The rapidly changing field of genetics affects society through advances in health-care and through implications of genetic research. This study addresses the impacts of new genetic discoveries and technologies on different segments of today's society. The book begins with a chapter on genetic complexity, and subsequent chapters discuss moral and ethical questions arising from today's genetics from the perspectives of health care professionals, the media, the general public, special interest groups and commercial interests.

This paper illustrates a role that bioethics should play in developing and criticizing protocols for breast cancer genetic screening. It demonstrates how a critical bioethics, using approaches and reflecting concerns of contemporary philosophy of science and science studies, may critically interrogate the normative and conceptual schemes within which ethical considerations about such screening protocols are framed. By exploring various factors that influence the development of such protocols, including politics, cultural norms, and conceptions of disease, this paper and the critical (...) bioethics' approach it endorses illuminate and critically assess some of the competing worldviews informing protocol development. One of the frequently neglected worldviews in traditional bioethics' treatment of protocols concerning breast care is constituted by women's own views of their breasts and breast cancer, both within the technologically-oriented social practice of American medicine and in light of the social construction of their breasted experience in American society. This paper attempts to redress and critically assess this neglect on the part of traditional bioethics. Finally, in contrast to traditional bioethics, critical bioethics critically interrogates its own normative and conceptual commitments. In this final capacity, a critical bioethics' approach makes a valuable contribution to the evolution of bioethics. (shrink)

Genetic testing for cancer susceptibility is an application of biotechnology that has the potential both to improve the psychosocial and physical wellbeing of the population and to cause significant psychosocia1 and physical harms. In spite of the uncertain value of genetic testing, it has captured the interest of biotechnology companies, researchers, health care providers, and the public. As more tests become feasible, pressure may increase to make the tests available and reimbursable. Both the benefits and harms of these tests (...) lie not as much in the tests themselves, as in their power to predict or alter the future. The value of the tests does not derive from the information per se, but from the ability to communicate effectively the information to patients and providers, and the behavioral responses of patients, providers, and others to this information. (shrink)

Genetic testing for cancer susceptibility is an application of biotechnology that has the potential both to improve the psychosocial and physical wellbeing of the population and to cause significant psychosocia1 and physical harms. In spite of the uncertain value of genetic testing, it has captured the interest of biotechnology companies, researchers, health care providers, and the public. As more tests become feasible, pressure may increase to make the tests available and reimbursable. Both the benefits and harms of these tests (...) lie not as much in the tests themselves, as in their power to predict or alter the future. The value of the tests does not derive from the information per se, but from the ability to communicate effectively the information to patients and providers, and the behavioral responses of patients, providers, and others to this information. (shrink)

The return of genetic research results after death in the pediatric setting comes with unique complexities. Researchers must determine which results and through which processes results are returned. This paper discusses the experience over 15 years in pediatric cancer genetics research of returning research results after the death of a child and proposes a preventive ethics approach to protocol development in order to improve the quality of return of results in pediatric genomic settings.

This article is based on a qualitative empirical project about a distinct kinship group who were among the first identified internationally as having a genetic susceptibility to cancer. 50 were invited to participate. 15, who had all accepted testing, were interviewed. They form a unique case study. This study aimed to explore interviewees’ experiences of genetic testing and how these influenced their family relationships. A key finding was that participants framed the decision to be tested as ‘common sense’; the (...) idea of choice around the decision was negated and replaced by a moral imperative to be tested. Those who did not follow ‘common sense’ were judged to be imprudent. Family members who declined testing were discussed negatively by participants. The article addresses what is ethically problematic about how test decliners were discussed and whether these ethical concerns extend to others who are offered genetic testing. Discussions showed that genetic testing was viewed as both an autonomous choice and a responsibility. Yet the apparent conflict between the right to autonomy and the moral imperative of responsibility allowed participants to defend test decliners’ decisions by expressing a preference for or defending choice over responsibility. The ‘right not to know’ seemed an important moral construct to help ethically manage unpopular decisions made by close family who declined testing. In light of this research, the erosion of the ‘right not to know’ in the genomic age could have subtle yet profound consequences for family relationships. (shrink)

