Race and prostate imaging: implications for targeted biopsy and image-based prostate cancer interventions

For men with an elevated prostate-specific antigen (PSA), there is a strong evidence for prostate MRI to assess the risk of clinically significant prostate cancer (CSPC) and guide targeted-biopsy interventions. Prostate MRI is assessed using the Prostate Imaging-Reporting and Data System (PI-RADS), which is scored from 1 to 5. Equivocal or suspicious findings (PI-RADS 3-5) are recommended for subsequent targeted biopsy, for which the risk of infection and sepsis is increasing. However, PI-RADS was developed primarily in men of European descent. We sought to elucidate PI-RADS and MRI-targeted biopsy outcomes in Asian men, a rapidly growing population in the USA, Europe, Australia and internationally.

A prospective cohort of 544 men with elevated PSA without a diagnosis of prostate cancer who underwent MRI-targeted biopsy at our institution from January 2012 to December 2018 was analyzed. We categorized the cohort by self-designated race then used a validated algorithm which uses surname lists to identify a total of 78 (14%) Asian-Americans. The primary outcome was the likelihood of diagnosing CSPC (Gleason grade group >1) in Asian-Americans versus non-Asian-Americans. Multivariable logistic regression was used to determine the association of demographic and other characteristics with CSPC.

Overall, MRI-targeted biopsy identified CSPC in 17% of Asian-American men versus 39% of non-Asian-American men (p<0.001). Notably for PI-RADS 3, only 6% of Asian-Americans versus 15% of others were diagnosed with CSPC. In adjusted analyses, Asian-American men were less likely to be diagnosed on MRI-targeted biopsy with CSPC (OR 0.30, 95% CI 0.14 to 0.65, p=0.002) and indolent prostate cancer (OR 0.37, 95% CI 0.15 to 0.91, p=0.030) than other races. Regardless of race those who were biopsy naïve were more likely (OR 2.25, 95% CI 1.45 to 3.49, p<0.001) to be diagnosed with CSPC.

We found that PI-RADS underperforms in Asian-American men. For instance, only 2 of 35 (6%) Asian-American men with PI-RADS 3 were diagnosed with CSPC on MRI targeted biopsy. This has significant implications for overuse of diagnostic and image-guided interventional approaches in Asian-Americans, given the increasing risk of infectious complications from biopsy. Additional validation studies are needed to confirm our findings.