This study will evaluate the efficacy of docetaxel and S-1 combination chemotherapy in Korean patients with 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.

Inclusion Criteria:

• Pathologically confirmed squamous cell carcinoma or adenocarcinoma of esophagus.
• Unresectable locally advanced, recurrent or metastatic disease.
• Measurable or evaluable disease by RECIST criteria 1.1.
• Minimum age of 18 years.
• ECOG Performance status 0-2.
• Prior chemotherapy is not allowed.
• More than 4 weeks since completion of prior radiotherapy (measurable or evaluable lesions are outside the radiation field)
• Adequate organ functions
• Patients must sign an informed consent indicating that they are aware of the investigational nature of the study in keeping with the policy of the hospital

Exclusion Criteria:

• Other tumor type than squamous cell carcinoma and adenocarcinoma
• Previous history of chemotherapy except neoadjuvant or adjuvant chemotherapy without docetaxel and S-1
• Obvious bowel obstruction unrelieved by proper management
• Evidence of serious gastrointestinal bleeding
• Patients with CNS metastases
• Patients with active infection, severe heart disease, uncontrollable hypertension or diabetes mellitus, myocardial infarction during the preceding 6 months, pregnancy, or breast feeding
• Any previous or concurrent malignancy other than non-melanoma skin cancer or in situ cancer of uterine cervix
• Known history of cerebral or leptomeningeal metastases or neurologic disease