Differences in the prognostic impact of post-operative systemic inflammation and infection in colorectal cancer patients: Using white blood cell counts and procalcitonin levels

Background: Systemic inflammatory responses cause poor prognosis in cancer patients. However, post-operative systemic inflammatory response may occur owing to post-operative infection as well as cancer-related inflammation. This study aimed to identify the prognostic impact of cancer-related inflammation and infection for colorectal cancer. Methods: Patients who underwent curative surgery for colorectal cancer between January 2011 and March 2015 were enrolled. Procalcitonin (PCT) levels were measured on the fourth post-operative day; white blood cell (WBC) counts were measured daily until the fourth post-operative day. Patients were divided into groups according to the number of post-operative days required for the leukocyte count to decrease to <10,000/mm³ and PCT levels (0.5 ng/ml) as follows: group I, 0–3 days; group II, ≥4 days and high PCT; group III, ≥4 days and normal PCT. Results: Totally, 248 patients were identified. A prolonged WBC normalization period was associated with poor disease-free survival (DFS). TNM stage III and IV and group III (hazard ratio [HR] 2.480, 95% confidence interval [CI] 1.137–5.410) were independently associated with poor DFS. In contrast, DFS was not significantly affected in group II. High PCT levels were significantly associated with post-operative infectious complications (odds ratio 10.579, 95% CI 4.182–26.764). Although infectious complication had no prognostic significance for DFS, it was an independently poor prognostic factor for overall survival (HR 3.728; 95% CI 1.291–10.766). Conclusions: The increased post-operative systemic inflammatory response was associated with poor prognosis of colorectal cancer. Otherwise, post-operative infection affected overall mortality but was not associated with disease progression.