A major approach to cancer research in the late twentieth century was to search for genes that, when altered, initiated the development of a cell into a cancerous state or failed to stop this development. But as researchers acquired the capacity to sequence tumors and incorporated the resulting data into databases, it became apparent that for many tumors no genes were frequently altered and that the genes altered in different tumors in the same tissue type were often distinct. To (...) address this heterogeneity problem, many researchers looked to a higher level of organization—to mechanisms in which gene products participated. They proposed to reduce heterogeneity by recognizing that multiple gene alterations affect the same mechanism and that it is the altered mechanism that is responsible for the cell developing one or more hallmarks of cancer. I examine how mechanisms figure in this research and focus on two heuristics researchers use to integrate proteins into mechanisms, one focusing on pathways and one focusing on clusters in networks. (shrink)

Aims: To describe individuals’ perceptions of the activities that take place within the cancer genetics clinic, the relationships between these activities and how these relationships are sustained. Design: Qualitative interview study. Participants: Forty individuals involved in carrying out cancer genetics research in either a clinical (n = 28) or research-only (n = 12) capacity in the UK. Findings: Interviewees perceive research and clinical practice in the subspecialty of cancer genetics as interdependent. The boundary between (...) research and clinical practice is described as vague or blurred, and this ambiguity is regarded as being sustained by a range of methodological, ethical and economic factors. The implications of these findings for the “therapeutic misconception” are explored. It is argued that while research participation is seen as having therapeutic benefit for individual patients, the interviewees are not labouring under any misconceptions about the relationship between research and clinical care. It is suggested that concepts such as the “therapeutic misconception” may have less relevance in highly technological specialities that are characterised by a developing evidence base. (shrink)

The aim of this study is to assess patients' recall of their previous research participation. Recall was established during interviews and compared with entries from clinical notes. Participants were 49 patients who had previously participated in different types of research. Of the 49 patients, 45 (92%) interviewees recalled 69 of 109 (63%) study participations. Level of recall varied according to the type of research, some participants clearly recalled the details of research aims, giving consent and research procedures. Others recalled procedures (...) (e.g. DNA testing) but were unclear about their purpose. There was no significant effect of time on recall. Some types of research participation (e.g. DNA testing) may be recalled as clinical care. We argue that such misunderstandings may have the potential to undermine participants' ongoing consent, particularly in ongoing/longitudinal studies. Valid consent may be best achieved by re-assessing the scope of consent and relating it to the nature of the interventions themselves rather than the reasons for undertaking them. (shrink)

Collaborative forms of work such as extended networks, expert groups, and consortia increasingly structure biomedical activities. They are particularly prominent in the cancer field, where procedures such as multicenter clinical trials have been instrumental in establishing the specialty of oncology, and subfields such as cancer genetics, where bioclinical activities—for example, testing for breast and ovarian cancer genes and follow-up interventions—are predicated on the articulation of a number of tasks performed by new clinical collectives. In this article, (...) we examine the founding and development of a French bioclinical collective—the Groupe Génétique et Cancer —that coordinates and structures the activities of most French actors in cancer genetics and operates simultaneously in the clinical, research, and regulatory domains. To examine the group’s structure and dynamics, the article combines information gathered through traditional fieldwork methods with information elicited from a coauthorship and semantic-network analysis of the publications of GGC members from 1969 to 2001. (shrink)

Research ethicists have recently declared a new ethical imperative: that researchers should communicate the results of research to participants. For some analysts, the obligation is restricted to the communication of the general findings or conclusions of the study. However, other analysts extend the obligation to the disclosure of individual research results, especially where these results are perceived to have clinical relevance. Several scholars have advanced cogent critiques of the putative obligation to disclose individual research results. They question whether ethical goals (...) are served by disclosure or violated by non-disclosure, and whether the communication of research results respects ethically salient differences between research practices and clinical care. Empirical data on these questions are limited. Available evidence suggests, on the one hand, growing support for disclosure, and on the other, the potential for significant harm. (shrink)

