Gefitinib 500mg Versus 250mg in Patients With NSCLC With Stable Disease After a Month Treatment of Gefitinib 250mg

Inclusion criteria

• Histologically or cytologically confirmed stage IIIB/IV lung cancer(exclude patients confirmed by sputum cytology)
• received at least one chemotherapy regimen
• with stable disease after a month treatment of gefitinib(CT scan)
• the radiotherapy focus is not the measurable disease within 4 weeks.the patients received palliative therapy can be included.
• Age >18 years, either sex
• with a measurable disease(longest diameters >=10mm with Spiral computed tomography (CT)and >=20mm with conventional CT) at least according to RECIST Criteria
• WHO performance status(PS)<= 2 ( Patients Whit PS=2 Should not get worsen within 2 weeks Before Included)
• N>=1.5×109/L, Plt>=1.5×109/L,Hb>=10g/dL
• ALP<2.5×ULN.If ALP>=2.5ULN, AST&ALT should <1.5ULN(without liver metastasis) or <5ULN(with liver metastasis).TBIL<=1.5ULN，AST&ALT<2.5ULN(without liver metastasis) or <5ULN (with liver metastasis).
• Signed and dated informed consent before the start of specific protocol procedures.
• recruiting and receiving treatment in 5 days after last CT scan
• Patients able to taken oral drug

Exclusion criteria

• Life expectancy <= 12 weeks.Patients with metastatic brain tumors without symptoms or had been treated can be included.
• experience of Anti-EGFR(the epidermal growth factor receptor) Monoclonal Antibody or small molecular compounds therapy such as erlotinib or Cetuximab.
• can not take drug orally, have active peptic ulcer,half upper gastrointestinal or have dyspepsia.
• allergic to gefitinib
• Prior exposure to drugs without approval from this research or other study drugs within 21days before the 1st day taken Gefitinib 500mg or 250mg.
• Pregnant or breast-feeding women
• Severe systemic disease out of control such as unstable or uncompensated respiratory,cardiac,liver,renal diseases.
• Previous or concurrent cancer that is distinct in primary site or histology from the cancer being evaluated in this study except of cervical carcinoma in situ,basal cell carcinoma within 5 years prior to study entry.