HEALTH : Cancer May Pass Heart Disease as No. 1 Killer
For all of this century, coronary heart disease has far exceeded cancer as the leading cause of death in the United States. But uneven success in reducing mortality from each of the diseases is causing researchers to speculate that cancer will replace heart disease as the top killer of Americans sometime around the year 2000.
Forty years ago, the death rate for coronary heart disease was more than double that of cancer. Today, the mortality rates for the two diseases are rapidly merging, and cancer tops heart disease in every age group under 65.
Although the cancer death rate for all age groups under 65 has declined since 1950, it is rising for some subgroups. And the decline in the rate of death from heart disease has been much steeper than for cancer. For example, people between the ages of 55 and 64 now die of heart disease at a rate of 376 for every 100,000 people in the nation. In 1950, the rate for that group was 803. Cancer mortality for the same group has risen from 390 in 1950 to 445 today. Similar disparities exist in the 45-to-54 age category as well as in younger groups.
Because cancer predominantly affects the aged, and the number of senior citizens is increasing, the merging of the two mortality rates is inevitable if the current trend continues.
While scientists at the federal cancer and heart institutes are not making predictions, they agree that a “crossing of the curves” may take place shortly after the year 2000. Factors that may interfere include more effective treatments of major types of cancer or a leveling off of the rapidly declining heart disease rate.
A computer projection conducted at the National Cancer Institute predicted that the death rate for cancer in males could pass that for heart disease in 2005. For females, the date is 2015.
An explanation of why the coronary heart disease death rate is down while cancer remains high has attracted much scientific speculation. An important consideration is that, unlike coronary heart disease, cancer is more than 100 diseases that affect many parts of the body, have different causes and have widely varying cure rates.
A new report by NCI researcher Donald Shopland concludes that lung cancer has now displaced coronary heart disease as the single leading cause of excess mortality among smokers.
