After a decline of 369 deaths from 2002 to 2003, the decline from 2003 to 2004 was 3,014 — or more than eight times greater, according to a review of U.S. death certificates by the American Cancer Society.
The drop from 2002 to 2003 was the first annual decrease in total cancer deaths since 1930. But the decline was slight that experts were hesitant to say whether it was a cause for celebration or a statistical fluke.
The most common cancers in men are prostate, lung and colon, and they are all showing lower death rates, reports CBS News medical correspondent Dr. Jon LaPook.
For women, the most common cancers are breast, colon and lung, with breast and colon death rates going down and the rate for lung cancer leveling of, LaPook reports.
The trend seems to be real, Cancer Society officials said.
"It's not only continuing. The decrease in the second year is much larger," said Ahmedin Jemal, a researcher at the organization.
Cancer deaths dropped to 553,888 in 2004, down from 556,902 in 2003 and 557,271 in 2002, the American Cancer Society found.
"Screening has made a very important difference for breast cancer and colorectal cancer," said Elizabeth Ward, a researcher with the Cancer Society.
Experts are also attributing the success to a decline in smoking and earlier detection and more effective treatment of tumors. Those have caused a fall in the death rates for breast, prostate and colorectal cancer — three of the most common cancers.
In December, a researchers concluded that breast cancer rates in the United States . The 7.2 percent decline came a year after a big federal study linked menopause hormones to a higher risk of breast cancer, heart disease and other problems. Within months, millions of women stopped taking the pills.
The largest drop in deaths among the major cancers was in colorectal cancer. Colorectal cancer deaths dropped by 1,110 in men and by 1,094 in women.
"The biggest driver in colon cancer's decline in mortality is colon cancer screening, which has proven to save lives," said Dr. Otis Brawley, an Emory University researcher specializing in cancer epidemiology.
President Bush on Wednesday hailed the downward trend in cancer deaths in the United States.
Before participating in a roundtable discussion of advances in cancer prevention, Mr. Bush visited a urological oncology laboratory run by the National Cancer Institute. He peered into a microscope at slides of kidney cancer cells and looked at family trees to show how the gene identified with the disease moves through generations.
For more than a decade, health statisticians have charted annual drops of about 1 percent in the cancer death rate — the calculated number of deaths per 100,000 people. But the actual number of cancer deaths still rose each year because the growth in total and elderly population outpaced falling death rates.
"This is a dramatic improvement over where we were before because the population continues to grow and it continues to age, and we would expect more people to die from cancer than fewer," Dr. Harmon Eyre of the American Cancer Society told CBS News.
In 2003 and 2004, the cancer death rate declined by about 2 percent each year — more than offsetting the effects of aging and population growth.
The Cancer Society also projected how many cancer cases and deaths will occur this year — more than 1.4 million new cases and 559,650 deaths.
The incidence estimate is based on nine previous years of data. The death projection, based on about 35 years of data, suggests annual cancer deaths will rise again. But the data did not fully capture the new trend in declining deaths, said Ward.
Despite that estimate, Cancer Society officials now believe cancer deaths will continue to drop, Ward and others said.