SAN ANTONIO, Dec. 10 (UPI) -- Most triple-negative breast cancer patients treated with chemotherapy to shrink a tumor before surgery may still have genetic mutations, U.S. researchers say.
Justin Balko and research faculty in the laboratory of Dr. Carlos Arteaga at the Vanderbilt University Medical Center-Ingram Cancer Center said finding multiple mutations instead of just one primary mutation could be another avenue for therapy.
Approximately 15 percent of U.S. breast cancer patients have triple-negative cancer -- a form of the disease that is more difficult to treat and disproportionately affects young African-American women.
"The standard of care for many patients with triple-negative breast cancer is to administer chemotherapy before surgery to shrink the tumor," Balko said in a statement. "Unfortunately, about 70 percent of patients still have some residual disease at the time of surgery, despite treatment."
Balko and colleagues profiled residual tumor tissue from 114 patients with triple-negative breast cancer who had received chemotherapy prior to surgeries and evaluated DNA from 81 tumors.
They used deep sequencing to examine 182 oncogenes -- genes with the potential to cause cancer -- in tumor cells and tumor suppressors known to be altered in human cancers. Instead of finding similar genes affected among the patients, they found a diverse set of genes were altered, the study said.
The findings were presented at The Cancer Therapy & Research Center -- American Association for Cancer Research San Antonio Breast Cancer Symposium.