Anticipating a national screening programme

A GP in Western Australia, Tom Brett has carried out a five year study of prostate cancer screening at his practice.  To enter the study any men over 40 who came to the surgery for any reason were invited to take part.  They were told about the risks of prostate cancer and offered an annual digital rectal examination(DRE) to be carried out by Dr Brett.  Most (91%) agreed to this.  The study population selected in this way varied year on year, the lowest number being 334 and the highest 355.

Over the first few years of the study a decline in suspicious DREs was noted from 13.9% in 1994 to 3.4% in 1997.  The incidence of new cancers diagnosed also dropped from 2.6% in 1994 to 0.9% in 1996 to 0.3% in both 1997 and the last year of the study - 1998.

What happened next following suspicious results from either the DRE or a PSA test was dependent on the patient's preference.  Men with abnormal tests were offered the choice of specialist referral with further diagnostic assessment or conservative management with watchful waiting.  Younger patients with a family history of prostate cancer were encouraged to undertake further diagnostic evaluation.

A total of 33 men had biopsies undertaken during the five year study period with 14 new cancers diagnosed.  In the first year, 16 biopsies were carried out resulting in nine new cancer patients being identified.  Of these nine, six had locally advanced or metastatic disease at the time of diagnosis.  This contrasts quite dramatically with the final three years when only fourteen biopsies were carried out in total.  From these came five new cancer patients of which four were organ confined and one was locally advanced.  There was a lowering of the age at diagnosis and a stage migration from a majority of locally advanced or metastatic at the start of the period to a total absence of metastatic disease presenting over the final years of the study.

Extrapolating the results of this study to the UK situation, one can anticipate that were screening for prostate cancer to be introduced at one time there would be an unacceptable peak of work for consultants and an overloading of the biopsy service during the first one or two years.  In the end however, the workload (and as a result, the cost) would be lower than it is even at present.  So what advice do we give our politicians?  They should phase in the introduction of screening over a number of years perhaps starting with the significant population of 'at risk' men who already want to be tested for the disease.

Reference: Prostate cancer in general practice.
Tom Brett.
Australian Family Physician Vol 30 No 7 July 2001.