2:1. A diagnostic algorithm (absolute diagnosis of melanoma vs benign lesion and estimated probability of melanoma) was developed and its performance described on the test set. High-quality clinical and dermoscopy images with a detailed patient history for 78 lesions (13 of which were melanomas) from the test set were given to various clinicians to compare their diagnostic accuracy with that of SolarScan.

Setting Seven specialist referral centers and 2 general practice skin cancer clinics from 3 continents. Comparison between clinician diagnosis and SolarScan diagnosis was by 3 dermoscopy experts, 4 dermatologists, 3 trainee dermatologists, and 3 general practitioners.

Patients Images of the melanocytic lesions were obtained from patients who required either excision or digital monitoring to exclude malignancy.

Main Outcome Measures Sensitivity, specificity, the area under the receiver operator characteristic curve, median probability for the diagnosis of melanoma, a direct comparison of SolarScan with diagnoses performed by humans, and interinstrument and intrainstrument reproducibility.

Results The melanocytic-only diagnostic model was highly reproducible in the test set and gave a sensitivity of 91% (95% confidence interval [CI], 86%-96%) and specificity of 68% (95% CI, 64%-72%) for melanoma. SolarScan had comparable or superior sensitivity and specificity (85% vs 65%) compared with those of experts (90% vs 59%), dermatologists (81% vs 60%), trainees (85% vs 36%; P =.06), and general practitioners (62% vs 63%). The intraclass correlation coefficient of intrainstrument repeatability was 0.86 (95% CI, 0.83-0.88), indicating an excellent repeatability. There was no significant interinstrument variation (P = .80).

Conclusions SolarScan is a robust diagnostic instrument for pigmented or partially pigmented melanocytic lesions of the skin. Preliminary data suggest that its performance is comparable or superior to that of a range of clinician groups. However, these findings should be confirmed in a formal clinical trial.

The health watch case - control study of leukemia and benzene:the story so far

A case–control study nested in the Health Watch cohort of petroleum industry workers, investigated whether the excess of lymphohematopoetic cancers, identified among male members of the Health Watch cohort, was associated with benzene exposure. Cases of non-Hodgkin’s lymphoma (n=31),multiple myeloma (n=15), and leukemia (n=33)were identified between 1981 and 1999. Cases were age-matched to five controls. Exposure was retrospectively estimated for each occupational history using an algorithm in a relational database. Benzene exposure measurements, supplied by Australian petroleum companies, were used to estimate exposure for specific tasks. The tasks carried out within the job, the products handled, and the technology used,were identified from interviews with contemporary colleagues. More than half of the subjects started work after 1965 and had an average exposure period of 20 years. Exposure was low, 85% of the cumulative exposure estimates were<10 ppm years. Matched analyses showed that non-Hodgkin’s lymphoma and multiple myeloma were not associated with benzene exposure. Leukemia risk, however, was significantly increased for the subjects with greater than 16 ppm years cumulative exposure, odds ratio (OR) 51.9 (5.6–477) or with greater than 0.8 ppm intensity of highest exposed job. Cumulative exposures were similar to those found in comparable studies.The inclusion of occasional high exposures, for example, as a result of spillages, reduced the ORs, when the exposure was treated as either a continuous or a categorical variable. Our data demonstrate a strong association between leukemia and modest benzene exposure. The choice of cut-point and reference group has a marked effect on the ORs, but does not change the overall conclusions.

People living with ALS/MND tell the diagnosis story : what happened before they knew

Background: Being told that one has a life threatening disease is shattering, but for some people it comes as a relief, following as it does the years of uncertainty and traumatic experiences that lead to diagnosis. The need to debrief the experience is paramount before the story of living with the disease can be told.
Objectives: The purpose of this paper is to describe the extended and often demoralising process of diagnosis for people with ALS/MND.
Methods: Grounded theory methodology was used to explore the life and world of people diagnosed and living with ALS/MND. Data were collected via in-depth interviews with 25 people with the disease, their stories and photographs, poems and books they identified as important, and field notes. The textual data were analysed using constant comparative analysis. All people who volunteered were included in the study. Many participants with communication challenges worked with the researcher to tell their stories.
Results: Participants recounted the processes they experienced prior to the time when they were finally given a reason for the perplexing behaviour of their bodies. The diagnosis story was revealed as a sequence of: ‘recognizing a problem’, ‘seeking medical help’, ‘being on the diagnostic roundabout’, ‘confirming ALS/MND’, ‘reevaluating life and the future’, then ‘living with ALS/MND’. Consequences included a loss of trust in the competence of the health care system, which had implications for seeking help later when living with the disease.
Discussion: Participant distress seemed to have more in common with the stress linked to post-traumatic stress disorder (PTSD). Participants continued to relive the diagnosis experience in their dreams and daily lives many months after diagnosis, which impacted negatively on their well-being. For this group of people, the diagnostic process itself was the traumatic stressor. It seemed that telling their stories gave them the opportunity to debrief and have their words recorded. Debrief support is recommended whenthe ALS/MND diagnosis is finalized, and continued, to prevent long-term reliving of the diagnostic process.
Conclusion: Health professionals continue to address the issues around the process of giving the ‘bad news’ of ALS/MND. This ‘diagnosis story’ may provide additional guidance in addressing the process so as to limit potential harm and promote well-being for people with the disease and their families.

