San Diego, CA USA (UroToday.com) In this session, Dr. Schaeffer was tasked with describing the influence of race on the underestimation of high-risk disease in patients being considered for active surveillance (AS). Why is race and important question in this context? Prostate cancer mortality is 2.4 times higher in African American (AA) men than Caucasian men. A natural follow-up question is “does this increased risk of adverse pathology in patients who die from prostate cancer also extend to men with low risk prostate cancer?”
In fact, this is exactly what is seen. Though limited to a small number of patients (n~110), AA men in AS cohorts have increased disease progression relative to other races.
Another way to get at the answer to this question is to look at patients who qualify for AS but choose surgery. In this setting, final pathology suggests that AA men harbor more aggressive disease in a number of single institution series. Specifically, AA race is associated with increased upgrading, upstaging, and positive margins.
Possible reasons for risk being underestimated in this patient population are undersampling and differences in tumor genetics with consequent disparate natural histories relative to tumors in Caucasian men.
With regard to undersampling, it is well reported that AA men may be under sampled due to anterior tumors. In an elevated PSA with prior negative prostate biopsy population, up to 50% of AA men have been found to harbor anterior tumors on MRI. Moreover, Gleason 6 tumors in AA men have different natural history and in fact recur at higher frequency compared to other races. Finally, low grade cancers in AA men are genetically different and demonstrate higher scores of genomic aggressiveness (Decipher) with PTEN loss being half as common.
Provocatively, these data have been replicated at some places in the US, but not in others. This can be explained by SNP analyses of 5,269 self-reported AA people. On average, self-reported AA folks across have 73.2% African, 24% European, and 0.8% Native American genes. Even more interesting was that these proportions varied significantly by region in the United States.
In conclusion, Dr. Schaeffer noted that most data suggest men of African American ancestry have increased risk of harboring more significant diesase than comparable Caucasian men. Active surveillance (AS) remains an option, but discussion of AS should focus on appropriate expectations. MRI may prove helpful in better selecting AA men for surveillance (and finding the increased number of anterior tumors). Lastly, the implications of distinct genetic profiles among races are yet to be determined
Presented By: Edward M. Schaeffer, MD
Written By: Benjamin T. Ristau, MD; Fox Chase Cancer Center, Philadelphia, PA at the 2016 AUA Annual Meeting - May 6 - 10, 2016 – San Diego, California, USA
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