Correlation between postoperative infections and long-term survival after colorectal resection for cancer

Predicting long-term survival and cancer recurrence in patients with colorectal cancer is difficult because of the many factors that may affect the prognosis. This study investigated the prognostic significance of postoperative infections for patient outcome.

From an electronic database we selected 192 patients undergoing elective radical surgery for Dukes' stage B and C colorectal adenocarcinoma. The five-year survival rates were analyzed by the Kaplan-Meier method. Univariate and multivariate analyses were carried out to evaluate the potential prognostic variables using the Cox proportional hazard model.

Forty-three patients developed deep incisional or organ/space surgical site infections, while the remaining 149 were complication free. The two groups were comparable for baseline, surgical and histopathological characteristics. At univariate analysis, Dukes' stage and infections were negative prognostic factors, while peritumoral infiltration of lymphocytes and eosinophils and fibrotic tissue appeared as protective variables. However, multivariate analysis showed that only Dukes' stage (P = 0.048) and occurrence of postoperative infectious complications (P = 0.011) were independently associated with outcome. In patients with infectious complications, the survival rate was significantly lower than in patients without infections (log-rank = 0.0004).

The present results suggest the importance of evaluating other variables besides tumor stage in the prediction of long-term outcome. In prognostic studies more attention should be paid to postoperative infections.