THURSDAY, Feb. 9, 2006 (HealthDay News) -- Biopsies remain the best technique to determine if a woman has breast cancer, after she has had an abnormal mammogram or physical examination, a new report contends.
Four other, noninvasive tests are just not accurate enough to replace what is now the gold standard, according to an anlysis presented in the report.
"A woman who has had an abnormal mammography or abnormal physical exam, in general, is going to need to go for a biopsy," said Dr. Carolyn M. Clancy, director of the Agency for Healthcare Research and Quality (AHRQ).
Dr. Jay Brooks, chairman of hematology/oncology at the Ochsner Clinic Foundation in Baton Rouge, La., added: "If there's a suspicious area in the breast, it should always be biopsied to rule out that it is not cancer. These other tests can give you reassurance, but if there is a high clinical suspicion that there could be cancer in the breast, no non-invasive test should ever dissuade the individual from having a biopsy."
The superiority of biopsy was affirmed in a report, Effectiveness of Noninvasive Diagnostic Tests for Breast Abnormalities, released Thursday by AHRQ's Effective Health Care Program. It is the second in a series of agency reports that compare the effectiveness of different medical treatments.
Both mammography and physical exams are used to detect early signs of breast cancer. If either test reveals a potential problem, the woman usually gets confirmation via a surgical biopsy.
This procedure, which requires taking a sample of breast tissue and analyzing it in a laboratory for signs of cancer, is quite accurate, although it is invasive. And only about 20 percent of women undergoing biopsies actually have cancer, adding urgency to the search for noninvasive tests, the researchers said.
"There's no question that we want noninvasive tests," Clancy said. "It would be lovely if having a second, noninvasive test could preclude the need for a biopsy."
The four tests evaluated in this report -- magnetic resonance imaging, ultrasonography, positron emission tomography scanning, and scintimammography -- have all been proposed as substitutes for biopsies.
But after analyzing 81 existing studies, the authors of the new report determined that the tests weren't as effective as a biopsy.
These noninvasive tests would miss 4 percent to 9 percent of cancer cases in women at an average risk for breast cancer, and probably more among women who are at a higher risk for the disease, the researchers said.
"The risk of missing a cancer is sufficiently high that these tests should not replace biopsies," Clancy said at a Thursday news conference, adding that "the report is not intended to be routinely negative about these tests."
Specifically, the new report found that:
- Using MRIs, there are 38 cancers not detected for every 1,000 women with a negative MRI.
- Using ultrasound, 50 tumors are not diagnosed for every 1,000 women with a negative test result.
- Using PET scans, 76 cancers are undetected for every 1,000 women with negative results.
- And using scintimammography, 93 tumors are not detected for every 1,000 women with negative test results.
The authors and sponsors of the report are hoping the findings will spur better communication between patients and doctors.
"For clinicians and patients making decisions today, that's the state of the evidence," Clancy said. "There may be some individual exceptions based on the personal characteristics of the woman, and we hope this prompts women to have serious and frank discussions with their doctors."
Carolina Hinestrosa, executive vice president of programs and planning at the National Breast Cancer Coalition, said, "This report gives us the answer that we are not ready to replace surgical biopsy and we would be missing an important number of cancers. It's important for us to have this information to make wise decisions."
More information
For more on breast biopsies, visit the National Library of Medicine.
