Prostate cancer patients who were monitored more frequently after treatment did not live significantly longer than patients who were monitored once a year, according to study findings led by a University of North Carolina Lineberger Comprehensive Cancer Centre researcher.
At the 2018 American Society of Clinical Oncology Annual Meeting in Chicago, researchers presented findings from an analysis of data from nearly 10,500 prostate cancer patients in the US from 2005 to 2010. The study's primary goal was to determine if more frequent monitoring with the prostate-specific antigen test after treatment improved patients' long-term survival. The researchers found that survival risk was not significantly different for patients who had PSA monitoring every three months compared with patients who had monitoring once a year.
"This suggests that for prostate cancer patients, once-a-year monitoring may be enough," said UNC Lineberger's Dr Ronald C Chen, associate professor in the UNC School of Medicine department of radiation oncology, who was the study's first author. "This is not a surprising finding because prostate cancer is often a slow-growing disease."
After completing treatment for prostate cancer, patients need routine monitoring to detect a potential recurrence of the cancer and get treated early, Chen said, with the goal of improving long-term survival. For patients who have finished either surgery or radiation, the PSA test is used to check regularly to look for recurrence. However, Chen said guidelines have differed as to how often the test is needed.
"If more frequent testing does not help patients live longer, then it can actually harm the patient in terms of the cost of testing, and causing stress and anxiety," said University of North Carolina School of Medicine's Dr Ramsankar Basak, a study co-author. "We hope that results of this study will help change future guidelines on monitoring of prostate cancer patients after treatment."
Abstract
Background: The optimal frequency of post-treatment PSA surveillance is undefined, and different existing guidelines based on expert opinions recommend frequencies ranging from 1x/year to 4x/year. Whether more frequent surveillance improves survival is unknown.
Methods: Using the backbone of the National Cancer Data Base (NCDB), medical records of 10,477 randomly sampled patients diagnosed with localized prostate cancer from 2005-2010 were abstracted from 1007 sites throughout the US to provide additional data for this study. 53% of the cohort received primary radiotherapy; 47% received radical prostatectomy. Primary exposure is number of post-treatment PSA tests in the first 2 years, and primary outcome is overall survival.
Results: There were 4,088 low-risk, 3,241 intermediate, and 3,148 high-risk patients. Median age at diagnosis was 64 years, and median follow-up was 8 years. At last follow-up, 17% (low-risk), 33% (intermediate), and 50% (high-risk) patients had died. Median numbers (IQR) of PSA tests in the first 2 post-treatment years were: 4 (2-5)(low-risk), 4 (2-5)(intermediate), and 4 (2-5)(high-risk). Cox multivariable models showed no significant association between frequency of PSA surveillance and overall survival in any risk group (Table).
Conclusions: More frequent PSA surveillance after definitive treatment for localized prostate cancer is not associated with improved survival. This is the first large-scale study to provide data to inform guidelines and patient/physician decisions. Based on these results, surveillance guidelines recommending PSA tests every 3-6 months likely represent overutilization of care.
Authors
Ronald C Chen, Zahed Mohammed, Jessica R. Schumacher, Amanda B Francescatti, Amanda Cuddy, George J Chang, Benjamin D Kozower, Caprice Christian Greenberg, Anne McCarthy, Stephen B Edge, David P Winchester, Ramsankar Basak
[link url="http://unclineberger.org/news/prostate-cancer-treatment-followup"]UNC Lineberger Comprehensive Cancer Centre material[/link]
[link url="https://meetinglibrary.asco.org/record/158435/abstract"]ASCO 2018 abstract[/link]