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There was some discussion a while back about a blood test to see if you were responding to treatment. The following presentation was made in San Antonio and we will be following up with Bayer shortly to get more information.
Regards
Joe
[6001] Clinical utility of circulating HER-2/neu in monitoring and prediction of progression-free survival in metastatic breast cancer patients undergoing trastuzumab-based therapy.
Esteva FJ, Cheli C, Fritsche HA, Fornier M, Slamon DJ, Thiel RP, Luftner D, Ghani F.. UT M. D. Anderson Cancer Center, Houston, TX; Bayer Healthcare, Tarrytown, NY; Memorial Sloan-Kettering Cancer Center, New York, NY; University of California Los Angeles, Los Angeles, CA; Thiel Consultants, Oxford, CT; Humboldt-Universitat, Berlin, Germany
The objective of this study was to determine the clinical utility of serum HER-2/neu in monitoring metastatic breast cancer patients undergoing trastuzumab-based therapy and to compare these results to those obtained using CA15-3. Additionally, we sought to determine whether early changes in serum HER-2/neu levels could be a predictor of progression-free survival (PFS). Patients and Methods: Patient sera were obtained retrospectively from 103 patients with HER-2/neu overexpressing metastatic breast cancer who were scheduled to be treated with trastuzumab, with or without additional therapies. Serum samples were taken prior to initiation of trastuzumab-based therapy, and at the time of clinical assessment over a 12-20 month period. Samples were tested using Bayer HER-2/neu and CA 15-3 ELISA assays. Results: Concordance with clinical status in monitoring patients undergoing trastuzumab-based treatment using HER-2/neu and CA15-3 as single tests were 0.793 and 0.627, respectively and when the tests were used in combination concordance increased to 0.829. Baseline HER-2/neu levels were not predictive of PFS (p=0.12). However, progression-free- survival was significantly different in patients with >75% of baseline levels of HER-2/neu as compared to those with < 75% of baseline levels at 2-4 weeks after the start of therapy. The median PFS for those patients whose HER-2/neu value was less than 75% of baseline was 587 days. In the cohort with > 75% of baseline the median PFS was 260 days (p=0.035). Conclusion: Serum HER-2/neu testing is clinically valuable in monitoring metastatic breast cancer patients undergoing trastuzumab-based treatment, and provides additional value over the commonly used CA 15-3 test. Futhermore, the percentage of baseline HER-2/neu levels in the early weeks after the start of therapy may be an early predictor of progression-free-survival.
Date: Saturday, December 11, 2004 07:00 AM
Session Info: Poster Session: Detection/Diagnosis: Circulating Markers (7:00 AM-9:00 AM)
Presentation Time: 07:00 AM
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