Study examines risk of developing prostate cancer after last invitation to screening

Men who participate in biennial PSA based screening have a lower risk of being diagnosed as well as dying from prostate cancer up to 9 years after their last PSA test, according to the results of a new study to be presented at the 28th Annual EAU Congress in Milan.

A joint Swedish-UK study aimed to examined the risk of developing prostate cancer after last invitation to screening. This investigation follows up on previous publication from the Göteborg randomized screening trial (part of ERSPC) by the same group which showed that biennial PSA screening lowered PC mortality with 44%.

In the course of the study, which launched in 1995, 20000 men were randomized and 9 952 have been invited every second year for PSA testing while 9952 were randomized to a control arm. All cases of prostate cancer in the screening (n= 6449) as well as the control arm (n= 6974) after reaching the upper age limit for invitation (median 69 range 67-71 years) were identified by matching with the Regional Cancer Register in western Sweden.

For all deaths in men with prostate cancer, a review of cause of death was performed by an independent committee, the date of follow-up being 30 June 2012 or at a maximum of 12 years. PCs diagnosed were classified into low, intermediate or high/advanced risk groups and all attendees were defined as participating at least once.

In the course of the study, a total of 173 men with were diagnosed with prostate cancer in the invited arm (with a median follow-up of 4.8 years) and 371 were diagnosed in the control arm (with a median follow-up of 4.9 years).

Up to 9 years after last invitation all risk groups were more commonly diagnosed in the control arm but after 9 years the rates in the screening arm caught up, other than those for the low risk group. In the invited arm, non-attendees had an incidence similar to that of the control arm. Also mortality in PC was lower in the screening arm up to 9 years, which is approximately 50 % of that in the control arm, after termination of screening. At the same time, in the interval of 9-12 years, the screening group had a similar mortality rate to the control.