Pemetrexed as Salvage Treatment in Squamous Cell Carcinoma of Head and Neck

Inclusion Criteria: * Age range: 18-65 years old * Histological confirmed incurable relapsed or metastatic squamous cell carcinoma of head and neck * Prior exposure of at least one line of platinum-containing regimen * At least one site of measurable disease according to RECIST criteria * ECOG performance status 0-1 * Life expectancy of more than 3 months * Bone marrow function: ANC≧1.5×109/L, PLT≧100×109/L, Hb≧80g/L * Liver function: total bilirubin, ALT and AST \<1.5×UNL * Renal function: Cr\<1.5×UNL, CCR≧45ml/min Exclusion Criteria: * With curable treatment option * Prior platinum exposure only in neo-adjuvant/adjuvant setting or concurrently used with radiotherapy * History of other malignancies except cured basal cell carcinoma of skin and carcinoma in-situ of uterine cervix * Significant active infection * Pregnant or lactating women