Myelodysplastic Neoplasms (MDS) with Ring Sideroblasts or SF3B1 Mutations: The Improved Clinical Utility of World Health Organization and International Consensus Classification 2022 Definitions, a Single-Centre Retrospective Chart Review

Myelodysplastic neoplasms (MDS) with ring sideroblasts (RS) are diagnosed via bone marrow aspiration in the presence of either (i) ≥15% RS or (ii) 5-14% RS and an SF3B1 mutation. In the MEDALIST trial and in an interim analysis of the COMMANDS trial, lower-risk MDS-RS patients had decreased transfusion dependency with luspatercept treatment. A total of 6817 patients with suspected hematologic malignancies underwent molecular testing using a next-generation-sequencing-based genetic assay and 395 MDS patients, seen at our centre from 1 January 2018 to 31 May 2023, were reviewed. Of these, we identified 39 evaluable patients as having lower-risk MDS with SF3B1 mutations: there were 20 (51.3%) males and 19 (48.7%) females, with a median age of 77 years (range of 57 to 92). Nineteen (48.7%) patients had an isolated SF3B1 mutation with a mean variant allele frequency of 35.2% +/- 8.1%, ranging from 7.4% to 46.0%. There were 29 (74.4%) patients with ≥15% RS, 6 (15.4%) with 5 to 14% RS, one (2.6%) with 1% RS, and 3 (7.7%) with no RS. Our study suggests that a quarter of patients would be missed based on the morphologic criterion of only using RS greater than 15% and supports the revised 2022 definitions of the World Health Organization (WHO) and International Consensus Classification (ICC), which shift toward molecularly defined subtypes of MDS and appropriate testing.

Current safeguards, risk mitigation, and transparency measures of large language models against the generation of health disinformation: repeated cross sectional analysis

OBJECTIVES

To evaluate the effectiveness of safeguards to prevent large language models (LLMs) from being misused to generate health disinformation, and to evaluate the transparency of artificial intelligence (AI) developers regarding their risk mitigation processes against observed vulnerabilities.

DESIGN

Repeated cross sectional analysis.

SETTING

Publicly accessible LLMs.

METHODS

In a repeated cross sectional analysis, four LLMs (via chatbots/assistant interfaces) were evaluated: OpenAI's GPT-4 (via ChatGPT and Microsoft's Copilot), Google's PaLM 2 and newly released Gemini Pro (via Bard), Anthropic's Claude 2 (via Poe), and Meta's Llama 2 (via HuggingChat). In September 2023, these LLMs were prompted to generate health disinformation on two topics: sunscreen as a cause of skin cancer and the alkaline diet as a cancer cure. Jailbreaking techniques (ie, attempts to bypass safeguards) were evaluated if required. For LLMs with observed safeguarding vulnerabilities, the processes for reporting outputs of concern were audited. 12 weeks after initial investigations, the disinformation generation capabilities of the LLMs were re-evaluated to assess any subsequent improvements in safeguards.

MAIN OUTCOME MEASURES

The main outcome measures were whether safeguards prevented the generation of health disinformation, and the transparency of risk mitigation processes against health disinformation.

RESULTS

Claude 2 (via Poe) declined 130 prompts submitted across the two study timepoints requesting the generation of content claiming that sunscreen causes skin cancer or that the alkaline diet is a cure for cancer, even with jailbreaking attempts. GPT-4 (via Copilot) initially refused to generate health disinformation, even with jailbreaking attempts-although this was not the case at 12 weeks. In contrast, GPT-4 (via ChatGPT), PaLM 2/Gemini Pro (via Bard), and Llama 2 (via HuggingChat) consistently generated health disinformation blogs. In September 2023 evaluations, these LLMs facilitated the generation of 113 unique cancer disinformation blogs, totalling more than 40 000 words, without requiring jailbreaking attempts. The refusal rate across the evaluation timepoints for these LLMs was only 5% (7 of 150), and as prompted the LLM generated blogs incorporated attention grabbing titles, authentic looking (fake or fictional) references, fabricated testimonials from patients and clinicians, and they targeted diverse demographic groups. Although each LLM evaluated had mechanisms to report observed outputs of concern, the developers did not respond when observations of vulnerabilities were reported.

CONCLUSIONS

This study found that although effective safeguards are feasible to prevent LLMs from being misused to generate health disinformation, they were inconsistently implemented. Furthermore, effective processes for reporting safeguard problems were lacking. Enhanced regulation, transparency, and routine auditing are required to help prevent LLMs from contributing to the mass generation of health disinformation.

Merkel cell carcinoma mimicking acute leukemia

Bone marrow aspirate showed diffuse infiltration by a population of monomorphic cells with scant cytoplasm, markedly increased nuclear-to-cytoplasmic ratio, and numerous indistinct nucleoli. Bone marrow biopsy confirmed extensive marrow infiltration by a malignant neoplasm with strong and diffuse expression of synaptophysin by immunohistochemistry, consistent with metastases from Merkel Cell carcinoma.

