The impact of reducing the frequency of prostate specific antigen (PSA) testing among men on active surveillance for prostate cancer
Matthew R. Cooperberg, Lisa F. Newcomb, Elissa C. Brown, Shanshan Zhao, Ziding Feng, James D. Brooks, Daniel W Lin, Canary PASS Investigators
University of California, San Francisco, San Francisco, CA; University of Washington, Seattle, WA; Fred Hutchinson Cancer Research Center, Seattle, WA; Stanford University, Stanford, CA
Background: Active surveillance is a management strategy for men with low risk prostate cancer. Most surveillance regimens include routine PSA assessments, typically performed q 3 mos, although recent studies have questioned the utility of short-term PSA kinetics. Moreover, frequent PSA assessments may be associated with repeated intervals of anxiety around the time of testing, decreasing overall quality of life and potentially leading to avoidable interventions. We hypothesized that PSA assessment q 6 mos rather than q 3 mos would yield similar PSA kinetics calculations.
Methods: We analyzed data from the Prostate Active Surveillance Study (PASS), a prospective, multicenter cohort accruing data and biospecimens from men on surveillance at 9 sites across North America. In PASS, PSAs are measured q 3 mos, with high completeness of data. We included data from men who had at least 5 PSA assessments after diagnosis, separated by ≥ 6 months (most had 10 PSAs separated by 3 months). PSA doubling time (PSADT) was calculated as ln(2) divided by the slope of a regression line drawn through the 5 PSAs. PSADT3 and PSADT6 were defined as the PSADT calculated from q 3 mos and q 6 mos data, respectively; for PSADT6, PSAs between each 6-month measurement were ignored. In each case, PSADT of 0-3 years defined progression, and PSADT > 3 years or declining PSA defined non-progression.
Results: 161 men had sufficient PSA followup for analysis. 133 had no progression by either PSADT3 or PSADT6, and 16 progressed by both PSADT calculations. 4 and 8 men, respectively, progressed only by the PSADT3 or PSADT6 calculation but not by the other calculation. The k score for agreement of progression ascertainment between PSADT3 and PSADT6 was 0.68, and McNemar’s test indicated no statistically significant difference between the two assessments (p50.39).
Conclusions: Calculating PSADT using 6-month rather than 3-month PSA assessments does not significantly change ascertainment of PSA progression in men on surveillance. Our finding suggests that surveillance protocols may reduce the frequency of PSA testing, potentially reducing unnecessary biopsy procedures and patient anxiety due to more frequent PSA measurements.
Matthew R. Cooperberg, MD, MPH received his undergraduate training from Dartmouth College, where he earned a degree in English with high honors. He then enrolled in Yale University's MD, MPH program, concurrently earning an MPH with a concentration in Health Policy from the School of Epidemiology and Public Health, and a MD from the School of Medicine. He completed his General Surgery and Urology training at the University of California, San Francisco, and subsequently continued at UCSF to complete a fellowship in Urologic Oncology under the guidance of Peter Carroll, MD, MPH. In 2009, Dr. Cooperberg was recruited to join the faculty at UCSF and the San Francisco Veterans Affairs Medical Center. Specializing in urologic cancer care, he is part of the multidisciplinary urologic oncology team of the UCSF Helen Diller Family Comprehensive Cancer Center, located primarily at the Mount Zion Medical Center. He also maintains privileges at San Francisco General Hospital.
Dr. Cooperberg's clinical interests include the early detection, diagnosis, and management of genitourinary malignancy, and using minimally invasive techniques to treat benign and malignant diseases. He performs robotic, laparoscopic, endoscopic, and percutaneous surgeries, and is interested in incorporating promising new technologies into his practice. He is particularly interested in risk-stratifying prostate, renal, and other tumors, and matching treatments appropriately to those patients most likely to benefit, using novel imaging tests and biomarkers together with clinical information. Cooperberg is a Fellow of the American College of Surgeons, and a member of the American Urological Association (AUA) and the Society for Urologic Oncology. Both clinician and patient decisions influence the choices about the type of treatment a patient will receive for localized prostate and kidney (renal) cancer. He is conducting an ongoing research program to study national prostate cancer management trends, based on data from CaPSURE and other sources. His analyses have looked at changes in cancer risk over time, testing and treatment for prostate cancer, local variation in treatment, and the impact of socio-demographic factors on type of treatment and outcomes. Through the creation of a San Francisco General Hospital (SFGH) prostate cancer patient registry, preliminary analysis show that low socioeconomic status patients are treated for a higher percentage of high-risk disease than patients with a higher socioeconomic status. Using data from CaPSURE, the NCDB, SFGH and in collaboration with the Urologic Diseases in America project he continues to explore these topic in depth.
Dr. Cooperberg has written over 110 peer-reviewed scientific articles, and has been invited to present his research findings at many national and international conferences. His primary research focus is prostate cancer, with particular areas of interest including: 1) health services research, documenting ongoing trends and regional variation in the use of diagnostic, imaging, and therapeutic interventions for men with all stages of prostate cancer; 2) risk assessment, developing and validating prognostic tools incorporating both standard clinical information and emerging biomarkers; 3) comparative effectiveness research, examining evidence regarding the relative benefits of surgery, radiation, and other treatments in terms of cancer control, quality of life, and cost; and 4) decision support and survivorship, helping men make better-informed decisions about both treatments and management of short- and long-term treatment sequelae. He is also very interested in prostate cancer as an international disease, and has helped forge a number of inter-continental collaborations which are yielding fascinating insights into prostate cancer’s variation in presentation and outcome around the world. He has received numerous awards for his research papers and is co-investigator on multiple grants. He holds a prestigious Young Investigator Award from the Prostate Cancer Foundation, and recently was invited to assume a secondary appointment in the Epidemiology and Biostatistics Department at UCSF.
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