Predictive values of proportional postoperative reduction of albumin for postoperative complications and long-term outcomes following sphincter-preserving surgery for rectal cancer

Objective To investigate clinical values of proportional postoperative reduction of albumin (ΔALB) in the prediction of postoperative complications following sphincter-preserving surgery for rectal cancer and evaluate whether it affects long-term outcomes. Methods A case-control trail was performed on 809 rectal cancer patients (345 females and 464 males, at an average age of 60.3±11.2 years) undergoing sphincter-preserving surgery in our department between July 2010 and June 2016. Postoperative complications were graded using Clavien-Dindo classification. Receiver operating characteristic (ROC) curve analysis was employed to assess the predictive values of ΔALB. The patients were divided into 3 groups based on the first and third quartiles of the ΔALB level. Chi-square test for trend was performed to analyze the change tendency in the incidence of postoperative complications among the 3 groups. Logistic regression analysis was conducted to identify independent risk factors for postoperative complications. Overall survival (OS) and disease-free survival (DFS) were calculated using Kaplan-Meier survival curve and compared by Log-rank test. Results Among the 809 surgical cases, laparoscopic surgery was accomplished in 669 cases, 22 cases required converted open surgery (a conversion rate of 3.2%), and 118 cases underwent open surgery. Postoperative complications occurred in 226 patients, with a rate of 27.9%, and an increased trend of the rate was displayed among the ΔALB groups (Chi-square=7.955, P=0.005). Multivariate analysis indicated that the risk for developing postoperative complications was 1.791 times higher in the patients with high ΔALB level (ΔALB≥34.7%) than those with low ΔALB level (ΔALB < 21.9%)(OR=1.791, 95%CI: 1.139~2.817, P=0.012). The complication and non-complication groups had a 5-year OS rate of 76.6% and 81.6% (Chi-square=2.836, P=0.092), and a 5-year DFS rate of 65.4% and 74.7%, respectively (Chi-square=5.875, P=0.015). There were no statistical differences in OS and DFS rate among the ΔALB groups. Conclusion ΔALB is an independent risk factor for postoperative complications in rectal cancer patients after sphincter-preserving surgery, with advantages of low-cost, convenience, and rapid response in prediction of postoperative complications. Since postoperative complications will influence patients' long-term survival, special attention should be paid to ΔALB to improve the long-term prognosis.