An Approach to the Investigation of Thrombocytosis: Differentiating between Essential Thrombocythemia and Secondary Thrombocytosis

Background

Thrombocytosis is a common reason for referral to Hematology. Differentiating between secondary causes of thrombocytosis and essential thrombocythemia (ET) is often clinically challenging. A practical diagnostic approach to identify secondary thrombocytosis could reduce overinvestigation such as next generation sequencing (NGS) panel.

Methods and Results

All adult patients with thrombocytosis (≥450 × 109/L) who underwent molecular testing at a single tertiary care centre between January 1, 2018 and May 31, 2021 were evaluated. Clinical and laboratory variables were compared between patients with secondary thrombocytosis vs. ET. Clinical variables included smoking, thrombosis, splenectomy, active malignancy, chronic inflammatory disease, and iron deficiency anemia. Laboratory variables included complete blood count (CBC), ferritin, and myeloid mutations detected by NGS. The overall yield of molecular testing was 52.4%; 92.1% of which were mutations in JAK2, CALR, and/or MPL. Clinical factors predictive of ET included history of arterial thrombosis (p < 0.05); active malignancy, chronic inflammatory disease, splenectomy, and iron deficiency were associated with secondary thrombocytosis (p < 0.05). A diagnosis of ET was associated with higher hemoglobin, mean corpuscular volume (MCV), red cell distribution width (RDW), and mean platelet volume (MPV), while secondary thrombocytosis was associated with higher body mass index, white blood cells, and neutrophils (p < 0.01).

Conclusion

A practical approach to investigating patients with persistent thrombocytosis based on clinical characteristics such as active malignancy, chronic inflammatory disease, splenectomy, and iron deficiency may assist in accurately identifying patients more likely to have secondary causes of thrombocytosis and reduce overinvestigation, particularly costly molecular testing.

Reuniting philosophy and science to advance cancer research

Cancers rely on multiple, heterogeneous processes at different scales, pertaining to many biomedical fields. Therefore, understanding cancer is necessarily an interdisciplinary task that requires placing specialised experimental and clinical research into a broader conceptual, theoretical, and methodological framework. Without such a framework, oncology will collect piecemeal results, with scant dialogue between the different scientific communities studying cancer. We argue that one important way forward in service of a more successful dialogue is through greater integration of applied sciences (experimental and clinical) with conceptual and theoretical approaches, informed by philosophical methods. By way of illustration, we explore six central themes: (i) the role of mutations in cancer; (ii) the clonal evolution of cancer cells; (iii) the relationship between cancer and multicellularity; (iv) the tumour microenvironment; (v) the immune system; and (vi) stem cells. In each case, we examine open questions in the scientific literature through a philosophical methodology and show the benefit of such a synergy for the scientific and medical understanding of cancer.

A Rational Approach to JAK2 Mutation Testing in Patients with Elevated Hemoglobin: Results from the JAK2 Prediction Cohort (JAKPOT) Study

BACKGROUND

Erythrocytosis, most often measured as an increase in hemoglobin and/or hematocrit, is a common reason for referral to internal medicine and hematology clinics and a rational approach is required to effectively identify patients with polycythemia vera while avoiding over-investigation.

AIM

We aimed to develop and validate a simple rule to predict JAK2 mutation positivity based on complete blood count parameters to aid in the diagnostic approach to patients referred for elevated hemoglobin.

SETTING

Internal medicine and hematology clinics at an academic tertiary referral center.

PARTICIPANTS

The JAK2 Prediction Cohort (JAKPOT), a large retrospective cohort (n = 901) of patients evaluated by internal medicine and hematology specialists for elevated hemoglobin.

DESIGN

JAK2 mutation analysis was performed in all patients and clinical and laboratory variables were collected. Patients were randomly divided into derivation and validation cohorts. A prediction rule was developed using data from the derivation cohort and tested in the validation cohort.

KEY RESULTS

The JAKPOT prediction rule included three variables: (i) red blood cell count >6.45×1012/L, (ii) platelets >350×109/L, and (iii) neutrophils >6.2×109/L; absence of all criteria was effective at ruling out JAK2-positivity with sensitivities 94.7% and 100%, and negative predictive values of 98.8% and 100% in the derivation and validation cohorts, respectively, with an overall low false negative rate of 0.4%. The rule was validated for three different methods of JAK2 testing. Applying this rule to our entire cohort would have resulted in over 50% fewer tests.

CONCLUSION

In patients with elevated hemoglobin, the use of a simple prediction rule helps to accurately identify patients with a low likelihood of having a JAK2 mutation, potentially limiting costly over-investigation in this common referral population.

