Breast cancer patients who received chemotherapy prior to surgery had heightened levels of cancer stem cells in their bone marrow, say scientists at The University of Texas M. D. Anderson Cancer Center. Additionally, the level of these cells correlated to a tumor's lymph node involvement.
James Reuben, Ph.D., associate professor in the department of hematopathology, will present the findings during the upcoming American Society of Clinical Oncology's annual meeting. “Our research showed a higher presence of cancer stem cells correlated with more advanced disease, suggesting that they may one day be a prognostic factor for identifying those at greatest risk for metastasis and recurrence.”
The study enrolled 90 breast cancer patients from September 2006 to October 2008. Bone marrow aspirations were performed in all women at the time of their surgery. Of the 90 women, 32% underwent neoadjuvant chemotherapy, and eight of those 29 patients had been treated with anti-HER2 targeted therapy. All other patients had early-stage disease and therefore did not need chemotherapy prior to surgery. Of the bone marrows collected, 61 were analyzed for estrogen receptor and HER-2 status as well as expression of the transcription factor Notch-1.
Using multicolor flow cytometry methods, the researchers found patients who received neoadjuvant therapy featured a significantly higher presence of breast cancer stem cells and higher percentage of specific markers that are associated with breast cancer stem cells compared to patients with early-stage disease.
“As the cancer stem cells were concentrated in patients who had already received therapy, our research indicates their true resilience and lack of sensitivity to chemotherapy as well as demonstrates a need for a more comprehensive study of micrometastasis and molecular markers that target these illusive cells,” notes Dr. Reuben.
The researchers also found the level of Notch-1 was lower in neoadjuvant-treated patients and inversely correlated to the percentage of breast cancer stem cells, suggesting that Notch signaling may play an integral role in the development of breast cancer stem cells.
Past News on Cancer Stem Cells
Neuroblastoma Cell Lines Found to Contain Cancer Stem Cells (Jan. 21, 2009)
Scientists Uncover Gene-Expression Signature for Prostate Cancer Stem Cells (May 20, 2008)
NextGen Acquires Pending Patent from Oxon Life Science Linked to Breast Cancer Stem Cells (Apr. 8, 2008)
Researchers Discover How Cancer Stem Cells Are Trapped at an Early Developmental Stage (Jan. 7, 2008)
Scientists Identify miRNA that Regulates Cancer Stem Cells (Dec. 14, 2007)