Longer Screening Intervals Delay Prostate Cancer Detection
Extending the prostate cancer screening interval to 2 or 4 years would substantially delay the detection of advanced prostate cancers, according to a report in the April, 2005 issue of The Journal of Urology.
“Even though a relatively small percentage of men have rapidly rising PSA levels, they are the ones with life-threatening prostate cancer,” Dr. William J. Catalona from Northwestern University, Chicago, told Reuters Health.
“The widespread use of infrequent screening intervals could lead to delays in the detection of these potentially lethal cancers until the opportunity for cure is missed.”
Dr. Catalona and colleagues used data from more than 18,000 men screened for prostate cancer at 6-month to 1-year intervals to determine the potential delay in detection that could result from 2- and 4-year PSA screening intervals.
Of the 18,000 men screened, 1,569 underwent a biopsy and 24% of them, 377 men or 2% of the 18,000, were found to have prostate cancer.
PSA level at the time of prostate cancer detection was less than 2.6 ng/mL in 21% of men, 2.6 to 4.0 ng/mL in 57% of men, and over 4.0 ng/mL in only 20% of men, the authors report.
Increasing the screening interval from 1 year to 2 years would have resulted in at least a 4-month delay in prostate cancer detection in 62% of the men, the researchers note. More than three quarters of the men (77%) would have experienced a mean delay of detection of 12 months were the screening interval extended to 4 years.
“Many of these diagnosed tumors had potentially aggressive histological phenotypes,” the investigators write. “Infrequent screening may also delay the detection of prostate cancer in men with rapidly increasing PSA, who most likely would benefit from early diagnosis.”
“We are monitoring my various databases for the possible effects of delayed diagnosis on relevant outcomes, such as progression-free survival, metastases-free survival, cancer-specific survival, and overall survival,” Dr. Catalona said.
“Further careful study is indicated before recommending screening intervals longer than 1 year,” he concluded.