Objective To analyze the mutation status of K‐ras gene in the patients with gastric cancer to provide the guidance for the personalized therapy of gastric cancer .Methods The nested and Cold‐PCR were adopted to analyze the K‐ras gene mutation status in 314 cases of gastric cancer .Results In 314 cases of gastric cancer ,the total mutation rate of K‐ras gene was 7 .32% .The mutation rate was 0% in 19 plasma samples and 7 .80% in 295 tissue samples .The types of mutation included G12D ,G13D ,G12V , the mutation rate of K‐ras gene had no statistically significant difference between the two kinds of different samples (P=0 .206 1);the mutation rate was 6 .79% in 221 male patients ,the types of mutation included G12D ,G13D ,the mutation frequency is 8 .60% in 221 female patients ,the types of mutation include G12D ,G13D ,G12V ,the mutation rate of K‐ras gene had no statistically signifi‐cant difference between different genders (P=0 .573 1);the mutation rate was 6 .67% in 45 youth patients ,the types of mutation included G12D ,G13D ,the mutation rate was 7 .87% in 127 middle age patients ,the types of mutation included G12D ,G13D ,G12V , the mutation rate was 7 .04% in 142 old age patients ,the types of mutation included G12D ,G13D ,there was no statistically signifi‐cant difference among different age patients (P=0 .995 3) .Conclusion The mutation rate of K‐ras gene is 7 .32% in 314 cases of gastric cancer ,the main mutation types include G12D and G13D ,and the mutation rate of K‐ras gene has no significant difference a‐mong different samples ,between different sexes and among different ages .

Objective To analyze the polymorphism of thymidylate synthase(TS)in colorectal cancer patients,further more,to provide guidance for personalized therapy of colorectal cancer.Methods PCR direct sequencing was used to detect the polymor-phism of TS in 252 patients with colorectal cancer.Results TS genotypes of 252 patients with colorectal cancer were detected total-ly,including 137 male and 115 female.3RG/3RC accounted for the largest proportion in both male and female(36.50% and 36.52%respectively).In female,2RC/3RC and 3RG/3RG both accounted for the second largest proportion(both 18.25%).While in fe-male,3RG/3RC accounted for the second largest proportion(26.09%).If patients were divided according to age groups,in youth patients(n=28),3RG/3RC accounted for the largest proportion(42.86%),and the second was 2RC/3RG(21.43%).In the middle aged patients(n=84),3RG/3RC(45.24%)and 2RC/3RC(16.67%)were the major genotypes.For old patients(n=115),the ma-jor genotypes were 3RG/3RC(36.52%)and 2RC/3RG(16.52%).Conclusion The polymorphism of TS are mainly 3RG/3RC in colorectal cancer patients.

Objective To analyze the polymorphism of excision repair cross-completion gene 1(ERCC1) in colorectal cancer pa-tients ,and to provide guidance for personalized therapy of colorectal cancer .Methods The polymorphism of ERCC1 in 259 patients with colorectal cancer was detected by PCR .Results The genotype of ERCC1 was mainly C/C(55 .71% ) in male patients ,and then C/T(37 .86% ) ,the genotype of T/T accounted for 6 .43% .The genotype of ERCC1 was also mainly C/C(59 .66% ) in female pa-tients ,and then C/T(36 .97% ) ,the genotype of T/T accounted for 3 .36% .The genotype was mainly C/C(51 .72% ) aged 25 to 44 patients ,and then C/T(41 .38% ) ,the genotype of T/T accounted for 6 .90% .The genotype was mainly C/C(57 .95% ) aged more than 44 to 59 patients ,and then C/T (40 .91% ) ,the genotype of T/T accounted for 1 .14% .The genotype was mainly C/C (58 .45% ) aged more than 59 patients ,and then C/T(34 .51% ) ,the genotype of T/T accounted for 7 .04% .Conclusion The poly-morphism of ERCC1 is mainly C/C in colorectal cancer patients .