Opportunistic prostate-specific antigen testing in Norwegian men: a public health challenge.

OBJECTIVE: To describe age-specific prostate-specific antigen (PSA) distributions and resulting prostate cancer diagnoses that arise from population-wide opportunistic PSA testing. PATIENTS AND METHODS: Over 8 million PSA tests were performed on >1.4 million Norwegian men from 2000 to 2020. During this period 43 486 men were diagnosed with localised prostate cancer. Most of the PSA testing reflected opportunistic testing. Age-specific PSA value distributions were constructed for men aged 45-75 years with and without prostate cancer. RESULTS: The distributions of PSA values in men with and without prostate cancer widened with age and overlapped extensively from 3 to 7 ng/mL. Localised prostate cancer diagnoses increased 10-fold from the age of 45 to 75 years. PSA testing identified intermediate- or high-grade cancers in 21% (95% confidence interval [CI] 19-23%) of men aged 50-54 years and 42% (95% CI 41-43%) of men aged 70-74 years. Grade group (GG)1, GG2, GG3 and ≥GG4 constituted 49%, 31%, 10% and 10% of cancers identified at age 50-54 years and 26%, 26%, 18%, and 30% of cancers identified at age 70-74 years. CONCLUSION: Opportunistic PSA testing increases with ageing and often generates values that cannot discriminate benign prostate enlargement from prostate cancer. A clinical cascade using additional imaging or serum tests is necessary to avoid negative biopsies and the overdiagnosis of indolent disease. The declining specificity of PSA testing with ageing poses a significant public health challenge especially among older men aged ≥70 years.