Circulating Tumor Cells Prove To Be Key Predictors of Survival in Newly Diagnosed Metastatic Breast Cancer Patients

Main Category: Breast Cancer
Article Date: 03 Mar 2005 - 9:00 PDT

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Homogenous test group reinforces value of information gleaned through simple blood test -

Veridex LLC, a Johnson & Johnson company, today announced that a study published in the Journal of Clinical Oncology (March 1, 2005) found that the presence of circulating tumor cells (CTCs) in the blood of patients newly diagnosed with metastatic breast cancer is highly predictive of progression-free, overall survival, and is associated with significant prognostic information. Further, the results indicate that the company's CellSearch™ System, which was used to identify and enumerate CTCs - cancer cells that detach from solid tumors and enter the bloodstream - may one day allow for design of tailored treatments earlier than ever before possible.

Researchers worked with an 83-patient subset of the 177 patients with metastatic breast cancer who were involved in a multi-institution, double blind study recently published in The New England Journal of Medicine (August 19, 2004). In order to obtain the most directly comparable results possible, the subset was limited to patients whose cancer had recurred but who had not yet received any treatment, thereby eliminating complicating factors such as differences among prior therapies, or stage and timing of treatments. Patients were tested for a CTC count prior to initial therapy, then approximately every four weeks and were followed clinically out to 18 months.

Patients with five or more CTCs per 7.5mL (the equivalent of one blood draw) at baseline and first follow-up (four weeks) ultimately had significantly shorter progression-free survival and overall survival. Patients with five or more CTC had a median PFS of 4.9 months and a median OS of 14.2 months OS prior to the administration of therapy versus patients with fewer than five CTCs prior to therapy (median PFS of 9.5 months and more than 18 months OS). At first follow-up after the administration of the first cycle of therapy, patients with five or more CTC had a median PFS of 2.1 months and 11.1 months OS versus patients with less than five CTC had median PFS of 8.9 months and more than 18 months OS.

"By studying a subpopulation of patients who are at precisely the same point in their illness, without having to take into account a variety of outside factors, we could have a clear picture of the biology of metastatic breast cancer and the role that CTCs played," said lead author Massimo Cristofanilli, M.D., associate professor in the Department of Medical Oncology at the University of Texas M. D. Anderson Cancer Center. "Our findings with this homogenous group of patients reinforce the value of this technology in identifying patients who might be resistant to a particular therapy and those who could benefit from early treatment change or a more investigational approach."

The CellSearch™ Circulating Tumor Cell Test requires only a simple blood draw from a patient, but its sensitivity and specificity allow physicians to observe true changes in CTCs that are greater than or less than the five CTC cutoff. This information may help physicians predict, with a high degree of certainty, progression-free and overall survival in individual patients both before and following a single cycle of therapy, develop individual patient treatment strategies and counsel and advise patients appropriately.

"Scientists have long believed that circulating tumor cells held a wealth of information, but there was no method to efficiently and objectively evaluate and utilize them for decision making in routine medical practice," said Robert T. McCormack, Ph.D., general manager, Cellular Diagnostics for Veridex, LLC. "We're pleased that this study has shown that our technology will go a long way toward addressing an unmet need in the cancer field and could change the course of treatment for many critically ill patients."

Immunicon Corp., of Huntingdon Valley, PA, developed the CellSearch™ System under a Development, License and Supply Agreement with Veridex, LLC.

About Veridex, LLC

Veridex, LLC, a Johnson & Johnson company, develops cancer diagnostic products that will enable earlier disease detection as well as more accurate staging, monitoring and therapeutic selection. The company is initially developing two complementary product lines: CellSearch™ assays that identify, enumerate and characterize circulating tumor cells directly from whole blood; and GeneSearch™ assays that use molecular technology to diagnose, stage and more accurately characterize tumors. For more information, visit http://www.veridex.com.

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