BIRMINGHAM, Ala--After 60 years of steadily increasing cancer mortality, the tide appears to have turned. From 1990 to 1995, age-adjusted cancer mortality declined by a total of 3.1%, say Philip Cole, MD, and Brad Rodu, DDS, of the University of Alabama at Birmingham School of Public Health and School of Dentistry.
BIRMINGHAM, Ala--After 60 years of steadily increasing cancermortality, the tide appears to have turned. From 1990 to 1995,age-adjusted cancer mortality declined by a total of 3.1%, sayPhilip Cole, MD, and Brad Rodu, DDS, of the University of Alabamaat Birmingham School of Public Health and School of Dentistry.
Mortality from all cancers peaked at 135 deaths/100,000 patient-yearsin 1990 and declined in each subsequent year to 130.8 in 1995,representing an average reduction of 0.6% per year (see tableon page 10). The bulk of this decline (40%, or 1.6 deaths/100,000person-years) stems from the fall in lung cancer mortality (Cancer78:2045-2048, 1996).
This is the news we've been waiting for," NCI director RichardKlausner, MD, said of the finding. "We are on the eve ofthe 25th anniversary of the National Cancer Act, the legislationthat made cancer research a high national priority. Now our nation'sinvestment is paying off by saving lives."
The UAB researchers drew on three sources for their analysis:Vital Statistics of the United States for cancer mortality ratesfor 1970 to 1990; CDC's Monthly Vital Statistics Reports for the1991 to 1995 mortality figures; and the Current Mortality Samplefor 1994 and 1995 statistics. [See page 27 for a report of theNCI's analysis of US cancer mortality rate trends based on SEERdata.]
Smoking prevalence began a steady decline in 1965, so "itwas inevitable that lung cancer incidence and mortality rateswould begin to decline some 20 or so years later," Drs. Coleand Rodu say. They note that reductions in smoking lead to reducedmortality from other cancers as well, such as bladder cancer.
Cancer prevention efforts, other than those aimed at smoking cessation,including cancer prevention programs in the workplace, also havehad an impact on cancer mortality, they say, as well as lowercase fatality rates due to earlier detection of disease and moreeffective treatments.
Unless there is a surge in incidence rates, the investigatorsbelieve the decline will likely continue for at least 20 yearsand may accelerate. "It will continue," they say, "becausewe are just beginning to see the effects of long-term reductionsin smoking and of reduced exposure to other lifestyle carcinogens(eg, alcohol and solar radiation) and to some industrial agents."
Factors that may work toward an even faster rate of decline includethe possible stabilization and decline of the currently risinglung cancer mortality rate among women, and further advances incancer screening, diagnosis, and treatment.
In a commentary accompanying the report, Curtis J. Mettlin, PhD,of Roswell Park Cancer Institute, says that the evidence may quietthe skepticism that many have had in recent years about the effectivenessof the national cancer program. "Meaningful progress is beingmade," Dr. Mettlin says.
Although the largest declines have been in lung cancer, Dr. Mettlinpoints to strides in other mortality rates as well, includingbreast and prostate cancer.
"When these favorable recent trends for some of the mostcommon cancers converged with the previously established decliningmortality trends for stomach carcinoma, testicular carcinoma,Hodg-kin's disease, uterine carcinoma, and a variety of childhoodcancers," he says, "it was inevitable that the trendof increasing overall cancer mortality would at some point bereversed."
Although most of these drops in cancer mortality can be tracedto specific public health interventions or improved treatments,at least one has been fortuitous, Dr. Mettlin says. Stomach cancerrates declined because of changes in diet and methods of foodpreservation that were not designed to reduce cancer risk.
For Dr. Mettlin, the news serves as a reminder of "the degreeto which control of cancer is a societal enterprise," withan important role for research, public and school health education,wider access to improved treatments, early detection outreachprograms, workplace screening, reduced exposure to environmentalcarcinogens, and improved nutrition.
He concluded with one caveat: with elderly people making up agrowing percentage of the population, the actual number of personsdiagnosed with and dying from cancer will increase, even as theage-adjusted cancer mortality rate continues to decline.
Year All cancer* Lung cancer*
1970 129.9 28.4
1980 132.8 35.4
1990 135.0 41.4
1991 134.5 41.1
1992 133.1 40.8
1993 132.6 40.8
1994 131.5 40.1
1995 129.8 39.5
*Deaths per 100,000 person-years.
Adapted from Cole P, Rodu B: Declining cancer mortality inthe United States (Cancer 78:2045-2048, 1996).