Jan. 4, 2012 -- Cancer death rates for men and women in the U.S. kept dropping through 2008, continuing a nearly 20-year-long trend.
According to a new report from the American Cancer Society, overall death rates have declined for both sexes and nearly every racial and ethnic group. The exception was American Indians/Alaska Natives, whose rates have remained steady.
As a result, more than 1 million Americans who would have been expected to die from cancer have not.
Despite the good news, experts cautioned against complacency.
Cancer is still the second-leading cause of death in the U.S. behind heart disease. About half of men and 1 in 3 women will develop cancer during their lifetimes.
“This is not an acceptable decrease. This is something that needs a lot more work,” says Raymond DuBois Jr., MD, PhD, provost and executive vice president of the University of Texas MD Anderson Cancer Center in Houston. “We definitely need to work on getting better treatments and much more sophisticated early detection approaches.”
What’s Behind the Decline
The declines noted in the report were largely driven by reductions in lung cancers among men and breast cancers in women.
Lung cancer deaths are down in large part because fewer Americans are smoking.
The report says breast cancer deaths are down because many women have stopped using hormone replacement therapy. Earlier detection and better breast cancer treatments have also improved survival.
“Most of the progress in cancer has been incremental,” says Michael V. Seiden, MD, PhD, president and CEO of Fox Chase Cancer Center in Philadelphia. “There are more and more Americans who have gotten a little farther away from their last cigarette. The colonoscopy screening rates are nowhere where they should be, but they are slowly creeping up. The mammography screening rates are better as compared to a decade ago.”
Racial Disparities Improve, but Persist
Gains were most impressive among African-American and Hispanic men. Death rates from 1999 to 2008 for African-American and Hispanic men dropped by 2.4% and 2.3% per year, respectively, compared to an annual decrease of 1.8% for all men.
Despite that progress, the report found that cancer disparities persist for many minorities.
African-American men, for example, have a 15% higher cancer incidence rate than white men and a 33% higher death rate.
There’s less cancer diagnosed among African-American women compared to white women, but African-American women have a 16% higher death rate than white women.
Some Cancers Increasing
The report includes a special section highlighting seven cancers that are on the rise.
- Mouth and throat cancers caused by the human papillomavirus (HPV), the same virus that causes cervical cancer
- Esophageal adenocarcinoma, which is linked to chronic acid reflux, obesity, and smoking
- Melanoma skin cancer, caused by exposure to UV radiation from the sun and tanning beds
- Liver cancer, which may be related in part to increases in hepatitis B and C infections
- Thyroid cancer, for unknown reasons, but may be because of better detection
- Kidney cancer, which may be related to rising obesity
- Pancreatic cancer, which is linked to smoking, obesity, and family history
The Rising Risk of HPV
Researchers saw some of the steepest increases in HPV-related oral cancers among middle-aged men.
“So rates were higher and increased at a faster rate for men in the 55 to 64 age group compared to men over 65,” says Edgar P. Simard, PhD, MPH, a senior epidemiologist at the American Cancer Society. That was surprising, Simard says, because cancer rates are typically higher in adults over age 65.
HPV infection of the mouth and throat has been linked to oral sex.
HPV-related cancers usually take years to grow, which is why they’re often successfully caught in women who get regular cervical cancer screenings.
But Simard notes that doctors don’t check for HPV infection in the throat. “There really is no early detection method that’s currently available.”
Additionally, doctors aren’t sure if the HPV vaccine will prevent oral as well as genital cancers. “At the moment, that’s unknown,” he says.
The Burden of Obesity
Obesity is thought to account for 30% to 40% of cases of kidney cancer, for example. And studies have shown that obesity increases the risk of esophageal cancer 16-fold.
“The increasing obesity epidemic might be increasing cancers of the stomach and digestive tract,” Seiden says.
That should be further motivation for many who have resolved to slim down this year.
“There’s still a lot of low-lying fruit. If we could get colonoscopy rates above 50%, if we could get 0% of people addicted to cigarettes, if everyone exercised and controlled their weight, we could make even more progress,” Seiden says.