Surgical risk and cause of death among octogenarian and nonagenarian patients with colorectal cancer: a Japanese multicenter study.

Background: The number of elderly people undergoing surgery for colorectal cancer has been increasing. We examine prognosis, including risks of surgery by age and cancer- and noncancer-related deaths.

Methods: This study retrospectively reviewed 1830 patients who underwent curative resection colorectal surgery. Patients were divided into oldest-old (>85 years old, n = 49), elderly (75-84 years old, n = 637), and young (<75 years old, n = 1144) patient groups.

Results: Physical status was poorer (P < .001), postoperative complications were more frequent (49.0% vs. 20.9% vs. 18.4%; P < .001), and adjuvant chemotherapy was less frequent (0% vs. 44.3% vs. 83.5%; P < .001) as patients got older. Multivariate analysis revealed oldest-old [odds ratio (OR) 4.373, 95% confidence interval (CI) 2.362-8.110; P < .001] as independent predictors of postoperative complications. Elderly patients [hazard ratio (HR) 2.494, 95%CI 1.707-3.642; P < .001], oldest-old patients (HR 5.969, 95%CI 3.229-11.035; P < .001), poor physical status (HR 2.546, 95%CI 1.694-3.827; P < .001), and postoperative complications (HR 1.805, 95%CI 1.252-2.602; P = .001) were predictive factors for noncancer-specific survival.

Conclusions: Elderly patients had many complications and a higher risk of dying from other causes. Surgical risk and general condition must be considered when deciding the appropriateness of surgery and adjuvant therapy.