Life Science and Medical News from Around the Globe
Unprecedented Genomic Sequencing of Metastatic Triple-Negative Breast Cancer Patients Yields Potential Drug Targets
Genomic sequencing has revealed therapeutic drug targets for difficult-to-treat, metastatic triple-negative breast cancer (TNBC), according to an unprecedented study by the Translational Genomic Research Institute (TGen) and US Oncology Research. The study was published online on November 19, 2012 in the journal Molecular Cancer Therapeutics. By sequencing, or spelling out, the billions of letters contained in the genomes of 14 tumors from ethnically diverse metastatic TNBC patients, TGen and US Oncology Research investigators found recurring significant mutations and other changes in more than a dozen genes. In addition, the investigators identified mutations previously unseen in metastatic TNBC and took the sequencing data into account in selection of therapeutic protocols specific to each patient's genetic profile. "This study stands as a one-of-a-kind effort that has already led to potentially beneficial clinical trials, and sets the stage for future investigations," said Dr. John Carpten, Ph.D., TGen's Deputy Director of Basic Science and Director of TGen's Integrated Cancer Genomics Division, and the study's senior author. The most frequently mutated gene among the tumors (7 of 14) was the TP53 tumor suppressor, and aberrations were observed in additional tumor suppressor genes including CTNNA1, which was detected in two of six African-American patients (who typically have more aggressive and treatment-resistant disease). Alterations were also seen in the ERBB4 gene, known to be involved in mammary-gland maturation during pregnancy and lactation, but not previously linked to metastatic TNBC. The study included an "outlier analysis," which assessed expression patterns for each tumor when compared against the other tumors examined in the study.