Because previous foreign studies have concluded that raltitrexed has a higher mortality rate than 5-FU and that the efficacy of raltitrexed is not superior to that of 5-FU, it has not received sufficient attention abroad. The domestic study was launched in 2010 by Nanjing Zhengda Tianqing (Safeguard) and was based on a rigorously designed multicenter, randomized blinded, positive drug parallel control. The indication for raltitrexed is that it can be used as a single agent in the treatment of advanced colorectal cancer patients who are not suitable for 5-Fu/calcium folinic acid when patients cannot receive combination chemotherapy. It has been widely used in China and is gradually gaining recognition. In fact, not only can raltitrexed be used as chemotherapy alone, but more scholars are using raltitrexed in combination with other drugs. More and more literature supports that for Chinese oncology patients, raltitrexed may be safer than westerners. 1.Raltitrexed is the best alternative drug for those who develop cardiotoxicity with fluorouracil drugs Clinically, fluorouracil drugs (5-FU, capecitabine, tegeo capsules, etc.) can cause serious cardiotoxicity, and fluorouracil drugs could only be abandoned in the past. 2012 European Society of Medical Oncology (ESMO) published ARCTIC trial, for patients who develop cardiotoxicity with receiving fluorouracil drugs. Patients with cardiotoxicity on fluorouracil may be replaced with raltitrexed, a specific inhibitor of thymidylate synthase (TS), and it is a safe alternative drug. The incidence of cardiotoxicity associated with 5-FU/capecitabine has been reported in the literature to be 0.55%-19% (mean: 5.0%, median: 3.85%), while cardiotoxicity associated with raltitrexed has not been reported. However, it has been recently reported that patients with a history of heart disease or 5-FU/capecitabine-induced cardiotoxicity, followed by raltitrexed, may experience cardiotoxicity in 4.5% of patients. 2, more adverse reactions, but easy to deal with Large domestic III clinical study (Journal of Clinical Oncology 2012): “A randomized controlled multicenter phase III clinical trial of raltitrexed or fluorouracil/calcium folinate in combination with oxaliplatin for locally advanced or recurrent metastatic colorectal cancer”, grade 1~2 neutropenia in the trial group The incidence of grade 1-2 neutropenia (48.2% vs. 29.4%, P = 0.005) and elevated transaminases (49.1% vs. 35.3%, P = 0.041) was significantly higher in the test group than in the control group. The incidence of vomiting was significantly higher in the control group than in the test group (61.8% vs. 40.2%, P = 0.0002). All adverse reactions were easily managed. It is noteworthy that the transaminase elevation was 49.1%, which was treated symptomatically and did not affect the chemotherapy regimen, suggesting that even if the application of raltitrexed caused transaminase elevation, it did not affect the chemotherapy. 3, the use of raltitrexed Domestic literature, raltitrexed mostly used 3mg/m2, day 1, repeated every 21 days. In combination with the author’s experience, it is suggested that raltitrexed should be lowered to 2.5 mg/m2 on day 2 and repeated every 21 days, which is clinically safer and the results of a small sample study showed no reduction in efficacy. 4.Extracolorectal malignant tumors The literature has reported that Raltitrexed can also be used for malignant pleural mesothelioma, advanced pancreatic cancer, advanced head and neck tumors, advanced gastric cancer, advanced cardia cancer, advanced esophageal cancer, advanced breast cancer, non-small cell lung cancer, biliary tract tumors, and leukemia. Among them, malignant pleural mesothelioma has been studied more frequently. It has been found that raltitrexed may also be effective against glioma. 5. Whether raltitrexed can be combined with 5-fluorouracil drugs There are reports in the literature that raltitrexed and 5-FU/CF not only have synergistic effects in cell lines, but also have promising therapeutic effects observed in clinical patients. The two act through different mechanisms without overlap in their toxicity profiles. In the author’s clinical work, no increase in toxicity was observed with the combination of raltitrexed and siroda in the treatment of advanced rectal cancer. It is suggested that the combined application can be tried. 6.Whether raltitrexed can be used for adjuvant chemotherapy of colorectal cancer Currently, it is not supported, and a foreign literature considers that it is not inferior to 5-FU/LV due to higher treatment-related mortality and higher adverse reactions compared with 5-FU, and at the same time, it is not confirmed. The dose of raltitrexed in this study was 4 mg/m2, and recently 3 mg/m2 has been suggested, as the latter disease is not inferior to the 5-FU/LV regimen. The current NCCN guidelines do not recommend a static 5-FU/CF regimen for the adjuvant treatment of colorectal cancer. Whether raltitrexed can be used for the adjuvant treatment of colorectal cancer is still inconclusive, and further research is still needed. 7.Raltitrexed can be combined with chemotherapeutic drugs Combination drugs mainly include irinotecan, oxaliplatin and cisplatin, among which raltitrexed, irinotecan and oxaliplatin can be used in combination. Raltitrexed can also be combined with carboplatin, capecitabine, 5-FU, mitomycin-C, gemcitabine, docetaxel, epi-amycin, adriamycin, gefitinib, etc. In my clinical work, the author has combined raltitrexed with Endo and the results showed safety, and related studies are in progress. Theoretically, chemotherapeutic drugs that can be combined with 5-FU can also be combined with raltitrexed. There are other applications and research advances of raltitrexed that will not be detailed here. What is of interest is that there is a lot of room for research on the clinical aspects of raltitrexed.