Sun Safety in the Physical Activity Context: Opportunities and Challenges
By Frank Perna
Skin cancer is the most common cancer in the US, affecting an estimated 1 in 5 Americans over their lifetime, and over eight billion dollars a year are spent treating melanoma and non-melanoma skin cancer. Melanoma, the deadliest form of skin cancer, has increased significantly in the US over the last 40 years, and over 91,000 new cases and 9,300 deaths are estimated to occur in 2018. Yet, unlike many cancers, we know the prominent cause of skin cancer (excessive ultraviolet radiation [UV]), know a robust proximal clinically relevant biomarker of risk (sunburn), and have efficacious treatments to decrease excessive UV exposure. This scenario seems like a significant public health problem, but also a prime opportunity for implementation science.
Earlier this fall, I had the honor of organizing the NCI Exercise Science and Skin Cancer Prevention Research meeting on September 26-27, 2018, in Rockville, MD. The meeting brought together a multidisciplinary group of approximately 30 researchers and practitioners spanning exercise science disciplines, scientific officers of professional organizations, sports apparel and material science experts, engineering and atmospheric scientists, exercise behavior change investigators, skin cancer prevention and dermatology experts, and implementation scientists. The goal of this meeting was to identify key research questions and measurement and methodological needs, and provide recommendations for research focused on developing and testing both interventions and implementation strategies to reduce the risk of sunburn and excessive UVR exposure for people engaging in sports and physical activity.
I’ve been asked (and you may be wondering) why the dual focus on physical activity and skin cancer? Understandably, the public may be aware of skin cancer risks attendant to indoor tanning, and fortunately, indoor tanning rates in general (about 3.5% among adults) and especially among teens (5.6%) have dropped significantly. The melanoma hazard ratio for sunburn history rivals the risk attendant to indoor tanning, but unlike indoor tanning, sunburn incidence is far more common among teens (57%) and adults (35%), has remained relatively unchanged since 2005, and is strongly related to engagement in physical activity. Physical activity is also associated with 28% increased risk of melanoma, ostensibly through significant increase in sunburn rather than any direct putative effects. Thus, we have identified a large target research population for implementation science.
The Exercise Science and Skin Cancer Prevention Research meeting addressed several themes, several of which present opportunities for conducting implementation science. One of the more fascinating sessions focused on physiology of skin health and function and the effects of UV exposure and implications for demands of exercise. A featured part of the session concerned dermal vasodilation, its thermoregulatory role, and the effects of UV light on this function. Vasodilatation affects blood flow to the skin and is the principal way the body cools, which is especially important during exercise physiologically as well as for comfort. The session described the literature and new experimental data regarding UV light and its potential for both positive and negative effects on skin vasodilatation. A related illuminating presentation provided a very practical overview of clothing for sun safety and the results from the investigator’s laboratory experiments on heat gain and thermal comfort. The take away: clothing will always increase heat gain, but people’s tolerance for it (thermal comfort) is variable and likely influenced by cognitive, affective, and social factors (e.g., Will it help my performance? What are others wearing?). These factors undoubtedly influence individuals, but also serve as potential barriers and opportunities to use the information to support effective implementation among stakeholder organizations involved in overseeing sport and recreation settings.
Another session addressed sun safety habits of exercisers as possible behavioral phenotypes (e.g., people who are vigilant about sun protection, people of average vigilance who get unintended sun exposure, and those who see physical activity as an opportunity to tan). Other presentations described an individually focused sun safety intervention for National Collegiate Athletic Association (NCAA) athletes across sports and highlighted potential next steps for implementation studies to test how best to scale-up the intervention to other academic institutions. Two presentations featured prominent examples of studying how best to implement evidence-based interventions within specific sport and recreation contexts: ski areas [Dave Buller and colleagues] and pools). A third session had a sociology and sport psychology theme that addressed the aspect of going onto the “turf” of sport and recreational settings and considerations for integrating a sun safety intervention for stakeholders who have other priorities and may have practical concerns where sun safety appears incompatible with sports (e.g., sunscreen in eyes, rules prohibit). That is, the ethos is related to being physically active and physical skill building and somewhat to performance. Where health motivations exist, they are likely related to proximal safety rather than distal effects of skin cancer. Discussion here related in some ways back to basic physiological principles of earlier presentations concerning skin function and how sun safety could serve performance motives or improve participation rates, and that sports and recreation are highly organized in the US. The presence of organizational structures (locally and in some cases nationally) for sports, policy-making authority, and coach/event-leader training requirements also provide a rich infrastructure for conducting implementation research that can involve partnerships with a variety of stakeholders and provide an opportunity for large-scale studies. A fourth session described engineering approaches and devices to capture actual UV exposure individually in real time, as well as approaches that could be used for surveillance, and examples of how it could be integrated with physical activity trackers that are ubiquitous among physically active (and relatively inactive) people. These developments offer rich prospects for data collection in implementation science.
A final session addressed cancer survivorship and the juxtaposition of interventions aiming to increase physical activity that may, in turn, present greater risk for skin cancer among many cancer survivors. In addition to those with a history of skin cancer, any cancer survivor treated with radiation therapy and medications that increase photosensitivity is at significantly increased risk for sunburn and secondary melanoma and non-melanoma skin cancers. Certainly, physical activity and sun safety can be compatible, but it was striking how to date, intervention research has not considered this intersection, as there is great interest in developing and disseminating evidence-based physical activity programs for cancer survivors. Similarly, for research among those without a cancer history, there are many efforts and opportunities to study the built environment to promote physical activity that could incorporate a sun safety element.
In sum, many favorable conditions exist for advancing the science of implementation with respect to skin cancer prevention among physically active people, but many questions remain. Fortunately, the tenor of the meeting suggests there is a lot of enthusiasm for multidisciplinary collaboration and great interest in implementation science generally that is not confined to sun safety. I encourage you to wade in and do your own exploration and welcome your questions. Come on in, the water’s fine.Share your comments or interest in this research area with me via email@example.com.
Frank Perna, Ed.D., Ph.D., is a Psychologist and Program Director at the National Cancer Institute (NCI), Division of Cancer Control and Population Sciences (DCCPS), Behavioral Research Program (BRP), Health Behaviors Research Branch (HBRB). Read More »