BERKELEY, CA (UroToday.com) - Using United States population-based data, our team recently published a study in the Journal of Urology charting temporal trends in the diagnosis and management of low- and intermediate-risk prostate cancer (PCa).
Specifically, our study sought to examine changes in the use of noncurative initial management (NCIM) approaches such as active surveillance. In an environment that has been encouraging responses to claims of overdiagnosis leading to overtreatment, active surveillance has emerged as a safe option for men with low-risk prostate cancer to reduce potential treatment-related comorbidities. However, data from a national sample of 40 urology-based practices in the United States showed, from 2004 to 2007, only 8.5% of low-risk PCa patients elected observation. With data from 2004 to 2010, our study was able to report updated measures of NCIM usage and, importantly, changes in management following the 2007 American Urological Association recommendation for active surveillance as an option for low-risk PCa (defined as Gleason < 7, cT1-2, and PSA < 10 ng/ml).
We chose to include data from two independently-managed cancer databases in an effort to confirm trends and findings in both datasets. The Surveillance, Epidemiology, and End Results (SEER) database is the preeminent cancer database in the United States, contributing to innumerable publications since its inception. The National Cancer Database (NCDB) has begun to contend itself as a worthy counterpart to SEER, boasting the largest patient population of any clinical dataset. We detailed the shortcomings of each database, highlighting the use of both in one study overcomes limitations inherent in one, but not the other. In general, trends and odds ratios were similar among the two databases, further strengthening our conclusions. Using two datasets to validate findings may be a consideration for future studies using administrative datasets.
We found the use of NCIM among low-risk men increased in SEER from 21% to 32% and in the NCDB from 13% to 20% over the study period. We were surprised, however, to find when patients with low- and intermediate-risk PCa were combined into one group, the use of NCIM changed only slightly over time. As we sought to explain this occurrence, we discovered fewer men were qualifying as low-risk in 2010 compared to 2004. During that time period, more men were presenting with cT1 vs cT2 disease and PSA < 10 ng/ml, but fewer were being diagnosed with Gleason < 7. This decline in Gleason < 7 was likely attributable to the 2005 changes in Gleason scoring guidelines, which made all cribriform patterns a Gleason pattern 4. Thus, while the proportion of men diagnosed with low-risk PCa who were electing NCIM increased, the actual number of men using NCIM remained about the same. This observation documents an effect of cancer grade migration that has not been published before, an increase in the use of a recommended treatment for one group of patients while overall use doesn’t change.
Our study attempted a new approach to analyzing administrative datasets and uncovered an interesting statistical phenomenon occurring in PCa epidemiology. Unfortunately, the implications of our findings suggest active surveillance may not have the desired effect of minimizing overtreatment if fewer men qualify as low-risk. However, our study does support investigating the safety of active surveillance for select intermediate-risk patients and a possible expansion of active surveillance candidacy requirements.
- Weiner, A. B., Patel, S. G., Etzioni, R. et al. National trends in the management of low- and intermediate-risk prostate cancer in the United States. J Urol, 2014
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- Epstein, J. I., Allsbrook, W. C., Jr., Amin, M. B. et al. The 2005 International Society of Urological Pathology (ISUP) Consensus Conference on Gleason Grading of Prostatic Carcinoma. Am J Surg Pathol, 29: 1228, 2005
Adam B. Weiner as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Pritzker School of Medicine, University of Chicago, Chicago, IL USA