Nearly 2 million adolescent and young adult cancer survivors reside in the United States [1]. In this study, adolescent and young adult cancer survivors are defined by their current developmental age (15-29 years) and include those diagnosed during childhood and adolescence and treated within pediatric cancer centers. This inclusive definition aligns with the Children’s Oncology Group framework for cancer survivorship care, which emphasizes that the psychosocial and medical needs of cancer survivors are based on their current developmental stage and navigation of transition-to-adulthood milestones [2]. Cancer profoundly disrupts normal developmental experiences and life transitions [3,4]. Consequently, adolescent and young adult cancer survivors are at elevated risk for long-lasting negative psychological late effects, with poorer health-related quality of life and psychosocial outcomes than their younger pediatric and adult counterparts [5]. Adolescent and young adult cancer survivors commonly struggle with reintegration into daily life after treatment; miss crucial social, educational, and vocational milestones; face disrupted peer and family relationships; navigate financial toxicity; and experience a forestalled transition to independence. All of these issues can be further exacerbated by discontinuation of comprehensive support from their oncology care team [6]. A seminal longitudinal population-based study (the AYA Health Outcomes and Patient Experience study) showed that more than half of adolescent and young adult cancer survivors, who require psychosocial services, remain untreated [7]. Barriers to psychosocial care include inadequate end-of-treatment transition care planning between pediatric and adult cancer centers and primary care settings, insufficient psychosocial screening and referrals to mental health providers, a shortage of psychosocial clinicians, and persistent mental health stigma [8,9].

Cancer-related anxiety is the most prevalent mental health problem, impacting one-third of adolescent and young adult cancer survivors [10-12]. Muzzin et al [13] aptly characterized this as a “living-dying” experience in which “a person never really ‘gets over’ cancer: it is a sword of Damocles that continues to hang over the individual and [their] family for the rest of the person’s life.” In addition to general anxiety, up to 85% of adolescent and young adults experience cancer-specific anxiety, most notably scan-associated anxiety and fear of cancer recurrence [11]. Cancer-related anxiety is associated with long-term negative outcomes such as poor quality of life, depression, distress, posttraumatic stress, substance use, sleep problems, fatigue, and pain [14]. Therefore, the identification and management of anxiety are important targets for follow-up care of adolescent and young adult cancer survivors.

Adopting a developmental science framework, “meeting teens where they are,” necessitates leveraging technology and a paradigm shift in traditional treatment norms [15]. Increasingly, mental health delivery models are being deployed in asynchronous mobile health formats. For adolescent and young adults, the internet serves as a primary platform for physical health and mental health–related information seeking and communication [16,17]. Adolescent and young adults prefer digital self-help interventions and may be reluctant to seek traditional forms of psychotherapy due to social stigma and discomfort discussing personal problems [16,18-20]. SMS text messaging interventions may be particularly appealing to younger generations who are accustomed to interacting on smartphones and using the internet [18,19,21,22].

Positive psychological interventions have demonstrated improvements in psychosocial outcomes for adolescent and young adult cancer survivors [23]. Such interventions, designed to increase positive emotions, have beneficial long-term impacts on emotion regulation, mental health, mindset broadening, coping resources, and functional outcomes [24]. Interventions that increase the frequency and duration of positive emotions through practices such as savoring (defined as the process of intentionally bringing focused attention to past, present, and future positive experiences, such as reminiscing about a happy memory or anticipating an upcoming vacation) and gratitude (defined as the process of appreciating the good in one’s life and ascribing their internal and external sources, such as writing a thank you note to someone who helped you) have been shown to decrease stress, promote psychological well-being, and improve health-related quality of life in the face of adversity (eg, a cancer diagnosis) [25-28]. Background literature suggests that positive psychological interventions involving gratitude and savoring activities increase treatment adherence [29,30] and have demonstrated efficacy and effectiveness of these interventions in systematic reviews [31-34]. Although few digital psychosocial interventions for adolescent and young adult cancer survivors currently exist, this is a burgeoning area of intervention research that is highly appealing and appropriate for adolescent and young adults [35-38]. To our knowledge, there are no existing adolescent and young adult cancer survivor–specific digital interventions that are designed to target anxiety, which is the most prevalent mental health symptom impacting adolescent and young adults.

Across pediatric and adult clinical populations alike, attention bias modification (ABM) is a widely used digital intervention for anxiety that has been adapted for a wide range of clinical populations and disease groups [39-41]. Systematic maladaptive patterns of information processing play a causal role in anxiety pathology [42,43]. Cognitive models of anxiety have consistently shown that clinically anxious individuals demonstrate an attention bias, meaning that they selectively attend to and have difficulty disengaging from negative information. Similarly, a systematic review has shown that cancer survivors demonstrate a negative attention bias [44]. For example, an individual with social anxiety may selectively attend to threatening stimuli in their environment, such as threatening facial expressions (eg, angry, judgmental, or disapproving), which can lead to sustained and increased anxiety and the avoidance of social situations [39,45-47].

