Clinical Health Updates

High rates of PSA use not associated with greater mortality reduction

Clinical Question:
Are higher rates of screening with prostate specific antigen associated with a greater reduction in prostate cancer mortality?

Bottom Line:
These study found no association between the intensity of PSA screening and subsequent decreases in prostate cancer mortality; perhaps the recent reductions in mortality are due to better treatment rather than screening. However, this type of study can only provide indirect, somewhat speculative evidence of the benefit, or lack thereof, of PSA testing. It is by no means the final answer, which will hopefully come in a few years with the publication of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Recruitment for that trial ended in 2001, and we can hope to begin to see results in 2006 or so.

Coldman AJ, Phillips N, Pickles TA. Trends in prostate cancer incidence and mortality: an analysis of mortality change by screening intensity. CMAJ 2003; 168:31-5.

The rate of death from prostate cancer has recently declined in many areas of the world. Over the past 15 years prostate-specific antigen (PSA) screening has increased in popularity, which has resulted in increases in the incidence of prostate cancer. Over the same period there have been changes in the management of the disease and, in particular, the use of androgen ablation. The authors examined the relation between changes in prostate cancer incidence (a surrogate for PSA screening) and subsequent changes in mortality in regions using common treatment recommendations. They used data from prostate cancer cases and deaths reported to the British Columbia Cancer Registry during 1985-1999 to examine trends in incidence and mortality in 88 small health areas (SHAs) among men aged 50-74 years. We conducted 2 analyses. In the first we classified the SHAs by intensity of PSA screening (low, medium or high) according to their ranked age-standardized incidence rate of prostate cancer in 1990-1994 and examined subsequent trends in prostate cancer mortality. In the second analysis we examined the SHA-specific relative change in prostate cancer incidence between 1985-1989 and 1990-1994 and correlated it with the relative change in mortality for cases diagnosed after 1990. Between 1985-1989 and 1990-1994 the incidence of prostate cancer increased by 53.2% and 14.6% among men aged 50-74 and those 75 and over respectively. Between 1985-1989 and 1995-1999 prostate cancer mortality declined by 17.6% and 7.9% in the 2 age groups respectively. Among men aged 50-74 years SHAs with low, middle and high levels of screening had respective increases in prostate cancer incidence of 5.4%, 53.6% and 70.5% between 1985-1989 and 1990-1994. Corresponding decreases in mortality between 1985-1989 and 1995-1999 were 28.9%, 18.0% and 13.5%. Mortality declines were greatest in SHAs with low screening levels (p = 0.032). Before 1990 prostate cancer mortality was similar in the 3 screening groups (p = 0.72). Regions with the smallest increases in incidence had the largest declines in mortality.