The Association Between Surgical Site Infection and Prognosis of T4 Colorectal Cancer

Patients with T4 colorectal cancer have poor prognosis, wherein no prognostic factors have been established. Surgical site infection (SSI) has been reported to be one of the risk factors for colorectal cancer recurrence. In this study, we evaluated the relationship between SSI occurrence and prognosis of T4 colorectal cancer and the prognostic impact of the site of SSI occurrence.

We examined 100 patients with T4 colorectal cancer who underwent radical surgery between April 2002 and December 2017, in a retrospective case-control study, excluding stage IV cases, and classified them into two groups: without SSI (non-SSI) and with SSI (SSI). The five-year relapse-free survival (RFS) and overall survival (OS) were calculated and compared between the two groups. The relationship between prognosis and the SSI site was also assessed according to the SSI site in the incisional/deep and organ/space SSI groups.  Results: The without SSI and with SSI groups included 73 and 27 patients, respectively. The five-year RFS was 55.1% and 22.2% in the without SSI and with SSI groups, respectively (hazard ratio (HR), 2.224; 95% confidence interval (CI), 1.269-3.898; P=0.005). The five-year OS was 67.0% and 38.4% in the without SSI and with SSI groups, respectively (HR, 2.366; 95% CI, 1.223-4.575; P=0.010). The patients in the with SSI group had a significantly poorer prognosis compared with the without SSI group. By SSI site, the prognosis was significantly worse in patients with SSI in the incisional/deep SSI group.

In T4 colorectal cancer, SSI occurrence was a high-risk factor for recurrence and may be a prognostic factor. This result suggested that patients with SSI occurrence may require close postoperative follow-up and appropriate adjuvant chemotherapy.