Cancer can be a very traumatic experience for the people affected and the majority of the psychological literature focuses on this. Less proliferated and researched is the increasingly recognized fact that as a result of struggling with such traumatic adversities, some people experience what is known as post-traumatic growth (PTG). PTG not only allows them to overcome their trauma (e.g., impact of cancer) and return to pre-diagnosis functioning (e.g., health, wellbeing, employment) but also results in them going over and above their previous state (e.g., increased resilience). This renders PTG an important phenomenon that could be enhanced as part of the support people with cancer receive. IC-Growth has two interconnected paths, namely a research one and another of health policy and best practice recommendations. On the first path, is a sequence of three studies, starting with a systematic review, followed by a cross-sectional study and concludes with a randomized control trial (RCT). The systematic review and close collaboration with experts (e.g., patient associations) will lead to the development of a novel manual to facilitate PTG in groups of people with cancer. The cross-sectional study will explore relationships between variables (e.g., PTG, quality of life, biological variables, illness perceptions, distress, anxiety, depression) in people with cancer (n = 150-180). Lastly, the RCT will evaluate the intervention's effects among three different groups (breast, colorectal, and head and neck cancers, n = 50-60 per group). On the other path, is the development of health policy and best practice recommendations regarding the psychosocial support of people with cancer in Greece. The project's results will be disseminated to stakeholders who provide support to people with cancer (e.g., oncologists, surgeons, psychologists, psychiatrists), through professional associations, a conference on "Psychosocial Support in Oncology", and publications in scientific journals. Overall, IC-Growth is a multidisciplinary project (i.e., psychology, medical, patient organizations, health policy) and joins the clinical, research and policy fields together to workable actions leading to empowering the wider community of people with cancer and improving their care.

Detailed Description IC-Growth is a 24-month, multidisciplinary research and clinical project aimed at enhancing psychosocial care for adults with cancer by promoting post-traumatic growth (PTG)-positive psychological changes following traumatic life crises. While most research emphasizes the negative psychological effects of cancer, IC-Growth focuses on understanding and facilitating PTG as a mechanism to improve well-being, resilience, and quality of life (QoL) beyond pre-diagnosis levels.

The project has two interconnected components:

Research - A sequence of three studies to build, test, and evaluate a novel, manualized PTG intervention for cancer patients:

A systematic review (using PRISMA 2020 and Cochrane standards) to synthesize evidence on PTG interventions.

A cross-sectional study (n = 210-240; breast, colorectal, and head & neck cancer) to examine associations among PTG, QoL, biological markers (e.g., cortisol), illness perceptions, distress, anxiety, and depression.

A randomized controlled trial (RCT) across two centers in Greece (AHEPA University General Hospital and Theageneio Cancer Hospital), comparing a manualized group-based PTG intervention (6-8 weekly sessions, 90 minutes each) with standard care in three cancer populations (70-80 participants per cancer type, randomized into intervention vs. control arms).

Health Policy and Best Practice Development - Using findings from the studies, patient and clinician feedback, and comparisons of national and European oncology guidelines to create evidence-based recommendations for integrating psychosocial interventions into Greek oncology care.

Intervention The PTG intervention will be delivered in groups of 8-10 participants with the same cancer type, facilitated by trained health psychologists. The manual integrates evidence-based therapeutic approaches, including cognitive processing techniques, psychoeducation, cognitive-behavioral elements (e.g., restructuring core beliefs), mindfulness, narrative and existential exercises (e.g., life review, meaning-making), and interpersonal support-building. Sessions are designed to promote growth across PTG's five domains (perception of self, relationships with others, new possibilities, spiritual change, and life appreciation). The intervention's duration is 6-8 weeks, with weekly 90-minute sessions.

Outcomes The primary outcome is PTG, measured via the Post-Traumatic Growth Inventory (PTGI).

Secondary outcomes include:

Quality of life and spiritual well-being (FACIT-Sp and cancer-type specific FACT scales),

Anxiety and depression (Hospital Anxiety and Depression Scale, HADS),

Illness perceptions (Brief Illness Perception Questionnaire, BIPQ),

Distress and trauma impact (Impact of Event Scale-Revised, IES-R),

Biomarkers (cortisol levels as a stress indicator).

Assessments will occur at baseline (pre-intervention) and post-intervention for both control and intervention groups.

Participants Eligible participants are adults (≥18 years) with a diagnosis of breast, colorectal, or head & neck cancer, who have completed planned chemotherapy and hospitalizations, and whose initial diagnosis occurred within the last five years. Exclusion criteria include active psychological or psychiatric treatment, unmanaged mental health conditions, severe cognitive impairment, inability to provide informed consent, non-Greek speakers, cancer relapse(s), diagnosis of another cancer within five years, or life expectancy under one year.

Analysis Statistical analyses will include Pearson and Spearman correlations, factor analysis, network analysis (for cross-sectional findings), and mixed ANOVA/ANCOVA for RCT outcomes. Reliability (Cronbach's alpha) will be assessed for all questionnaires. Qualitative thematic analysis will be used for feedback from participants and professionals to inform feasibility and implementation strategies.

Impact IC-Growth will generate the first manualized PTG intervention in Greece and one of the first RCTs internationally to evaluate PTG across multiple cancer types. Findings will inform the creation of evidence-based best practice and policy recommendations for psychosocial support in oncology care, disseminated via professional associations, a dedicated national conference, and peer-reviewed publications.

Inclusion Criteria:

1. Adults (≥ 18 years)
2. Having a diagnosis of a. Breast Cancer, b. Colorectal Cancer, or c. Head and Neck Cancer.
3. Having concluded the planned chemotherapy courses and related hospital admissions
4. Having no more than 5 years since the initial diagnosis.

Exclusion Criteria:

1. Being in active psychological or psychiatric treatment
2. Having an unmanaged mental health difficulty
3. Having a severe cognitive impairment
4. Being unable to give informed consent
5. Being unable to speak or read Greek
6. Having one or more relapses
7. Diagnosed with another type of cancer within 5 years prior to recruitment.
8. Having less than one-year life expectancy