Population-wide screening using the prostatespecific antigen (PSA) test would not help to reduce the number of deaths from prostate cancer, concludes a study by Sweden’s Karolinska Institute.
PSA is a protein made by the prostate that is sometimes elevated in men with prostate cancer. However, it is currently unreliable as a screening tool, as men with normal PSA levels can still have prostate cancer, while PSA may rise as a result of non-cancerous prostate conditions, sexual activity, infection or vigorous exercise in cancer free males. Researchers analysed data on 9,026 men, aged 50 to 69 years, who took part in a trial that started in Sweden in 1987. Of these, 1,494 were randomly chosen to have screening every third year between 1987 and 1996, while the remaining men did not undergo screening. Those who had screening underwent digital rectal examination on their first two visits, and this exam was combined with PSA testing from 1993 onwards. The researchers followed all men who were diagnosed with cancer before the end of 1999 until December 2008. Their analysis revealed that 5.7% of men in the screening group were diagnosed with prostate cancer, compared with 3.9% in the control group. Tumours in men who were screened tended to be smaller and were less likely to have spread than those found in the control group. This suggests that screening helped to detect prostate cancers at an earlier stage. Despite this, survival was not significantly longer or more likely for men in the screening group.