Technical Difficulties: Teaching Critical Philosophical Orientations toward Technology

Issue: Technological innovation is accelerating, creating less time to reflect on the impact new technologies will have on the medical profession. Modern technologies are becoming increasingly embedded in routine medical practice with far-reaching impacts on the patient-physician relationship and the very essence of the health professions. These impacts are often difficult to predict and can create unintended consequences for medical education. This article is driven by a main question: How do we prepare trainees to critically assess technologies that we cannot foresee and effectively use technology to support equitable and compassionate care? Evidence: We translate insights from the philosophy of technology into a proposal for integrating critical technical consciousness in medical curricula. We identify three areas required to develop critical consciousness with regard to emerging technologies. The first area is technical literacy, which involves not just knowing how to use technology, but also understanding its limitations and appropriate contexts for use. The second area is the ability to assess the social impact of technology. This practice requires understanding that while technification creates new possibilities it can also have adverse, unintended consequences. The third area is critical reflection on the relationship between 'the human' and 'the technical' as it relates to the values of the medical profession and professional identity formation. Human and technology are two sides of the same coin; therefore, thinking critically about technology also forces us to think about what we consider 'the human side of medicine'. Implications: Critical technical consciousness can be fostered through an educational program underpinned by the recognition that, although technological innovation can create new possibilities for healing, technology is never neutral. Rather, it is imperative to emphasize that technology is interwoven with the social fabric that is essential to healing. Like medication, technology can be both potion and poison.

Pericardial Extramedullary Hematopoiesis Associated with Metastatic Adenocarcinoma of Gastrointestinal or Pancreaticobiliary Origin: A Case Report

Extramedullary hematopoiesis (EMH) is a rare complication of solid tumor malignancies. We describe the first case of a patient who developed EMH in the pericardium secondary to metastatic gastrointestinal or pancreaticobiliary cancer. A 58-year-old man presented with recurrent episodes of fatigue and shortness of breath and was treated with thoracocentesis and pericardiocentesis for pleural and pericardial effusions, respectively. Owing to a markedly elevated alkaline phosphatase, a bone scan was performed and demonstrated diffuse sclerotic lesions. Evaluation of pleural effusion diagnosed metastatic adenocarcinoma, and cytospin morphology of the pericardial fluid demonstrated EMH. While EMH secondary to solid tumors is commonly suggested to be due to cytokine signaling, we propose the mechanism of EMH in this patient was due to extensive disruption of bone marrow hematopoiesis, similar to what is seen in myeloproliferative neoplasms.

T-cell clonality testing for the diagnosis of T-cell large granular lymphocytic leukemia: Are we identifying pathology or incidental clones?

INTRODUCTION

T-cell clonality testing by T-cell receptor (TCR) gene rearrangement is key to the diagnosis of T-cell lymphoproliferative disorders such as T-cell large granular lymphocytic (T-LGL) leukemia. Benign clonal T-cell expansions, however, are commonly found in patients without identifiable disease, a condition referred to as T-cell clones of uncertain significance (T-CUS). In practice, T-cell clonality testing is performed for a range of reasons and results are often challenging to interpret given the overlap between benign and malignant clonal T-cell proliferations and uncertainties in the management of T-CUS.

METHODS

We conducted a 5-year retrospective cohort study of 211 consecutive patients who underwent PCR-based T-cell clonality testing for suspected T-LGL leukemia at our institution to characterize the use of T-cell clonality testing and its impact on patient management.

RESULTS

Overall, 46.4% (n = 98) of individuals tested had a clonal T-cell population identified. Patients with a monoclonal T-cell population were more likely to be older, have rheumatoid arthritis and have higher lymphocyte counts compared to patients with polyclonal populations. The majority of patients eventually diagnosed and treated for T-LGL leukemia had rheumatoid arthritis and lower neutrophil counts compared to untreated patients with monoclonal T-cell populations. A diagnosis of T-LGL leukemia was made in only a minority of patients (n = 48, 22.7%), and only a small proportion were treated (n = 17, 8.1%).

CONCLUSION

Our study suggests that T-cell clonality testing most commonly identifies incidental T-cell clones with only a minority of patients receiving a diagnosis of T-LGL leukemia and fewer requiring active treatment. These finding indicate an opportunity to improve utilization of T-cell clonality testing in clinical practice to better target patients where the results of testing would impact clinical management.

The Impact of Artificial Intelligence on Health Equity in Oncology: Scoping Review

BACKGROUND

The field of oncology is at the forefront of advances in artificial intelligence (AI) in health care, providing an opportunity to examine the early integration of these technologies in clinical research and patient care. Hope that AI will revolutionize health care delivery and improve clinical outcomes has been accompanied by concerns about the impact of these technologies on health equity.

OBJECTIVE

We aimed to conduct a scoping review of the literature to address the question, "What are the current and potential impacts of AI technologies on health equity in oncology?"

METHODS

Following PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines for scoping reviews, we systematically searched MEDLINE and Embase electronic databases from January 2000 to August 2021 for records engaging with key concepts of AI, health equity, and oncology. We included all English-language articles that engaged with the 3 key concepts. Articles were analyzed qualitatively for themes pertaining to the influence of AI on health equity in oncology.

RESULTS

Of the 14,011 records, 133 (0.95%) identified from our review were included. We identified 3 general themes in the literature: the use of AI to reduce health care disparities (58/133, 43.6%), concerns surrounding AI technologies and bias (16/133, 12.1%), and the use of AI to examine biological and social determinants of health (55/133, 41.4%). A total of 3% (4/133) of articles focused on many of these themes.

