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 Center researcher.

At the 2018 American Society of Clinical Oncology Annual Meeting in Chicago, researchers presented findings on Friday, June 1, from an analysis of data from nearly 10,500 prostate cancer patients in the United States 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 Ronald C. Chen, MD, MPH, 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 Ramsankar Basak, PhD, a study co-author. "We hope that results of this study will help change future guidelines on monitoring of prostate cancer patients after treatment."