What Is patientINFORM?

Summary: Yet another study shows that mammography rates are going down in the US. In the latest one, researchers from the National Cancer Institute find that the trend is national and not restricted to just a few states. The decline raises troubling questions for those concerned with lowering the toll breast cancer takes in the US.

Why it's important: A mammogram is one of the best tools available for catching breast cancer early, when tumors are small and easier to treat successfully. That's why the American Cancer Society and many other organizations recommend regular mammograms for all women 40 and older. If the group of women not following this recommendation is getting larger, as these studies suggest, experts fear this will lead to more women being diagnosed with advanced disease that is harder to control. And ultimately that will translate into higher breast cancer death rates overall.

"That's the thing we worry about the most," says lead researcher Nancy Breen, PhD, of the National Cancer Institute. "Women who weren't diagnosed early because they didn't get their on-schedule mammogram might be diagnosed later with a later stage of cancer."

What's already known: Between 1987 and 2000, the percentage of US women 40 and older who were getting regular mammograms grew steadily. This increase is partially credited for lowering the death rate from breast cancer. Since 2000, a series of studies has shown mammogram rates first leveling off and then declining. While those studies looked primarily at data from individual states, this new report is based on a comprehensive national survey designed to give a clearer picture of national mammography usage. The findings are reported in the journal Cancer.

How this study was done: Breen and colleagues used several years' worth of data from the National Health Interview Survey, a yearly survey conducted in person by trained government interviewers. About 35,000 people across the US are surveyed each time. Women 40 and older were asked if they'd ever had a mammogram and if so, when they last had one.

What was found: As expected, mammography use increased between 1987 and 2000 for all women 40 and older. Between 2000 and 2003, rates stayed about the same. But by 2005, mammography rates for women overall had dropped to about 66%, which was nearly 4% lower than the peak rate of 70% in 2000. This was a statistically significant decline, and one Breen calls "disturbing."

What's more, the decline was seen not just across the board but also in many subgroups of women -- including some who have traditionally had the highest rates of mammography use. For instance, significant drops were seen among white women, those with higher levels of education, those with a regular source of medical care, and those with private health insurance.

When the researchers looked at women according to their age, they found that mammography use had dropped by nearly 7% (from about 79% to about 72%) among women 50-64, the group with the largest number of breast cancer cases in the US. This is the same age group, Breen notes, that has been shown to benefit the most from mammography.

The study doesn't explore what could be causing the drop in mammography, although it cites numerous possibilities. Perhaps fewer women have insurance coverage, or co-pays for mammogram visits have gotten higher. Maybe women are no longer convinced mammograms are effective at preventing breast cancer deaths, or maybe they simply are not be as worried about breast cancer as they used to be. Or it could be the end result of a cascade of events -- cost-cutting by insurers leading to lower reimbursements for doctors who perform mammograms, leading to fewer doctors getting specialized in reading the tests, leading to less availability and longer appointment delays for the patient.

Most likely, it's a combination of many factors, Breen says.

The bottom line: Whatever the cause, the drop in mammography rates is worrisome, Breen adds. She and her group are trying to develop new studies that could shed light on why mammogram use is declining.

"We really need to know why it is that screening isn't happening before we can talk about developing strategies that are going to work [to raise levels again]," she notes.

However, at least one strategy has already been proven to help boost screening rates: reminder systems. People are more likely to get screened if they get a phone call or card or email reminding them to make that appointment.

Another thing that could help, Breen says, is to keep the message about screening front and center.

"We can't assume that people who have been screening will continue to screen, and we need to continue to make it clear that this is of benefit to them," she says.

Citation: "Reported Drop in Mammography: Is This Cause for Concern?" Published online May 14, 2007, in Cancer. First author: Nancy Breen, PhD, National Cancer Institute.