The impact of anastomotic leakage on oncologic outcomes and the receipt and timing of adjuvant chemotherapy after colorectal cancer surgery

Purposes: To evaluate the impact of anastomotic leakage on oncologic outcomes in patients with colorectal cancer. We also evaluated the influence of anastomotic leakage on receipt and commencement time of adjuvant chemotherapy. Methods: A total of 809 consecutive patients undergoing major resection for colorectal cancer were categorized into leak (n = 33, 4.1%) and non-leak (n = 776, 95.9%) groups. Results: The 5-year local recurrence rates of stage II disease were 0.6% and 20.0% for non-leak and leak groups respectively (p = 0.046), and the equivalent rates for stage III disease were 9.1% and 59.4% respectively (p < 0.001). For stage III disease, receipt of adjuvant therapy was lower in the leak group (63% vs. 87%, p = 0.007) and mean time to initiation of chemotherapy was longer in the leak group (52 days vs. 37 days) but this did not reach statistical significance (p = 0.080). Older age (hazard ratio [HR] = 2.8), advanced TNM classification (HR = 3.6), and anastomotic leakage (HR = 8.9) were adverse risk factors for local recurrence based on multivariate analysis. Conclusions: Anastomotic leakage adversely influenced local recurrence rates in stage II and III disease and was an independent risk factor for local recurrence. Additionally, anastomotic leakage contributed to failure to receive adjuvant chemotherapy in patients with stage III disease.