Epidemiologic aspects of cancer prevention in Germany

In Germany, as in other highly industrialized countries, cancer is the seco nd most common cause of death. With approximately 210,000 individuals dying each year from malignant tumours, roughly one in four deaths in Germany ca n currently be attributed to cancer. Only in the past few years has there b een 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 mo rtality steadily increased and then persisted at a high level. The reversal , however, does not mean that the situation is no longer a cause for concer n. In fact, for the most common cause of death, namely the cardiovascular d iseases, a much greater decrease in mortality has been observed for many ye ars 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 en d of the 1960s that the majority of cancers are caused by environmental inf luences and are thus, in principle. avoidable. In the present contribution we present: (a) the fundamental arguments to support the thesis that a larg e proportion of cancers, and of cancer deaths, could be avoided; and (b) an estimate for Germany of both the theoretical potential of primary cancer p revention and also the practically attainable potential. The estimates are based on very conservative assumptions. They yield, for the theoretical pot ential, values in the range 43-65% and for the reduction actually obtainabl e in the medium term due to primary prevention, values of 18-31%.