Defining dual diagnosis : a qualitative study of the views of health care workers

Background: 'Dual diagnosis' is the term of choice in many countries to describe clients with co-occurring mental health and alcohol and other drug (AOD) issues. However, it is not known if its meaning is consistently represented within and across health care services. This uncertainty has significant implications for referral, consultation and research.
Aim: To obtain information about the way that different health care professionals understand the term 'dual diagnosis'.
Method: Twenty-nine health care workers across five service types (medical, mental health, AOD, dual diagnosis and community health) in Victoria, Australia were interviewed about their understanding of the term 'dual diagnosis'.
Results: The findings indicated that service providers working in AOD and Mental Health had a shared general understanding of what was meant by 'dual diagnosis', despite uncertainties about more specific inclusion criteria. In contrast, medical and community health staff lacked a similar shared understanding, and were more likely to recommend change, but offered no consensus on alternatives.
Conclusion: The results indicate that while the term 'dual diagnosis' has value in efficiently directing attention to the complexity of treatment issues, health practitioners cannot assume it will convey the intended meaning outside mental health or AOD services. Clear articulation of the intended definition may be a necessary requirement in wider health care communication.

An examination of the 'gold standard' diagnosis of major depression in aged-care settings

Objectives: Individual clinical interviews are typically viewed as the “gold standard” when diagnosing major depressive disorder (MDD) and when examining the validity of self-rated questionnaires. However, this approach may be problematic with older people, who are known to underreport depressive symptomatology. This study examined the effect of including an informant interview on prevalence estimations of MDD in an aged-care sample.

Design: The results of an individual clinical interview for MDD were compared with those obtained when an informant interview was incorporated into the assessment. Results from each diagnostic approach were compared with scores on a self-rated depression instrument.

Setting: Low-level aged-care residential facilities in Melbourne (equivalent to “residential homes,” “homes for the elderly,” or “assisted living facilities” in other countries).

Participants: One hundred and sixty-eight aged-care residents (mean age: 84.68 years; SD: 6.16 years) with normal cognitive functioning.

Measurements: Individual clinical interviews were conducted using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I Disorders. This interview was modified for use with staff informants. Self-reported depression was measured using the Geriatric Depression Scale-15 (GDS-15).

Results: The estimated point prevalence of MDD rose from 16% to 22% by including an informant clinical interview in the diagnostic procedure. Overall, 27% of depressed residents failed to disclose symptoms in the clinical interview. The concordance of the GDS-15 with a diagnosis of MDD was substantially lower when an informant source was included in the diagnostic procedure.

Conclusion: Individual interviews and self-report questionnaires may be insufficient to detect depression among older adults. This study supports the use of an informant interview as an adjunct when diagnosing MDD among cognitively intact aged-care residents.

Factors associated with dropout and diagnosis in child and adolescent mental health services

Objective: Dropout from child and adolescent mental health services has ramifications for children, families and the services themselves. Understanding the factors that are associated with dropout for different diagnoses has the potential to assist with tailoring of services to reduce dropout. The aim of the current study was to identify such factors.

Method: A file audit was conducted for all referrals to a child and adolescent mental health service over a 12 month period, yielding 520 subjects for analysis (264 male, 256 female, mean age = 12.6 years). Parent, child and service variables of interest were recorded as were diagnoses, which were categorized into 25 superordinate categories.

Results: Almost 50% of subjects dropped out of treatment. Factors associated with dropout varied across diagnosis, and no factor was associated with dropout for all diagnoses.

Conclusion: There are differences in the factors that were associated with dropout for different disorders. This is a useful finding in terms of understanding and preventing dropout in child and adolescent mental health settings, but more research is needed.