Non-small cell lung cancer (NSCLC) accounts for 75%-80% of primary lung cancers. 70%-80% of patients are already in intermediate or advanced stages at the time of diagnosis and have lost the chance of surgery. In the past, high-dose radiotherapy was the conventional treatment for localized or locally advanced NSCLC, but the 5-year survival rate was only 5%-7%. 1980, it was found that radiotherapy combined with platinum-containing chemotherapy regimen was better than radiotherapy alone. 1988 onwards, some new chemotherapy drugs, such as vinorelbine, gemcitabine, paclitaxel and Tylenol, were introduced. paclitaxel) and decetaxel have significantly improved the single-agent efficiency in the treatment of NSCLC. The combination of platinum with these new agents improves remission rates and survival in patients with III-IV. Simultaneous or sequential chemotherapy and radiotherapy for some patients can further improve remission rates and survival. Chemotherapy as adjuvant therapy to surgical resection can help prolong patient survival. Meaningful clinical studies on second-line treatment of NSCLC have also been conducted abroad. This article provides a brief review of the new developments in the above issues. I. Postoperative adjuvant chemotherapy for early resectable NSCLC Surgery is still the most effective treatment for early resectable NSCLC, but the long-term survival rate after surgery is not ideal, with a 5-year survival rate of 65-75% for stage I; 35-45% for stage II; and an overall 5-year survival rate of only 50%. In 1995, the International NSCLC Collaborative Group conducted a meta-analysis of 52 clinical studies [1], which showed that postoperative adjuvant chemotherapy improved overall 5-year survival by 5%, but there was no statistically significant difference. Several subsequent multicenter, randomized comparative studies, such as ECOG3590 [2], ALPI [3], and BLT [4], have failed to confirm the benefit of postoperative adjuvant chemotherapy, further clouding the future of adjuvant chemotherapy in the treatment of early resectable NSCLC. The International Adjuvant Lung Cancer Trial (IALT), the largest multicenter, randomized, controlled clinical study to date, enrolled 1867 patients who were randomly divided into a postoperative adjuvant chemotherapy group and a control group, with the former given postoperative platinum-containing combination chemotherapy and The results of IALT [4] showed (Table 1) that adjuvant chemotherapy resulted in an absolute survival advantage of 4.1% in patients with early resectable NSCLC. The investigators concluded that IALT is more capable of detecting this relatively small differential advantage than the ECOG3590, ALPI and BLI studies with larger sample sizes. Based on the results of IALT, foreign scholars have recommended that two to three small cycles of combination chemotherapy with platinum-containing regimens should be given postoperatively to patients with surgically resected NSCLC. Kato, a Japanese scholar, observed the adjuvant effect of eflornithine on early resectable NSCLC. 999 patients with I~IIIA (of which 20 were excluded) were randomly divided 1:1 into eflornithine-treated and control groups after surgical resection. The results (Table 2) revealed a significant survival advantage in the eflornithine treatment group (P=0.035), which was more pronounced in stage II patients. Since this study was conducted only in Japan, it remains to be confirmed whether the same results were found in patients outside Japan. II. Preoperative neoadjuvant chemotherapy Preoperative neoadjuvant chemotherapy plus surgery for NSCLC started in the late 1980s. Preoperative neoadjuvant chemotherapy can reduce the tumor load, lower the tumor stage, increase the chance of complete surgical resection and reduce the possibility of tumor recurrence after surgery. However, preoperative neoadjuvant chemotherapy may also increase the risk of surgical resection and complications, and after the 1980s, domestic scholars have conducted in-depth studies on the efficacy and safety of neoadjuvant chemotherapy and achieved clinically significant results. Pre-operative chemotherapy and radiotherapy can reduce tumor load and make surgical resection more complete. Some data show that preoperative chemoradiotherapy can give stage IIIA patients an absolute survival advantage of significant significance. Whether adjuvant chemotherapy is administered preoperatively or postoperatively is more beneficial to patients deserves further study. Chemotherapy for advanced NSCLC Advanced NSCLC refers to unresectable locally advanced or distant metastases. Local radiotherapy is an important method to treat locally advanced NSCLC. Although local radiotherapy can result in a reduced tumor load and a lower recurrence rate, the overall survival rate is not satisfactory. Sequential chemoradiotherapy is superior to radiotherapy alone and can lead to a significant improvement in long-term patient survival. This therapy is based on the idea that locally advanced NSCLC is actually a systemic disease and that not only local lesions should be controlled, but also distant micro-metastases should be controlled using chemotherapy. Synchronized chemoradiotherapy is another new integrated treatment for NSCLC, which can significantly improve the remission rate of local tumor and further improve the survival rate through the synergistic effect between chemoradiotherapy, and the overall efficacy is better than radiotherapy alone and sequential radiotherapy. Since the toxic side effects of synchronous chemoradiotherapy are significantly increased, appropriate cases should be selected and supportive symptomatic treatment should be enhanced. Smith et al. failed to confirm the superiority of MVP regimen chemotherapy with more than 3 small cycles over 3 small cycles of chemotherapy. Patients did not differ significantly in terms of survival and quality of life. At the 10th World Conference on Lung Cancer, Sverre Sorens reported the results of a multicenter, prospective, randomized study of 3 and 6 cycles of carboplatin + novobiocin for advanced NSCLC. This study included 300 patients with IIIB and IV, and found that the near-term efficacy of 6 cycles of chemotherapy was significantly better than that of the 3-cycle group, with a significantly increased incidence of anemia of 3rd to 4th degree There were no significant differences in other adverse effects, as well as survival and quality of life. Whether maintenance therapy is required after achieving partial or complete remission with chemotherapy for advanced NSCLC Krzakowski et al. divided 207 patients with advanced NSCLC treated with 4 mini-cycles of cisplatin+Kenzyme chemotherapy, and then subsequently divided into the Kenzyme+best supportive care group and the best supportive care group alone on a 2:1 basis. The results (Table 2) revealed that the time to disease progression was significantly longer in the Kinzel + best supportive care group than in the best supportive care alone group. Due to the small number of cases in this study, the need for maintenance therapy should be studied more thoroughly. V. Second-line therapy for advanced NSCLC Second-line therapy refers to the treatment of patients who have failed first-line therapy or relapsed after first-line therapy. Tysodex is the only drug approved by the US FDA for second-line treatment of NSCLC. However, the drug is associated with grade 3 to 4 neutropenia in approximately 54% to 67% of patients every 3 weeks at 75 mg/m2. Dr. Frances compared the efficacy of Pemetrexed and Tysodex in second-line treatment of NSCLC. The results found median survival of 8.3 months and 7.9 months in the two groups, respectively, with 1-year survival rates of 29.7% in both groups, but grade III/IV hematologic toxicity of 5% and 40% in the two groups, respectively, and fever due to leukopenia of 0% and 3%, respectively. One study reported that weekly administration of Tysotil (25 mg/m2) resulted in a significant reduction in the incidence of grade 3 to 4 neutropenia and a significant increase in survival. the Pemetrexed group was significantly superior to the Tysotil group. In addition, Dr. Carlos reported the results of a randomized comparative study of a three-week regimen of Tysodi and a weekly regimen for second-line treatment of NSCLC. A total of 246 patients were enrolled, and differences in overall survival were found, with 7.1 and 5.4 months, respectively, with the 3-week regimen being superior to the weekly regimen. However, the incidence of leukopenia was lower with the weekly regimen, so patients who cannot tolerate leukopenia should be treated with either the weekly regimen of Tysodi or Pemetrexed.