ObjectiveTo analyze the neoadjuvant therapy of colorectal cancer in this center in the background of real world data by studying Database from Colorectal Cancer (DACCA) in West China Hospital of Sichuan University.MethodsData was selected from DACCA who was updated on August 15, 2019. After deleting duplicate value, patients whose tumor location and tumor pathologic characteristic showed colon or rectum, as well as adenocarcinoma, mucinous adenocarcinoma, and signet ring cell carcinoma were enrolled.ResultsThere were 2 783, 2 789, 2 790, 2 811, 4 148,3 824, 4 191, 3 676, 4 090, and 499 valid data of T, N, and M stages, clinical stages, tumor site, distance from tumor to anal dentate line, tumor pathologic characteristics, degree of tumor differentiation, neoadjuvant therapy, and compliance, respectively. There were 1 839 lines that " nature of the tumor pathology” was not empty and neoadjuvant scheme for the pure chemotherapy, radiotherapy alone or radiation, and chemotherapy, including 50 lines of signet ring cell carcinoma (2.7%), 299 lines of mucous adenocarcinoma (16.3%), 1 490 lines of adenocarcinoma (81.0%), various kinds of pathology in selection of neoadjuvant therapy difference was statistically significant (χ2=9.138, P=0.041). Except for the data lines with null value in the column of " operation date”, there were 2 234 (82.1%) and 486 (17.9%) effective data lines of " recommended” and " not recommended” for the use of neoadjuvant therapy, respectively. In the years with a large amount of data, among the patients who completed neoadjuvant therapy, the proportion of patients meeting the recommended indications was 27.4%–67.6%, with an average of 47.4%. Patients who did not meet the recommended indications but were recommended (off-label use) accounted for 7.3%–70.0%, with an average of 39.8%. According to regression analysis, the proportion in line with the recommendation (\begin{document}$\hat y $\end{document}=–0.032 5x+66.003 2, P=0.020) varies with the year, and the overall trend shows a gradual decline. The proportion of the use of super indications (\begin{document}$\hat y $\end{document}=–0.054 5x+110.174 6, P=0.002) changed with the year, and the overall trend showed a decline. A total of 1 161 valid data with non-null values of " eoadjuvant therapy regimen” and " recommended or not recommended” showed statistically significant difference in the use rate of neoadjuvant therapy among patients with different recommendation groups (χ2=9.244, P=0.002). " Patient compliance” was shown as " active cooperation” and " passive acceptance”, and " neoadjuvant therapy” was shown as " radiotherapy alone”" chemotherapy alone”, and " chemoradiotherapy” were 470 lines. There was no statistically significant difference in neoadjuvant therapy between patients receiving active and passive treatment (χ2=0.537, P=0.841). The effective data of clinical remission degree meeting the research conditions were 388 lines, including 121 lines of complete response (31.2%), 180 lines of partial response (46.4%), 79 lines of stable disease (20.4%), and 8 lines of progressive disease (2.1%). There was no statistically significant difference in clinical response degree among patients with different neoadjuvant therapy (H=0.435, P=0.783). There were 346 lines with effective data of pathologic tumor regression grade (TRG) meeting the study conditions, including 47 lines with TRG0 (13.6%), 39 lines with TRG1 (11.3%), 180 lines with TRG2 (52.0%), and 80 lines with TRG3 (23.1%). There was no statistical difference in the degree of TRG among patients with different neoadjuvant therapy (H=1.816, P=0.518).ConclusionsThe real world study reflects that in the western regional medical center, the demand for neoadjuvant therapy among the patients with colorectal cancer covered is huge. Although the implementation of neoadjuvant therapy is greatly influenced by the doctor’s recommendation behavior, the selection and recommendation of neoadjuvant therapy according to some specific clinical application guidelines are not fully met. The impact of more behavioral factors requires further in-depth analysis and research.