Comparison of Mexican-American vs Caucasian Prostate Cancer Active Surveillance Candidates - Beyond the Abstract

The Hispanic/Latino population represents the largest racial/ethnic group after Caucasians in the United States. Moreover, within the Hispanic/Latino population, Mexican-Americans represent the largest subgroup (63.2%). Despite the importance of the proportion of Mexican-Americans within the United States population, this patient group received relatively little attention in urologic oncology literature.

Within the Surveillance, Epidemiology, and End Results (SEER) database (2010-2015), we identified low-risk and favorable intermediate-risk prostate cancer (PCa) patients according to the National Comprehensive Cancer Network (NCCN) guidelines. Two main endpoints were examined: 1) rate of upgrading, defined as an increase of one or more Gleason Grade Group (GGG) units at radical prostatectomy (RP) compared to biopsy, and 2) rate of upstaging, defined as pT3 or higher (pT3+) and/or pN1 stages. Our analyses yielded several noteworthy findings.

First, in low-risk PCa patients, we did not identify any clinically meaningful or statistically significant differences in upgrading or upstaging rates, between Mexican-American and Caucasian PCa patients. However, the absolute rates of upgrading in low-risk PCa patients were high, in both Mexican-Americans and Caucasians (49.3 vs. 45.5%, odds ratio [OR] 1.17, p=0.1). Although these rates may appear elevated, more detailed analyses demonstrated that the vast majority of upgrading that occurred was recorded from GGG I to GGG II.

Second, in favorable intermediate-risk PCa patients, we identified a clinically meaningful and statistically significant higher upgrading rate in Mexican-Americans relative to Caucasian PCa patients (31.4 vs. 25.5%, OR 1.33, p=0.044). It is of interest that the vast majority of upgrading that occurred was recorded to GGG III, IV, or V. In consequence, the vast majority of upgraded favorable intermediate-risk PCa patients harbored unfavorable intermediate or high-risk PCa GGG when gold standard (RP) GGG assessment was made.

Third, unlike upgrading rates, upstaging rates defined as pathological T3 or higher stages and/or pathological N1 stage did not differ between Mexican-American and Caucasian low risk and favorable intermediate-risk PCa patients. We recorded that approximately 10 and 20% of low risk and favorable intermediate-risk PCa patients were upstaged, respectively.

In conclusion, within this large contemporary cohort, we recorded no differences in upgrading or upstaging rates between Mexican-American and Caucasian low-risk PCa patients. Conversely, Mexican-American racial/ethnic status predicts a higher probability of upgrading at RP, in favorable intermediate-risk PCa patients. This information should be considered in treatment decision making.

Written by: Claudia Collà Ruvolo, MD, Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Naples, Italy; Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montréal Health Center, Montréal, Québec, Canada

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