Analysis of effects of trastuzumab assisted modified DOF fortnightly regimen on serum tumor markers and survival rate in patients with cisplatin-resistant gastric cancer

Background and purpose: Trastuzumab has a relatively low incidence of drug resistance, which can be used as an adjuvant treatment to improve clinical efficacy. It has been used to treat breast cancer in the past, but its application in other cancers has been less studied. This study aimed to explore the effects of trastuzumab assisted modified DOF fortnightly regimen on serum tumor markers and survival rate in cisplatin-resistant gastric cancer patients, in order to provide more references for the selection of clinical treatment methods for cisplatin-resistant gastric cancer. Methods: Eighty patients with cisplatin-resistant gastric cancer treated in Harison International Peace Hospital from January 2017 to January 2019 were selected as the study objects, and they were divided into observation group and control group according to random number table method. All of them received improved DOF fortnightly treatment, and trastuzumab adjuvant treatment was added to the observation group on this basis. The serum tumor markers [serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), CA72-4], serum neovascular markers [vascular endothelial growth factor (VEGF), pigment epithelial derived factor (PEDF), angiopoietin-2 (Ang-2)], biochemical indicators [N-terminal pro B type natriuretic peptide (NT proBNP), aspartate transaminase (AST), blood urea nitrogen (BUN), alanine aminotransferase (ALT)], adverse reactions and survival rate were compared between two groups. This study was approved by the Ethics Committee of Harison International Peace Hospital (number: 20160511). Results: After treatment, CEA, CA19-9 and CA72-4 in both groups decreased, and CEA, CA19-9 and CA72-4 levels were lower in the observation group than in the control group with statistical significance (P0.05). The levels of NT-proBNP, AST, BUN and ALT were compared between the two groups before and after treatment, and there was no statistically significant difference (P>0.05). The number of patients with fatigue, gastrointestinal reaction and myelosuppression and the total incidence of adverse reactions were compared between the two groups, and there was no statistically significant difference (P>0.05). At 5 years after treatment, 11 cases (27.5%) survived and 29 cases (72.5%) died in the observation group. There were 3 cases (7.5%) of survival and 37 cases (92.5%) of death in the control group. The median survival was 2 years (95% CI: 1.8-2.2) in the observation group and 1 year (95% CI: 0.6-1.4) in the control group. The survival rate of 1-5 years was higher in the observation group than in the control group. The difference was statistically significant (log-rank χ2 = 13.853, P = 0.001). Conclusion: In the clinical treatment of cisplatin-resistant gastric cancer, trastuzumab assisted modified DOF fortnightly regimen suggests that it can reduce the expression levels of serum tumor markers, improve the 5-year survival rate of patients, and has certain drug safety.