ABM is a brief, self-guided digital intervention in which individuals complete repetitive association reaction-time tasks. These tasks target automatic and unconscious negative attention biases to retrain attention away from perceived threat and toward neutral or positive stimuli (ie, a modified dot-probe task) [48]. For example, ABM for social anxiety may involve a series of image pairs on a computer screen—one of a neutral or positive face and one of a threatening face. By rapidly and repeatedly training anxious individuals to disengage their attention from the threatening face and direct it toward the neutral or positive face, ABM implicitly modifies their negative attention bias.

ABM delivered digitally for the treatment of anxiety disorders (including social anxiety, generalized anxiety, and posttraumatic stress) has demonstrated moderate treatment effects [49-52]. The effectiveness of ABM is comparable to that of the gold-standard evidence-based treatment for anxiety (ie, cognitive behavioral therapy) [53]. A recent systematic review revealed that adult cancer survivors also experience negative attention biases with large effect sizes [44]. Recent research efforts have successfully adapted ABM for adult cancer survivors, demonstrating feasibility in pilot studies [54]. Notably, a pilot randomized controlled trial (RCT) of ABM in adult breast cancer survivors showed significant improvements in health-related anxiety and fear of cancer recurrence [55]. However, ABM has not yet been adapted or tested for adolescent and young adult cancer survivors.

This paper describes the protocol for an ongoing pilot RCT. This study aims to test the feasibility and acceptability of a novel digital positive psychological intervention for adolescent and young adult cancer survivors, the Attention Bias in Cancer survivors (ABCs) intervention, using a pilot RCT. The ABCs intervention consists of an ABM mobile intervention combined with a gratitude and savoring texting intervention. We hypothesize that the ABCs intervention will meet benchmarks for feasibility (enrollment and retention) and acceptability (user satisfaction and system usability).

The primary aim of this study is to evaluate the feasibility and acceptability of a digital health intervention for adolescent and young adult cancer survivors. We hypothesize that the ABCs intervention will be feasible as measured by ≥50% enrollment of eligible patients and ≥70% retention of participants in both arms (with retention defined as completion of primary outcome measures after treatment). These benchmarks are based on our previous research and known challenges in the recruitment and retention of adolescent and young adult cancer survivors and background literature on expected enrollment and retention rates for remote digital health studies [56,57]. We hypothesize that the ABCs intervention will be acceptable, as measured by the Client Satisfaction Questionnaire (established cutoff score of ≥26 indicating satisfaction) [58-61] and the System Usability Scale (SUS; established cutoff score of ≥70 indicating usability) [62]. An exploratory aim is to examine preliminary efficacy assessed via validated patient-reported outcome measures after treatment.

All study procedures were approved by the Seattle Children’s Hospital institutional review board (STUDY00004811). The trial is registered at ClinicalTrials.gov (NCT06682039). Informed consent (for individuals aged 18 to 29 years) or assent with parental consent (for individuals aged 15 to 17 years) will be obtained from all participants. Privacy and confidentiality protections are in accordance with institutional ethics guidelines. Participants will be compensated US $100 in electronic gift cards for completing a standardized survey assessment battery and attention bias assessment at T1 (baseline) and T2 (4 weeks after the intervention), each designed to be approximately 30 minutes long. Refer to Table 1 for the schedule of assessments. This protocol follows the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines. The completed SPIRIT checklist is provided in Multimedia Appendix 1 [63].

This pilot RCT uses a parallel, 2-arm design (Figure 1). A total of 60 participants will be enrolled at a single site and then randomized in a 1:1 allocation ratio after completing baseline surveys. The randomization schedule will be stratified by age group (those aged 15 to 18 years and those aged 19 to 29 years). Age was selected as the stratification factor to account for developmental considerations and to ensure the appropriateness of the intervention design across developmental stages. Randomization was seeded based on the exact date and time of randomization for reproducibility. All randomization was conducted by the study coordinator and data manager in R (version 4.4; R Foundation for Statistical Computing) using the blockrand package [64]. Randomization was conducted using permuted varying block sizes of 2, 4, and 6. Participants will be assigned to either the active ABCs intervention condition (ABM and daily savoring and gratitude SMS text messages) or a sham control condition (sham ABM and daily mood SMS text messages). Participants will remain blinded to their study condition for the duration of the study. The principal investigator and the biostatistician responsible for data analysis are blinded to the study condition. The study coordinators responsible for study procedures could not be feasibly blinded to study conditions due to study management and logistics. However, the active treatment and sham treatment are entirely remotely and digitally delivered with no personnel involvement in the administration or facilitation of the intervention.

