Our results showed that patients with POD had higher CRP concentrations preoperatively and on postoperative day 2. However, the configured multivariate logistic regression model suggested plasma CRP concentrations as a predictor of POD preoperatively instead of postoperative day 2. Therefore, preoperative plasma CRP concentrations may be an important risk biomarker for POD prediction in elderly patients with colon carcinoma after laparoscopic surgery. The pathophysiologic preexisted differences in the inflammatory activity during patients before the surgery might lead to different incidences of POD. This might support our findings from a pathophysiologic standpoint and offer new important targets for investigation. However, the association between preoperative CRP concentrations and POD still remains controversial until now with different conclusions in different patient samples. Previous literature examining the relationship between POD and CRP has suggested the potential predicative role of preoperative and postoperative CRP concentrations for POD in older patients undergoing major elective surgery . Other reports conducted in small samples undergoing hip and vascular surgery showed positive associations between postoperative CRP concentrations and POD [21, 22], which is not so aligned with our results. In contrast to our findings, another two studies conducted in small cohorts observed no significant association between POD and preoperative CRP concentrations [12, 23]. No close correlations were observed in critically ill medical patients . Different small sample sizes of cohort-based studies, different age ranges, different surgery types, and some other confounding factors may be potential explanations for the disparate conclusions between other previous reports and our study. Those individuals with a heightened inflammatory response are at greater risk of POD occurrence as proposed by current POD pathophysiology models . With no well-defined etiology of multifactorial POD, the hypothesis of inflammatory processes leading to neuroinflammation has gained wide attraction in recent years .