Background: Participation in treatment decision-making (TDM) is important to patients with cancer and TDM experiences and preferences for how to make treatment decisions have been extensively studied in men with localised prostate cancer. Their preferences for how to partake in TDM are diverse and influenced by several factors. A significant proportion of men with localised prostate cancer, however, develop metastatic disease (mPC), after which the disease is considered incurable. The life-prolonging treatment possibilities at the most advanced stage of mPC, metastatic castration-resistant prostate cancer (mCRPC) have increased dramatically over the past decade, and far less is known about experiences and TDM in these advanced phases of the disease.

Aim: The overall aim of the thesis was to explore experiences, expectations and treatment decision-making in men with metastatic prostate cancer.

Methods: Studies I and IV were prospective, longitudinal cohort studies, study II was qualitative and study III had a qualitative, serial design. In study I, two matched groups of men with mPC (n=106) and non-mPC (n=211) were followed over 5 years with repeated questionnaires. Quality of life, symptoms and functioning were compared between the groups using independent samples Mann–Whitney U tests. The samples in studies II-IV comprised men with mCRPC who underwent life-prolonging treatment. In study II, 16 men were interviewed about their perspectives when faced with a life-prolonging treatment. Data was analysed using interpretive description. In study III, 17 men partook in serial qualitative interviews about their experiences of TDM and data was analysed with qualitative content analysis. In study IV, 114 men answered repeated questionnaires about satisfaction with TDM regarding the life-prolonging treatment and treatment experiences over the course of one year. Associations between satisfaction with TDM at baseline and treatment experiences and wellbeing at six and 12 months were explored using Spearman’s rank correlation.

Results: Compared to men with localised prostate cancer, men with mPC report increasing symptoms and worsening quality of life and functioning over time once they develop metastases. TDM was twofold and contained both the desired treatment outcome and aspects of the structure of how the treatment decision was made. When men with mCRPC are faced with a life-prolonging treatment, they weigh the potential treatment benefits – prolonging life – against the possible treatment side effects and their intrusion on the men’s everyday lives. Receiving personalised information was important to the men, and the treating physician was a key party in TDM to whom the men modified their TDM role and -actions. Their satisfaction with the TDM structure was also associated with their physical and emotional wellbeing over time.

Conclusion: TDM regarding life-prolonging treatment was found to be a complex, balancing act in which men with mPC face and manage a number of complex situations and have diverse experiences and preferences. Given that men with mPC report declining quality of life, symptoms and functioning and had unmet needs regarding information, continuity of care, communication and TDM, early integration of a palliative approach into the care of men with mPC could work as a way to identify and manage needs that need to be addressed.