Docetaxel combined with low-dose S1 compared with docetaxel monotherapy in an open randomized phase II clinical study of advanced non-small cell lung cancer (second/third line)

INTERVENTION: Group 1:Docetaxel;Group 2:Docetaxel+S1(1);Group 3:Docetaxel+S1 (2); CONDITION: None small cell lung cancer PRIMARY OUTCOME: PFS; INCLUSION CRITERIA: 1. aged than 18 years old; 2. Histological or cytological diagnosis of none small cell lung cancer; 3. patients were diagnosed of stage IV non‐small‐cell lung cancer (American Joint Committee on Cancer version 8); 4. an Eastern Cooperative Oncology Group performance status of 0 or 1; 5. At least one imaging Computed Tomography (CT) or mri Magnetic Resnane Iamge (MRI) can be measured or assessed. The short diameter of lymph node lesions was more than 15mm, which could be measured without local treatment such as radiotherapy and freezing; 6. patients have a life expectancy of roughly 4 months; 7. First line therapy was given after stage IV diagnosis Docetaxel and S1 have not been used before; 8. Patients who had been treated with radiation before can be enrolled, but the treatment must be completed at least 4 weeks, and the acute toxic response to previous radiation must be recovered; Local lesions that have been treated with radiation can