Objective:To evaluate the efficacy and adverse reaction caused by Capecitabine compared with S-1 as maintenance treat-ments for patients with advanced gastric cancer (AGC) after first-line induction chemotherapy. Methods:A total of 130 AGC patients who did not suffer disease progression after first-line chemotherapies, including XELOX (four to six cycles), SOX (four to six cycles), and mFOLFOX6 regimen (six to eight cycles), were randomized into three groups. The Capecitabine group (Cap) received maintenance che-motherapy with Capecitabine (1 000 mg/m2 twice daily for 14 days, 21 days/cycle), while the S-1 group (S1) received S-1 (40, 50, or 60 mg according to the body surface area and orally administered twice a day for 14 days, 21 days/cycle). The control group was consid-ered as the observation group. Patients with maintenance treatments received drugs until disease progression or observation of intol-erant toxicity. Results:A total of 44, 33, and 53 patients received XELOX, SOX, and mFOLFOX6 regimens, respectively. The overall DCR was 63.1%. Among the 82 patients, 35, 28, and 19 belonged to the Cap, S1, and observation groups, respectively. The comparison be-tween the efficacy of treatments in the Cap and S1 groups did not show statistically significant differences (P=0.678). The median time of progression was 8.5 months in the Cap group and 9.0 months in the S1 group (P>0.05). Both groups showed better responses than the observation group, which demonstrated a median progression of 6.0 months (P<0.001). The median overall survivals were 14.5, 15.0, and 14.0 months in the Cap, S-1, and observation groups, respectively (P=0.188). The most common adverse effects observed among the patients with maintenance treatments included myelo-suppression, gastrointestinal reaction, fatigue, hand-foot syndrome, and stomatitis. No death occurred in relation to the therapy. Conclusion:The effectiveness of Capecitabine and S-1 as maintenance chemotherapies in AGC patients after the first-line induction chemotherapy are similar, and both can prolong the time of disease pro-gression with low toxicity.

AIM: To investigate the relationship between genotypes of rs628031, rs650284, rs683369 of SLC22A1 gene and the toxicities and clinical response of oxaliplatin in patients with colorectal cancer. METHODS: A total of 72 patients diagnosed as colorectal cancer during January 2018 to June 2018 were selected and all patients received oxaliplatin treatment. Their peripheral venous blood was collected and genotyping was conducted by using SNaPshot. The toxicities including gastrointestinal toxicity, hematological toxicity and peripheral neurotoxicity were evaluated according to the Common Terminology Criteria Adverse Events (CTCAE) Version 5.0. Clinical response was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST Version 1.1). RESULTS: The results of Chi-test showed that different genotypes of SLC22A1 SNP sites rs628031 and rs683369 may be related to the toxicities and clinical response of oxaliplatin significantly. Specifically, when compared with the patients with GG type of rs628031, the patients with the GA or AA type had a lower incidence of grade 3 nausea and vomiting (P=0.017) and may also be less responsive to efficacy (P=0.008). When compared with the patients with CC type of rs683369, the patients with the GC or GG type had a lower incidence of grade 3 nausea and vomiting (P=0.002) and may also be less responsive to efficacy (P=0.014).CONCLUSION: The polymorphisms of SLC22A1 gene are closely related to the toxicities and clinical response of oxaliplatin in patients with colorectal cancer, which may be helpful for improving clinical treatment.