title: Rare Though Not Mutually Exclusive: A Report of Three Cases of Concomitant KRAS and BRAF Mutation and a Review of the Literature.
abstract: KRAS mutations occur frequently in colorectal cancers (CRC) and predict lack of response to anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy. CRC BRAF mutations, most commonly at V600E, occur less than 10% of the time, and occur usually in KRAS wild-type tumors, and more frequently in microsatellite instable tumors. Concomitant KRAS and BRAF mutant CRCs are rare (occurring in 0.001%); BRAF mutations should not be routinely tested in patients with KRAS mutant tumors, unless the patients is participating in a clinical trial enriching for the presence of a KRAS or BRAF tumor. Clinical trials treating patients with either KRAS or BRAF mutant tumors should address eligibility of patients with concomitant KRAS and BRAF mutations.
authors.affiliation: Department of Gastrointestinal Medical Oncology, The University of Texas M.D. Anderson Cancer Center, Unit 426, 1515 Holcombe Boulevard, Houston, Texas, 77030-4009.
authors.forename: Ibrahim Halil
authors.initials: IH
authors.lastname: Sahin
authors.forename: Syed M A
authors.initials: SM
authors.lastname: Kazmi
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Yorio
authors.forename: Nishin A
authors.initials: NA
authors.lastname: Bhadkamkar
authors.forename: Bryan K
authors.initials: BK
authors.lastname: Kee
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Garrett
keywords: BRAF; Concomitant KRAS