The Effect of Start and Stop Age at Screening on the Risk of Being Diagnosed with Prostate Cancer

Abstract

We investigated the effect of age and number of screens on the risk of prostate cancer diagnosis. Since 1995 the Göteborg randomized population based prostate cancer screening trial has invited men biennially for prostate specific antigen testing, until the upper age limit of 70 years. Men with a prostate specific antigen above the threshold of 2.5 ng/ml were recommended further evaluation including 10-core biopsy (sextant before 2009). The present study comprises 9,065 men born between 1930 and 1943 (1944 excluded due to different screening algorithm). Complete attendees were defined as men who accepted all screening invitations (maximum 3 to 9 invitations). The cumulative incidence of prostate cancer was calculated using standard methods. Of the 3,488 (38%) complete attendees 667 were diagnosed with prostate cancer (followup 1995 to June 30, 2014). At age 70 years there was no significant difference in prostate cancer risk among those who started screening at the age of 52 (9 screens), 55 (7 screens) or 60 (5 screens) years. However, the cumulative risk of prostate cancer diagnosis increased dramatically with age, and was 7.9% at age 60, 15% at age 65 and 21% at age 70 for men who had been screened 4 or more times. There was no clear association between risk of prostate cancer and the number of screens. Starting screening at an early age appears to advance the time of prostate cancer diagnosis but does not seem to increase the risk of being diagnosed with the disease. Age at termination of screening is strongly associated with the risk of being diagnosed with prostate cancer.