In 2020, around 60,000 people were diagnosed with cancer in Portugal, and many of them suffered some level of Fear of Progression (FoP) of the disease. Although this FoP is realistic, and is part of the normal and appropriate response to this type of disease, there is no instrument to assess and understand whether it is exaggerated in the face of the situation. The present study aimed to translate and validate the Fear of Progression Questionnaire-Short Form (FoP-Q-SF) for the Portuguese population. The sample consisted of 220 volunteers, aged 18 years or over and diagnosed with cancer for at least six months. Participants completed the FoP-Q-SF, the Hospital Anxiety and Depression Scale (HADS), the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 (EORTC QLQ-C30) and the Post-Traumatic Stress Disorder Checklist-Civilian Version (PCL-C). The FoP-Q-SF demonstrated high internal reliability (α = 0.86) and the confirmatory factor analysis supported the one-dimensional structure of the FoP-Q-SF. Convergent validity was supported with significant positive correlations with psychological distress, especially anxiety (0.68). The FoP-Q-SF has been found to be a valid instrument to measure FoP in Portuguese cancer survivors.

Background/Objectives: The global prevalence of cancer is increasing, with 50% of new diagnoses occurring in people over 65 years old. Despite this demographic trend, psychosocial research has focused largely on younger populations, leaving a limited understanding of how middle-aged and older adults adjust to cancer. Fear of progression (FoP) has emerged as a key component of emotional vulnerability in cancer survivors, yet its role in shaping psychological distress and health-related quality of life (HQoL) in these age groups remains understudied. This study aimed to examine psychosocial adjustment in middle-aged and older women with cancer and to test the mediating role of FoP in the relationship between emotional distress, post-traumatic stress and HQoL. Methods: The sample consisted of 135 women aged 45 to 79 years (M = 52.94; SD = 6.58), of whom 80.7% (n = 109) were middle-aged (45–59 years) and 19.3% (n = 26) were older (60–79 years). In addition to a clinical and sociodemographic questionnaire, the following self-report measures were used: Fear of Progression Questionnaire—Short Form (FoP-Q-SF), Hospital Anxiety and Depression Scale (HADS), Post-Traumatic Stress Disorder Checklist—Civilian Version (PCL-C), and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 (EORTC QLQ-C30). Mann–Whitney tests were used to explore age-group differences as part of the sample characterization. Correlational analyses examined associations among FoP, anxiety and depression, post-traumatic stress, and HQoL. The mediating role of FoP was tested using path analysis with bias-corrected percentile bootstrapping. Results: Older women reported slightly higher levels of depression and poorer physical and social functioning compared to middle-aged women, but with a small effect size (0.2). Path analysis revealed a significant indirect effect of FoP on the relationship between post-traumatic stress and HqoL (indirect effect 1; estimated effect = −0.174; 95% CI [−0.293, −0.084]; p < 0.001), as well as between depression and HqoL (indirect effect 2; estimated effect = −0.181; 95% CI [−0.301, −0.086]; p < 0.001). Conclusions: Middle-aged and older women with cancer showed broadly similar psychosocial profiles. FoP emerged as a central mechanism linking psychological distress to poorer HQoL across age groups. Interventions targeting FoP may therefore be beneficial for improving psychosocial adjustment in women living with cancer, regardless of age.