This study is for patients with previously diagnosed advanced non small cell lung cancer (NSCLC, stage IIIb or IV) who had progression of their disease during or after first-line therapy containing platinum. Patients will be assigned to receive 6 cycles of therapy from one of four treatment regimens:~docetaxel~docetaxel + vinorelbine~docetaxel + gemcitabine~docetaxel + capecitabine
The purpose of this study is to compare the overall survival of patients with advanced non small cell lung cancer treated with docetaxel as single therapy versus docetaxel in combination with either gemcitabine or vinorelbine or in combination with capecitabine.