The "Report to the Nation" on cancer also shows the rate of new diagnoses among men dropped 1.8 percent a year between 2001 and 2005, while for women the drop was just over half a percent a year.
The improvements are due to gains against some leading cancers -- prostate, colorectal, breast and, for men, lung cancer. Numerous other types still are on the rise, including melanoma and kidney cancer.
Regular screening for breast and colorectal cancer, declining smoking rates and improved treatments helped lead to the improvements, the study by government and private health experts showed.
"This decline is seen in blacks, it's seen in whites, it's seen in Hispanics, it's seen in all Americans," Otis Brawley, chief medical officer for the American Cancer Society, told Reuters.
Cancer remains the second-highest cause of death for Americans, with more than half a million deaths annually, topped only by heart disease.
"[T]his is first time that we've got declines in incidence. We've never had incidence go down since we've been keeping records starting in the 1930s," Brawley said.
Tuesday's report also highlights regional variations in anti-smoking policies that translate into big differences in lung cancer rates. California, for example, through higher cigarette taxes and other steps, has seen a 2.8 percent-a-year decline in lung cancer death rates, compared with less than a percent a year for Kentucky.
Smoking accounts for about 30 percent of all cancer deaths, including about 87 percent of lung cancer deaths. Between 2001 and 2005, new cases of lung cancer dropped about 1.8 percent a year among men, but rose among women, about half a percent a year.
The rate of new breast cancer dropped 2.2 percent a year, due largely to millions of women stopping hormone replacement therapy starting around 2002. The death rate dropped 1.8 percent a year.
Prostate cancer dropped 4.4 percent a year between 2001 and 2005.
Melanoma jumped 7.7 percent a year among men and by nearly 3 percent a year among women, and kidney cancer incidence rose about 2 percent a year for both sexes.
Rising death rates were seen in esophageal cancer for men, pancreatic cancer for women and liver cancer for both sexes.
"I think it speaks to improved public health measures, improved awareness about risk factors for cancer in general and improved therapies," Louis Weiner, director of the Lombardi Comprehensive Cancer Center at Georgetown University, told Reuters.
Weiner said progress occurred in conjunction with a doubling in funding for the National Cancer Institute from 1998 to 2003, but that funding has stagnated since.
"We've had some hard-won gains," Weiner told the Associated Press. "To slow down progress when we're so close to a fundamental understanding of cancer biology that we need to really made advances is really tragic."