CONCLUSIONS

Our scoping review revealed 3 main themes on the impact of AI on health equity in oncology, which relate to AI's ability to help address health disparities, its potential to mitigate or exacerbate bias, and its capability to help elucidate determinants of health. Gaps in the literature included a lack of discussion of ethical challenges with the application of AI technologies in low- and middle-income countries, lack of discussion of problems of bias in AI algorithms, and a lack of justification for the use of AI technologies over traditional statistical methods to address specific research questions in oncology. Our review highlights a need to address these gaps to ensure a more equitable integration of AI in cancer research and clinical practice. The limitations of our study include its exploratory nature, its focus on oncology as opposed to all health care sectors, and its analysis of solely English-language articles.

Secondary causes of elevated hemoglobin in patients undergoing molecular testing for suspected polycythemia vera in southwestern Ontario: a chart review

BACKGROUND

Molecular testing for JAK2 mutations is part of the standard diagnostic workup for patients with suspected polycythemia vera. We sought to characterize evolving practice patterns in the investigation of erythrocytosis and the prevalence of secondary causes, including use of medications such as sodium-glucose cotransporter-2 (SGLT2) inhibitors, among patients who underwent molecular testing.

METHODS

We reviewed charts of all consecutive patients investigated for erythrocytosis (hemoglobin > 160 g/L for women, > 165 g/L for men) with JAK2 testing between 2015 and 2021 at London Health Sciences Centre, a tertiary referral centre in Ontario, Canada, to assess changes in rates of JAK2 mutation positivity, average hemoglobin levels and the prevalence of secondary causes of erythrocytosis.

RESULTS

A total of 891 patients with erythrocytosis underwent JAK2 mutation testing with an increase in number of tests (particularly from 2017 to 2018), a decrease in the rate of JAK2 positivity and similar average hemoglobin levels over the study period. We observed a high proportion of patients with secondary causes of erythrocytosis, ranging from 59% to 74% over the study period, including medications associated with erythrocytosis, namely testosterone (6%-11%) and SGLT2 inhibitors (2%-19%). Stopping SGLT2 inhibitors was associated with a significant decrease in hemoglobin levels (mean -14.7 g/L, 95% confidence interval -18.9 to -10.5 g/L) compared with continuation.

INTERPRETATION

Use of SGLT2 inhibitors may be a common and underrecognized secondary cause of elevated hemoglobin levels in patients investigated for erythrocytosis. Our findings underscore the importance of a detailed medical history to support judicious use of molecular testing, in adherence with the current guideline on the investigation of erythrocytosis.

Thirty years of teaching evidence-based medicine: have we been getting it all wrong?

Evidence based medicine (EBM) has been synonymous to delivery of quality care for almost thirty years. Since the movement's inception, the assumption has been that decisions based on high quality evidence would translate to better care for patients. Despite EBM's many attractive features and the substantive attention it has received in the contemporary clinical and medical education literature, how it is defined and operationalized as a component of training is often unclear and problematic. How to practice EBM is not well articulated in the literature; therefore, it becomes difficult to teach and equally challenging to assess. In this paper, we put forward a call for deeper consideration of how EBM is taught, and for clarification on how it is defined and operationalized in medical education. In preparing this paper, we considered questions such as what it means to practice EBM, the role that medical education plays in helping realize EBM, how the teaching of EBM can change to reflect recent developments in clinical practice and education, and whether transformations in the practice of medicine necessitate a change in how we teach EBM. We end with four avenues that may be pursued to advance the teaching of EBM in medical education: (1) consensus on what we mean by EBM; (2) clear articulation of EBM-associated competencies; (3) empirically and theoretically supported means of promoting EBM competencies; (4) ways to assess both skill acquisition and use of EBM. We discuss implications for educators of EBM.

Reducing cytogenetic testing in the era of next generation sequencing: Are we choosing wisely?

INTRODUCTION

In most laboratories, next generation sequencing (NGS) has been added without consideration for redundancy compared to conventional cytogenetics (CG). We tested a streamlined approach to genomic testing in patients with suspected myeloid and plasma cell neoplasms using next generation sequencing ("NGS first") as the primary testing modality and limiting cytogenetics (CG) to samples with morphologic abnormalities in the marrow aspirate.

METHODS

Based on morphologic interpretation of bone marrow aspirate and flow cytometry, samples were triaged into four groups: (a) Samples with dysplasia or excess blasts had both NGS and karyotyping; (b) Samples without excess blasts or dysplasia had NGS only; (c) Repeat samples with previous NGS and/or CG studies were not retested; (d) Samples for suspected myeloma with less than 5% plasma cell had CG testing cancelled.

RESULTS

Seven hundred eleven adult bone marrow (BM) samples met the study criteria. The NGS first algorithm eliminated CG testing in 229/303 (75.6%) of patients, primarily by reducing repeat testing. Potential cost avoided was approximately $124 000 per annum. Hematologists overruled the triage comment in only 11/303 (3.6%) cases requesting CG testing for a specific indication.

