Factors associated with postoperative complications and 1-year mortality after surgery for colorectal cancer in octogenarians and nonagenarians

Purpose: To identify the factors affecting 30-day postoperative complications and 1-year mortality after surgery for colorectal cancer in octogenarians and nonagenarians. Methods: Between 2005 and 2014, a total of 204 consecutive patients aged ≥80 years who underwent major colorectal surgery were included. Results: One hundred patients were male (49%) and 52 patients had American Society of Anesthesiologists (ASA) score ≥3 (25%). Combined surgery was performed in 32 patients (16%). Postoperative complications within 30 days after surgery occurred in 54 patients (26%) and 30-day mortality occurred in five patients (2%). Independent risk factors affecting 30-day postoperative complications were older age (≥90 years, hazard ratio [HR] with 95% confidence interval [CI] =4.95 [1.69−14.47], P=0.004), an ASA score ≥3 (HR with 95% CI =4.19 [1.8−9.74], P=0.001), performance of combined surgery (HR with 95% CI =3.1 [1.13−8.46], P=0.028), lower hemoglobin level (<10 g/dL, HR with 95% CI =7.56 [3.07−18.63]<P,0.001), and lower albumin level (<3.4 g/dL, HR with 95% CI =3.72 [1.43−9.69], P=0.007). An ASA score ≥3 (HR with 95% CI =2.72 [1.15−6.46], P=0.023), tumor-node-metastasis (TNM) stage IV (HR with 95% CI =3.47 [1.44−8.39], P=0.006), and occurrence of postoperative complications (HR with 95% CI =4.42 [1.39−14.09], P=0.012) were significant prognostic factors for 1-year mortality. Conclusion: Patient-related factors (older age, higher ASA score, presence of anemia, and lower serum albumin) and procedure-related factors (performance of combined surgical procedure) increased postoperative complications. Avoidance of 30-day postoperative complications may decrease 1-year mortality.