Retrospective analysis of stage IV advanced gastric cancer treated with S-1 or other chemotherapy

BACKGROUND

We retrospectively analyzed the influence of various clinicopathologic factors on the survival of patients treated with chemotherapy.

METHODS

A retrospective analysis was made of 110 patients with stage IV gastric cancer who were treated from January 1996 to June 2004.

RESULTS

Median survival time was 429 days for patients treated with S-1 therapy and 236 days for patients without S-1 therapy. A better survival was demonstrated in patients who had good performance status, one metastatic site, or had been given a second-line chemotherapy (P < 0.01). But very few patients (17%; 5/29) with multiple metastatic sites were able to receive the second-line chemotherapy.

CONCLUSION

Patients treated with S-1 therapy had a better prognosis than patients without S-1. One metastatic site and being given second-line chemotherapy were other factors for better prognosis. For patients with only one metastatic site, a good prognosis can be obtained by second-line chemotherapy for those refractory to S-1. The prognosis of patients who had more than two metastatic sites remained poor; more effective chemotherapy might improve the survival of such patients if they retain good performance status.

Chemotherapy for gastric cancer

Metastatic gastric cancer remains a non-curative disease. Palliative chemotherapy has been demonstrated to prolong survival without quality of life compromise. Many single-agents and combinations have been confirmed to be active in the treatment of metastatic disease. Objective response rates ranged from 10-30% for single-agent therapy and 30-60% for polychemotherapy. Results of phase II and III studies are reviewed in this paper as well as the potential efficacy of new drugs. For patients with localized disease, the role of adjuvant and neoadjuvant chemotherapy and radiation therapy is discussed. Most studies on adjuvant chemotherapy failed to demonstrate a survival advantage, and therefore, it is not considered as standard treatment in most centres. Adjuvant immunochemotherapy has been developed fundamentally in Korea and Japan. A meta-analysis of phase III trials with OK-432 suggested that immunochemotherapy may improve survival of patients with curatively resected gastric cancer. Based on the results of US Intergroup 0116 study, postoperative chemoradiation has been accepted as standard care in patients with resected gastric cancer in North America. However, the results are somewhat confounded by the fact that patients underwent less than a recommended D1 lymph node dissection and the pattern of recurrence suggested a positive effect derived from local radiotherapy without any effect on micrometastatic disease. Neoadjuvant chemotherapy or chemoradiation therapy remains experimental, but several phase II studies are showing promising results. Phase III trials are needed.