Classification of lung cancer chemotherapy: Radical chemotherapy: mainly used for the treatment of SCLC, characterized by sufficient amount and duration of combination chemotherapy to achieve the ultimate goal of long-term survival or cure. Palliative chemotherapy: mainly used for advanced lung cancer, characterized by delaying the development of lesions, reducing patients’ symptoms, improving the quality of life and prolonging the survival period. Zhao Jun, Department of Thoracic Oncology, Peking University Cancer Hospital Neoadjuvant chemotherapy: It is preoperative chemotherapy, through which the lesions are transformed into operable, while expecting to reduce micro-metastases, while improving long-term survival. Adjuvant chemotherapy: It is chemotherapy after complete resection, expecting to improve long-term survival rate by reducing micro-metastases, especially to improve tumor-free survival time. Local chemotherapy: direct injection of chemotherapeutic drugs into the bronchial arteries or blood vessels supplying the lesion under image-mediated guidance, resulting in high intra-tumor drug concentrations to improve the efficacy of the treatment Sensitization chemotherapy: chemotherapy administered concurrently with radiotherapy to enhance the sensitivity of tumor cells to radiotherapy. Principles of systemic therapy for advanced or metastatic NSCLC Advanced NSCLC: Survival can be predicted by baseline prognostic factors including stage, general condition, gender, etc. Platinum-containing chemotherapy regimens can prolong survival, improve symptom control, and enhance quality of life compared with best supportive care. In patients with better PS, the efficacy of newer drugs combined with platinum-based chemotherapy reached a more stable level: overall efficacy of 〉25-35%, time to disease progression of 4-6 months, intermediate survival of 8-10 months, 1-year survival of 30-40%, and 2-year survival of 10-15%. No new drug combined with a platinum-based chemotherapy regimen is superior to any other regimen. Older patients with better PS should be treated appropriately. Patients of any age with poor PS do not benefit from chemotherapy (cytotoxic drug therapy). First-line treatment Bevacizumab (not yet approved in China) + chemotherapy or chemotherapy alone is indicated for patients with advanced or relapsed NSCLC with PS0-2. A two-drug combination regimen is preferred; a three-drug combination regimen has no further benefit, with the exception of bevacizumab (not yet approved domestically), which can be added in treatment-naive patients with NSCLC with PS 0-1, no history of hemoptysis, non-squamous cancer, no brain metastases, and no current anticoagulation therapy. For locally advanced NSCLC, chemoradiotherapy is superior to radiotherapy alone, and synchronized chemoradiotherapy appears to be superior to sequential chemoradiotherapy. For advanced, incurable disease, cisplatin-containing chemotherapy regimens are effective due to best supportive care: prolonging median survival by 6-12 weeks and doubling 1-year survival (absolute improvement of about 10-15%) Cisplatin or carboplatin in combination with any of the following agents: paclitaxel, docetaxel, gemcitabine, vincristine, irinotecan, etoposide, vincristine. Monotherapy is a reasonable choice for elderly or PS2 patients. Systemic chemotherapy is not indicated for patients with PS=3 or 4. Second-line treatment In patients with disease progression during or after first-line therapy, single-agent docetaxel, pemetrexed, or the tyrosine kinase inhibitors erlotinib and gefitinib, may be used as second-line agents. Docetaxel has been shown to prolong survival and improve quality of life with better efficacy than best supportive care, vincristine or isocyclophosphamide. Foreign data show that pemetrexed has similar efficacy and mild toxicity to docetaxel, but it has not been approved as second-line treatment for NSCLC in China. Erlotinib has been shown to be significantly better than best supportive care, improving survival and delaying symptom deterioration, but has not been approved for second-line treatment of NSCLC in China. International clinical studies (ISEL trials) have shown that gefitinib prolongs TTP and median survival compared to best supportive care in oriental, female, non-smoking, adenocarcinoma patients. Third-line treatment Erlotinib has been shown to be statistically superior to best supportive care in terms of survival For patients who have not used a tyrosine kinase inhibitor, gefitinib may be used as third-line treatment.