Utilizing CellSearch® technology, the ability to both enumerate and reliably and reproducibly characterize circulating tumor cells (CTC) for tumor markers that predict endocrine sensitivity (estrogen receptor \[ER\] and Bcl-2) and resistance (HER2 and Ki67) has been demonstrated. An algorithm for a CTC-Endocrine Therapy Index (CTC-ETI) has been constructed that can be calculated for each patient using the CTC enumeration and marker results. The primary goal of this study is to determine a CTC-ETI in ER positive, HER2 negative metastatic breast cancer patients before the initiation of a new endocrine therapy for the identification of patients that will progress rapidly.
Patients with estrogen receptor (ER) positive metastatic breast cancer (MBC) starting their first line of endocrine therapy (ET) only have a 30-50% chance of receiving clinical benefit. For the other 50-70% of patients, ET is ineffective and these patients should probably be treated with chemotherapy, as is done for ER negative patients. More importantly, in nearly every clinical trial of ET in ER positive, MBC patients, between 15-30% of enrolled patients progress in the first 2-3 months, regardless of whether they are receiving first or later lines of ET. Currently there is no validated method to identify which ER positive MBC patients will be refractory to ET. Therefore, almost all ER positive patients are treated with serial endocrine therapies before switching to chemotherapy. The investigators propose that a subset of these patients would be better served with chemotherapy, in spite of its increased toxicity profile, rather than delaying chemotherapy during a several month trial of ineffective, albeit less toxic, ET. To try and predict benefit from or resistance to ET, an index (the CTC-ETI) has been created that takes into account the number of CTC (which is prognostic) as well as the phenotype of the CTC, based on the hypothesis that relative levels of ER and Bcl-2 (high=benefit) and HER2 and Ki67 (high=resistance) are predictive of ET responsiveness or resistance. Although the preliminary data demonstrate the ability to detect, enumerate, and characterize CTC utilizing the CellSearch® System, the purpose of the current study is to establish proof of principle that these 4 markers can be used to generate a CTC-ETI which can be performed at baseline from patients enrolled at different centers, and that baseline CTC-ETI predicts relative outcome for patients with ER positive MBC starting a new ET, and can be monitored in such patients during ET. Successful completion of this study will set the stage for a larger, definitive study designed to demonstrate the clinical utility of a "refined" CTC-ETI in patients with ER positive, HER2 negative MBC.
Study Type
OBSERVATIONAL
Enrollment
121
Patients will have blood drawn for circulating tumor cell (CTC) endocrine therapy index (CTC-ETI) calculation at baseline (within 30 days prior to the initiation of endocrine therapy) and then subsequently 1, 2, 3 and up 12 months after the initiation of therapy, or at the time of disease progression, whichever occurs first.
Arizona Oncology Associates
Phoenix, Arizona, United States
Florida Cancer Specialists
Fort Myers, Florida, United States
Florida Cancer Specialists
St. Petersburg, Florida, United States
Dana-Faber Cancer Institute
Boston, Massachusetts, United States
University of Michigan Comprehensive Cancer Center
Ann Arbor, Michigan, United States
Minnesota Oncology Hematology
Minneapolis, Minnesota, United States
Mayo Clinic
Rochester, Minnesota, United States
Nebraska Cancer Specialists
Omaha, Nebraska, United States
Comprehensive Cancer Centers of Nevada
Henderson, Nevada, United States
New York Oncology Hematology
New York, New York, United States
...and 10 more locations
Rapid Disease Progression
Within 30 days prior to the initiation of therapy, chest \& abdomen body imaging (computed tomography \[CT\], or magnetic resonance imaging \[MRI\] scanning) plus bone scintigraphic imaging (bone scans or PET scans) or PET-CT scans which encompass both will be performed to identify target and non-target lesions that will be followed with the same imaging techniques 3 months after the initiation of therapy. Objective tumor response will be determined using RECIST v1.1 criteria. Rapid disease progression will be defined as disease progression according to RECIST v1.1 criteria or death due to metastatic breast cancer within 3 months of starting a new ET.
Time frame: Within 3 months after initiation of a new line of enrocrine therapy
Progression Free Survival (PFS)
Within 30 days prior to the initiation of of a new line of endocrine therapy (ET), chest \& abdomen body imaging (computed tomography \[CT\], or magnetic resonance imagine \[MRI\] scanning) plus bone scintigraphic imaging (bone scans or PET scans) or PET-CT scans which encompass both will be performed to identify target and non-target lesions that will be followed with the same imaging techniques 3 months, 6 months, 9 months, and up to 12 months after the initiation of therapy. Objective tumor response will be determined using RECIST v1.1 criteria. Progression Free Survival (PFS) will be measured as the time from the date of starting ET until the date of first documentation of progressive disease according to RECIST v1.1 criteria or death due to any cause. In the absence of these events, PFS will be censored at the date of the last objective disease assessment (up to a maximum of 12 months after the initiation of ET).
Time frame: Up to 12 months after initiation of therapy
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