The current mainstream in cancer research favours the idea that malignant tumour initiation is the result of a genetic mutation. Tumour development and progression is then explained as a sort of micro-evolutionary process, whereby an initial genetic alteration leads to abnormal proliferation of a single cell that leads to a population of clonally derived cells. It is widely claimed that tumour progression is driven by natural selection, based on the assumption that the initial tumour cells acquire some properties that (...) endow such cells with a selective advantage over the normal cells from which the tumour cells are derived. The standard view assumes that the transformed bodily cell somehow acquires "responsiveness" to natural selection independently of the whole organism to which the cell belongs. Yet, it is never explained where such an acquired capacity to respond to natural selection by the individual bodily cell comes from. This situation poses many difficult questions that so far have been left unanswered. For example, there is no explanation why some cells belonging to an organised whole and as such having no independent capacity for survival, apparently become 'independent' entities, able to respond to selective pressures in an autonomous fashion and then to be evaluated by natural selection. Hereunder it is argued that such a qualitative change cannot be the consequence of specific genetic mutations. Moreover, it is shown that natural selection is unlikely to be acting within the organism during tumour development and progression and that tumour evolution is a random, non-adaptive process, driven by no fundamental biological principle. Thus, mutations in the so-called oncogenes and tumour suppressor genes observed in epithelial cancers (that constitute more than 90% of all cancers) are not the result of selection for better cellular growth or survival under restrictive conditions. Instead, here it is suggested that they are the consequence of genetic drift acting upon gene functions that become non-relevant, either for the individual or the species fitness, once the organism is past its reproductive prime and as such, they also become superfluous for cell survival in the short term. It is proposed that the origin of cancer is epigenetic and it is a consequence of the need for a continued turnover of the individuals that constitute a species. (shrink)

Background Genetic testing is moving from targeted investigations of monogenetic diseases to broader testing that may provide more information. For example, recent health economic studies of genetic testing for an increased risk of breast cancer suggest that it is associated with higher cost-effectiveness to screen for pathogenic variants in a seven gene panel rather than the usual two gene test for variants in BRCA1 and BRCA2. However, irrespective of the extent to which the screening of the panel is cost-effective, (...) there may be ethical reasons to not screen for pathogenic variants in a panel, or to revise the way in which testing and disclosing of results are carried out. Main text In this paper we discuss the ethical aspects of genetic testing for an increased risk of breast cancer with a special focus on the ethical differences between screening for pathogenic variants in BRCA1/2 and a seven gene panel. The paper identifies that the panel increases the number of secondary findings as well as the number of variants of uncertain significance as two specific issues that call for ethical reflection. Conclusions We conclude that while the problem of handling secondary findings should not be overstated with regard to the panel, the fact that the panel also generate more variants of uncertain significance, give rise to a more complex set of problems that relate to the value of health as well as the value of autonomy. Therefore, it is insufficient to claim that the seven gene panel is preferable by only referring to the higher cost effectiveness of the panel. (shrink)

Acetyltransferase enzymes expressed in hepatic and extrahepatic tissues are products of an acetyltransferase gene locus. Acetylation capacity is regulated by simple autosomal Mendelian inheritance of two codominant alleles at this locus. Human slow acetylators are predisposed to bladder cancer from arylamine chemicals. The role of the bladder in arylamine metabolism and of bladder acetyltransferases in the etiology of bladder cancer is not fully understood, but the acetylator genotype‐dependent expression of arylamine N‐acetyltransferase and N‐hydroxyarylamine O‐acetyltransferase in bladder cytosol may (...) contribute towards the genetic predisposition of human slow acetylators to arylamine‐induced bladder cancer. (shrink)

In November 2003, researchers at Cambridge University announced they had identified a gene associated with an elevated risk of breast and related ovarian cancers. The gene—christened EMSY in honor of a breast-cancer nurse who is the sister of the study's lead author—is particularly significant because it is linked to so-called sporadic cancers. Such cancers do not arise from hereditary mutations of the BRCA1 and BRCA2 genes, in which genes that ordinarily prevent breast and ovarian cancers are altered, often giving (...) rise to multiple cases of cancer within a family as the mutation is passed along. The Cambridge researchers determined that the presence of extra copies of EMSY in an individual may instead switch off a healthy BRCA2 gene. (shrink)

Thousands of candidate cancer biomarkers have been proposed, but so far, few are used in cancer screening. Failure to implement these biomarkers is attributed to technical and design flaws in the discovery and validation phases, but a major obstacle stems from cancer biology itself. Oncogenomics has revealed broad genetic heterogeneity among tumors of the same histology and same tissue (or organ) from different patients, while tumors of different tissue origins also share common genetic mutations. Moreover, there is (...) wide intratumor genetic heterogeneity among cells within any single neoplasm. These findings seriously limit the prospects of finding a single biomarker with high specificity for early cancer detection. Current research focuses on developing biomarker panels, with data assessment by machine‐learning algorithms. Whether such approaches will overcome the inherent limitations posed by tumor biology and lead to tests with true clinical value remains to be seen. (shrink)

