Background: African American men are much more likely than Caucasian men to be diagnosed with and to die of prostate cancer. Genetic differences likely play a role.The cBioPortal database reveals that African American men with prostate cancer have higher rates of CDK12 somatic mutations compared to Caucasian men. However, this does not account for prior prostate cancer treatments, which are particularly important in the castrate-resistant setting. We aimed to compare somatic mutations based on circulating tumor DNA (ctDNA) in metastatic castrationresistant prostate cancer (mCRPC) between African American and Caucasian men after exposure to abiraterone and/or enzalutamide.Methods: This single-institution retrospective study characterizes the somatic mutations detected on ctDNA for African American and Caucasian men with mCRPC who had progressed after abiraterone and/or enzalutamide from 2015 through 2022. We evaluated the gene mutations and types of mutations in this mCRPC cohort.Results: There were 50 African American and 200 Caucasian men with CRPC with available ctDNA data. African American men were younger at the time of diagnosis (p = 0.008) and development of castration resistance (p = 0.006). African American men were more likely than Caucasian men to have pathogenic/likely pathogenic (P/ LP) mutations in CDK12 (12% vs. 1.5%; p = 0.003) and copy number amplifications

A 61-year-old man underwent a piflufolastat 18F prostate-specific membrane antigen (PSMA) PET/CT scan due to a rising prostate-specific antigen level. The scan noted a focal cortical erosion on the CT scan in the right anterolateral tibia, and the PET showed an SUVmax of 4.08. A biopsy of this lesion revealed a chondromyxoid fibroma. This rare case of a PSMA PET-positive chondromyxoid fibroma illustrates the importance of radiologists and oncologists not to assume an isolated bone lesion on a PSMA PET/CT scan as a bone metastasis from prostate cancer.