Objective To investigate the influencing factors for complications after radical resection of colorectal cancer.

Methods The retrospective case-control study was conducted. The clinical data of 347 patients with primary colorectal cancer who were admitted to The First Affiliated Hospital of Shantou University Medical College from January 2016 to December 2020 were collected. There were 200 males and 147 females, aged (63±11)years. Observation indicators: (1) incidence of postoperative complications; (2) analysis of factors associated with postoperative complications after radical resection of colorectal cancer; (3) comparison of clinical characteristics of patients with different preoperative serum cholinesterase. Comparison of measurement data with normal distri-bution between groups was conducted using the independent sample t test. Comparison of measure-ment data with skewed distribution between groups was conducted using the Mann-Whitney U test. Comparison of count data between groups was conducted using the chi-square test. The rceiver operating characteristic (ROC) curves were plotted to determine the optimal cut-off values. Univariate and multivariate analyses were conducted using the Logistic regression model.

Results (1) Incidence of postoperative complications. Of 347 patients, 117 cases developed postoperative complications, including 75 cases with Clavien-Dindo grade Ⅰ-Ⅱ complications and 42 cases with Clavien-Dindo grade Ⅲ-Ⅳ complications. (2) Analysis of factors associated with postoperative complications after radical resection of colorectal cancer. ROC curve analysis determined the optimal cut-off values for preoperative neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, albumin, serum cholinesterase, and carcinoembryonic antigen to identify postoperative com-plications after radical resection of colorectal cancer as 2.13, 132.72, 3.71, 36.92 g/L, 7 436.50 U/L, and 7.90 ng/mL, respectively. Multivariate analysis identified preoperative serum cholinesterase <7 436.50 U/L, and American Society of Anesthesiologists (ASA) classification >grade 2 as indepen-dent risk factors influencing postoperative complications after radical resection of colorectal cancer (hazard ratio=2.928, 2.214, 95% confidence interval as 1.699-5.047, 1.109-4.420, P<0.05). (3) Comparison of clinical characteristics of patients with different preoperative serum cholinesterase. There were 120 patients with preoperative high serum cholinesterase (≥7 436.50 U/L) and 227 pati-ents with preoperative low serum cholinesterase (<7 436.50 U/L). Age of patients with preoperative high and low serum cholinesterase was 60.38(54.00,67.00)years and 62.93(56.00,70.00)years, the body mass index was (23.11±3.02)kg/m² and (21.68±3.49)kg/m², and the skeletal muscle area index was 41.68(37.89,45.34)cm²/m² and 39.56(34.60,44.29)cm²/m², the neutrophil-to-lymphocyte ratio was 1.84(1.45,2.37) and 2.23(1.59,3.16), the platelet-to-lymphocyte ratio was 124.01(93.74,160.29) and 143.82(106.52,204.72), the lymphocyte-to-monocyte ratio was 4.26(3.29,5.41) and 3.47(2.57,4.52), the albumin was 38.80(36.75,41.30)g/L and 35.50(32.20,38.50)g/L, the hemoglobin was 130.33(120.00,140.75)g/L and 115.36(103.00,132.00)g/L, cases with tumor location at colon were 49 and 149, cases with tumor location at rectus were 71 and 78, cases with tumor of T1-2 stage were 29 and 31, cases with tumor of T3 stage were 91 and 196, cases with postoperative overall complications were 22 and 95, respectively, showing significant differences in the above indicators between them (Z=-2.669, t=3.787, Z=-2.542, -3.564, -3.863, -3.871, -7.595, -5.872, χ²=19.714, 6.064, 19.426, P<0.05).

Conclusion Preoperative serum cholinesterase <7 436.50 U/L and ASA classification >grade 2 are independent risk factors influen-cing postoperative complications after radical resection of colorectal cancer. Compared to patients with preoperative high serum cholines-terase, patients with preoperative low serum cholinesterase are older, with higher proportion of T3 stage tumors, more pronounced systemic inflammatory state, poorer nutritional status, and high incidence of postoperative complications.