Long-term oncologic outcome of postoperative complications after colorectal cancer surgery

The impact of postoperative complications on long-term oncologic outcome after radical colorectal cancer surgery is controversial. The aim of this study was to examine the risk factors and oncologic outcomes of surgery-related postoperative complication groups. From January to December, 2010, 310 patients experienced surgery-related postoperative complications after radical colorectal cancer surgery. These stage I - III patients were classified into two subgroups, minor (grade I, II) and major (grade III, IV) complication groups, according to extended Clavien-Dindo classification system criteria. We analyzed the clinicopathological differences between the two groups to identify risk factors for increasing major complications. We also compared the disease-free survival of surgery-related postoperative complication groups. The minor and major complication groups were stratified with 194 (62.6%) and 116 (37.4%) patients, respectively. The risk factors influencing the major complication group were the pathologic N category and operative method. The prognostic factors associated with disease-free survival were preoperative perforation, perineural invasion, tumor budding, and receiving neoadjuvant therapy. With a median follow-up period of 72.2 months, the 5-year disease-free survival rates were 84.4% in the minor group and 78.5% in the major group, but there was no statistical significance between the minor and major groups (P = 0.392). Advanced cancer and open surgery were identified as risk factors for increased surgery-related major complications after radical colorectal cancer surgery. However, the severity of postoperative complications did not affect disease-free survival from colorectal cancer.