Abstract:Objective To investigate the relationship between the expression of dihydropyrimidine dehydrogenase (DPD),thymidylate synthase (TS) and the clinicopathological data,the short-term effect of chemotherapy and prognosis of gastric cancer patients received fluorouracil based neoadjuvant chemotherapy. Methods A total of 50 gastric cancer patients who received neoadjuvant chemotherapy at First Hospital of China Medical University from July 2011 to October 2015 were selected as study objects.The patients were treated with fluorouracil combined with oxaliplatin or docetaxel before operation.The hematology was examined before and after chemotherapy.The expression level of DPD and TS proteins was detected by immunohistochemistry in each patient,and their relationship with curative effect and prognosis was analyzed. Results The positive rate of DPD and TS was 52.0% and 48.0% in gastric cancer tissues respectively.There was no significant difference of DPD expression in age,gender,tumor size,Borromann type,tissue type,T stage and N stage (all P>0.05).There was no significant difference in the negative expression rate of TS in different age,gender,tumor size,Borromann type,histological type and N stage (all P>0.05).The positive expression rate of TS protein in different T stages was significantly different (P<0.05).The effective rate of chemotherapy in DPD positive expression group was significantly higher than that in DPD negative expression group ［76.9% (20/26) vs 25.0% (6/24),P<0.01］.There was no significant difference in the effective rate of chemotherapy in TS positive expression group and TS negative expression group ［58.3% (14/24) vs 46.2% (12/26),P>0.05］.The hematological indexes before and after chemotherapy showed that WBC,PLT and carbohydrate antigen (CA)-199 decreased significantly (all P<0.01),while globin (HGB),carcinoembryonic antigen (CEA) and alph hemoa fetoprotein (AFP) had no significant difference (all P>0.05).The 3-year survival rate in DPD positive group was significantly higher than that in DPD negative group (65.5% vs 45.9%,P<0.05),and TS negative group was significantly higher than that TS positive group (65.4% vs 41.7%,P<0.05). ConclusionDPD protein can be used as a predictor of the efficacy of fluorouracil combined chemotherapy in locally advanced gastric cancer,and it can also guide the prognosis.TS protein is related to the prognosis of locally advanced gastric cancer.