FRIDAY, Nov. 14 (HealthDay News) -- Non-small cell lung tumors tend to have a different genetic makeup in blacks than in whites, a finding that may explain why treatment and outcomes are different among races, a new study says.

In blacks, the tumors are more likely to carry more copies of the epidermal growth factor receptor (EGFR) gene and fewer mutations of EGFR itself, according to researchers who presented their findings Nov. 13 at the 2008 Chicago Multidisciplinary Symposium in Thoracic Oncology. Previous studies have shown that more copies, regardless of mutation, predict patient responses to EGFR inhibitor drugs, such as erlotinib and gefitinib, the researchers said.

Blacks with this type of lung cancer typically do not fare well, based on past studies.

"The findings of this study were surprising, since it was not expected that drug-sensitizing EGFR mutations would be so rare in this patient population," study co-author Dr. Rom Leidner, a clinical fellow in hematology/oncology at Case Western Reserve University in Cleveland, said in a news release issued by the conference organizers. "African-American patients remain underrepresented in clinical studies in oncology, and therefore our knowledge base about how to modify our treatment strategies for this patient population remains poorly defined."

The study's researchers said they hope their findings influence the design of future clinical studies and the future use of EGFR-targeted agents.