Somatic mutations of KRAS gene were identified in 146 cases, with the mutation rate of 33.2% (146/440). Among these 146 patients, KRAS mutation involved
codon 12 in 118 patients, including 35G > A (Gly12Asp, 62 cases), 35G > T (Gly12Val, 35 cases), 34G > T (Gly12Cys, 9 cases), 34G > A (Gly12Ser, 6 cases), 35G > C (Gly12Ala, 5 cases), and 34G > C (Gly12Arg, 1 case); in 27 patients the mutation involved
codon 13, including 38G > A (Gly13Asp, 25 cases), 38G > C (Gly13 Val, 1 case) and 37G > T (Gly13 Cys, 1 case); and in one patient, the mutation involved
codon 14 with 40G > A (Val14Ile). The status of KRAS or
codon 12 mutations in colorectal
adenocarcinoma was related to patients' gender (P = 0.021 and P = 0.030, respectively), and this significant correlation to females was conserved in clinical stage III (P = 0.007 and P = 0.003, respectively), but not in stages I, II, and IV. The status of KRAS or
codon 12 mutations was also related to
tumor stage. Between stage II and stage IV, the mutation rate of KRAS and
codon 12 showed significant difference (P = 0.028 and 0.034, respectively). Between stage III and stage IV, only the
codon 12 mutation rate showed significant difference (P = 0.011).
Codon 13 mutation was not related to
tumor stage.
CONCLUSION: