The Tyrol, Austria and King County, Washington screening studies

Two major, non-randomized prostate cancer screening studies have been ongoing in recent years. The first of these (the Tyrol Prostate Cancer Demonstration Project) was initiated in the federal state of Tyrol in Austria in 1988 (when prostate specific antigen testing first became available). The second was carried out in King County, Washington (which includes Seattle).

The data from these two studies need to be considered in conjunction with the data from the PLCO trial and the ERSPC trial, both of which were initially published in April 2009.

The Tyrol Prostate Cancer Demonstration Project

The data reported here are taken from a review published by key investigators involved in the project in the British Urology Journal International in April 2008. A complete report of the study is available on line in the American Journal of Epidemiology.

The objective — The objective of the project was to investigate the effectiveness of a well-controlled program of early detection and treatment of prostate cancer in the male population of the Tyrol, where PSA testing has been offered free to all men aged between 45 and 75 years of age since 1993.

The study population — Since the start of the project, prostate cancer mortality rates among men in the Tyrol have been compared to prostate cancer mortality rates among men in the rest of Austria, using a carefully constructed statistical model.

The basic results — More than 86 percent of the eligible men in the Tyrol have been tested at least once since 1993 (which is more than men 283,700 men), and the investigators state the following results of the project:

  • Cancer deaths in the Tyrol in 2005 were 54 percent lower than expected (compared to 29 percent lower for the rest of Austria).
  • The decreasing probability of prostate cancer mortality was significantly higher in the Tyrol compared to the rest of Austria.
  • By 2005, men in the Tyrol tended to be diagnosed with earlier stage disease then in the rest of Austria (this is called “stage migration”).
  • Treatment with radical prostate surgery was associated with low morbidity (i.e., relatively few complications and adverse effects).

The conclusions — The investigators draw two key conclusions from these results:

  • In the Tyrol, where both testing and treatment for prostate cancer are “free” (i.e., they are paid for by the state government under the state’s health insurance plan), there has been a significant reduction in prostate cancer-specific deaths as compared to the rest of Austria.
  • This reduction in the number of prostate cancer deaths is a direct consequence of early disease detection, “down-staging” of disease (i.e., a greater likelihood of diagnosis with localized prostate cancer), and effective treatment.

Commentary — At least in the short term (after all, this is only 12 years), this study would certainly appear to demonstrate that mass screening for prostate cancer is an effective method for reducing the risk of death from this disease.

Critics might suggest that until this “experiment” has been carried out for at least another 13 years (to give 25 years of accumulated data), it may be difficult to know whether these results can be maintained over time. That is a fair comment, but the “preliminary” evidence for success appears to be strong. Other Austrian investigators have questioned the statistical validity of the model used in the Tyrol, but the analysis by these other Austrian investigators is also questionable. The bottom line is that (at least as yet) there is no consensus on exactly what the Tyrol Project has proven.

The King County Screening Study

The King County study is far smaller than the Tyrol experiment, but has also generated provocative results and conclusions.

The objective — To test the theory that prostate cancer screening with DRE and PSA tests in a well defined population of middle-aged men might affect prostate cancer mortality.

The study population — A total of 1,351 men, aged between 50 and 64 years, and living in King County, WA, of whom 706 were diagnosed with prostate cancer between 1993 and 1996. The 645 control patients (matched by age to the actual patients) were followed through June 1, 2007 and had to report one or more PSA and DRE exams as part of a regular check up within 5 years preceding a diagnosis of prostate cancer or the end of the study period.

The results — There were two primary results of the study:

  • A lower proportion of the men diagnosed with fatal prostate cancer had had a PSA test and/or a DRE in the 5-year period preceding their diagnosis compared to the control patients.
  • There was no association between PSA and/or DRE testing and “other-cause mortality” (which means that PSA and DRE testing was not linked to death from anything except prostate cancer).

The conclusions — The authors state three conclusions:

  • The results suggest a reduction in prostate cancer-specific mortality as a consequence of PSA and/or DRE screening in middle-aged men.
  • These results should be interpreted with caution (because of the size of the study and the way it was carried out).
  • The study was not able to tell whether either PSA testing or DRE testing had greater impact on the results.

Commentary — Again, we have a set of results that are suggestive of (but not conclusive for) the idea that mass screening (ideally with PSA and DRE testing) is capable of lowering population risk for death from prostate cancer. The authors clearly recognize the limitations of this study, and they do not draw an absolute conclusion that “screening works” to reduce prostate cancer mortality.

What’s the Take-Away?

The bottom line seems to be as follows:

  • These two studies offer strong (but not conclusive) evidence that population-based prostate cancer screening can and does lower men’s risk for death from prostate cancer.
  • The evidence suggests that  such screening requires both a PSA test and a DRE test to be fully effective.
  • The results of these studies appear to be in some degree of conflict with the data from the only two randomized clinical trials orginally intended to test whether population-based prostate cancer screening could reduce prostate cancer mortality (the PLCO and ERSPC trials mentioned above).
Content on this page last reviewed and updated May 4, 2009.
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