Researchers identify prognostic marker in chronic lymphocytic leukemia

 Published on June 13, 2012 at 5:50 AM  Researchers have identified a prognostic marker in the most common form of chronic leukemia that can help to distinguish which patients should start treatment quickly from those who can safely delay treatment, perhaps for years.  The study, led by researchers at the Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC - James), focused on chronic lymphocytic leukemia (CLL), a malignancy expected to occur in 16,000 Americans this year and cause 4,600 deaths.  The researchers examined a gene called ZAP-70 in CLL cells for a chemical change called methylation. They found that when the gene in leukemia cells is methylated, patients are likely to have the slow-progressing form of CLL, and when the ZAP-70 gene is unmethylated, patients are likely to have aggressive disease and should consider beginning treatment immediately.  Currently, doctors must simply observe newly diagnosed patients to determine which type of CLL they have. This can delay the start of treatment in patients with aggressive disease, or it can lead to treating patients who don't yet require it.  The findings are published in the Journal of Clinical Oncology.  "This study demonstrates that ZAP-70 methylation status is a highly predictive, reproducible biomarker of poor prognosis in this disease, and a clinically useful prognostic test for CLL," says principal investigator Dr. John Byrd, a CLL specialist and professor of Medicine, of Medicinal Chemistry and of Veterinary Biosciences at the OSUCCC - James.