Cancer prevention research is a rich and diverse field. Two underlying considerations have received considerable attention: health disparities and social determinants of cancer, and the role of genetic factors in cancer prevention and control.
Social Determinants of Cancer
There is extensive evidence to document subgroup differences in cancer-related outcomes, including incidence, survival and quality of life. It is beyond the scope of this article to review this literature, but suffice it to say that virtually all studies that have looked at this issue have found disparate cancer outcomes (e.g., in the USA, UK, Australia, New Zealand and Canada). Many of the worse outcomes occur in ethnocultural subgroups, such as African–Americans and the medically underserved (in the USA), black and minority ethnic populations (in the UK) and indigenous populations in Australia, New Zealand and Canada.[60,61]
These observations have given rise to the field of 'health disparities', which investigates causes for these group differences and seeks to reduce them. Possible explanations for differential cancer incidence rates include socioeconomic status (education, income and employment), access to, and use of, healthcare (a concern particularly in areas that do not have universal health care, such as the USA, and in rural and remote populations), cancer-related health behaviors (physical activity, diet and tobacco use all vary according to population subgroups, with unhealthy behaviors more prevalent in individuals of lower socioeconomic status), social environment (e.g., educational and economic opportunities, racial or ethnic discrimination, and neighbourhood and work conditions, including food security), exposure to carcinogens (which are affected by a person's physical environment, workplace, socioeconomic status), and, in a few instances, biological differences.
Tackling such basic aspects of life – the cause of the cause – requires attention to the 'social determinants of health', defined by the WHO as "conditions in which people are born, grow, live, work and age, including the health system". The WCRF/AICR Report II, building on their landmark study of cancer causes, is entitled 'Policy and Action for Cancer Prevention'. In this volume, the authors argue that addressing the multifaceted root causes of cancer will require a multifaceted approach, involving multiple sectors of society (which the report refers to as 'actors'), including individuals, health professionals, institutions (including workplaces and schools), the media, industry, government, civil society (or advocacy) organizations, as well as multinational bodies. As this report states:
"The prevention of cancer is a great public health challenge…and all actors…need to agree that cancer can be prevented, and also commit to being partners in the task."
As Hiatt and Breen suggest, a focus on social determinants of cancer also provides a rich opportunity for transdisciplinary research to integrate biological and sociobehavioral variables.
Role of Genetics in Cancer Prevention
Sequencing of the human genome is one of the greatest scientific accomplishments of the past century, and its implications for health – while they may be 'revolutionary' – are still being explored. The potential contributions of genetics research to public health have been hotly debated. Merikangas and Risch argue that genetics are likely to have a great contribution to rare diseases in individuals and families (e.g., individuals who have one of the genetic defects associated with breast cancer [BRCA-1 or BRCA-2], whereas public health interventions [e.g., smoking cessation and obesity reduction] are likely to make a greater difference for common diseases [most cancers] at the population level). Berrettini et al., in response, point out that many public health challenges, such as tobacco control, can benefit from greater use of genetic data; for example, despite high-quality tobacco cessation interventions, many individuals fail to quit, or relapse, and understanding the genetic basis of their addiction could lead to more successful targeted interventions.
A number of points of debate have been raised, including the concern that focusing on genetics may lead to genetic determinism, and a lack of attention to environmental influences that have been shown to be highly important in determining health outcomes. It has been shown that the public continues to overestimate the role of genetics and uncontrollable factors, such as air pollution rather than lifestyle in cancer etiology; thus, increased professional attention to genetic aspects of cancer prevention could further undermine the use of potentially life-saving behavior changes in the population. Khoury et al. and Halliday et al. propose a middle ground that public health and genetics have points of intersection that can be useful for both disciplines; and that interventions directed both at the population at large and genetically at-risk subgroups are complementary. It is likely that the dynamic interplay between these two schools of thought will continue for some time to come.
Expert Rev Pharmacoeconomics Outcomes Res. 2010;10(2):143-154. © 2010 Expert Reviews Ltd.
Cite this: Cancer Prevention: Major Initiatives and Looking into the Future - Medscape - Apr 01, 2010.