New cancer cases show slight decline

Scientists find cause for optimism in 1999-2005 figures

November 26, 2008|By Thomas H. Maugh II | Thomas H. Maugh II,Los Angeles Times


For the first time since the U.S. government began compiling records, the rate of cancer has declined, possibly 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 new cases indicates that major progress is being made in prevention.

"The drop in incidence ... is something we have been waiting to see for a long time," said Dr. Otis W. Brawley, chief medical officer of the American Cancer Society. 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."

But the declines might be temporary, said Dr. Robert Figlin of the City of Hope Comprehensive Cancer Center in Duarte, Calif. "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 that the economic meltdown could trigger a new increase in incidence as fewer people feel comfortable paying for screening tests and increased stress leads some people 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 Association of Central Cancer Registries. The report was published online yesterday in the Journal of the National Cancer Institute.

Incidence rates of all cancers combined for men and women dropped by 0.8 percent per year from 1999 through 2005, with the rates for men dropping at about three times the rate for women. The overall trend did not become clear, researchers said, until the data from 2005 were included.

Blacks 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 Alaskan natives.

The overall cancer death rate declined by an average of 1.8 percent per year over the same period.

The incidence for men in 2005 was 562 cases per 100,000 individuals, while that for women was 417 per 100,000. The death rates were 234 per 100,000 men and 159 per 100,000 women.

Currently, about 1.4 million Americans are diagnosed with cancer each year, and an estimated 560,000 die of it.

The declines in incidence and death rates were due in large part to declines in five of the six most common cancers - lung, colorectal and prostate in men and breast and colorectal in women. The sixth most common form, lung cancer in women, leveled off.

Those cancers account for about half of new cases and deaths.

"Lung cancer is the big one when it comes to cancer in the United States," said Dr. John Glaspy of the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles.

The decline in breast cancer incidence is most likely due to the sharply reduced use of hormone replacement therapy beginning in 2002, as has been noted in several previous studies.

The drop in colon and rectal cancer, the report said, most likely stems from increases in screening, which leads to the identification and removal of polyps before they become cancerous.

Overall, the incidence rates dropped for 10 of the top 15 cancers.

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