Nowadays, the era of targeted therapy and immunotherapy for lung cancer has significantly improved patients’ quality of life and prolonged their survival period. Lung cancer treatment has really entered the time of targeted therapy and immunotherapy. Compared with targeted therapy and immunotherapy, chemotherapy is poorly tolerated and has big toxic side effects, which is not accepted by many patients, and many media also boast that “lung cancer has entered the time of de-chemotherapy”, but is it really so? Chemotherapy is a kind of treatment that uses chemical drugs to kill tumor cells, inhibit the growth and reproduction of tumor cells and promote the differentiation of tumor cells. Chemotherapeutic drugs are quickly distributed to the whole body after entering the body, which can kill both local tumors and distant metastatic tumors, so it is a systemic treatment, which has therapeutic effects on primary foci, metastatic foci and subclinical metastatic foci. However, chemotherapy treatment of tumors kills normal cells and immune (resistance) cells together with the killing of tumor cells, so chemotherapy can be considered as a kind of Therefore, chemotherapy can also be regarded as a treatment method that “kills one thousand enemies and damages eight hundred”. 1, chemotherapy combined with targeted therapy Gefitinib, erlotinib, ectinib and other generation of targeted drugs EGFR gene sensitivity mutations in advanced non-small cell lung patients of the standard first-line treatment mode, the median progression-free survival of 10 to 14 months. egfr mutation patients can benefit from targeted therapy, but drug resistance is still inevitable. The NEJ009 study of chemotherapy combined with targeted drugs showed that the combined program of gefitinib and chemotherapy group could significantly improve the progression-free survival of patients (20.9 months vs. 11.2 months), and the median overall survival of patients in the gefitinib and chemotherapy group was significantly better than that of the single-drug gefitinib group (52.2 months vs. 38.8 months). 2.Chemotherapy combined with immunotherapy The effective rate of immunotherapy monotherapy in the second-line treatment of NSCLC is about 20%, and the effective rate of first-line treatment used in NSCLC patients with PD-L1 greater than 1% is about 30-50%, while the effective rate of chemotherapy combined with immunotherapy reaches 50-60%. The KEYNOTE-189 study of chemotherapy combined with immunotherapy showed that the objective effectiveness rate (ORR) of pabolizumab combined with pemetrexed + platinum versus placebo combined with pemetrexed + platinum for the first-line treatment of patients with metastatic non-squamous non-small-cell lung cancer in the two groups was 48.3% and 19.9%, respectively, and progression-free survival (9.0 months vs. 4.9 months). The median OS of combination pembrolizumab treatment was 22.0 months, which was superior to 10.6 months with chemotherapy alone. Results from the KEYNOTE-407 study in metastatic squamous non-small cell lung cancer showed that pabolizumab in combination with chemotherapy improved overall survival (17.1 months vs. 11.6 months), progression-free survival (8.0 months vs. 5.1 months), objective effectiveness rate (62.6% vs. 38.4%) and duration of remission ( DoR) (8.8 months vs. 4.9 months). 3, chemotherapy combined with antivascular drugs Phase III clinical trial of chemotherapy combined with bevacizumab for the treatment of non-small cell patients with locally advanced, metastatic or recurrent advanced non-squamous carcinoma (BEYOND study) showed that patients in the chemotherapy combined with bevacizumab group had a significantly prolonged median progression-free survival compared with patients in the chemotherapy-only group, with median progression-free survival of 9.2 and 6.5 months, and a significantly higher objective effective rate, with median progression-free survival of 54% and 26%; median survival was also significantly prolonged, 24.3 months and 17.7 months, respectively. 4.The application of chemotherapy in postoperative adjuvant therapy Various guidelines recommend the use of 3-4 cycles of postoperative chemotherapy in patients with stage II-IIIA and some patients with stage IB non-small cell lung cancer with high risk factors. Adjuvant immunotherapy with atilizumab monotherapy is recommended for patients with ≥1% tumor cell (TC) PD-L1 staining positive, surgically resected, stage II-IIIA NSCLC following platinum-based chemotherapy. In postoperative patients with EGFR-sensitive mutations in stage IB-IIIA non-small cell lung cancer, the median recurrence-free survival in the ositinib-targeted therapy group was similarly significantly better than that in the placebo group, at unattained and 27.5 months, respectively (HR=0.20, P<0.001), and the 2-year recurrence-free survival rates in the two groups were 89% vs. 52%, respectively. All patients benefited from subsequent adjuvant ositinib regardless of whether adjuvant chemotherapy had been used, and the benefit was more pronounced in patients who had received prior adjuvant chemotherapy. 5, chemotherapy combined with immunotherapy in neoadjuvant therapy CheckMate-816, a phase III clinical study of neoadjuvant therapy, confirmed that compared with platinum-containing two-drug chemotherapy alone, nabulizumab in combination with platinum-containing two-drug chemotherapy significantly improved the patients' event-free survival and pathological complete remission. The U.S. Food and Drug Administration (FDA) has approved nabulizumab in combination with platinum-containing two-agent chemotherapy for the neoadjuvant treatment of adult patients with resectable non-small cell lung cancer (NSCLC) whose tumors are ≥4cm or lymph node-positive, regardless of the patient's PD-L1 expression level. Although targeted and immune drugs are widely used in NSCLC, chemotherapy is still the cornerstone of NSCLC treatment, and chemotherapy combined with targeted drugs, chemotherapy combined with immune drugs, and chemotherapy combined with anti-vascular drugs have all achieved very good efficacy. Some patients who cannot tolerate chemotherapy due to their physical condition can choose other drugs besides chemotherapy as appropriate, but chemotherapy is often indispensable for patients to get better curative effect and longer survival.