AUA 2022: Grade Migration of Prostate Cancer at Diagnosis Following the US Preventive Services Task Force Recommendations on Prostate Cancer Screening

( In a podium presentation at the 2022 American Urologic Association Annual Meeting held in New Orleans and virtually, Dr. Leonardo Borregales presented results of an analysis examining grade migration in prostate cancer as a result of changes in guidelines regarding prostate cancer screening.

While prostate cancer screening using prostate specific antigen (PSA) testing has been shown to decrease prostate cancer related mortality, it remains controversial as there is a significant risk of morbidity due to testing and the downstream treatments, as well as concerns of overdiagnosis. As a result, there have been many guideline recommendations over the past 10 years. Among the most influential of these are the US Preventive Services Task Force Recommendations which have changed twice in the past two decades.

The authors used population-based tumor registry data from the Surveillance, Epidemiology, and End Results (SEER) dataset to identify 438,432 men diagnosed with prostate cancer between 2010 to 2018. Within this context, they primarily sought to examine temporal changes in PCa Gleason Grade Group (GGG) at diagnosis over the last decade. To do so, they calculated age-adjusted PCa incidence rates (per 100,000 men), standardized to the 2000 US population. These were used to examine temporal trends in incidence by GGG, Prostate-Specific Antigen (PSA) levels, and PCa metastasis at diagnosis, relative to annual incident cancers. To support this epidemiologic analysis, the authors used the National Health Interview Survey to evaluate patient-reported trends in prostate cancer screening.

The authors noted a decline in the incidence of low-grade prostate cancer (GGG1) as a proportion of all PCa from 47% in 2010 to 32% in 2018 (p<0.001). There was also a decline in the proportion of GGG1 at radical prostatectomy surgical pathology from 31.5% in 2010 to 9.9% in 2018 (p<0.001). Overall, the age-adjusted rate of GGG1 disease dropped from 52 to 26 cases per 100,000 over the same interim.

Conversely, there was an increase in the incidence of higher grade, clinically significant disease (GGG 2-5), particularly from 2014 to 2018. Notably, the incidence of GGG3 increased as a proportion of all PCa from 10.7% in 2014 to 13.5% in 2018, GGG4 from 9.6% in 2014 to 10.8% in 2018, and GGG5 increased from 9.3% in 2010 to 11.0% in 2018. Additionally, the median PSA at diagnosis rose from 6.2 to 7.1 ng/ml (p <0.001). We confirmed a previously reported increase in the incidence of distant metastases at diagnosis, from 3.0% to 5.2% (p<0.001).

The authors conclude that, based on data from the SEER registry, there has been a significant decline of GGG1 PCa at diagnosis with an upward grade migration between 2010 and 2018. There are a number of potential explanations of these findings. Changes in screening practices are the best primary explanation for the grade shift observed, as there was relatively low uptake of pre-biopsy MRI during our study period and there was insufficient data to support a significant effect of biomarkers or increased incidence of risk factors of high-grade PCa such as obesity. However, further research is needed to examine the downstream effects of these changes on prostate cancer related mortality.

Presented by: Leonardo D. Borregales, MD, Urologic Oncology Fellow, The University of Texas Health Science Center in Houston

Written by: Christopher J.D. Wallis, University of Toronto Twitter: @WallisCJD during the 2022 American Urological Association (AUA) Annual Meeting, New Orleans, LA, Fri, May 13 – Mon, May 16, 2022.

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