August 31, 2009

Protein levels may affect chemo therapy

U.S. scientists studying Ewing's sarcoma -- a type of bone cancer -- have found high levels of a specific protein can suppress chemotherapy effects.

Researchers at the University of Utah's Huntsman Cancer Institute discovered some patients with Ewing's sarcoma -- which typically afflicts children and young adults -- have poor outcomes if their tumors have high levels of a protein known as GSTM4.

Our research shows that GSTM4 is found in high levels among those patients where chemotherapy doesn't seem to work, said Dr. Stephen Lessnick, who led the research. It's found in low levels in patients where chemotherapy is having a more positive effect.

He said the protein doesn't seem to suppress the benefits of all chemotherapy drugs, just certain ones, therefore a test for that specific protein could help identify the best therapy for each individual patient.

Ewing's sarcoma is the second most common bone cancer in children and adolescents, Lessnick said. The five-year survival rate is considered poor at about 30 percent if the cancer has spread by the time it is diagnosed, and there is an even poorer prognosis for patients who have suffered a relapse.

The study is reported in the early online edition of the journal Oncogene.