AimTo examine the relative cost-effectiveness of predictive genetic tests for familial breast and ovarian cancer provided by Genetic Services of Western Australia.MethodsThe relative cost-effectiveness was assessed using a decision analytic model.ResultsThe cost and outcomes of genetic testing was compared in first-degree relatives of known BRCA1/2 mutation-carriers who have a 50% risk of carrying the mutated gene (intervention group) to individuals with the same a priori risk but who do not undergo a genetic test (control subjects).Since genetic testing enables the (...) restriction of intensive surveillance to individuals with an identified BRCA1/2 gene mutation, net savings in the period observed (age 25-70) were $980-$1008 per woman in the ovarian intervention group and $1681-$1795 per woman in the breast intervention group, and delayed the onset of breast cancer (6mths BRCA1, 3mths BRCA2).Compared to control subjects undergoing population surveillance, it was estimated the onset of breast cancer could be delayed at a total net cost of $3055 (5.1yrs) to $3389 (3.2yrs) for women in the breast intervention group with BRCA1/2 mutations. Since population surveillance is not currently recommended for ovarian cancer, control subjects undergoing no surveillance were compared with the intervention group. The onset of ovarian cancer was delayed at a net cost of $1630 (3.5yrs) to $2509 (1.2years) for women with BRCA1/2 mutations.ConclusionsTesting allows targeted high-level surveillance for gene mutation carriers, which ensures the cost-effective use of resources and reduces cancer-related morbidity if clinical recommendations for intervention are adopted. (shrink)

Recent years have seen an emergence of the field of comparative cancer genomics. However, the advancements in this field are held back by the hesitation to use knowledge obtained from human studies to study cancer in other animals, and vice versa. Since cancer is an ancient disease that arose with multicellularity, oncogenes and tumour‐suppressor genes are amongst the oldest gene classes, shared by most animal species. Acknowledging that other animals are, in terms of cancer genetics, (...) ecology, and evolution, rather similar to humans, creates huge potential for advancing the fields of human and animal oncology, but also biodiversity conservation. Also see the video abstract here: https://youtu.be/UFqyMx5HETY. (shrink)

Studies on informed consent to medical research conducted in low or middle-income settings have increased, including empirical investigations of consent to genetic research. We investigated voluntary participation and comprehension of informed consent among women involved in a genetic epidemiological study on breast cancer in an urban setting of Nigeria comparing women in the case and control groups.

As in other areas of medical practice, relatives accompany patients to genetic consultations. However, unlike in other areas, the consultations may be relevant to the relatives’ health because they may be at risk of developing the same genetic condition as the patient. The presence of relatives in genetic consultation may affect the decision‐making process and it raises questions about the perception of patient autonomy and the way it is practiced in genetics. However, these issues have not been examined in (...) previous empirical studies. This article aims to fill this gap by reporting findings from a qualitative study with clinicians working in the area of inherited breast cancer. The findings indicate that family presence has an impact on the patient's decisions to undergo genetic testing and preventative operations when she is diagnosed as a carrier. The findings further indicate that, unlike in other areas of medical practice, blood relatives who are present in consultations are perceived by clinicians as patients or potential patients, and this in turn increases their involvement in discussions in the consultation room. Finally, the findings indicate that in genetics, a relational approach to autonomy is applied. Decisions are made in a social context, where the relatives’ views are heard and taken into account. The findings suggest that the conventional bioethical approach to autonomy, which perceives the decision‐making unit as comprising a clinician and an individual patient, is challenged in genetics. The findings thus suggest that bioethicists, lawyers and policy‐makers should consider whether this individualistic approach is still valid and applicable. (shrink)

