TUESDAY, April 22 (HealthDay News) -- The factors behind cancer death rates seem to have leveled off, a new report shows. The effectiveness of smoking prevention and mammography screening that fueled recent declines in cancer deaths appears to have reached its limit.

"We've run into plateaus in terms of people smoking and getting necessary screening. The next big barrier is the obesity epidemic," said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La.

Nevertheless, Brooks stressed, the progress already made is substantial. "When you step back and think about where we've come in this country, it's phenomenal," he said. "The report is a tremendous example of the work that's been done over the past 20 years in showing that the efforts to reduce smoking and increase screening have been tremendous in terms of decreasing death rates from cancer."

But the trends, detailed in the American Cancer Society's annual report, Cancer Prevention & Early Detection Facts and Figures 2008, do point to a need for more effort.

"If we see sustained declines in prevention and early detection efforts that could really have, down the road, an impact on [cancer deaths], that's why we're picking up the pace now and emphasizing the importance so we can correct this," said study co-author Vilma Cokkinides, strategic director in risk factor surveillance, department of epidemiology and surveillance at the American Cancer Society in Atlanta.

Earlier this year, the American Cancer Society reported that death rates in the United States had dropped by 18.4 percent in men and 10.5 percent in women since the early 1990s, when mortality rates first began to decline. This means a total of more than half a million deaths from cancer have been averted in those years.

Here are the report's main findings:

• About 40 percent of the reduction in cancer deaths in males between 1991 and 2003 can be attributed to declines in smoking that have taken place over the last century. But efforts have stalled: Almost 24 percent of men and 18 percent of women smoke, a rate that has remained unchanged for the past two years.
• The percentage of high school students who smoke (currently 23 percent) has also leveled off since 2005.
• According to the U.S. Centers for Disease Control and Prevention, if all state tobacco control programs were funded at their recommended level for five years, there would be about 5 million fewer smokers in the United States. But in 2008, only three states (Maine, Colorado and Delaware) met or exceeded CDC minimum recommended levels for funding of these programs.
• Twenty-nine states, the District of Columbia and Puerto Rico have bans on smoking in workplaces and/or restaurants and/or bars, while almost 3,000 municipalities have passed some of smoke-free legislation. "Comprehensive tobacco control programs are really key," Cokkinides said. "They have been demonstrated to be effective. We just need to keep up the pace."
• The rate of mammography screening has remained stagnant since 2000. In 2005, about two-thirds of women aged 40 and older reported having had a mammogram within the past two years (four percentage points lower than in 2000) and only 51.2 percent reported having had a mammogram within the past year. Women without health insurance and recent immigrants had the lowest levels of screening.
• Rates of colorectal cancer screening are improving, but still leave ample room for improvement. Less than half (46.8 percent) of American men and women aged 50 and over have had a recent colorectal cancer screening test, up from 42.5 percent in 2000. So far, 22 states plus the District of Columbia have legislation in place that requires coverage for all colorectal cancer screening tests. Again, the uninsured and recent immigrants were least likely to have been screened.
• Twenty-two states plus the District of Columbia have legislation mandating that private health insurance plans cover all colorectal cancer screening tests.
• Exposure to sunlight (outside or in the tanning booth) remains a major risk factor for different types of skin cancer. According to the report, 68.7 percent of youth reported getting sunburned during the summer, although only one-third reported using sunscreen all the time or often, not to mention other forms of protection (such as seeking shade or wearing long-sleeved clothing).
• Overweight and obesity are significant risk factors for different types of cancer. Currently, 17.1 percent of adolescents and 35.2 percent of adults are considered obese. These startling figures go hand-in-hand with relatively low levels of physical activity (less than 36 percent of U.S. residents were physically active for at least 60 minutes on most days of the week, while 23.9 percent of adults reported no leisure-time physical activity) and poor eating habits (only one in five U.S. high school students and less than one-quarter of adults ate vegetables and fruits five or more times a day in 2005).

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