Folic acid deficiency as a modifiable risk factor for anastomotic leak in patients undergoing colorectal cancer surgery.

Sarcopenia predicts negative outcomes in colorectal surgery, including anastomotic leakage (AL). Folic acid (FA) is essential for cellular processes such as DNA synthesis and tissue repair, which may indicate that it could impact anastomotic healing. The objective of this study was to evaluate the association between preoperative blood levels of FA, sarcopenia defined radiologically by psoas density, and postoperative outcomes in patients undergoing resection for colorectal cancer. A prospective study was conducted on patients undergoing oncological colorectal resection with anastomosis between June 2022 and November 2024. FA levels and the average psoas density at the L3 level on computed tomography (CT) were analyzed. Postoperative complications were recorded. Of the 250 patients that were analyzed, 12% had low FA levels (< 2.7 ng/ml) and 16% were diagnosed with sarcopenia. Furthermore, low FA levels were associated with a higher risk of sarcopenia diagnosis [RR 4.63 (95% CI 2.26-9.49)], and radiological sarcopenia was associated with an increased risk of AL [RR 1.98 (95% CI 1.3-2.83)]. Low FA levels are associated with an increased risk of sarcopenia, therefore FA deficiency could be considered a modifiable risk factor for sarcopenia and, consequently, its supplementation preoperatively could reduce the risk of anastomotic dehiscence in colorectal cancer patients.