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Dormant Cancer Cells

U.S. Department of Health and Human Services NATIONAL INSTITUTES OF HEALTH (NIH) News National Cancer Institute (NCI)


Scientists using a three-dimensional cell culture system have identified a mechanism by which dormant, metastatic tumor cells can begin growing again after long periods of inactivity. The new findings indicate that the switch from dormancy to proliferative, metastatic growth may be regulated, in part, through signaling from the surrounding microenvironment, which leads to changes in the skeletal architecture of dormant tumor cells. Targeting this mechanism may also provide strategies for inhibiting the switch from dormancy to proliferation. The results of this study by National Cancer Institute (NCI) scientists and their collaborators, appears in the August 1, 2008, issue of “Cancer Research.”  NCI is part of the National Institutes of Health.

The recurrence of breast cancer often follows a long latent period in which there are no signs of cancer, and metastases may not become clinically apparent until many years after removal of the primary tumor and follow-up therapy. According to NCI’s Jeffrey E. Green, M.D., one of the lead researchers of this study, “Recent evidence suggests that, in many cases, tumor cells have already seeded metastatic sites even when the primary tumor is diagnosed at an early stage.”  Approximately 30 percent of breast cancer patients diagnosed with early-stage disease have been found to have breast cancer cells in their bone marrow.  However, these cells seem to exist primarily as micrometastases that do not manifest themselves clinically in any way.

Although many of these disseminated tumor cells may not survive for extended periods of time, a subset of them may represent dormant but viable cells that could begin to proliferate years later. These dormant cells can be resistant to conventional therapies, such as chemotherapy, that target actively dividing cells; such cells could account for disease recurrence after apparently successful treatment of primary tumors.

Dr Jarir Nakouzi.Com