Background: With multiple options available today to become a parent, how does the matter of genetic relatedness factor into adolescent cancer patients’ fertility preservation decision making? This study reports on and normatively analyzes this aspect of FP decision making. Methods: A convenience sample of Israeli adolescent cancer survivors and their parents were invited to participate in individual, semi-structured interviews. Results: In discussing the importance of genetic relatedness to future children or grandchildren, participants repeatedly brought up the interrelated issues (...) of nature, normalcy, and personal identity. Regardless of preference or ambivalence for genetic relatedness, the majority of participants were aware of alternative parenting options and noted both their advantages and disadvantages. However, knowledge of alternative parenting options was not uniform. Conclusions: To ensure that adolescent patients and their parents make informed FP decisions that meet their personal goals and values, it is important for physicians to discuss alternative parenting options with them in a culturally sensitive manner. Greater credence also should be given to those who question the importance of genetic relatedness. (shrink)

© 2015, Springer-Verlag Berlin Heidelberg.Genetic studies have identified single nucleotide polymorphisms associated with the risk of prostate cancer. It remains unclear whether such genetic variants are associated with disease aggressiveness. The NCI-SPORE Genetics Working Group retrospectively collected clinicopathologic information and genotype data for 36 SNPs which at the time had been validated to be associated with PC risk from 25,674 cases with PC. Cases were grouped according to race, Gleason score and aggressiveness. Statistical analyses were used to compare (...) the frequency of the SNPs between different disease cohorts. After adjusting for multiple testing, only PC-risk SNP rs2735839 was significantly and inversely associated with aggressive and high-grade disease in European men. Similar associations with aggressive and high-grade disease were documented in African-American subjects. The G allele of rs2735839 was associated with disease aggressiveness even at low PSA levels in both European and African-American men. Our results provide further support that a PC-risk SNP rs2735839 near the KLK3 gene on chromosome 19q13 may be associated with aggressive and high-grade PC. Future prospectively designed, case-case GWAS are needed to identify additional SNPs associated with PC aggressiveness. (shrink)

Women who had had breast cancer and had been enrolled in a large genetic breast cancer epidemiological study were interviewed about their experience of participation in the study, their attitudes to the confidentiality of data, and the feedback of personal and general research results. Collection of family history information seemed more salient in indicating the genetic nature of the study than the enrolment information sheet. There were no concerns about confidentiality.While participants would have welcomed general feedback about the (...) results of the study and were critical that this had not been provided, the feedback of personal information proved complicated and, sometimes, difficult. It is suggested that individual feedback of genetic test information in epidemiological studies should be undertaken only when there are specific reasons. (shrink)

Genetic cancer predisposition testing in the paediatric population poses unique ethical dilemmas. Using the hypothetical example of a teenager with cancer with a high probability of having an underlying cancer predisposition syndrome, we discuss the ethical considerations that affect the decision-making process. Because legally these decisions are made by parents, genetic testing in paediatrics can remove a child’s autonomy to preserve his or her own ‘open future’. However, knowledge of results confirming a predisposition syndrome can potentially be (...) beneficial in modifying treatment and surveillance plans and enabling at-risk family members to obtain cascade testing for themselves. Considering virtue ethics to envision the best characters of the patient, parents and healthcare providers can guide them to the better choice to test or not to test, with the ultimate goal of achieving the best outcome for survival andeudaimonia, human flourishing reliably sought out. (shrink)

This book explores a variety of conceptual and methodological questions about cancer and cancer research: Is cancer one disease, or many? If many, how many exactly? How is cancer classified? What does it mean, exactly, to say that cancer is “genetic,” or “familial”? What exactly are the causes of cancer, and how do scientists come to know about them? When do we have good reason to believe that this or that is a risk factor (...) for cancer? How is cancer a product or byproduct of multilevel evolution? Is cancer research unified? What sort of models, or theories, govern cancer research? This book takes a close look at these philosophical questions, by examining work in disciplines as diverse as cell and molecular biology, epidemiology, clinical medicine, and evolutionary biology. (shrink)

The purpose of this article is to provide a critical examination of two aspects of culture and biomedicine that have helped to shape the meaning and practice of genetic testing for breast cancer. These are: the cultural construction of fear of breast cancer, which has been fuelled in part by the predominance of a ‘risk’ paradigm in contemporary biomedicine. The increasing elaboration and delineation of risk factors and risk numbers are in part intended to help women to contend (...) with their fear of breast cancer. However, because there is no known cure or foolproof prevention for breast cancer, risk designations bring with them recommendations for vigilant surveillance strategies and screening guidelines. We argue that these in effect exacerbate women’s fears of breast cancer itself. The volatile combination of discourses of fear, risk and surveillance have significant ethical and social consequences for women’s lives and well-being. Genetic testing decisions are made within this context; if nurses understand this context they can play an important role in helping women to cope with the anxiety and fear of breast cancer risk. (shrink)

