After Breast Cancer Diagnosis, Tests Overdone?
Routine X-Rays, Bone Scans Show Low Detection Rate for Spotting Breast Cancer Spread
Low Detection Rates continued...
In the U.S., patients typically get one or two of the tests, followed in many cases by more sophisticated imaging screening with CT, PET, or MRI.
There's no set cost for tests -- a chest X-ray runs from $200 to $900, she says. Bone scan and liver ultrasounds also cost hundreds of dollars, while the more advanced imaging tests cost thousands. "But even if the cost of a test is only $100, the total cost is huge when you multiply by thousands of breast cancer patients," she says.
Despite their pervasiveness, there is no solid evidence showing the routine use of these tests to spot metastatic disease, or cancer spread outside the breast area, improves patients' health. So the researchers posed the following question: "Among women with newly diagnosed breast cancer that are otherwise asymptomatic (without symptoms), does evaluation with bone scanning, liver ultrasound, and chest radiograph help to determine the extent of metastatic disease?"
The answer: Not really.
The tests had very low detection rates of cancer spread, particularly for the 1,482 women with stage I and II cancer: 2.43% for bone scans, 0.82% for liver ultrasound, and 0.51% for chest X-ray.
In the 400 women with stage III cancer, the detection rates were somewhat higher, particularly with bone scans: 12.5%, vs. 4.2% and 4.57% for liver ultrasound and chest X-ray, respectively.
"We must rethink the utility of these tests. Are they saving lives? How many false positives are there? How many false negatives? Likely a lot. Women with early-stage cancer may not need any of these tests," Staley says. "And we don't even know which tests are best for women with stage III cancer."
Although she and Seidman don’t have the answers, they agree a head-to-head comparison of these radiological tests with more sensitive imaging, such as CT or PET, looking at effectiveness and cost, is a logical next step.
ASCO isn't the only medical group taking a long hard look at whether procedures and tests work and work well enough to justify their cost. The American Board of Internal Medicine Foundation’s Choosing Wisely campaign, for example, developed a list of commonly used tests or treatments whose necessity is not supported by high-level evidence.
These findings were presented at a medical conference. They should be considered preliminary, as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.