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.

We have retrospectively evaluated to prognosis of patients with unresectable gastric cancer (UGC) and the effect of postoperative chemotherapy on that prognosis. One hundred patients who died of UGC included 37 patients who received postoperative chemotherapy (chemotherapy group) and 63 patients who did not receive postoperative chemotherapy (control group). Chemotherapy regimens were as follows: intravenous mitomycin (MMC) plus 5-fluorouracil (5-FU) (n=15), oral 5-FU alone (n=10), intravenous methotrexate (MTX) plus 5-FU (n=8), intravenous cisplatin plus 5-FU (n=2), and hepatic arterial infusion of 5-FU plus oral 5-FU (n=2). No prior chemotherapy or radiation therapy was given. All patients' cancers were stage IV. Median survival of the chemotherapy group (238 days) was significantly longer than the control group (137 days). The 1-year survival rate in the treated group was 19.0% but only 2.4% in the control group (p < 0.01). Patients with palliative gastrojejunostomy did not survive significantly longer than those having laparotomy alone or ileal tube insertion. We conclude that the prognosis for patients with UGC remains very poor, but postoperative chemotherapy may contribute to prolonged survival in patients with UGC.

Although many drug combination therapies have been proposed, there is no standard therapy for patients with advanced gastric carcinoma. The superiority of combination therapy over monochemotherapy has not been demonstrated convincingly. To explore the role of monochemotherapy, the authors evaluated 5-fluorouracil (5-FU), modulated by 6S-leucovorin (6S-LV) and a cisplatin-containing regimen, which was comprised of epirubicin, etoposide, and cisplatin with the addition of the reversal agent lonidamine (EEP-L).

After stratification according to performance status (PS) and resection of the primary tumor, 72 patients with advanced gastric carcinoma were randomized to 2 parallel Phase II trials with 5-FU/6S-LV and EEP-L, respectively. Thirty-six patients in Study A received bolus 6S-LV, 100 mg/m2, followed by bolus 5-FU, 370 mg/m2, on Days 1-5 and 36 others in Study B received epirubicin, 30 mg/m2, on Days 1 and 5; etoposide, 100 mg/m2, on Days 1, 3, and 5; cisplatin, 30 mg/m2, on Days 2 and 4; and lonidamine, 150 mg/day.

There were 6 partial responses (18.2%) (95% confidence interval [CI] +/- 13.2) in Study A and 7 partial responses (21.9%) (95% CI +/- 14.3) in Study B. Partial responses were more frequent in patients with resected tumors or with an Eastern Cooperative Oncology Group PS of 0-1. The median duration of response was 8.8 and 8.3 months, respectively, in Study A and Study B. The median survival reached 8 months in Study A and 9 months in Study B. In the whole population of patients survival was significantly higher in patients with a PS of 0-1 (P < 0.05). Patients with a PS of 0-1 and a resected tumor had the significantly longest survival both in EEP-L treated patients and in all evaluable patients in the two studies. The most frequent World Health Organization Grade 3-4 toxic effects were gastrointestinal in Study A and hematologic in Study B. No treatment-related death was observed.

The efficacy of 5-FU, modulated with 6S-LV, is moderate in patients with advanced gastric carcinoma, similar to cisplatin-containing regimens. PS and other prognostic factors could influence the response rate, which does not appear to be a reliable parameter for evaluating the outcome of chemotherapy trials.