termsTerm
Wild-type (WT)
aka wild type, wildtype, RAS wild-type, KRAS wild-type, BRAF wild-type, TP53 wild-type, TP53-wild-type, EGFR wild-type, unmutated
The normal, unmutated version of a gene. Saying a tumour is 'RAS wild-type' means its RAS gene is not mutated, which for colorectal cancer means EGFR antibodies can work.
Borrowed from genetics, wild-type is the reference sequence against which mutations are defined. It matters when a mutation predicts resistance rather than sensitivity: only RAS/BRAF wild-type colorectal cancers respond to cetuximab or panitumumab; TP53 wild-type tumours can respond to MDM2 inhibitors; unmutated IGHV in CLL predicts shorter remissions with chemoimmunotherapy. Because 'wild-type' depends on what was tested, a tumour can be wild-type on a small panel and mutated on a larger one.
Category
Pathology & biomarkers