Inclusion Criteria:
To be eligible for inclusion, each subject must fulfill all of the following criteria:
- histologically or cytologically confirmed non-small cell bronchogenic carcinoma
- Stage IIIb or IV disease
- presence of at least one measurable disease which is defined as lesion that can be measured in at least 1 dimension as ≥20 mm with conventional CT/MRI or ≥10 mm with spiral CT scan
- performance status of ECOG 0, 1
- age between 20 and 74 years at registration
- life expectancy of at least 12 weeks
- ability to take the oral study medication (TS-1)
- voluntarily signed the written informed consent form.
Exclusion Criteria:
- other malignancy with the exception of curative treated non-melanoma skin cancer or cervical carcinoma in situ within 5 years prior to the entry of study
- previously received chemotherapy or therapy with systemic anti-tumor effect
- significant co-morbid medical conditions, including, but not limited to , heart failure, renal failure, hepatic failure, hemorrhagic peptic ulcer, mechanical or paralytic ileus, or poorly controlled diabetes
- fertile women of child-bearing potential unless using a reliable and appropriate contraceptive method throughout the treatment period and for three months following cessation of treatment
- Presence of mental disease or psychotic manifestation
- Participation in another clinical trial with any investigational drug within 30 days prior to entry
- judged ineligible by physicians for participation in the study due to safety concern.