Association of marginalization and PSMA-PET in prostate cancer: An analysis of the Ontario PSMA-PET Registry for Recurrent Prostate Cancer

INTRODUCTION: Prostate-specific membrane antigen-positron emission tomography (PSMA-PET) is a new standard for the imaging of high-risk or recurrent prostate cancer. While marginalization disparities exist for prostate cancer, less is known in the context of PSMA-PET. The objective of the study was to determine if marginalization was associated with access, PET positivity, management change, radiation use, and survival of prostate cancer in a universal healthcare system. METHODS: Patients enrolled in the Ontario PSMA-PET Registry for Recurrent Prostate Cancer (PREP) between 2018 and 2022 were included. The Ontario Marginalization Index (material resources, racialized/newcomer, age/labor force, household/dwellings) was used. Outcomes included access, PET positivity, management change, radiation use, and survival. Cox proportional hazards and logistic regression models examined the association between marginalization and outcomes. Provincial administrative databases were leveraged to generate a diagnosis and a survivorship cohort of prostate cancer patients who received primary treatment to compare with the PSMA-PET cohort. RESULTS: There were 4034 patients in the PSMA-PET cohort. Patients at higher material marginalization quintiles were under-represented in the PSMA-PET Registry Database. Similar under-representation was noted in the diagnosis (n=123 128) and survival (n=56 753) cohorts. Within the PSMA cohort, marginalization dimensions were not significantly correlated with PET positivity, management change, or radiation use. CONCLUSIONS: Marginalization quintiles across PSMA-PET access were similar in distribution to prostate cancer diagnoses and survivor cohorts. We found no association of marginalization with PET positivity, management change, or radiation use among those receiving PSMA-PET.