MetronomIc CApecitabine and DOcetaxel as Second-line Chemotherapy for Advanced Gastric Cancer

Despite a declining incidence in many developed countries, gastric cancer remains the second most common cause of cancer deaths, and it is responsible for about 12% of all cancer-related deaths worldwide. More than two-thirds of patients diagnosed with gastric cancer will have unresectable disease and despite the fact that surgical pathological resection can be curative for many patients, most of them develop recurrent disease. Evidence supports the use of palliative chemotherapy with the aims of improving symptoms, quality of life, and possibly prolonging survival. Combination chemotherapy regimens have been developed in the hopes of improving response rate and overall survival (OS). Unfortunately, the benefits of combination chemotherapy have been modest. In general, regimens containing fluoropyrimidine and platinum agents are widely accepted as potential standard therapies. Although a large proportion of patients with metastatic or recurrent gastric cancer may initially respond to chemotherapy, they ultimately progress. In addition, many patients have primary refractory disease. The median survival at progression after first-line chemotherapy for metastatic gastric cancer is about 2.5 months.

Docetaxel is one of the most active single agents in the treatment of gastric cancer. In the first line setting, at a dose of 60-100 mg/m2 repeated every 3 weeks, response rates ranged from 17% to 20%. Docetaxel is the only taxane that has been evaluated in the context of a phase III study.

Low-dose metronomic chemotherapy represents a new strategy to treat solid tumors by exhibiting stronger anti-angiogenic activity and less side effects, especially in combination with other anti-angiogenic agents. Capecitabine is a fluoropyrimidine carbamate, which has a broader spectrum of antitumor activity than other fluoropyrimidines. In gastric cancer xenografts. metronomic capecitabine inhibited angiogenesis, growth of gastric cancer and improved survival with less toxicity. In combination with other drugs, the treatment with metronomic capecitabine has proven its efficacy with minimal toxicity in breast cancer, in metastatic renal-cell carcinoma, in advanced adrenocortical carcinoma, in hepatocellular carcinoma, in prostate cancer.

The "metronomic" strategy was also considered in pretreated elderly patients with advanced gastric cancer. Eligible patients with advanced gastric cancer were treated with capecitabine until disease progression or significant toxicity. Metronomic chemotherapy achieved a disease control rate at 8 weeks of 51.1% , and the objective response rate was 20.9% . The median time-to-progression and median overall survival were 3.6 months and 7.6 months, respectively. Grade II neutropenia and thrombocytopenia were observed in 13.3 and 2.2% of patients, respectively. Grade II/III nonhematological toxicities included diarrhea (4.4%), stomatitis (13.4%), and hand-foot syndrome (15.5%). No grade 4 toxicity, neutropenic fever or treatment-related deaths occurred.

Based on these premises and to the fact that the role of metronomic chemotherapy remains controversial, its optimal therapeutic use has not yet been defined, we designed this phase II study with tha aim to assess efficacy and tolerability of metronomic capecitabine in combination with the conventional use of docetaxel in patients with advanced gastric cancer previously treated with a fluoropyrimidine-based and platinum-based chemotherapy.