Click to see cancer trend percentages between 1996 and 2005.
For the first time, the rate of new cancers is down among all Americans, according to the nation's annual report card on cancer, released Tuesday.
Overall cancer incidence — the annual rate of new cancer cases — is going down annually by 0.8 percent among men and 0.4 percent among women in the U.S. That's not much, but it marks a milestone many thought might never come.
Experts give credit to a dramatic decline in smoking rates over the past two decades and an increase in use of preventive measures such as colonoscopy.
Colonoscopy actually prevents colorectal cancer, a major cancer killer, by identifying and removing precancerous polyps.
Experts say there's more mileage to be gained from cancer prevention. Robert Croyle, director of Cancer Control and Population Sciences at the National Cancer Institute, hopes the new numbers will reduce people's fatalism about cancer — the feeling that it's something beyond their control.
"We've been saying for some years that mortality is declining," Croyle says. "But then of course people say, 'Well, gee, it seems like everybody I know is getting cancer.' So to turn the corner on incidence is an important and significant event."
Cancer And Women
Part of the decrease in cancer incidence is due to the fact that lung cancer rates among women have leveled off in recent years. Lung cancer incidence among men has been decreasing for several years.
"Everybody's been waiting for the lung cancer incidence and death rates in women to begin to go down," says Dr. Michael Thun of the American Cancer Society.
Experts see signs that this is beginning to take place. It might have happened earlier, Thun says, except for something that occurred more than three decades ago: the advent of cigarette brands targeted to young women.
"The big marketing of Virginia Slims that caught the people who were passing through adolescence in the '60s really boosted smoking rates in that age group," Thun says.
Some of those women have already died of lung cancer, although it will take many years for that phenomenon to play out.
Another big contributor to the decline in new cancers among women occurred over the past decade. Millions of menopausal women stopped taking hormone replacement therapy. That made the rate of breast cancer cases decline.
But Thun says there is another contributor to the decline in breast cancer cases that's not good news.
"The decrease in breast cancer incidence in women is also partly due to a leveling off and decrease in mammography," he says. Fewer mammograms means fewer breast tumors get diagnosed. Presumably those cancers, or many of them, will eventually emerge, and that will affect overall cancer incidence among women.
"Whether cancer incidence continues to go down in women as well as men, time will tell," Thun says.
A Federal Tobacco Control Program?
Dr. Tim Byers, a cancer epidemiologist at the University of Colorado, says the new report contains some other important insights about lung cancer.
"The most striking thing about lung cancer in this report is the enormous variation between states in getting lung cancer and dying from it," Byers says.
For instance, California has the nation's most aggressive program of tobacco control. And lung cancer death rates have recently been dropping by nearly 3 percent a year. Kentucky, where rates of smoking remain high, has a lung cancer incidence three times higher than that of the lowest state, Utah.
"One of the questions that this observation raises in my mind is whether or not we should be thinking about the control of tobacco as more of a federal or national program," Byers says. "Up to now we've left it to the states, which is why we're seeing this enormous state-by-state disparity."
Dr. Ahmedin Jemal of the American Cancer Society agrees. He points out that states raise about $25 billion from excise taxes plus legal settlements from tobacco companies. "But they're expected to spend less than 3 percent of this — about $700 million — on tobacco control," Jemal says.
Congress is expected to consider giving the Food and Drug Administration regulatory authority over tobacco products. That would make possible, for instance, much more prominent health warnings on cigarette cartons and in tobacco advertising, as European nations do.
There's also debate about increasing the federal excise tax on cigarettes to cut smoking rates.
Croyle, of the National Cancer Institute, says there's something else Americans need to do to keep cancer incidence on the downturn: lose weight.
"The one concerning area, in terms of cancer rates as a whole, concerns obesity," Croyle says. "We're seeing upticks in some of the obesity-related cancers." The rate of thyroid cancer, for example, is going up by 6 percent a year among men and 7 percent among women.
'A Pleasant Surprise'
Still, cancer specialists are pausing to savor the news that overall cancer incidence has finally turned around. Dr. Ed Benz, president of Boston's Dana Farber Cancer Institute, says he "would not have imagined we'd see a decline in cancer rates back in 1979," when he entered the field.
Back then, Benz says, "the rate at which people were smoking was increasing. The rate at which atmospheric pollution was going up was increasing. And all the things that people imagined would cause more cancer were going up. So this is actually a pleasant surprise for me."
Thirty years from now, Benz thinks some cancers will be curable. Others will have become treatable chronic diseases, like diabetes. But he doesn't think the war on cancer will be won. "Cancer will still probably be a significant public health problem," Benz says.