Prostate cancer diagnosed after prostate-specific antigen testing of men without clinical signs of the disease: A population-based study from the National Prostate Cancer Register of Sweden

Abstract

To investigate the effects of prostate-specific antigen (PSA) testing of men without clinical signs of prostate cancer on the incidence of prostate cancer in Sweden. Information on the cause of diagnosis, tumour characteristics and primary treatment for patients diagnosed with prostate cancer between January 1999 and December 2007 was extracted from the National Prostate Cancer Register of Sweden. This register includes data for 95% of Swedish prostate cancer cases. The total age-standardized annual incidence of prostate cancer per 100,000 men increased from 187 in 1999 to 233 in 2004, but decreased thereafter to 196 in 2007. The incidence of asymptomatic cases also peaked in 2004 (at 62 per 100,000 men), but varied six-fold between different counties in that year (16-98 per 100,000 men). Asymptomatic cases (n = 17,143) constituted 15% of all new cases in 2000 and 30% in 2007. Almost as many cases were diagnosed in stage T1c in men with symptoms, usually from the lower urinary tract. Together these two groups constituted 29% of all new cases in 2000 and 52% in 2007. It was estimated that at least one-third of all Swedish men aged 50-75 years had a PSA test between 2000 and 2007. Even though screening for prostate cancer is not recommended in Sweden, PSA testing of men without clinical signs of prostate cancer is common. The effects on the Swedish incidence of prostate cancer were similar to those reported from the USA.