Background:Major abdominal surgery,including colorectal cancer (CRC) surgery,leads to systemic inflammatory response syndrome that can be detected and monitored with inflammatory markers testing.The aims of the study were to evaluate the usefulness of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1),interleukin-6 (IL-6),procalcitonin (PCT),and C-reactive protein (CRP) in following the inflammatory response in CRC surgery and postoperative period,as well as to determine if duration of the surgery and the time that the colon has been opened during the surgery (open colon time [OCT]) reflect a larger surgical stress through inflammatory markers rise.Methods:The study included 20 patients who underwent CRC surgery and 19 healthy volunteers from June 2011 to September 2012.We determined inflammatory markers 1 day before surgery (T0),24 h (T1),48 h (T2),and 7 days after the surgery (T3).All statistical analyses were calculated using MedCalc Statistical Software version 14.8.1 (MedCalc Software bvba,Ostend,Belgium).Results:Concentrations ofCRP,PCT,and IL-6 in all measurement times were statistically different and sTREM-1 did not yield statistical significance.A weak positive correlation was found between IL-6 in T 1 and T2 with the duration of the surgery (T1:r =0.4060,P ＜ 0.0001;T2:r =0.3430,P ＜ 0.0001) and OCT (T1:r =0.3640,P ＜ 0.0001,T2:r =0.3430,P ＜ 0.0001).A weak positive correlation between CRP in T2 and OCT (r =0.4210,P ＜ 0.0001) was also found.The interconnectivity of tested parameters showed a weak positive correlation between CRP and IL-6 in T 1 (r =0.3680;P ＜ 0.0001),moderate positive correlation in T2 (r =0.6770;P ＜ 0.0001),and a strong positive correlation in T3 (r =0.8651;P ＜ 0.0001).Conclusions:CRP,IL-6,and PCT were shown to be reliable for postoperative monitoring.Simultaneous determination of CRP and IL-6 might not be useful as they follow similar kinetics.sTREM-1 might not be useful in CRC postoperative monitoring.