The relationship between perceived control and psychological distress in cancer patients has been widely studied, but longitudinal designs are scarce. The aim of this study was to examine whether perceived control could predict changes in the evolution of psychological distress in breast cancer patients at stages I or II. One hundred and one women were assessed on five occasions: one week after surgery, and again 1, 3, 6 and 12 months later, using the Mental Adjustment to Cancer (MAC) Scale, a Self-Efficacy Scale, the Personal Competence Scale, the Hospital Anxiety and Depression Scale (HADS), the Profile of Mood Sates (POMS), and the EORTC questionnaire of quality of life. Latent growth curve (LGC) model analysis was used to test the relationship between perceived control and psychological distress in a longitudinal, 1-year study. The results showed that perceived control increases linearly and that distress also decreases linearly. Moreover, the evolution of distress can be predicted from the initial value and the rate of change of perceived control. This close relationship between perceived control and psychological distress was found to be independent of the evolution of the physical state. These findings suggest that perceived control could be used as an early predictor of psychological adjustment to illness.

These data fit well with previous research and suggest that psychological interventions which emphasize a sense of personal control would be effective in enhancing well-being in breast cancer patients at the early stages.