For the first time since the government began compiling records, the rate of cancer has begun to decline, marking a tipping point in the fight against the second leading cause of death among Americans.
Researchers already knew that the number of cancer deaths was declining as the result of better treatment, but the drop in incidence indicates that major progress is also being made in prevention.
"The drop in incidence . . . is something we have been waiting to see for a long time," Dr. Otis W. Brawley, chief medical officer of the American Cancer Society, said in a statement. And "the continuing drop in mortality is evidence once again of real progress made against cancer, reflecting real gains in prevention, early detection and treatment."
The decline was boosted by California, largely because of a comprehensive ban on smoking. It was the only state to show declines in both incidence and deaths from lung cancer in women.
"It's a testament to the change in the lifestyle of the people of California," said Dr. Robert Figlin of the City of Hope Comprehensive Cancer Center in Duarte.
But the declines may be temporary, Figlin said. "Baby boomers are reaching the age at which they develop cancer . . . so we should not be surprised if it changes direction again."
Researchers also fear the economic meltdown may trigger an increase in incidence with fewer people willing to pay for screening tests and increased stress leading others to resume smoking. The growing number of unemployed also means fewer people have health insurance.
The report was compiled by the National Cancer Institute, the American Cancer Society, the Centers for Disease Control and Prevention and the North American Assn. of Central Cancer Registries.
The report was published online Tuesday in the Journal of the National Cancer Institute.
Incidence rates for all cancers combined and for men and women combined dropped by 0.8% per year from 1999 through 2005, with the rates for men dropping about three times the rates for women. The overall trend did not become clear, researchers said, until the data from 2005 were included.
African Americans had the highest rates of cancer, but the decline in that group was similar to that among whites. The only ethnic groups for which rates did not decline were American Indians and Alaska Natives.
The overall death rate declined by an average of 1.8% per year over the same period.
