Impact of preoperative anemia on short- and long-term outcomes of sphincter-preserving rectal cancer surgery

Preoperative anemia is associated with an increased risk of postoperative complications and poor survival in colorectal cancer; however, its effects on long-term outcomes in sphincter-preserving rectal surgery remain unclear. Therefore, we analyzed the correlation among preoperative anemia, postoperative complications and surgical outcomes in sphincter-preserving rectal cancer surgeries. Data from patients who underwent sphincter-preserving surgery for stage I–III rectal cancer between 2011 and 2015 were reviewed. Anemia was defined as a preoperative baseline hemoglobin concentration < 12.5 g/dL in men and < 11.5 g/dL in women. Disease-free survival (DFS), overall survival (OS) and 30-day overall complications according to the Clavien–Dindo (CD) classification were compared between the anemia and non-anemia groups. Overall, 120 of the 638 patients (18.8%) analyzed had preoperative anemia. The most common postoperative complications were ileus (6.7%), urinary retention (5.0%), wound complications (4.7%), and anastomotic leakage (2.7%). The anemia group exhibited significantly more overall complications, major complications, and anastomotic leaks compared to the non-anemia group. However, the 5-year DFS and OS were comparable between groups. Male sex, ileostomy, vascular invasion, and anemia correlated with overall complications. Preoperative anemia was linked to postoperative complications, especially anastomotic leaks, but did not affect OS or DFS. Thus, our results suggest that rectal cancer surgery requires tailored management in patients with anemia.