Epidemiologic aspects of cancer prevention in Germany

In Germany, as in other highly industrialized countries, cancer is the second most common cause of death. With approximately 210,000 individuals dying each year from malignant tumours, roughly one in four deaths in Germany can currently be attributed to cancer. Only in the past few years has there been a slow decline in the age-standardized mortality rates for cancer, even among men. This follows a long period of some decades, during which the mortality steadily increased and then persisted at a high level. The reversal, however, does not mean that the situation is no longer a cause for concern. In fact, for the most common cause of death, namely the cardiovascular diseases, a much greater decrease in mortality has been observed for many years now. If this trend continues, cancer could become the largest killer in another 15 to 20 years. On the other hand. we have been aware since the end of the 1960s that the majority of cancers are caused by environmental influences and are thus, in principle. avoidable. In the present contribution we present: (a) the fundamental arguments to support the thesis that a large proportion of cancers, and of cancer deaths, could be avoided; and (b) an estimate for Germany of both the theoretical potential of primary cancer prevention and also the practically attainable potential. The estimates are based on very conservative assumptions. They yield, for the theoretical potential, values in the range 43-65% and for the reduction actually obtainable in the medium term due to primary prevention, values of 18-31%.