The Story: A new European study has shown that a thorough screening for prostate cancer every 4 years is adequate. The screening comprises a PSA blood test, a digital rectal exam, and a transrectal ultrasound. "Very few, if any, aggressive prostate cancers escape (this) screening...."
Comment: It looks as if the American Cancer Society guidelines for prostate cancer screening may be changing. Transurethral ultrasound is a procedure used to examine the prostate. An instrument (the ultrasound probe) is inserted into the rectum, and sound waves bounce off the prostate. These sound waves create echoes, which a computer uses to create a picture called a sonogram of the prostate.
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Prostate Cancer Screening Interval of 4 Years Misses Few Cancers, Study Shows
Linda Wang, Assistant News Editor, Katherine Arnold, News Editor, Journal of the National Cancer Institute
A 4-year screening interval was adequate to detect most cancers in a large European randomized trial of prostate cancer screening, according to a study in the October 1 issue of the Journal of the National Cancer Institute.
The European Randomized Study of Screening for Prostate Cancer (ERSPC) is an ongoing randomized trial to determine the effect of screening on deaths from prostate cancer. Study participants randomly assigned to the intervention arm are screened every 4 years with a prostate-specific antigen (PSA) test, a digital rectal exam, and a transrectal ultrasound exam. Little is known about the sensitivity, or the percentage of people who test positive for a disease among people who have the disease, of these screening tests and the appropriateness of the 4-year screening interval.
To address these issues, Ingrid W. van der Cruijsen-Koeter, M.D., T. H. van der Kwast, M.D., Ph.D., and Fritz H. Schroder, M.D., Ph.D., of the Erasmus MC, University Medical Center in Rotterdam, Netherlands, looked at the rate of interval cancers (i.e., cancers detected between screening visits) among 17,226 men ages 55 to 74 who were enrolled in the Rotterdam section of the ERSPC. The occurrence of interval cancers can be used to determine whether screening tests are sensitive enough, and whether the screening interval is appropriate.
In the study, men were divided into two groups: an intervention group that received two scheduled screens 4 years apart, and a control group that did not receive scheduled screening. The researchers checked the Dutch national cancer registry annually for cases of prostate cancer among the study participants.
During the 4-year screening period, 18 "true" interval cancers were diagnosed in men in the intervention group and 135 cancers were diagnosed in men in the control group, suggesting a low rate of interval cancers among men in the intervention group. The authors determined that the screening procedure has a high sensitivity of 85.5%.
The authors conclude that the low rate of interval cancers found within the ERSPC-Rotterdam confirms a high sensitivity of the screening procedure. They add that the interval cancers were at a locally confined stage, suggesting that "very few, if any, aggressive prostate cancers escape screening with the procedures used within the ERSPC."