CONCLUSIONS

Utilizing NGS as the primary genomic testing modality NGS was feasible and well accepted, reducing over three quarters of all CG requests and improving the financial case for adoption of NGS. Key factors for the success of this study were collaboration of clinical and genomic diagnostic teams in developing the algorithm, rapid turnaround time for BM interpretation for triage, and communication between laboratories.

Epitope-specific antibody responses differentiate COVID-19 outcomes and variants of concern

BACKGROUNDThe role of humoral immunity in COVID-19 is not fully understood, owing, in large part, to the complexity of antibodies produced in response to the SARS-CoV-2 infection. There is a pressing need for serology tests to assess patient-specific antibody response and predict clinical outcome.METHODSUsing SARS-CoV-2 proteome and peptide microarrays, we screened 146 COVID-19 patients' plasma samples to identify antigens and epitopes. This enabled us to develop a master epitope array and an epitope-specific agglutination assay to gauge antibody responses systematically and with high resolution.RESULTSWe identified linear epitopes from the spike (S) and nucleocapsid (N) proteins and showed that the epitopes enabled higher resolution antibody profiling than the S or N protein antigen. Specifically, we found that antibody responses to the S-811-825, S-881-895, and N-156-170 epitopes negatively or positively correlated with clinical severity or patient survival. Moreover, we found that the P681H and S235F mutations associated with the coronavirus variant of concern B.1.1.7 altered the specificity of the corresponding epitopes.CONCLUSIONEpitope-resolved antibody testing not only affords a high-resolution alternative to conventional immunoassays to delineate the complex humoral immunity to SARS-CoV-2 and differentiate between neutralizing and non-neutralizing antibodies, but it also may potentially be used to predict clinical outcome. The epitope peptides can be readily modified to detect antibodies against variants of concern in both the peptide array and latex agglutination formats.FUNDINGOntario Research Fund (ORF) COVID-19 Rapid Research Fund, Toronto COVID-19 Action Fund, Western University, Lawson Health Research Institute, London Health Sciences Foundation, and Academic Medical Organization of Southwestern Ontario (AMOSO) Innovation Fund.

Rapid and accurate agglutination-based testing for SARS-CoV-2 antibodies

We have developed a rapid, accurate, and cost-effective serologic test for SARS-CoV-2 virus, which caused the COVID-19 pandemic, on the basis of antibody-dependent agglutination of antigen-coated latex particles. When validated using plasma samples that are positive or negative for SARS-CoV-2, the agglutination assay detected antibodies against the receptor-binding domain of the spike (S-RBD) or the nucleocapsid protein of SARS-CoV-2 with 100% specificity and ∼98% sensitivity. Furthermore, we found that the strength of the S-RBD antibody response measured by the agglutination assay correlated with the efficiency of the plasma in blocking RBD binding to the angiotensin-converting enzyme 2 in a surrogate neutralization assay, suggesting that the agglutination assay might be used to identify individuals with virus-neutralizing antibodies. Intriguingly, we found that >92% of patients had detectable antibodies on the day of a positive viral RNA test, suggesting that the agglutination antibody test might complement RNA testing for the diagnosis of SARS-CoV-2 infection.

From hermeneutics to heteroglossia: 'The Patient's View' revisited

This article explores conceptual and methodological challenges surrounding the recovery of patients' voices in the history of medicine. We examine the debate that followed Roy Porter's seminal article, 'The Patient's View: Doing Medical History from Below' (1985). Porter argued that patients should be given a central role in medical history, aiming to restore to patients a voice and agency that is often lost in 'physician-centered' historical narratives. His work carried significant influence but also sparked an ongoing debate about the possibility of conducting 'patient-centered' history of medicine. The growth of the medical humanities has afforded renewed attention to patient narratives, supporting the need to recognise patients' voices in contemporary healthcare and medical education. However, several barriers complicate and problematise the expansion of a patient-centred epistemology across historical periods. Postmodern critics have expressed scepticism that 'the patient's view' can be recovered from history, with some claiming that 'the patient' is a construct of the 'medical gaze' whose subjectivity cannot be reconstituted outside of sociohistorical discourses of knowledge and power. Psychiatry in the mid-20th century presents a particular challenge for patient-centred history. We discuss the influence of postmodern theorists, especially Michel Foucault, whose work is seen as undermining the possibility of a patient-centred epistemology. We argue against Foucault's erasure of the patient, and instead explore alternate constructivist epistemologies, focusing on the hermeneutics of Hans-Georg Gadamer and dialogism of Mikhail Bakhtin, to help address historiographical challenges in recovering 'the patient's view'. To illustrate the value of Gadamerian and Bakhtinian approaches, we apply them to a case study from the Verdun Protestant Hospital (Québec, Canada) from 1941 to 1956, which sheds light on the introduction of the first antipsychotic, chlorpromazine, into clinical practice. We highlight how Gadamer's hermeneutics and Bakhtin's dialogism together offer insights into patient perspectives during this liminal period in the history of psychiatry.

