Jane Albright
Inova Health System
703-204-3350
FOR IMMEDIATE RELEASE
June 24, 1997
Blood Test to Detect Recurrent Breast Cancer As Reported in Journal of Clinical Oncology Study
FALLS CHURCH, Va. -- A study in this month's issue of the Journal of Clinical Oncology reports on a blood test that can help predict cancer recurrence in women previously treated for stage II and stage III breast cancer. Roy A. Beveridge, M.D., with the cancer center at Inova Fairfax Hospital, was one of the lead investigators. The test, TRUQUANTÆ BR Radioimmunoassay (RIA), was the first test cleared by the U.S. Food and Drug Administration for detection of breast cancer recurrence in this patient group.
≥The CA 27.29 test is a significant and independent predictor of breast cancer recurrence,≤ said Dr. Beveridge. ≥Determining recurrence before the development of symptoms presents an opportunity to treat metastatic disease when the tumor burden is low and, hopefully, when therapy is likely to be more effective.≤
The objective of the study was to determine the ability of the TRUQUANT BR test to predict disease recurrence through measuring levels of the breast tumor marker CA 27.29, a mucinous glycoprotein of the MUC-1 gene, which is present in breast cancer cells. The glycoprotein is shed into the bloodstream in high levels as breast cancer metastasizes (spreads). The study was a three-year prospective, double-masked, multicenter clinical trial that evaluated 166 women with stage II or III breast cancer who were clinically free of disease at the time of enrollment.
Researchers found that use of the TRUQUANT BR test provided an average lead time of 5.3 months when detecting a distant metastasis. In patients with locoregional disease, the average lead time was 2.3 months. The difference in lead time may reflect the differing levels of the breast tumor marker, CA 27.29, present in different types of tumors. Metastatic tumors generally have high levels of CA 27.29 whereas locoregional tumors have lower levels of CA 27.29. Lead times are likely to be greater than those obtained by using intensive follow-up methods over a longer period of time. [In this study, the mean patient follow-up time was only 13.5 months.]
In addition, the study showed that TRUQUANT BR RIA had a sensitivity of 57.7 percent (the probability that a patient having a disease will be correctly identified by a clinical test) and a specificity of 97.9 percent (the probability that a patient who does not have a disease will be correctly identified by a clinical test). In comparison to other commonly used diagnostic methods, its relatively high sensitivity and specificity gave the test strong predictive values. The positive predictive value was 83.3 percent (how often a positive test result predicts a disease occurrence) and the negative predictive value was 92.6 percent (how often a negative test result predicts that the patient is disease-free).
In addition to Inova Fairfax Hospital the following institutions participated in the trial: Johns Hopkins Medical Institutions (Baltimore, Maryland), University of Minnesota (Minneapolis, Minnesota), Bowman Gray School of Medicine (Winston-Salem, North Carolina), and University of Texas M.D. Anderson Cancer Center (Houston, Texas).
≥The potential of the CA 27.29 test will grow as increasingly effective treatments in breast cancer are developed,≤ said Dr. Beveridge. ≥CA 27.29 will be used as an adjunct in new and ongoing trials that evaluate asymptomatic patients who are postdiagnosis. These results will further define how we will use CA 27.29 in determining breast cancer treatment.≤ According to a 1995 study on patient preferences for treatment of metastatic breast cancer published in the Journal of Clinical Oncology, more than 50 percent of breast cancer patients told that they would have recurrent disease would opt for chemotherapy in the absence of symptoms for the potential of increased life span.
TRUQUANT BR RIA, manufactured and marketed by Biomira Diagnostics Inc., was cleared for marketing by the U.S. Food and Drug Administration on March 29, 1996. The test, which is easy to administer and cost-effective, may reduce the need for more invasive and expensive diagnostic tests, such as bone scans.
NOTE: Patients available for interview upon request.
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