Epidemiological aspects of cancer screening in Germany

Since 1971, a statutory early detection programme has operated in Germany which comprises health-insurance-paid annual examinations of the breast, cervix, prostate, rectum, and the skin. Since the programme is conceptualised as opportunistic screening, the attendance rates have been low and only reached about 50% among females and 13% among males by the end of the 1990s. Based on these figures and present knowledge on the efficacy of screening modalities, we assessed past benefits and the future potential of cancer screening in Germany.

We used published data on the efficacy of screening procedures and German attendance rates, and internationally available data on incidence and mortality in Germany and, for cervical cancer, in other countries. Incidence and mortality rates have been standardised to the world standard, and screening benefit has been given as the population preventable fraction given in percentage.

The past benefits of the statutory early detection programme ranged around 2.0-6.5%. Since the upper limit was due to generous assumptions regarding efficacy or inclusion of treatment effects, the true value might be closer to the estimates of the effect of cervical cancer screening (2.0-4.7%). The achievable future benefit of exploiting the theoretical potential of more exhaustive screening could provide a further mortality reduction of about 3.4% (50% compliance) or 4.7% (70% compliance).

Screening partially requires an expensive medical infrastructure and is not without risks for the participants. The overall benefit is critically dependent upon the quality of the programme and its in-time control. Any benefit may be annulled by poor quality while costs are overflowing. Well-organised high-quality screening may be a sound basis for cancer control. To preserve or increase the impact of screening and control its expenses: (a) further research efforts are needed towards new or better targeted screening tools or modalities; (b) the efficacy of new modalities has to be evaluated carefully in advance; (c) the programme has to be reconceptualised as organised screening; (d) in-time quality control based on the collection of the basic performance data must be an intrinsic part of the programme.