Purpose: We investigated the effect of race and age on the distribution of prostate cancer metastases.
Materials and methods: Records for patients with metastatic prostate cancer were abstracted from the National Inpatient Sample database (2008-2015).
Results: Of 6,963 patients with metastatic prostate cancer 3,881 (72.2%) were Caucasian and 1,494 (27.8%) were African American. Bone metastases were the most common site of metastases in Caucasian and African American patients (83.9% and 87.0%, respectively), followed by distant lymph node metastases in Caucasian (13.9% of Caucasian vs 13.2% of African American), liver metastases in African American (13.8% of African American vs 13.3% of Caucasian) and lung metastases in Caucasian and African American patients (9.3% and 13.1%, respectively). No clinically meaningful differences were recorded in age and race analyses, except for lymph node metastases (61.1% to 23.4% in Caucasian vs 39.0% to 25.1% in African American patients), which decreased with age. Specific single organ metastatic sites, outside of bone and lymph nodes, were low in both racial groups (2.1% or less). The rate of brain metastases was also rare in both racial groups at 1.4% or less, regardless of other metastatic locations. Thoracic metastases, in the absence of bone and abdominal metastases, were present in 1.9% of Caucasian and African American patients.
Conclusions: The most important finding according to age and race resided in rates of lymph node metastases. Conversely, all other racial and age related differences were subtle. Nonetheless, they are important in the context of planning and/or design of clinical trials. Finally, brain (1.4%) and thoracic (1.9%) metastases affect few patients and routine brain and chest imaging may not be warranted.
Keywords: African-Americans; epidemiology; prostatic neoplasms.