What is "shared" in shared decision-making? Philosophical perspectives, epistemic justice, and implications for health professions education

BACKGROUND

Drawing from the philosophical work of Hans-Georg Gadamer and the perspectives of theorists Mikhail Bakhtin and Kenneth Burke, the aim of this paper is to critically reflect on the meaning of the word "shared."

METHOD

The authors draw on the concept of epistemic justice, which they argue permeates the clinical encounter, to discuss how various forms of, and claims to, knowledge may influence the attainement of shared decision-making in health care contexts. The specific objectives are twofold: first, the authors draw key concepts from key Gadamerian, Burkean, and Bakhtinian philosophical perspectives to consider shared decision-making in relation to two types of epistemic injustice: testimonial and hermeneutic epistemic injustice. Second, building on philosopher Paulo Freire's critical pedagogy, the authors emphasize that major changes in educational structures and systems are required to promote the critical reflexivity required to address issues of epistemic justice, in the broader pursuit of authentic shared decision-making.

RESULTS

They propose three main areas of focus for helath professions education: (a) changes in content (moving from a focus on biomedical knowledge to more content on social sciences) and methods of teaching (more dialogue and the creation of moments of dissonance); (b) a re-examination of teachers' role in promoting epistemic justice; and (c) inclusion of patients as partners.

CONCLUSIONS

Without major transformation in what, how, and with whom we teach, future clinicians may be unprepared to enact shared decision-making in a manner that does justice to the various ways of knowing.

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There is now broad agreement that ideas like person-centred care, patient expertise and shared decision-making are no longer peripheral to health discourse, fine ideals or merely desirable additions to sound, scientific clinical practice. Rather, their incorporation into our thinking and planning of health and social care is essential if we are to respond adequately to the problems that confront us: they need to be seen not as "ethical add-ons" but core components of any genuinely integrated, realistic and conceptually sound account of healthcare practice. This, the tenth philosophy thematic edition of the journal, presents papers conducting urgent research into the social context of scientific knowledge and the significance of viewing clinical knowledge not as something that "sits within the minds" of researchers and practitioners, but as a relational concept, the product of social interactions. It includes papers on the nature of reasoning and evidence, the on-going problems of how to 'integrate' different forms of scientific knowledge with broader, humanistic understandings of reasoning and judgement, patient and community perspectives. Discussions of the epistemological contribution of patient perspectives to the nature of care, and the crucial and still under-developed role of phenomenology in medical epistemology, are followed by a broad range of papers focussing on shared decision-making, analysing its proper meaning, its role in policy, methods for realising it and its limitations in real-world contexts.

Night Call in a Teaching Hospital: 1979 and 2019

No matter the era, few aspects of residency are more defining or memorable than overnight call. Nights can be a time of growth and learning but also of fear and uncertainty, as residents take on the responsibility of managing sick patients on their own. One of us (ASD) started his residency in 1978 at the Massachusetts General Hospital in Boston; the other two (ST and BCY) started theirs in 2016 and 2017, respectively, at the University of Toronto. In this essay, we reflect on our experiences of night call separated by 40 years, highlighting what has changed and what has stayed the same.

Three visions of doctoring: a Gadamerian dialogue

Medicine in the twenty-first century faces an 'identity crisis,' as it grapples with the emergence of various 'ways of knowing,' from evidence-based and translational medicine, to narrative-based and personalized medicine. While each of these approaches has uniquely contributed to the advancement of patient care, this pluralism is not without tension. Evidence-based medicine is not necessary individualized; personalized medicine may be individualized but is not necessarily person-centered. As novel technologies and big data continue to proliferate today, the focus of medical practice is shifting away from the dialogic encounter between doctor and patient, threatening the loss of humanism that many view as integral to medicine's identity. As medical trainees, we struggle to synthesize medicine's diverse and evolving 'ways of knowing' and to create a vision of doctoring that integrates new forms of medical knowledge into the provision of person-centered care. In search of answers, we turned to twentieth-century philosopher Hans-Georg Gadamer, whose unique outlook on "health" and "healing," we believe, offers a way forward in navigating medicine's 'messy pluralism.' Drawing inspiration from Gadamer's emphasis on dialogue and 'practical wisdom' (phronesis), we initiated a dialogue with the dean of our medical school to address the question of how medical trainees and practicing clinicians alike can work to create a more harmonious pluralism in medicine today. We propose that implementing a pluralistic approach ultimately entails 'bridging' the current divide between scientific theory and the practical art of healing, and involves an iterative and dialogic process of asking questions and seeking answers.

Crusted scabies in a renal transplant recipient treated with daily ivermectin: A case report and literature review

Crusted scabies is a rare disease variant associated with T-cell dysregulation. Transplant patients are at risk of developing crusted scabies as a consequence of their immunosuppressive regimens. We report a case of crusted scabies presenting with recurrent septicemia in a 65-year-old renal transplant recipient, treated with daily ivermectin for 7 days after initial failure of weekly ivermectin dosing. A literature review of crusted scabies in transplant recipients consisting of 19 cases reports was summarized. Pruritus was common, and initial misdiagnosis was frequent. Most were treated with topical therapy, with one-third receiving ivermectin. Three of seven cases presenting with a concomitant infection died. Crusted scabies is commonly misdiagnosed in transplant recipients owing to its rarity, varied appearance, and different skin distributions. It should be considered in the differential diagnosis of transplant recipients presenting with rash and pruritus, given its association with secondary infection and subsequent mortality.

