Comprehensive genomic profiling in colorectal cancer (CRC) to identify differing frequencies of clinically relevant genomic alterations (CRGA) in tumors of patients (pts) less than age 50 as compared to those of pts over age 65.

570 Background: CRC is increasing in young pts and are believed to have worse pathological features than older pts. Mutational profiles may differ in pts. The objective of this study was to compare and describe the genomic complexity of CRC in pts 65 in the FoundationOne database. Methods: DNA was extracted from 2,267 FFPE clinical specimens with colorectal cancer (CRC) ( 65 yo, n = 987). CGP was performed on hybridization-captured, adaptor ligation based libraries to a mean coverage depth of 603X for 3,769 exons of 236 cancer-related genes plus 47 introns from 19 genes frequently rearranged in cancer. All classes of genomic alterations (GA) were identified. Clinically relevant genomic alterations (CRGA) were defined as GA linked to drugs on the market or under evaluation in mechanism driven clinical trials. Results: Among the 50 genes analyzed, the > differences were noted in BRAF and FAM123B in pts > 65. KRAS mutations occurred in 50.5% vs 51.3%; NRAS, 2.6% vs 4.8%, BRAF, 5.5...