More prostate cancers were detected among men who were screened every two years than men screened every four years, according to a study published online August 28 in the Journal of the National Cancer Institute.
But the shorter time between screenings did not reduce the number of aggressive cancers found between the scheduled screening tests.
Since the introduction of PSA (prostate specific antigen) testing in the late 1980s, the incidence of prostate cancer has risen dramatically. The rise is mainly due to widespread screening of asymptomatic men. Screening for prostate cancer is a controversial issue because evidence is lacking that PSA screening prevents prostate cancer deaths. Looking at the rate of interval cancers—cancers diagnosed based on symptoms during the years between screening tests—may give an indication of how well a screening program is working.
Monique Roobol, Ph.D., of Erasmus Medical Centre in Rotterdam, The Netherlands, and colleagues conducted a study to determine whether the time between PSA screenings influenced the incidence of prostate cancer. They analyzed data collected at two European medical centers that participated in the European Randomized Study of Screening for Prostate Cancer. At a center in Gothenburg, Sweden, 4,202 men were screened every two years, and in Rotterdam, The Netherlands, 13,301 men were screened every four years. The researchers compared both the number and characteristics of the interval prostate cancers diagnosed in these men. Serious, potentially life threatening interval cancers were analyzed separately.