to see if a similar response is indicative of efficacy in the adjuvant setting
A paper whose abstract I previously posted seems to show similar applicability of this in the neoadjuvant setting--
It might have been helpful to have a serum her2 ECD ELISA test prior to starting herceptin and then a retest around 2-3 weeks later to see if
the serum concentration of the shed extracellular domaiin decreased.
This is still being worked out and is far from accepted practice.
Just letting you know where the research may be leading.
: Breast Cancer Res. 2005;7(4):R436-43. Epub 2005 Apr 8. Links
Clinical utility of serum HER2/neu in monitoring and prediction of progression-free survival in metastatic breast cancer patients treated with trastuzumab-based therapies.
Esteva FJ, Cheli CD, Fritsche H, Fornier M, Slamon D, Thiel RP, Luftner D, Ghani F.
The University of Texas, MD Anderson Cancer Center, Houston, TX, USA.
festeva@mdanderson.org
INTRODUCTION: The purpose of this retrospective study was to determine the clinical utility of serum HER2/neu in monitoring metastatic breast cancer patients undergoing trastuzumab-based therapy and to compare these results with those obtained using cancer antigen (CA) 15-3. We also sought to determine whether early changes in serum HER2/neu concentrations could be a predictor of progression-free survival. METHODS: Sera were obtained retrospectively from 103 women at four medical institutions. Patients eligible for participation were women with metastatic breast cancer who had HER2/neu tissue overexpression and were scheduled to be treated with trastuzumab with or without additional therapies as per the established practices of the treating physicians. A baseline serum sample for each patient was taken before trastuzumab-based therapy was started. Patients were subsequently monitored over 12 to 20 months and serum samples were taken at the time of clinical assessment and tested with Bayer's HER2/neu and CA15-3 assays. RESULTS: Concordance between clinical status in patients undergoing trastuzumab-based treatment and HER2/neu and CA15-3 used as single tests was 0.793 and 0.627, respectively, and increased to 0.829 when the tests were used in combination. Progression-free survival times did not differ significantly in patients with elevated baseline HER2/neu concentrations (> or = 15 ng/mL) and those with normal concentrations (<15 ng/mL). However, progression-free survival differed significantly (P = 0.043) according to whether the patient's HER2/neu concentration at 2 to 4 weeks after the start of therapy was >77% or < or = 77% of her baseline concentration. The median progression-free survival times for these two groups were 217 and 587 days, respectively. A similar trend was observed for a subcohort of patients treated specifically with a combination of trastuzumab and taxane. CONCLUSION: These findings indicate that serum HER2/neu testing is clinically valuable in monitoring metastatic breast cancer patients undergoing trastuzumab-based treatment and provides additional value over the commonly used CA15-3 test. The percentage of baseline HER2/neu concentrations in the early weeks after the start of therapy may be an early predictor of progression-free-survival.
PMID: 15987448 [PubMed - indexed for MEDLINE]
YEARS NED!
Is Herceptin working??
Linear Mode
