Well established cancer-risk behaviours include smoking and alcohol use. The association between tobacco use and the development of various cancers is strong, dose-dependent and insensitive to covariate-adjustment, with systematic reviews demonstrating that smoking considerably enhances and cessation delays the risk of developing and dying of cancer [
1‐
5]. Causal relationships between alcohol consumption and cancer of the oral cavity, pharynx, larynx, esophagus, liver, colorectum and breast are well established, with relative risks rising in a dose-response fashion with increasing alcohol consumption for all named sites [
6‐
10]. There is no safe threshold of alcohol intake for cancer risk [
9,
11,
12]. Alcohol is a major contributor to cancer mortality and years of potential life lost due to cancer. The habitual consumption of sugar-sweetened beverages is an emerging risk factor for cancer associated with the increased incidence of pancreatic, gallbladder and biliary tract cancer; with cancer reoccurrence and mortality generally; and with important risk factors for cancer (e.g., type 2 diabetes, obesity) [
13‐
17].
Much of the effort to prevent cancer-risk behaviours have been based on the theory that lack of knowledge is a key driver. Thus, mass media campaigns have been a central focus for prevention efforts [
18]. Yet, despite the enormous amount of resources invested, a recent systematic review of reviews found limited evidence that mass media campaigns have an impact on alcohol use and diet, and mixed evidence for impacts on tobacco use [
19]. To make progress, there is a need to move beyond the assumption that cancer-risk behaviours are wholly determined by
individual susceptibility due to lack of knowledge. We must also consider
population susceptibility due to common agents present within the social milieu in which we grow, live, work and age [
20].
Social trauma and cancer-risk behaviour
Humans are naturally inclined to establish and maintain profound bonds within society [
21]. Factors that interfere with this natural process such as adverse childhood experiences (ACEs) have been shown to increase cancer-risk behaviour. A review of 155 quantitative, peer-reviewed US studies indicates adults will use the psychoactive properties of nicotine and alcohol, or may engage in emotional eating and/or excessive sugar consumption to manage the dysphoria associated with ACEs [
22]. ACEs include physical, emotional and sexual abuse; emotional and physical neglect; and/or household dysfunction experienced before 18 years of age (i.e., domestic violence, mental illness and addiction in the household, parental separation and parental incarceration) [
23].
In North America exposure to ACEs is common with the majority of adults reporting at least one ACE (52–67%), two ACEs (26–42%), and up to as many as four or more ACEs (6–16%) by the age of 18 years [
23‐
28]. In Canada, the prevalence of ACEs and other forms of social trauma may be further elevated among Indigenous adults given child maltreatment was a common experience in residential school up until the last school closed in 1996, and Indigenous adults also report high levels of racial discrimination and social exclusion across the life course [
29‐
32].
Interventions
In North America, there is a strong focus on the verbal narrative in psychological and psychiatric treatment. Yet the rational, executive brain has been shown to have limited capacity to control emotional and physiological arousal in response to trauma triggers [
33]. Specifically, the autonomic nervous system interferes with executive function once sensory triggers of past trauma activate the brain to engage in habitual, self-protective behaviour [
34]. Compounding this problem, decreased activation of the medial prefrontal cortex among individuals who have experienced trauma makes it more difficult to become aware of these internal states, and when they are being activated [
35]. Further, many traumatized individuals have also learned to disassociate from the body as a form of self-protection [
36,
37]. Thus, it may be more difficult to remain aware of, or concerned about, the ways in which tobacco use, alcohol use, and sugar-sweetened beverage consumption are affecting the physical body. Body-oriented interventions designed to increase awareness of physical sensations, muscle activation, and the movement of the body may offer the opportunity to reprogram automatic physiologic hyperarousal in response to triggers, while at the same time increasing positive body awareness, and mindful attention to the ways in which various habitual self-protective behaviours may be impacting physical health.
Given most traumatic experiences occur in the context of interpersonal relationships, the resulting boundary violations and loss of autonomous action can interfere with the ability to form trusting relationships with others [
38]. Alexander has posited that such experiences result in
social dislocation, defined as an enduring lack of psychosocial integration in society, an experience that is both individually painful and socially destructive [
21]. From this perspective, engaging in cancer-risk behaviour may be a way of adapting to the discomfort of sustained social dislocation by providing the rewards an individual would normally receive through their social world. Group interventions designed to build social trust may be effective in reducing these behaviours.
The premise for this study is that adults in Canada are susceptible to cancer-risk behaviour due to the pervasiveness of ACEs and other forms of social trauma within society, and that addressing the psychological symptomology, physiologic sequelae, and social dislocation associated with interpersonal trauma may reduce cancer-risk behaviour and increase healthy coping behaviour. We will examine this premise by comparing three 12-session interventions that have been designed to emphasize the connection between mind and body and build group trust, to control on three primary endpoints (tobacco use, alcohol use, and sugar-sweetened beverage consumption). We will also examine changes in four secondary endpoints (psychological stress symptomology, physiological stress symptomology, social dislocation, and coping behaviour choices).
Trauma-informed yoga. Twelve group yoga sessions, delivered weekly, will use breathing exercises, physical postures, and mindfulness meditation to direct participant attention toward internal states and the connection between mind and body [
39]. Yoga has been shown to impact both psychological and physiological sequelae associated with trauma [
40‐
42]. It has been theorized that trauma-informed yoga (TIY) that emphasizes choice, as well as curiosity about bodily sensations may strengthen these impacts [
39,
43]. In the present study, licensed yoga instructors with TIY training will guide participants using language modified to reduce the likelihood it may trigger traumatic memories. Invitatory language will encourage participants to make choices (e.g., when you are ready, I invite you to experiment with lifting your arms), and reflect on how the movements and breathing they choose to engage in resonates within their body (e.g., you might consider what it feels like to stretch your calf in this way).
Trauma-informed drumming. Twelve group drumming sessions, delivered weekly, will offer a patterned, repetitive, rhythmic experience that can be effective in regulating the brainstem and neural network among adults who have experienced trauma. At a psychological level, group drumming has been shown to improve mood and reduce trauma-related symptoms including PTSD, anxiety, and impulsivity; and promote self-expression, social cohesion, and engagement in treatment [
44‐
46]. At a physiologic level, group drumming that emphasizes camaraderie, group acceptance, and nonjudgmental performance has been shown to attenuate physiological stress response patterns, resulting in statistically significant increases in plasma dehydroepiandrosterone-to-cortisol ratios, natural killer cell activity, lymphocyte-activated killer cell activity; as well as improve pain tolerance; and decreased blood pressure and inflammation [
47‐
52]. In this study, group drumming will be delivered using trauma-informed, invitatory language. Participants will be invited to engage various drums and rhythms, and to reflect on how these sensations resonate within their body.
Trauma-informed psychoeducation. Twelve group psychoeducation sessions, delivered weekly, will be delivered using trauma-informed, invitatory language. Licensed counsellors will teach adults about various forms of social trauma, how these experiences impact the body and mind, and ways to respond to and cope with stress in healthy ways.