Postoperative intra-abdominal infection is an independent prognostic factor of disease-free survival and disease-specific survival in patients with stage II colon cancer

Background: Recurrence occurs in up to 20% of patients with stage II colon cancer operated on for cure. Although postoperative intra-abdominal infection has been linked with an increased risk of recurrence, the association is controversial. The aim was to investigate the impact of postoperative intra-abdominal infection on disease-free survival and disease-specific survival in patients with stage II colon cancer.

Methods: Patients undergoing elective surgery for colon cancer stage II, between 2003 and 2014, were included. Patients with anastomotic leak or intra-abdominal abscess were included in the infection group. We used the Kaplan-Meier method to represent the distribution of survival and the Cox proportional hazards model to estimate the contribution of relevant clinicopathological factors with prognosis.

Results: Postoperative intra-abdominal infection was diagnosed in 37 of 363 (10.2%) patients. Perioperative blood transfusion was more frequent in patients with infection (p = 0.008). Overall 5-year disease-free survival rate was 85.1%. Disease-free survival at 5 years was lower in patients with postoperative intra-abdominal infection (52.8 vs 88.7%; p < 0.001), perineural invasion (p = 0.001), lymphovascular invasion (p = 0.001), pT4 (p = 0.013), and in patients with adjuvant chemotherapy (p = 0.013). Multivariate analysis showed that postoperative intra-abdominal infection (HR 4.275; p < 0.001), perineural invasion (HR 2.230; p = 0.007), and lymphovascular invasion (HR 2.052; p = 0.016) were all significant independent predictors of reduced disease-free survival. Regarding specific survival, independent significant prognostic factors were the number of lymph nodes, lymphovascular invasion, and postoperative intra-abdominal infection.

Conclusion: In this series of patients with stage II colon cancer, postoperative intra-abdominal infection has an independent negative impact on disease-free survival and disease-specific survival.