The Impact of Anastomotic Leak and Intra-Abdominal Abscess on Cancer-Related Outcomes After Resection for Colorectal Cancer: A Case Control Study

PURPOSE: This study was designed to analyze the impact of anastomotic leak and intra-abdominal abscess on cancer recurrence and survival in patients who underwent resection for colorectal cancer. METHODS: Data for patients who underwent resection for colon or rectal cancer were retrieved from a prospective colorectal cancer database. Patients with inflammatory bowel disease, familial adenomatous polyposis, hereditary nonpolyposis colorectal cancer, palliative resection, or perioperative mortality were excluded. Patients with postoperative anastomotic leak or intra-abdominal abscess were matched at a 1: 2 ratio to patients from the same database who had no leak or abscess. Matched characteristics were age, gender, cancer stage, tumor histology, and operation occurring within three years of eachother. Survival and cancer recurrence at five-year follow-up were evaluated with the Kaplan-Meier method and log rank test. RESULTS: In patients with colon cancer, comparison of the 59 patients with a leak or an abscess with 118 matched controls showed no differences in demographic or treatment characteristics, recurrence, or mortality. In patients with rectal cancer, comparison of the 97 patients with a leak or an abscess with 194 matched controls showed that at five-year follow-up the complication group had higher rates of overall mortality (46.8 vs. 28.9, P < 0.01), cancer-specific mortality (28.7 percent vs. 18.0 percent, P = 0.03), overall recurrence (28.6 vs. 15.7, P = 0.01) and local recurrence (11.0 percent vs. 5.0 percent, P = 0.04). CONCLUSION: Anastomotic leak and intra-abdominal abscess were not associated with worsened 5-year survival or recurrence in patients who underwent resection for colon cancer. However, these complications were associated with increased overall and cancer-specific mortality and increased overall and local recurrence in patients who underwent resection for rectal cancer.