Abstract 1456P
Background
The efficacy of S-1 combined with a platinum agent in the first-line setting and in patients with advanced gastric cancer has been previously demonstrated in randomized clinical trials. However, real-world evidence on effectiveness in European populations remains limited.
Methods
In the present study, we reviewed the data of a European cohort of patients with advanced gastric cancer treated with first-line therapy including S-1 combination with a platinum agent according to established schedules.
Results
48 patients (29 with locally advanced/inoperable and 19 with metastatic disease) were treated with S-1 plus a platinum agent. The clinicopathologic data and outcomes are shown in Table. The multivariate Cox regression analysis indicated that the use of cisplatin as compared to oxaliplatin was associated with worse survival and increased risk of death [PFS HR: 2.791; (CI 95%:1.326-5.875); p=0.007 and OS HR:9.272; (CI 95%:1.336-64.33); p=0.024]. Similarly, tumor grade III versus II was associated with worse survival [PFS HR: 3.009; (CI 95%:1.340-6.760); p=0.008 and OS HR: 3.736; (CI 95%:1.158-12.06); p=0.027]. Four SAEs GIII where recorded (1 fatigue, 1 neutropenia, 1 anemia, 1 diarrhea) in 3 patients. Table: 1456P
Clinicopathologic data and outcomes
| n (%) | Oxaliplatin + S-1 | Cisplatin + S-1 | |
| 48 (100) | 33 (100) | 15 (100) | |
| Median Age (range) | 63 (24-84) | 60 (24-84) | 66 (47-81) |
| Male | 37 (77,1) | 25 (75.8) | 12 (80,0) |
| Stomach primary | 25 (52,1) | 14 (42.4) | 11 (73.3) |
| Gastroesophageal primary | 23 (47,9) | 19 (57.6) | 4 (26.7) |
| Grade II | 17 (35,4) | 11 (33.3) | 6 (40.0) |
| Grade III | 31 (64,6) | 22 (66.7) | 9 (60.0) |
| Adjuvant Chemotherapy | 5 (10.4) | 5 (15.2) | 0 (0.0) |
| Best response | |||
| CR | 6 (12,5) | 6 (18.2) | 0 (0.0) |
| PR | 14 (29,2) | 9 (27.3) | 5 (33.3) |
| SD | 12 (25,0) | 9 (27.3) | 3 (20.0) |
| PD | 15 (31,3) | 8 (24.2) | 7 (46.7) |
| 1yr OS | 55,9% | 81.4% | 22.5% |
| mOS m (95%CI) | 14,6 (8,4-20,8) | 24.7 (10.1-39.3) | 5.4 (3.9-6.8) |
| 1-yr PFS | 18,1% | 18.9% | 13.3% |
| mPFS m (95%CI) | 5.1 (3. 7-6,5) | 8.4 (5.0-11.9) | 3.7 (1.4-6.0) |
Conclusions
S-1 combination with a platinum agent in the first-line setting of European patients with advanced gastric cancer results in similar survival outcomes and toxicity with previously reported data from Asian populations. S-1 combination with oxaliplatin is associated with superior efficacy as compared to cisplatin.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.