Trends in cancer mortality and epidemiology.

The increase in lung cancer in men has ceased at younger ages and is slowing at older ages. However, in women the increase continues and, by the end of this decade, lung cancer may be the most important cause of cancer deaths in women. The incidence of prostate and breast cancer continues to increase, but mortality is stable, suggesting changes in diagnostic practices. Mortality from stomach cancer and from cancer of the cervix in women continues to fall. Increasingly, it is necessary to recognize the multifactorial causes of cancer, requiring detailed information on lifestyle, occupational, and sometimes residential histories to unravel etiology. Physicians need to understand the requirement for access to patients in order to obtain data for studies. Monitoring unexpected hazards will require linkage, particularly using the National Death Index. Such sources can be used with preservation of confidentiality while increasing knowledge for primary prevention.