Individuals are eligible for study participation if they are currently aged 15 to 29 years. Although the National Cancer Institute definition of adolescent and young adults includes ages 15 to 39 years, we targeted a narrower age range (15 to 29 years) to align with the pediatric and adolescent and young adult populations typically treated within pediatric cancer centers, such as Seattle Children’s Hospital, where this study is conducted. Eligibility criteria include a pediatric cancer diagnosis (inclusive of those diagnosed before the age of 15 years); completion of cancer treatment and in active follow-up cancer survivorship care at Seattle Children’s Hospital; proficiency in English (speaking, reading, and writing); having no cognitive limitations that would make participation difficult; and having access to a smartphone with SMS text messaging capabilities. adolescent and young adults are excluded from study participation if they are receiving active or curative treatment, are not proficient in English (speaking, reading, and writing), or are cognitively or physically unable to participate. Clinical research coordinators are identifying potential participants and conducting their prescreening assessments through clinic rosters and electronic medical records. Recruitment by clinical research coordinators occurs in person at clinic visits and remotely by phone, video, or text.

Study participants who have opted in will receive a layperson-accessible summary of study findings after we have completed primary data analysis. Deidentified study results will be disseminated to the scientific and clinical community through national and international conference presentations, peer-reviewed publications, and social media platforms.

The sham control condition is designed to mirror the active intervention condition, providing a nontherapeutic sham ABM mobile intervention plus daily mood monitoring texts.

The primary aim of this study is to determine the feasibility and acceptability of the ABCs intervention. Feasibility will be defined by meeting the following criteria: (1) ≥50% enrollment of eligible patients and (2) ≥70% retention of participants in both arms. Acceptability will be defined as (1) an average score ≥26 on the Client Satisfaction Questionnaire and (2) an average score ≥70 on the SUS.

All participants who complete baseline surveys and are randomized will be included in intent-to-treat analyses to explore the preliminary efficacy of all patient-reported outcome measures in our assessment battery. Preliminary efficacy will be examined using 2-sample comparisons and regression models. Two-sample comparisons will be based on 2-tailed t tests or chi-square tests, depending on the type of outcome. The regression models aim to assess the intervention’s effect on continuous patient-reported outcomes while controlling for baseline scores and other potential confounders. Potential covariates include age, gender, cancer diagnosis, and other sociodemographic or disease-related or treatment-related characteristics previously shown to influence psychosocial outcomes. All statistical analyses will be performed in the R software [64].

This manuscript describes the protocol for a pilot RCT designed to evaluate the feasibility and acceptability of the ABCs intervention, which is a novel digital intervention tailored for adolescent and young adult cancer survivors. The ABCs intervention is specifically designed to target anxiety, addressing a critical gap in cancer survivorship care. We hypothesize that the ABCs digital intervention will demonstrate feasibility and acceptability within the adolescent and young adult cancer survivor population. The exploratory patient-reported outcomes data collected from this pilot trial will provide effect size estimates to inform power calculations and sample sizes for future multisite efficacy trials.

Digital health interventions offer a unique opportunity to address existing access care gaps by using technologies that align with adolescent and young adult communication and learning preferences. The ABCs intervention builds on a robust body of literature establishing ABM as a digital anxiety intervention across the age continuum and in various disease groups [39-41]. A previous systematic review has confirmed that cancer survivors, such as individuals with clinical anxiety disorders, demonstrate a negative attention bias [44]. However, existing digital psychosocial interventions for adolescent and young adult cancer survivors have not been designed to target anxiety symptoms [35-38]. To our knowledge, this protocol represents the first study to design and test a digital anxiety intervention for adolescent and young adult cancer survivors, targeting cognitive mechanisms of anxiety [42,43].

A primary strength of this study is the use of a widely used digital anxiety intervention, ABM, that we have adapted for adolescent and young adult cancer survivors. The development of the ABCs intervention followed a rigorous user-centered co-design approach involving a multidisciplinary group of stakeholders. The digital deployment model allows for remote delivery and scalability and helps overcome the access care gap that adolescent and young adult cancer survivors face when seeking traditional mental health services.

Our study has several anticipated limitations. First, this is a single-site pilot trial, which limits the generalizability of findings. However, a strength of this approach is the presence of preexisting relationships with the clinic to ensure project completion and the collection of pilot data for future clinical trials. Second, cognitive late effects may present difficulties in engaging with ABM, which consists of repetitive reaction-time association tasks. Although not yet tested in adolescent and young adult cancer survivors, findings from attention bias assessment and ABM studies in pediatric medical populations and adult breast cancer survivors support its potential feasibility. On the basis of the results of this ongoing trial and participant feedback, we may vary stimulus presentation times for future intervention refinement.

Findings from this pilot trial will inform a larger multisite hybrid effectiveness-implementation trial. This is a critical next step in digitizing evidence-based positive psychological interventions and co-designing for engagement and sustainability. This study and future studies building on this work aim to expand the adoption and reach of evidence-based mobile health psychosocial interventions.