CHICAGO (MCT) — Breast cancer screening rates, which have increased steadily for decades, have begun slipping, a trend public health officials warned could cost women’s lives.
A weekly report issued Thursday by the federal Centers for Disease Control and Prevention found that the proportion of U.S. women who reported having a mammogram in the last two years had dropped from 76.4 percent in 2000 to 74.6 percent in 2005.
The statistically significant decline represents “over 1.1 million fewer women getting recommended mammograms,” said Blythe Ryerson, author of the report.
But no one knows why.
Dr. Carol Lee, professor of diagnostic radiology at Yale University, said she feared the decline “may reflect problems with access to mammograms.”
Lee cited a 2006 Government Accounting Office report, which found that the number of mammography facilities declined between 2001 and 2004 – even though the number of women over 40 is rising dramatically.
But that same report nevertheless concluded that “current nationwide capacity is adequate.”
Dr. Leonard Berlin, head of radiology at Rush North Shore Medical Center in Skokie, also was skeptical that the drop in screening rates was due to fewer mammography facilities.
“A more likely cause,” he said, “is apathy and indifference. Women may be sick of hearing, ‘Get your mammogram.'”
The CDC report did not analyze the data by age, geographic region or socio-economic status. It’s possible mammography use is declining among certain groups — such as the poor and the uninsured — while remaining steady or even increasing in better-off populations.
Blythe Ryerson, an epidemiologist at the CDC and author of the new report, said her agency planned to look more closely at the data.
“We need to know if this is affecting all women or if it is an issue affecting certain racial/ethnic groups or age groups,” she said in an interview.
Although the decline was less than 2 percent, Ryerson said, “Any decline of any size is concerning, since we know mammograms work.”
“Continued declines in mammography use might result in increased breast cancer mortality,” the report said.
More than 200,000 U.S. women are diagnosed with breast cancer every year, and about 40,000 die of the disease. The death rate has been dropping steadily since 1990, and experts have estimated that about half of the decrease in mortality rates is due to early detection through mammograms. The other half is due to improved treatments.
The U.S. Preventive Services Task Force advises women over 40 to get a mammogram — a specialized X-ray of the breast — once every year or two.
Dr. Peter Ravdin, an oncologist and biostatistician at M.D. Anderson Cancer Center, said a couple of factors might be playing into the declining mammography rates.
First, he said, “people get used to it and take it for granted. The importance wanes a little.”
Another possibility is that the number of uninsured is going up and general funding for public health is tight.
Doctors at the Cook County Bureau of Health Services estimate that 11,000 women are currently waiting for a mammogram because of staff shortages and other problems.
“That’s a barrier,” Ravdin said. “People get tired of waiting and give up.”
Ravdin discounted the possibility that women have stopped getting mammograms because of controversy or confusion over the test’s effectiveness.
A study published in 2002 found there was no evidence screening mammography saved any lives. But Ravdin pointed out that no medical organizations had changed its recommendations as a result of that report, which he called “largely discredited.”