Nguyen Thi Van Hong Institution: Hanoi Medical University Novel conclusion and distribution of the thesis: From our study of the colorectal cancer patients, the mutation proportion of both gen KRAS and gen BRAD is 33, 8% (49/145), the mutation ratio of gen KRAS is 30, 4% (44/145), the mutation proportion of gen BRAF is 3, 4% (5/145), and 4, 9% (5/101) of these patients do not have the mutation of gen KRAS.