Trauma and posttraumatic growth in cancer: Validation of the Post-traumatic Stress Disorder Checklist for DSM-5 (PCL-5) and the Posttraumatic Growth Inventory-Short Form (PTGI-SF) in patients with breast cancer

Cancer diagnosis is a highly stressful event that may trigger trauma symptoms or post-traumatic stress disorder (PTSD), while also fostering positive psychological changes known as post-traumatic growth (PTG). Although distinct, PTSD and PTG often co-occur among women with breast cancer. Despite their clinical relevance, validated self-report measures of PTSD and PTG remain limited in oncology. This study aimed to validate the Portuguese versions of the PTSD Checklist for DSM-5 (PCL-5) and the Posttraumatic Growth Inventory – Short Form (PTGI-SF) in women with breast cancer. A total of 147 women diagnosed with early-stage breast cancer completed the PCL-5 and the PTGI-SF at 12 and 18 months after diagnosis, considering the cancer experience as the traumatic event. Confirmatory factor analyses were conducted to examine factor structure. Internal consistency was assessed using Cronbach’s alpha and McDonald’s omega, and test-retest reliability using intraclass correlation coefficients. Construct validity was examined with the Positive and Negative Affect Schedule – Short Form (PANAS-SF) and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). The PCL-5 demonstrated excellent fit to a four-factor structure, high internal consistency, and acceptable test-retest reliability. Convergent validity was supported by positive correlations with negative affect (PANAS-SF), and divergent validity by negative correlations with positive affect (PANAS-SF) and quality of life (EORTC QLQ-C30). The PTGI-SF showed a good fit to an unidimensional model, with excellent internal consistency (α = 0.91; ω = 0.91) and high test-retest reliability (ICC = 0.91), although correlations with affect and quality of life were non-significant, indicating limited convergent and divergent validity. Overall, findings support the psychometric adequacy of the PCL-5 and, to a lesser extent, the PTGI-SF, in patients with breast cancer. The PCL-5 appears robust for assessing PTSD symptoms in this population, while the PTGI-SF captures global growth experiences, despite weaker evidence for validity. Combined use of both instruments may provide a comprehensive assessment of vulnerability and resilience following breast cancer, supporting more individualized psychosocial care and guiding future research on psychological responses to cancer.