Cancer is generally defined as uncontrollable growth of cells caused by genetic aberrations and/or environmental factors. Yet contagious cancers also occur. The recent emergence of a contagious cancer in Tasmanian devils has reignited interest in transmissible cancers. Two naturally occurring transmissible cancers are known: devil facial tumour disease and canine transmissible venereal tumour. Both cancers evolved once and have then been transmitted from one individual to another as clonal cell lines. The dog cancer is ancient; having evolved (...) more than 6,000 years ago, while the devil disease was first seen in 1996. In this review I will compare and contrast the two diseases focusing on the life histories of the clonal cell lines, their evolutionary trajectories and the mechanisms by which they have achieved immune tolerance. A greater understanding of these contagious cancers will provide unique insights into the role of the immune system in shaping tumour evolution and may uncover novel approaches for treating human cancer. (shrink)

The purpose of this article is to provide a critical examination of two aspects of culture and biomedicine that have helped to shape the meaning and practice of genetic testing for breast cancer. These are: (1) the cultural construction of fear of breast cancer, which has been fuelled in part by (2) the predominance of a ‘risk’ paradigm in contemporary biomedicine. The increasing elaboration and delineation of risk factors and risk numbers are in part intended to help women (...) to contend with their fear of breast cancer. However, because there is no known cure or foolproof prevention for breast cancer, risk designations bring with them recommendations for vigilant surveillance strategies and screening guidelines. We argue that these in effect exacerbate women’s fears of breast cancer itself. The volatile combination of discourses of fear, risk and surveillance have significant ethical and social consequences for women’s lives and well-being. Genetic testing decisions are made within this context; if nurses understand this context they can play an important role in helping women to cope with the anxiety and fear of breast cancer risk. (shrink)

This paper presents a narrative history of technologies in cancer research circa 1920-1978 and a theoretical perspective on the complex, intertwined relationships between scientific problems, material practices and technologies, concepts and theories, and other historical circumstances. The history presents several active lines of research and technology development in the genetics of cancer in the United States which were constitutive of protooncogene work in its current form. I write this history from the perspective of technology development. Scientists participating (...) in cancer research created tools with which to study their problems of interest, but the development of the tools also influenced the questions asked and answered in the form of concepts and theories developed. These tools included genetic ideas of the 1920s, inbred mouse colonies, chemicals and antibiotics developed during World War Two, tissue cultures and their technical procedures, and viruses. I examine these tools as standardized experimental systems that standardized materials as well as practices in laboratories. Inbred animals, tissue culture materials and methods, and tumor viruses as experimental systems gave materiality to 'genes' and 'cancer'. They are technical-natural objects that stand-in for nature in the laboratory. (shrink)

Cancer is a paradigmatic case of a complex causal process; causes of cancer operate at a variety of temporal and spatial scales, and the respects in which these causes act and interact are diverse. There are, for instance, temporal order effects, organizational effects, structural effects, and dynamic relationships between causes operating at different temporal and spatial scales. Because of this complexity, models of cancer initiation and progression often involve deliberate choices to focus on one time scale, one (...) causal pathway, or one aspect of cancer’s dynamics. As in most of biology, modeling cancer involves simplification and idealization. At the same time, theoretical perspectives inform the construction of these models. Such perspectives might involve viewing cancer ‘as’ a genetic disease, metabolic disease, stem cell disease, an infectious disease, or a disease of tissue disorganization. This paper will argue that purportedly competing theoretical views of cancer are not at odds, but can be viewed as mutually informative. Models are most often developed in the service of asking very specific questions, and this requires limiting our view of the phenomena to a specific temporal or spatial scale, a particular cause, or a particular outcome, dynamic, or pattern. Thus, while some models may seem at odds, often they are simply concerned with different questions, or, they are complementary and mutually informative. I hope to bring this case to bear on debates among philosophers of science over perspectivism and realism, as well pluralism about the aims and scope of scientific theory. (shrink)

