Women with breast cancer who receive compounds that stimulate white blood cell production to help their bodies better tolerate chemotherapy are at an increased risk of developing a type of leukemia or a condition called myelodysplastic syndrome, according to a new study in the February 7 Journal of the National Cancer Institute. The authors note that the absolute risk of the conditions is very small, but that risk should still be taken into consideration when making treatment decisions.

The growth factors granulocyte or granulocyte-macrophage colony-stimulating factor (G-CSF or GM-CSF) have been used to reduce the risk of infections from neutropenia, an abnormally low count of a certain type of white blood cell that helps control infections. Chemotherapy destroys these cells, and it is difficult for the body to quickly replace them.

However, there is some concern that these growth factors may keep cells alive that have been mutated by chemotherapy. Ordinarily, certain cell processes would recognize such damage and instruct the cell to die, but growth factors may save the mutant cell, allowing it to develop into a cancer called acute myelocytic leukemia (AML). There's also concern about the risk of a disease called myelodysplastic syndrome (MDS), in which the bone marrowwhich produces blood cellsdoes not function normally. Indeed, some studies have hinted that cancer patients who receive growth factors with chemotherapy may have an increased risk of these two diseases.

Dawn Hershman, M.D., of the Herbert Irving Comprehensive Cancer Center at Columbia University Medical Center and New York Presbyterian Hospital, and colleagues set out to determine the association between G-CSF or GM-CSF use and the risk of AML or MDS among women treated with chemotherapy for early-stage breast cancer. Using a database that links cancer registry data from the Surveillance, Epidemiology, and End Results (SEER) program with data from Medicare, th
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Contact: Liz Savage
jncimedia@oxfordjournals.org
301-841-1287
Journal of the National Cancer Institute
6-Feb-2007