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New cancer cases and the death rate from the disease have both dropped significantly over the last five years. Researchers say one reason is that decades of pushing to improve diets and reduce bad habits has begun to pay off. NPR's Patti Neighmond reports on the findings published in the journal Cancer.
PATTI NEIGHMOND: In order to understand what the slow but steady decline in cancer death means, look at it this way, says oncologist Otis Brawley, chief medical officer for the American Cancer Society. Compare the risk in 2006 to 15 years earlier, in 1991.
Dr. OTIS BRAWLEY (American Cancer Society): All told, the population as a whole has a 16 percent lower risk of dying from cancer in 2006 versus 1991.
NEIGHMOND: Men are still more likely to get cancer, but they did see the greatest reduction in risk. 2006 is the most recent year data's available. These findings confirm earlier evidence that cancer rates are down. One huge reason: People are quitting smoking and fewer are starting.
Dr. BRAWLEY: The population went from about 50 percent of people smoking, or men smoking especially, in the 1960s, to now about 25 percent smoking. And that's driven down lung cancer.
NEIGHMOND: The biggest cancer killer. Lung cancer cases are down. So are cases of the second biggest cancer killer - colon cancer. Brawley says people are changing their diets to include more colon-friendly food like fruits, fiber and vegetables. People are exercising more, which also helps. But overwhelmingly, he says, the biggest change is in screening for the disease. Epidemiologist and study researcher Elizabeth Ward with the American Cancer Society says the most effective screening method is colonoscopy.
Dr. ELIZABETH WARD (American Cancer Society): Colonoscopies is in many ways the gold standard of colorectal screening tests, because it allows for examination of the entire colon. The physician can actually visualize polyps or early cancers and in some cases remove them during the exam itself.
NEIGHMOND: Ward says the cancer declines are remarkable but adds quickly it could be better. For example, with colon cancer only about half the people who should be screened are. Many of those who aren't screened are African-American and Hispanic.
Dr. WARD: Both African-American and Hispanic populations still have lower rates of private health insurance and either lack health insurance or are covered by some public programs that don't have access to the full range of colorectal cancer screening tests and may not even be able to readily see a physician when they note signs and symptoms of colorectal cancers such as blood in the stool.
NEIGHMOND: In the meantime, health experts like Brawley worry that the obesity epidemic could undo many of these recent cancer gains.
Dr. BRAWLEY: The increasing obesity epidemic in the United States could very well cause a tsunami of cancer in the next 20 to 30 years. Already we have increases in esophageal cancer, increases in pancreas cancer, that are all related to obesity.
NEIGHMOND: Obesity is also linked to breast, prostrate, uterine, colon, liver and kidney cancer.
Patti Neighmond, NPR News.