A Phase III clinical trial will study whether using the CellSearch test can help physicians determine more quickly whether a woman's advanced breast cancer is responding to chemotherapy treatment.
The National Cancer Institute will study whether women with metastatic breast cancer that have elevated levels of circulating tumor cells (CTCs) after their first chemotherapy treatment can live longer by changing to a different chemotherapy regimen immediately rather than waiting until their disease progresses.
An earlier study published in the Journal of Clinical Oncology suggested that the presence of CTCs may help doctors determine the aggressiveness of a women's breast cancer. For example, a blood sample that contains fewer than five CTCs may indicate a cancer that will be slower to spread; a blood sample with five or more CTCs may suggest a cancer more likely to progress quickly.
The test CellSearch measures the number of circulating tumor cells in a sample of blood. Many women affected by metastatic breast cancer undergo initial chemotherapy to fight the cancer. In most cases, the women will receive a specific treatment until the cancer begins to progress. Researchers hope that by measuring the CTC count before a women begins treatment and following it over time, they may be able to determine whether the treatment is working before symptoms of progression appear.
1. I have been following this tumor cell counting test since its inception in 2005/2006. JNJ's Veridex unit markets the test. My friend Mary and other women that I have been advising have been successfuly using the CellSearch (circulating tumor cell) test to monitor their health and cancer treatment.
University of Michigan's Dan Hayes, MD Anderson's Massimo Cristofanilli, and Budd @ the Cleveland Clinic (Journal of Clinical Oncology article cited above) are all involved with this research.
The results continue to come in and consistently a robust and direct correlation between CTCs (circulating tumor cells) and progression free survival.
CTCs under 5 indicate a therapy is working well, one is in remission, or vice versa, greater than 5 CTCs indicate a need to change therapies, or start therapy.
If you have question, feel free to E-mail @ dechaumontquitry at gmail dot com or talk with your oncologist. Lastly, you can see, veridex.com's website.
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Circulating Tumors Show Aggressive Disease
Provided by: M. D. Anderson
Number of Cells Determine Breast Cancer Treatment
Massimo CristofanilliPatients with advanced breast cancer who have more than five circulating tumor cells in the blood may have a more dangerous form of the disease, according to an M. D. Anderson study.
The pivotal study, published in the August issue of The New England Journal of Medicine, could lead to more tailored treatments that would spare some women from the most potent chemotherapy. It could also recognize which patients need more aggressive therapy at the start of treatment, says lead author Massimo Cristofanilli, M.D., associate professor in M. D. Anderson's Department of Breast Medical Oncology.
"This is the first time that we can actually stratify metastatic breast cancer patients based on their risk," Cristofanilli says. "When a physician assesses a woman with metastatic breast cancer, it is very difficult to make an accurate prediction of her prognosis. Now we may know more about what the prognosis will be, based on a simple blood test and a new technology. One day we may be able to suggest to a patient - based on personal risk - a more aggressive treatment, a less aggressive treatment, or no treatment at all."
Circulating tumors identified
Metastasis is the most life-threatening aspect of cancer, Cristofanilli says. To metastasize, cancer cells must leave the primary tumor site, travel through the blood and proliferate in a new site. Until recently, doctors have not been able to reliably isolate circulating tumor cells in the blood. Within the last few years, several methods have been developed to label tumor cells with antibodies that can then be measured precisely, identifying even one tumor cell in a vial of blood.
The multi-center trial was conducted at 20 institutions in the United States - including the Cleveland Clinic, Duke University, the University of Arizona, and the University of Michigan - with M. D. Anderson as the lead site.
The 177 women patients in the trial were first tested for circulating tumor cell counts prior to therapy, and then again at their first follow-up three to four weeks later.
First test results:49%, or 87 women, were found to have five or more circulating tumor cells per 7.5 milliliters of blood, the equivalent of one blood draw. These patients had significantly shorter progression-free survival (2.7 months versus seven months) and overall survival (10.1 months versus greater than 18 months) than women with fewer than five circulating tumor cells per blood draw.
Follow-up visit findings:Circulating tumor cells again were collected. Then, 30% of the women had five or more circulating tumor cells per blood draw, indicating that a portion of the study group responded to therapy. The difference in progression-free survival between the two groups remained consistent - 2.1 months for women with five or more circulating tumor cells, versus seven months for women with fewer than five circulating tumor cells.
Overall, survival in women with more than five circulating tumor cells was 8.2 months, compared to greater than 18 months in women with fewer than five circulating tumor cells.
Moreover, Cristofanilli says, the presence of cancer cells in the blood predicted prognosis more accurately than the site of metastasis or the presence of estrogen receptors on the tumor cells, thereby having even more potential to impact standard treatment and future research.
"You can see there is a difference in efficacy or benefit of treatment in women who are selected based on the presence of cells or not," Cristofanilli says. "The most obvious case is estrogen-receptor positive disease. Some doctors are reluctant to give these women a hormonal treatment at diagnosis, but would rather be safe and give chemotherapy, the most aggressive treatment. Utilizing this test, we may one day definitively tell estrogen-receptor positive women if they have a worse prognosis and that chemotherapy is the right approach. Or, for those with few or no circulating cells, it is safe to go ahead with hormonal treatment alone."
Research has invaluable future
Cristofanilli and his M. D. Anderson colleagues have long been working with circulating tumor cell technology and were the first to recognize its prognostic implications in women with metastatic disease. At the 2003 annual American Association of Cancer Research meeting, they reported a preliminary analysis of 41 patients evaluated at M. D. Anderson. These initial observations are further validated by the results of this multi-center trial.
Christofanilli's future plans for circulating tumor cells include:
Using the cells prospectively to group patients for future clinical trials.
Collecting the circulating tumor cells to see how they are representative of the primary tumor, then perhaps replacing a biopsy with the ability to evaluate how the metastatic patient is responding to therapy.
Studying the correlation of circulating tumor cells to determine how patients respond to various types of treatments.
Technology drives research
The diagnostic technology utilized in this study, the CellSearch System, is the first of its kind to automate the detection and enumeration of circulating tumor cells in peripheral blood. It works by detecting cancer cells that detach from solid tumors and enter the blood stream. The test is not yet commercially available to patients; however, it is expected to be available soon.
Cristofanilli cautions that information generated by the technology is a powerful tool for both patients and physicians, and must be utilized with care.
"The majority of women facing metastatic breast cancer want to know their prognosis, good or bad, but they are afraid of bad news," he says. "If we can discover in a newly diagnosed patient that tumor cells are already in the blood, both patient and physician would be aware that we are dealing with a more aggressive cancer that requires more aggressive treatment early on."
Posted at 7:06PM on Jan 9th 2007 by Theo de Chaumont-Quitry