For the first time since 1900, overall cancer death rates have shown a sustained decline, a new analysis has shown.
Although death rates of some particularly deadly cancers are rising, a study of all cancer deaths from 1990 to 1995 documented the historic drop.
Experts attributed the decline to preventive measures, especially anti-smoking efforts, and to improvements in early detection and treatment, which have increased the chances of surviving many common cancers.
"This is the news we've been waiting for," said Dr. Richard Klausner, director of the National Cancer Institute.
"The 1990s will be remembered as the decade when we measurably turned the tide against cancer."
The declining mortality rate, which shows signs of accelerating, suggests that the prediction that cancer deaths would overtake heart deaths early in the next century may be wrong.
The death rate from heart disease, which has dropped precipitously since 1970, is still declining but more slowly than previously.
The analysis, to be published in the Nov. 15 issue of the journal Cancer, shows that the overall cancer mortality rate, adjusted for age, dropped each year from 1990 to 1995, for a total decline of about 3.1 percent.
In 1990, the death rate peaked at 135 deaths for every 100,000 people. The rate then fell annually, reaching 129.8 deaths per 100,000 in 1995, or about five fewer deaths per 100,000 than in 1990.
The study was done because analysts noticed the trend in statistics from 1994 and preliminary data from 1995.
The researchers -- Dr. Philip Cole, epidemiologist at the University of Alabama School of Public Health, and Dr. Brad Rodu of the university's School of Dentistry in Birmingham -- attributed the bulk of the decline to the reduction in cigarette smoking among American men, which has resulted in a "major reduction" in lung cancer of 3.9 percent and a decline of 2 percent in other smoking-related cancers.
Dr. Harmon Eyre, chief medical officer for the American Cancer Society, said that, while lung cancer deaths continued to rise in women, the rate had slackened in recent years and was expected to decline as a result of a reduction in smoking among women.
Also contributing to the fall in mortality rates has been reduced occupational exposure to cancer-causing agents like asbestos, radon and vinyl chloride, Eyre said.
"Without lung cancer," he said, "beginning in the 1970s, all other cancer death rates began declining slightly."
Eyre attributed the "turnaround" in the overall cancer mortality rate to the combined result of reducing the incidence of common fatal cancers like lung cancer and improving the cure rates for common cancers.
For example, the death rate from breast cancer, which has been declining since 1989, fell 6.3 percent between 1991 and 1995, the cancer institute reported.
An editorial in the same issue of Cancer -- published by the American Cancer Society -- Dr. Curtis Mettlin, head of the society's committee on prevention and detection, wrote that the analysis by Cole and Rodu provided "new evidence that meaningful progress is being made" in the fight against cancer. Although the magnitude of the decline is not great, he said, "the trend is clear."
Also clear, Mettlin noted, is that "there has been no `magic bullet.' " Rather, the favorable mortality trend is the result of "several different cancer control activities," all of which must be continued to keep the trend going.
Eyre pointed out that death rates from some cancers still are rising, among them non-Hodgkin's lymphoma (partly because of a rise among people infected with the virus that causes AIDS), cancer of the pancreas, multiple myeloma and chronic leukemia in older people.
"We must continue to support research to find ways to control these cancers through prevention and treatment," he said.
Another problem is that not all segments of the population have equal rates of cancer.
Although the largest reductions in cancer death rates since 1991 have been among African-Americans, their death rates from cancer are still higher than among whites.
In his editorial, Mettlin pointed out that new problems will arise in the future as more people live to advanced ages, causing cancer diagnoses and deaths to increase, thus creating a greater need for prevention and a greater demand for care.
He concluded that "the cancer-control milestone Cole and Rodu have set perhaps should be viewed as the end of the beginning rather than the beginning of the end."