Cancer is an evolutionary and ecological process in which complex interactions between tumour cells and their environment share many similarities with organismal evolution. Tumour cells with highest adaptive potential have a selective advantage over less fit cells. Naturally occurring transmissible cancers provide an ideal model system for investigating the evolutionary arms race between cancer cells and their surrounding micro‐environment and macro‐environment. However, the evolutionary landscapes in which contagious cancers reside have not been subjected to comprehensive investigation. Here, we (...) provide a multifocal analysis of transmissible tumour progression and discuss the selection forces that shape it. We demonstrate that transmissible cancers adapt to both their micro‐environment and macro‐environment, and evolutionary theories applied to organisms are also relevant to these unique diseases. The three naturally occurring transmissible cancers, canine transmissible venereal tumour (CTVT) and Tasmanian devil facial tumour disease (DFTD) and the recently discovered clam leukaemia, exhibit different evolutionary phases: (i) CTVT, the oldest naturally occurring cell line is remarkably stable; (ii) DFTD exhibits the signs of stepwise cancer evolution; and (iii) clam leukaemia shows genetic instability. While all three contagious cancers carry the signature of ongoing and fairly recent adaptations to selective forces, CTVT appears to have reached an evolutionary stalemate with its host, while DFTD and the clam leukaemia appear to be still at a more dynamic phase of their evolution. Parallel investigation of contagious cancer genomes and transcriptomes and of their micro‐environment and macro‐environment could shed light on the selective forces shaping tumour development at different time points: during the progressive phase and at the endpoint. A greater understanding of transmissible cancers from an evolutionary ecology perspective will provide novel avenues for the prevention and treatment of both contagious and non‐communicable cancers. (shrink)

Since the 1970s, the origin of cancer is being explored from the point of view of the Somatic Mutation Theory (SMT), focusing on genetic mutations and clonal expansion of somatic cells. As cancer research expanded in several directions, the dominant focus on cells remained steady, but the classes of genes and the kinds of extra-genetic factors that were shown to have causal relevance in the onset of cancer multiplied. The wild heterogeneity of cancer-related mutations and phenotypes, (...) along with the increasing complication of models, led to an oscillation between the hectic search of 'the' few key factors that cause cancer and the discouragement in face of a seeming 'endless complexity'. To tame this complexity, cancer research started to avail itself of the tools that were being developed by Systems Biology. At the same time, anti-reductionist voices began claiming that cancer research was stuck in a sterile research paradigm. This alternative discourse even gave birth to an alternative theory: the Tissue Organization Field Theory (TOFT). A deeper philosophical analysis shows the serious limits of both reductionist and anti-reductionist positions and of their polarization. This book demonstrates that a radical philosophical reflection is necessary to drive cancer research out of its impasses. At the very least, this will be a reflection on the assumptions of different kinds of cancer research, on the implications of what cancer research has been discovering over 40 years and more, on a view of scientific practice that is most able to make sense of the cognitive and social conflicts that are seen in the scientific community (and in its results), and, finally, on the nature of living entities with which we entertain this fascinating epistemological dance that we call scientific research. The proposed Dynamic and Relational View of carcinogenesis is a starting point in all these directions. (shrink)

A major challenge for The Cancer Genome Atlas (TCGA) Project is solving the high level of genetic and epigenetic heterogeneity of cancer. For the majority of solid tumors, evolution patterns are stochastic and the end products are unpredictable, in contrast to the relatively predictable stepwise patterns classically described in many hematological cancers. Further, it is genome aberrations, rather than gene mutations, that are the dominant factor in generating abnormal levels of system heterogeneity in cancers. These features of (...) class='Hi'>cancer could significantly reduce the impact of the sequencing approach, as it is only when mutated genes are the main cause of cancer that directly sequencing them is justified. Many biological factors (genetic and epigenetic variations, metabolic processes) and environmental influences can increase the probability of cancer formation, depending on the given circumstances. The common link between these factors is the stochastic genome variations that provide the driving force behind the cancer evolutionary process within multiple levels of a biological system. This analysis suggests that cancer is a disease of probability and the most‐challenging issue to the TCGA project, as well as the development of general strategies for fighting cancer, lie at the conceptual level. BioEssays 29:783–794, 2007. © 2007 Wiley Periodicals, Inc. (shrink)