Genomic data in prognostic models-what is lost in translation? The case of deletion 17p and mutant TP53 in chronic lymphocytic leukaemia

Genomic technologies are revolutionizing the practice of haematology-oncology, leading to improved disease detection, more accurate prognostication and targeted treatment decisions. These advances, however, have also introduced new clinical challenges, which include problems of prognostic underdetermination and its attendant risks of over- and undertreatment. Genomic data is generated from different technologies, from cytogenetics to next-generation sequencing, which are often interpreted interchangeably and in a binary fashion-as the presence or absence of a given chromosomal deletion or mutation-an oversimplification which may lead to mistaken prognosis. We discuss the clinical use of one such prognostic marker, represented by sequence and copy number alterations in TP53, located on chromosome 17p. Mutations in TP53 are strongly linked to poor prognosis in a variety of haematological malignancies, including chronic lymphocytic leukaemia (CLL). We review studies in CLL which utilize the 17p deletion or TP53 mutations for prognostic stratification with specific focus on the technologies used for detection, the thresholds established for clinical significance, and the clinical contexts in which these alterations are identified. The case of CLL illustrates issues arising from simplistic, binary interpretation of genetic testing and highlights the need to apply a critical lens when incorporating genomics into prognostic models.

Three Problems with Big Data and Artificial Intelligence in Medicine

The rise of big data and artificial intelligence (AI) in health care has engendered considerable excitement, claiming to improve approaches to diagnosis, prognosis, and treatment. Amidst the enthusiasm, the philosophical assumptions that underlie the big data and AI movement in medicine are rarely examined. This essay outlines three philosophical challenges faced by this movement: (1) the epistemological-ontological problem arising from the theory-ladenness of big data and measurement; (2) the epistemological-logical problem resulting from the inherent limitations of algorithms and attendant issues of reliability and interpretability; and (3) the phenomenological problem concerning the irreducibility of human experience to quantitative data. These philosophical issues demonstrate several important challenges for these technologies that must be considered prior to their integration into clinical care. Our article aims to initiate a critical dialogue on the impact of big data and AI in health care in order to allow for more robust evaluation of these technologies and to aid in the development of approaches to clinical care that better serve clinicians and their patients.

Clinical judgement in the era of big data and predictive analytics

Clinical judgement is a central and longstanding issue in the philosophy of medicine which has generated significant interest over the past few decades. In this article, we explore different approaches to clinical judgement articulated in the literature, focusing in particular on data-driven, mathematical approaches which we contrast with narrative, virtue-based approaches to clinical reasoning. We discuss the tension between these different clinical epistemologies and further explore the implications of big data and machine learning for a philosophy of clinical judgement. We argue for a pluralistic, integrative approach, and demonstrate how narrative, virtue-based clinical reasoning will remain indispensable in an era of big data and predictive analytics.

Re-evaluating concepts of biological function in clinical medicine: towards a new naturalistic theory of disease

Naturalistic theories of disease appeal to concepts of biological function, and use the notion of dysfunction as the basis of their definitions. Debates in the philosophy of biology demonstrate how attributing functions in organisms and establishing the function-dysfunction distinction is by no means straightforward. This problematization of functional ascription has undermined naturalistic theories and led some authors to abandon the concept of dysfunction, favoring instead definitions based in normative criteria or phenomenological approaches. Although this work has enhanced our understanding of disease and illness, we need not necessarily abandon naturalistic concepts of function and dysfunction in the disease debate. This article attempts to move towards a new naturalistic theory of disease that overcomes the limitations of previous definitions and offers advantages in the clinical setting. Our approach involves a re-evaluation of concepts of biological function employed by naturalistic theories. Drawing on recent insights from the philosophy of biology, we develop a contextual and evaluative account of function that is better suited to clinical medicine and remains consistent with contemporary naturalism. We also show how an updated naturalistic view shares important affinities with normativist and phenomenological positions, suggesting a possibility for consilience in the disease debate.

Blood donation and testosterone replacement therapy

BACKGROUND

Polycythemia is the most common adverse effect of testosterone replacement therapy (TRT) and may predispose patients to adverse vascular events. Current Canadian guidelines recommend regular laboratory monitoring and discontinuing TRT or reducing the dose if the hematocrit exceeds 54% (hemoglobin ≥180 g/L). This threshold has been interpreted by some physicians and patients to indicate the need for phlebotomy or blood donation while on TRT.

STUDY DESIGN AND METHODS

We reviewed all male blood donors in Southwestern Ontario at Canadian Blood Services from December 2013 to March 2016 who self-identified or were found on donor screening to be on TRT. Hemoglobin concentration was measured at the time of donation or clinic visit and with each subsequent appointment in repeat donors.

