Phase II study of docetaxel and S-1 combination therapy for advanced or recurrent gastric cancer

PURPOSE

To evaluate the efficacy and toxicity of docetaxel in combination with a novel oral 5-fluorouracil analogue S-1 for patients with advanced or recurrent gastric cancer.

EXPERIMENTAL DESIGN

Patients with advanced or recurrent adenocarcinoma of the stomach and up to one previous chemotherapy regimen were treated with i.v. docetaxel 40 mg/m2 on day 1 and oral S-1 80 mg/m2/d on days 1 to 14 every 3 weeks.

RESULTS

Forty-eight patients (median age, 65 years; range, 25-75 years) received a total of 272 treatment cycles (median, 4; range, 1-17). No complete responses and 27 partial responses were observed for an overall response rate of 56.3% [95% confidence interval (95% CI), 38-66%]. Eighteen patients (37.5%) had stable disease and three patients (6.3%) had progressive disease as best response. The tumor control rate (complete response + partial response + stable disease) was 93.8% (95% CI, 83-98%). Median overall survival was 14.3 months (95% CI, 10.7-20.3 months) and median time to tumor progression was 7.3 months (95% CI, 4.3-10.0 months). The most common grade 3 to 4 hematologic toxicities were neutropenia (58.3%), leukopenia (41.7%), febrile neutropenia (8.3%), and anemia (8.3%). The most common grade 3 nonhematologic toxicities included anorexia (14.6%), stomatitis (8.3%), and nausea (6.3%). No grade 4 nonhematologic toxicities were reported and all treatment-related toxicities were resolved.

CONCLUSION

Docetaxel/S-1 combination is highly active and well tolerated in advanced or recurrent gastric cancer. Further investigation in randomized studies is warranted.

Infusional 5-fluorouracil and cisplatin as first-line chemotherapy in patients with carcinoma of unknown primary site

A combination chemotherapy of 5-fluorouracil (5-FU) and cisplatin (CDDP) has demonstrated activities in various malignancies, including head and neck, lung, esophageal, gastric, and pancreatic cancers. We reviewed our experience of 11 patients diagnosed as carcinoma of unknown primary site (CUPS), who were treated with infusional 5-FU and CDDP between January 1998 and December 2005. The median number of cycles administered was three (range: 1-12). All patients had measurable disease. Six partial responses were obtained (response rate: 54.5%, 95% confidence interval: 23.4-83.3%). The median survival time for all patients was 10 mo (range, 2-37 mo). The median time to disease progression was 3 mo (range, 1-6 mo). This regimen was well tolerated, with grade 3-4 neutropenia (two patients), febrile neutropenia (one patient), grade 3 nausea/vomiting (one patient), and grade 3 stomatitis (two patients). Grade 2 leukoencephalopathy was observed in one patient. No treatment-related death was observed. The combination chemotherapy of infusional 5-FU and CDDP was feasible and tolerated with promising activity for CUPS.

Longterm survival of a Western patient with metastatic gastric cancer treated with S-1 plus cisplatin

The prognosis for patients with metastatic gastric cancer is poor. Fewer than 10% of patients with metastatic gastric cancer live beyond 2 years. Chemotherapy is offered with a palliative intent. We report the case of a Western patient with metastatic gastric cancer successfully treated with S-1 plus cisplatin. S-1 was administered orally every 12 h at a dose of 30 mg/m2 (60 mg/m2 daily) for 21 consecutive days, followed by 7 days of recovery. Cisplatin was administered intravenously on day 1, at a dose of 60 mg/m2. The cycles were repeated every 28 days. The patient first received seven cycles of S-1 plus cisplatin; however, cisplatin was discontinued secondary to nephrotoxicity, and S-1 was administered alone for an additional five cycles. The patient achieved a clinical complete response to S-1 plus cisplatin. The complete response has now been maintained for 12 months without any chemotherapy. A total of 28 months have elapsed since the date of registration on the study and the patient currently has no symptoms. This patient exemplifies the strategy of maintenance therapy with S-1 alone and shows a prolonged and excellent response to S-1 and cisplatin.

Disparities in gastric cancer chemotherapy between the East and West

There are still remarkable disparities in the treatment of gastric cancer between the East and West. Treatment outcomes for this disease have improved in Japan due to early detection and surgical resection with systematic node dissections, such as D2, whereas gastric cancer remains a virulent disease in Western countries. Differences in the types of surgery and their outcomes affect how adjuvant trials are conducted and interpreted. Recent Western randomized trials demonstrated the significant survival benefit of adjuvant chemoradiotherapy or intensive combination chemotherapy. However, baseline surgical quality and outcomes were quite different from those in Japan, and Japanese surgical/medical oncologists have not accepted the Western results. Several disparities are also evident in the results of chemotherapy trials for advanced gastric cancer. Although similar results were obtained with randomized studies using older regimens, the interpretation of the results differed between Japan and other countries. A combination of cisplatin and fluorouracil was used as the reference arm in ongoing randomized trials in most countries, whereas single-agent fluorouracil or S-1 alone was used in Japanese trials. Two triplet regimens have already demonstrated significant prolongation of survival in Western studies. However, these benefits seem to be marginal and these regimens may be replaced by newer regimens, which will soon be available in Europe and Asia, where a total of 2,600 patients have been accrued. Although these disparities between regions must be overcome, it is time for both Eastern and Western investigators to pursue further benefits by incorporating new agents into treatment regimens.

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.