PSA measurement and prostate cancer--overdiagnosis and overtreatment?

BACKGROUND

Growing attention is being paid to PSA testing and the risk of overdiagnosis of prostate cancer. This paper investigates how the number of PSA tests has developed over time in Norwegian counties, and relates this development to the incidence of cancer in the various counties and the rates of prostate cancer surgery.

METHOD

Data on incidence, survival and mortality were obtained from public registers. The numbers of PSA tests carried out were acquired from Norwegian laboratories. The PSA testing rates per county and correlation with prostate cancer incidence rates and surgery rates were surveyed. Developments in Sogn og Fjordane, which has the highest incidence of prostate cancer in Norway, were examined separately. A net-based survey of primary doctors' attitudes and practice was carried out.

RESULTS

The number of PSA tests increased substantially in the period 1999-2011 and in 2011 corresponded to testing of 45% of the total male population aged over 40 in Norway. The number of PSA tests in 2011 correlated with the incidence by county of prostate cancer in the previous period (Pearson's r = 0.41). The correlation between the incidence of cancer and surgical procedures was 0.66. In Sogn og Fjordane, the prostate cancer incidence and survival are rising steeply, while mortality is at the same level as in Norway generally. Primary doctors often comply with their patients' wish for PSA testing and find it difficult not to refer them to specialists if values are elevated.

INTERPRETATION

There is probably a correlation between the increased incidence of prostate cancer and the amount of PSA testing. Compliance with the guidelines for testing should be better and clinicians could practice more watchful waiting with regard to further treatment in cases of elevated PSA values.