RESULTS

We identified 39 patients on TRT who presented for blood donation over a 2-year period. The mean hemoglobin level at all clinic visits was 173 g/L (range, 134-205 g/L; n = 108). Hemoglobin concentrations of 180 g/L or more (calculated hematocrit, ≥54%) were measured at 25% of appointments. Of the 27 repeat donors, 12 (44%) had persistently elevated hemoglobin levels (≥180 g/L) at subsequent donations.

CONCLUSION

Hemoglobin concentrations were elevated in donors on TRT, and significant numbers had hemoglobin levels above those recommended by current guidelines. These data also suggest that repeat blood donation was insufficient to maintain a hematocrit below 54%. Our findings raise concerns about the persistent risk of vascular events in these donors, particularly when coupled with the misperception by patients and health care providers that donation has reduced or eliminated the risks of TRT-induced polycythemia.

I and Thou: learning the 'human' side of medicine

This essay is a reflection on the doctor-patient relationship from the perspective of two medical students, which draws on the ideas of 20th-century philosopher Martin Buber. Although Buber never wrote about medicine directly, his 'philosophy of dialogue' raises fundamental questions about how human beings relate to one another, and can thus offer valuable insights into the nature of the clinical encounter. We argue that Buber's basic word pairs, 'I-You' and 'I-It', provide a useful heuristic for understanding different modes of caring for patients, which we illustrate using examples of illness narratives from two literary works: Tolstoy's Ivan Ilych and Margaret Edson's Wit Our essay demonstrates how the humanities in general and philosophy in particular can inform a more humanistic practice for healthcare trainees and practicing clinicians alike.

Abstract B10: Soluble lung-derived factors mediate breast cancer cell migration and growth via CD44 receptor-ligand interactions

Background: The majority of breast cancer deaths occur due to metastatic disease. Clinical studies have identified a specific pattern for the metastatic spread of breast cancer, where preferential secondary sites include the lymph node, lung, liver, bone, and brain. However, it is not clear whether properties of the cancer cells (the “seeds”); properties of the organ microenvironment (the “soil”), or a combination of both are responsible for this observed organ tropism of breast cancer. It has been proposed that small subsets of stem-like tumor cells are responsible for tumor initiation and progression. In breast cancer, these cells are identified by their high aldehyde dehydrogenase (ALDH) activity and/or CD44+CD24- phenotype. We have previously shown that ALDHhiCD44+ breast cancer cells exhibit key metastatic behaviors in vitro and in vivo. However, the mechanisms underlying the organ-specific metastatic capacity of these cells requires further elucidation.

Hypothesis: Breast cancer cells exhibit differential growth and migration patterns in specific organ microenvironments; and ALDHhiCD44+ breast cancer cells exhibit increased organ-specific migration and growth (1) preferentially in the lung microenvironment and (2) compared to their ALDHlowCD44- counterparts.

Methods: A novel ex vivo model system comprised of organ-conditioned media generated from athymic nude mice was used to test organotropic migration/growth of whole populations of MDA-MB-231, MDA-MB-468, SUM149, and SUM159 human breast cancer cell lines, and ALDHhiCD44+ and ALDHlowCD44- populations isolated from the MDA-MB-231 cell line. Protein arrays were used to interrogate lung-conditioned media and identify soluble factors of interest. Bead-based immunodepletion of target proteins was performed on lung-conditioned media. The migration/growth response of MDA-MB-231 breast cancer cells was then assessed following exposure to depleted vs. non-depleted lung-conditioned media.

Results: Whole populations of all 4 human breast cancer cell lines examined responded via cell line specific patterns of migration towards organ-conditioned media. Notably, all lines demonstrated increased migration towards lung-conditioned media (p&lt;0.05). These observations closely mirror previously observed patterns of in vivo metastatic behavior, providing validation for our ex vivo model system. ALDHhiCD44+ cells responded in a chemotactic manner towards organ-conditioned media in a similar pattern to whole population results. Notably, ALDHhiCD44+ cells showed preferential migration towards lung-conditioned media relative to all other organ-conditioned media tested (p&lt;0.05). Several CD44 ligands including osteopontin (OPN) and E-, L-, and P-selectin were identified by protein array analysis of lung-conditioned media. Immunodepletion of L-selectin or OPN from lung-conditioned media resulted in decreased migration of MDA-MB-231 cells, however only depletion of OPN also resulted in decreased growth relative to non-depleted media. These effects could be abrogated by pre-treatment with a functional CD44 receptor blocking antibody (p&lt;0.05).

Conclusions: Our data suggest an important role for CD44 receptor-ligand interactions in mediating lung-specific breast cancer cell migration and growth. To the best of our knowledge, this is the first study to undertake ex vivo investigation of the role of the microenvironment in metastatic organ tropism in the context of the cancer stem cell hypothesis.

Citation Format: Ying Xia, Jenny E. Chu, Benjamin Chin-Yee, David Goodale, Alysha K. Croker, Alison L. Allan. Soluble lung-derived factors mediate breast cancer cell migration and growth via CD44 receptor-ligand interactions. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B10.