Implementing chronic disease prevention amongst cancer survivors

In this issue, Lajous and colleagues outline the need for greater attention to the risk of cardiovascular disease (CVD) and CVD death in cancer survivors as most cancer survivors die from noncancer causes, largely CVD [1, 2]. The CVD risk in cancer survivors, both as a result of shared risk factors and the treatment side effects from radiation and cardiotoxicity of some chemotherapy regimens, was previously detailed in the 2006 Institute of Medicine (IOM) Report, ‘From Cancer Patient to Cancer Survivor: Lost in Transition’ [3]. Yet, despite this and previous calls for greater attention to the CVD risks in patients with cancer, little progress has been made. It is time that we move beyond descriptions of the problem and calls for change to taking systematic approaches to implementing evidence-based programmes. To implement an effective advance in prevention, we need the scientific knowledge base; political will to allocate resources; and a strategy to achieve the risk reduction [4]. Whilst Lajous and colleagues note the challenges associated with such implementation, their report does not advance the field by moving beyond summaries of associated lifestyle factors to next steps or practical solutions such as effectiveness trials [5] (knowledge base) and studies of dissemination and implementation of evidence-based interventions [6] (strategy). For example, an AHRQ review of the dissemination of cancer control interventions, components of which would be included in CVD risk reduction interventions, found ‘no strong evidence for effective dissemination strategies for smoking cessation interventions’ [7]. Taking physical activity as an example from the list of lifestyle behaviours, Lajous et al. provided as important to promote for cardiovascular risk reduction in cancer survivors, we see numerous missed opportunities. In a recent report from the American College of Sports Medicine (ACSM), issuing guidelines for exercise in cancer survivors [8], the effect of exercise on cardiovascular risk and risk factors (e.g., blood pressure, cholesterol) in cancer survivors was not evaluated as the panel determined that evidence base does not yet exist. We can extrapolate in the interim, as Lajous et al. have carried out, borrowing evidence from prevention of CVD in the general population, although attention needs to be paid to the unique needs of cancer survivors, as the ACSM physical activity guidelines do. This gap in the knowledge base highlights the need for greater refinement of the health messages within the setting for cancer survivors. Specifically, observational research has suggested that higher levels of physical activity may be necessary to reduce risk of recurrence and mortality in colon cancer survivors [9, 10]. It is possible that patients with cancer who have undergone cardiotoxic treatment regimens may need more (or less) physical activity to alter CVD risk. Thus, we think it is important to highlight gaps in the evidence base as we move forward so that prevention messages may be refined. Given these gaps, and the ample evidence base that exists for the prevention of CVD in the general population, we agree that advising 30 min of moderate intensity activity daily is a wise recommendation particularly as it has been shown to have numerous other benefits, as detailed by Schmitz et al. [8] in the ACSM Guidelines. However, as we have seen with prevention of CVD, diabetes and cancer in the general population, such prescriptions are not enough as the majority of the US population still fails to meet these recommendations as do the majority of cancer survivors. Dissemination of evidence-based guidelines, such as those from the ACSM, to patients, providers and policy makers is a first step, but we also need studies of demonstrated effectiveness (not just efficacy) if implementation of lifestyle recommendations and guidelines is to occur on a wide basis. As Lajous et al. note, individual-level approaches cannot operate in a vacuum, and there is little data on how system and environmental changes can affect survivor health. However, it is important to note that many of the health care system policy and practice changes called for in the IOM report remain largely unimplemented, let alone is there any movement to broader societal changes that will sustain these changes. Thus, the need for implementation research is not limited to individual behaviour change, but also applies to systems and policies – in particular guiding medical centres and practices in evaluation and implementation of evidence-based programs, practices and policies. A plan for implementation has been outlined by Proctor et al., [11] who argue that implementation success can be modelled as a function of effectiveness, acceptability and sustainability. If lifestyle programmes for cancer survivors are to succeed beyond where lifestyle interventions in the broader population have met with limited success, each factor must be considered in bringing the intervention to clinical practice and then in evaluating the intervention. At present, few efficacy study interventions are designed with future effectiveness studies or dissemination and implementation in broad scale clinical practice in mind. In our physical activity example, as we noted before, the effectiveness evidence comes largely from studies of healthy individuals where physical activity does prevent CVD or from studies of cancer survivors, where physical activity has been shown to be safe and has benefits on other end-points. There is little data on the effectiveness of physical activity for preventing CVD specifically amongst cancer survivors. That these data do not exist may limit the acceptability of such a programme amongst clinicians, who are used to relying on data only from randomized controlled trials when providing patients with a prescription. It may also limit patient enthusiasm for such a programme. Thus, successful implementation may need to include greater understanding of how patients with cancer respond to such programmes and interventions to assist providers with providing referrals. Despite the existence of training and certification programmes for exercise professionals, such as that offered by the ACSM, relatively few exercise professionals have obtained certification at the present time. Given the often unique needs of patients with cancer, our experience is that both patients and clinicians want to work with someone with expertise and experience in this area. The limited capacity at present may thus limit the sustainability of such programmes in the long term. Emerging data also indicates that staff turnover is high in exercise facilities so training fitness professionals may not result in sustainable capacity at a local level [12]. However, little data are available on the sustainability of physician recommendations and referrals. Whilst one would hope a cancer diagnosis provides a powerful teachable moment, as argued by Lajous et al., intervention studies in cancer survivors face the same recruitment challenges as other research endeavours and the prevalence of adverse risk factors (e.g., smoking, physical inactivity and obesity) remain high within this population. It is time to move beyond describing the problem to now implementing studies and programmes designed with broad dissemination and community-based implementation in mind. No conflict of interest was declared. GAC is supported by an American Cancer Society Clinical Research Professorship. KYW and GAC are supported by CA 091842