ATLANTA — Cancer rates in the U.S. continue to fall, according to a report released Wednesday.
New cancer cases have been falling at a rate of about half a percent each year since 1999. And the overall cancer death rate has dropped by 1.5 percent annually in adults and 1.7 percent in children.

“This is good news,” said Dr. Marcus Plescia of the Centers for Disease Control and Prevention, one of four organizations that worked on the report. “There has been positive momentum for several years now and that continues.”

The figures come from a report issued annually since 1998 by a group of government agencies and other organizations, including the CDC and the American Cancer Society. The new report includes nearly every cancer case reported in the United States through 2008.

Officials say the improvement is the result of better screening and treatment, and efforts to eliminate unhealthy behaviors, such as tobacco use.

One pay-off from anti-smoking efforts: In 2008, for the second consecutive year, lung cancer death rates declined for women. Lung cancer death rates for men have been falling since the 1990s.

Prostate cancer death rates continued to fall, and colon cancer death rates for men and women continued to drop. Rates of new cases of those diseases fell, too.

The breast cancer death rate also continues to decline, but the rate of new breast cancer cases – which was falling in the years 1999 through 2004 – has leveled off since then. Health officials believe that’s partly related to a plateau in breast cancer screening rates.

While there’s a lot of good news in the report, the authors noted some looming concerns. One is increases in skin cancer cases and deaths, which experts believe are being boosted by the use of tanning beds. “I think this is a future epidemic in the making,” said Plescia, director of the CDC’s Division of Cancer Prevention and Control.

The authors also cited the nation’s weight problem. Two out of every three adults are overweight or obese, and that seems to be contributing to rising case rates for cancers of the esophagus, uterus, pancreas and kidney. Excess weight triggers production of insulin and certain hormones that can play a role in cancer growth.

“For people who do not smoke, excess weight and lack of sufficient physical activity may be among the most important risk factors for cancer,” John Seffrin, the Cancer Society’s chief executive officer, said in a statement.