Mammography follow-up catches cancers at low cost

It costs just 16¢ per patient screened to ensure that women return for recalls after mammography, and the price is well worth paying, according to a study from Michigan. Another study from Pennsylvania suggests that women are happy to be called back for follow-up if it means a cancer might be detected at the very earliest stage. And a second study from the Wolverine State finds that women's expectations of mammography are unrealistic.

Researchers at the University of Michigan Health Center in Ann Arbor examined hidden costs and effectiveness of a system that tracks patients after screening mammography in a batch reading setting. To help achieve higher compliance rates, the center uses software to flag patients who have not returned for an indicated diagnostic study. Follow-up mammography slots are set aside based on screening volume and average recall rates, and scheduling staff make a special effort to book studies at times convenient for patients.

A multilayered system of patient tracking led to a 99.5% compliance rate at the additional cost of about $4700 over three years for 30,000 patients screened.

"The cost of the system is only 16¢ a screened patient, with an enhanced safety net for picking up cancer," said Dr. Caroline Blane, who presented results at the 2006 American Roentgen Ray Society meeting. "As a side benefit to patient safety issues, the system also decreases risk exposure."

Cost data for the study are based largely on the time spent by clerical staff responsible for calling patients to schedule a diagnostic study after an inconclusive mammogram. Of the screened patients, 4025 required a follow-up diagnostic exam. After initial contact from staff, 3977 women returned, equivalent to a 98.8% patient compliance rate at a cost of about $4000. Efforts to reach the remaining patients by phone and registered mail resulted in roughly another $700 in costs. Of the 48 initially noncompliant patients, 28 came back, including one woman who was then diagnosed with invasive breast cancer.

The study shows that high compliance is achievable in an offline screening program, meaning screening mammograms are read in batches after patients' departure, rather than on the same day of screening. Batch reading of screening mammograms allows greater collaboration with colleagues and may improve cancer detection, Blane said.

In another study, women who underwent routine screening reported they were more than willing to be called back for follow-up if it meant early diagnosis of breast cancer (Radiology 2006;238:793-800). Of the 1500 women surveyed by Dr. Marie A. Ganott, a radiologist at the University of Pittsburgh, 97% reported that a false-positive result would not keep them from having routine checks in the future. Participants overestimated the probability that a cancer would be found during each exam, and more than 80% said they were willing to be called back for additional checks to detect cancer at the earliest stages.

"The women in our survey by far preferred a conservative approach from the radiologist," said senior author David Gur, Sc.D., a professor of radiology at the University of Pittsburgh.

Responses indicated the women prefer a definitive diagnosis, whether positive or negative, Gur said, adding that these results might not hold true in a broader patient population.

UNREALISTIC EXPECTATIONS

Another survey of 397 patients found that many have unrealistic expectations about both their lifetime risk of cancer and the diagnostic value of mammography. When asked if they agreed with the statement that mammograms detect all cancers, even if they are extremely small, 21% said yes and another 12% were neutral. The majority thought their risk of getting breast cancer was more than 20%, whereas statistically the actual risk in the U.S. is 12.5% (one in eight women).

The survey results suggest a need to educate women about the limitations of mammography, said Dr. Marilyn Roubidoux, a professor of radiology at the University of Michigan Health Systems, who presented the study at the ARRS meeting. She concluded that expectations of mammography sensitivity may contribute to greater anxiety for patients and medicolegal risk for providers.