A Phase II Study of Docetaxel and S-1 as First-line Chemotherapy in Patients With Advanced Esophageal Cancer

Esophageal cancer is the ninth most common cancer in male population in Korea. It was estimated that 1,864 new cases of esophageal cancer were reported and 1,434 deaths occurred in Korea in 2005. Although half of the patients with esophageal cancer initially present with locoregional disease amenable to radical surgery or radiation-based therapy, most patients eventually develop metastatic disease with or without local recurrence. Chemotherapy plays a major role in palliative therapy and remains to be the primary mode of treatment for the recurrent or metastatic esophageal cancer. Although various chemotherapy regimens are available, esophageal cancer carries a very poor prognosis, with a mean survival time of less than 8.1 months with current chemotherapies used singly or in combination with 5-fluorouracil (5-FU), vindesine, mitomycin, docetaxel, paclitaxel, cisplatin, irinotecan, vinorelbine, or capecitabine. The majority of the trials performed were in small numbers of patients with reported response rates from 15 to 40%. The response was usually of short duration and there was no survival benefit with single agent chemotherapy. Combination chemotherapy has slightly improved the results in terms of duration of response (3-6 months), but still there was little improvement in overall survival. Therefore, the identification of new active agents is essential to prolong the survival. Clinical trials of single agent docetaxel have been reported in patients with esophageal cancer and the response rate is about 18-25%. S-1, a new biochemical modulator of 5-FU, is an oral dihydropyrimidine dehydrogenase(DPD) inhibitory fluoropyrimidine. The advantages of S-1 compared with 5-FU are greater convenience because of its oral formulation and continuous delivery, without intravenous infusion. S-1 is frequently used as a substitute for 5-FU in gastric cancer, but limited data is available for esophageal cancer. The combination of docetaxel and S-1 is highly active and well tolerated in advanced or recurrent gastric cancer, and the synergistic antitumor activity has been fully elucidated. Therefore, we will evaluate the efficacy of docetaxel and S-1 combination chemotherapy in Korean patients with esophageal cancer.