Blood samples for inflammation markers are carried out from patients with сolorectal cancer surgery in a single center on the day of the surgery in the operating room before intravenous fluid application started. Each patient receives systemic antibiotic prophylaxis for gramnegative and anaerobic bacteria on induction of anesthesia and prior to skin incision. A standardized protocol for general and epidural anesthesia is used. Values of WBC count, CRP, PCT, CD64n and HLA-DR monocyte are recorded before surgery and after surgery on POD (postoperative day) 1, 3 and 6 or 7. SIRS criteria on POD 1, 3, 6 or 7 and postoperative infections up to 30 days after surgery are recorded. SSIs (incisional, organ / space), pneumonia, central venous catheter related bloodstream infections (CRBSIs), urinary tract infections (UTIs) and enterocolitis records are taken. Microbial cultures are using as the gold standard. Criteria for SIRS reconsidered in the year 2001 by SCCM / ESICM / ACCP / ATS / SIS International Sepsis Definitions Conference and criteria for Dosage Control and Prevention (CDC) are taken into consideration. After discharge, each patient is being monitored by outpatient clinic examinations. The study will recruit approximately 100 patients during three consecutive years.