Clinical effect of S-1 in treatment of circulating tumor cell-positive patients after radical surgery for primary hepatic carcinoma

Objective To investigate the clinical effect of tegafur, gimeracil, and oteracil ( S-1) in the treatment of circulating tumor cell ( CTC) -positive patients after radical surgery for primary hepatic carcinoma ( PHC) . Methods A total of 56 CTC-positive patients after radical surgery for PHC who were admitted to Chongqing Cancer Hospital from June 2014 to January 2016 were enrolled and randomly divided into treatment group and control group, with 28 patients in each group. The two groups were observed in terms of the change in the number of CTCs after treatment, toxic and side effects, and disease-free survival time. The t-test was used for comparison of continuous data between groups; the chi-square test or the Fisher's exact test was used for comparison of categorical data between groups; the Kaplan-Meier method was used to plot survival curves and the Breslow test was used for comparison of survival rates between the two groups. Results There were significant differences in the number of CTCs between the two groups at 3 months ( 2. 1 ± 1. 2 vs 3. 8 ± 1. 2, t = 5. 52, P < 0. 000 1) , 6 months ( 1. 9 ± 1. 3 vs 4. 0 ± 1. 4, t = 5. 96, P < 0. 000 1) , 12 months ( 1. 5 ± 1. 2 vs 4. 5 ± 1. 5, t = 8. 17, P < 0. 000 1) , and 18 months ( 1. 6 ± 1. 4 vs 5. 5 ± 0. 9, t = 12. 33, P < 0. 000 1) after treatment. The treatment group had a significant reduction in the number of CTCs at one month after treatment ( t = 8. 10, P < 0. 000 1) . The control group had a significant increase in the number of CTCs over time. The treatment group had a significantly longer disease-free survival time than the control group ( t = 5. 279, P = 0. 021 6) , and there was a significant difference in the time to progression between the treatment group and the control group ( 11. 8 ± 2. 4 months vs 10. 8 ± 2. 3 months, t = 4. 31, P < 0. 05) . No patient died during the observation period. Five patients in the treatment group experienced adverse events, among whom 2 had gastrointestinal reaction, 2 had liver injury, and 1 had myelosuppression, and all of them were improved after symptomatic treatment, without any influence on the administration of therapeutic drugs. No patient experienced grade ≥III side effects. Conclusion S-1 can increase the disease-free survival time of CTC-positive patients after radical surgery for PHC and does not increase toxic and side effects.