Abstract
INTRODUCTION: Cancer affects not only physical health but also leads to considerable psychological difficulties for patients. A subset of survivors' experiences post-traumatic growth (PTG), reflecting positive psychological changes following trauma. Despite increasing interest, the mechanisms and interventions that enhance PTG are not well understood. This randomized controlled trial (RCT) aims to evaluate the efficacy of an Acceptance and Commitment Therapy (ACT)-based group intervention in fostering PTG in cancer patients diagnosed with breast, head and neck, or colorectal cancer across major oncology centers in northern Greece. METHODOLOGY: In addition to PTG, the trial assesses related psychological and physiological factors, including anxiety, depression, illness perception, spiritual well-being, and stress-related biomarkers, to explore the potential mechanisms and broader outcomes of ACT. The study will utilize a parallel-group design, comparing the ACT intervention with standard care. Participants, that is, patients who have completed their oncological therapy, will be randomized and engaged in six weeks of group sessions, with outcomes assessed through standardized questionnaires (Post-traumatic Growth Inventory (PTGI), Functional Assessment of Chronic Illness Therapy-Spiritual Well-being (FACIT-Sp), Impact of Event Scale-Revised (IES-R), Hospital Anxiety and Depression Scale (HADS)), measuring post-traumatic growth, clinical symptoms, spirituality, and biomarkers. The protocol was developed in accordance with the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) 2025 guidelines. DISCUSSION: By examining the impact of the ACT-based intervention, this study seeks to elucidate the therapeutic approaches that can foster PTG, ultimately enhancing empowerment in cancer survivors. The findings will contribute to the growing body of literature on PTG, informing clinical practice and the development of evidence-based interventions.