Conceptual assessment of HRQOL among Japanese non‐metastatic castration‐resistant prostate cancer (nmCRPC) patients

OBJECTIVE: The study objectives were to understand how patients view the quality of life in non‐metastatic castration‐resistant prostate cancer (nmCRPC), including unmet needs and what patients consider most important in treatment outcomes. A gap analysis was conducted on existing patient‐reported outcomes (PROs) measures versus what is missing from the patient perspective, to guide future development of PRO‐based real‐world evidence for nmCRPC in Japan. A conceptual model for nmCRPC Japanese patients’ HRQOL was also created. METHODS: This non‐interventional, qualitative study consisted of a targeted literature review, PRO instrument review, and interviews with 20 nmCRPC patients and five treating physicians. Triangulation of the gap analysis, evidence from the targeted review of the literature, and qualitative interview findings were employed to assess the comprehensiveness of current nmCRPC and HRQOL measures. RESULTS: Symptoms most reported by patients were frequent urination (70%), nocturia (65%), and general pain (65%). Others reported included lack of strength (30%). HRQOL impacts most reported were anxiety (45%) and worry (50%) about their diagnosis. Additional impacts mentioned were weight changes, loss of sleep, difficulty walking, loss of appetite, and difficulty traveling and seeking toilets in public. The gap analysis revealed 31 symptoms and 33 impacts not covered in existing prostate cancer‐specific PRO instruments. Patients mentioned musculoskeletal symptoms such as fractures, leg pain, cramps, numbness, and loss of leg bone strength. Impacts not previously discussed in the literature or in outcome measures were feelings of self‐consciousness around diagnosis, stigma around illness, and the impact on mobility including traveling. CONCLUSION: Key results reveal pain and urinary symptoms are the most experienced by Japanese nmCRPC patients. The diagnosis and treatment of disease leads to significant impacts in patient lives. Analysis revealed that symptoms and life impacts are missing in the current literature and outcome measures. Testing and debriefing of specific items could further substantiate these dimensions.