Objectives:

1. Primary Objective:

   To bridge the data of efficacy in term of overall response rate of TS-1 plus cisplatin in Taiwanese advanced NSCLC patients from that gained from Japanese population

2. Secondary Objectives:

A. To assess progression free survival B. To assess overall survival C. To bridge the safety profile by assessing the toxicities and tolerability

Inclusion Criteria:

To be eligible for inclusion, each subject must fulfill all of the following criteria:

1. histologically or cytologically confirmed non-small cell bronchogenic carcinoma
2. Stage IIIb or IV disease
3. 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
4. performance status of ECOG 0, 1
5. age between 20 and 74 years at registration
6. life expectancy of at least 12 weeks
7. ability to take the oral study medication (TS-1)
8. 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.