Clinical characteristics and survival of colorectal cancer patients in Korea stratified by age

Background/Aims: This nationwide study was undertaken to determine differences in clinicopathologic characteristics and survival of patients with colorectal cancer (CRC) according to age using big data from the Korean National Health Insurance Service (NHIS). Methods: The NHIS data including quality assessment of CRC by the Health Insurance Review & Assessment Service in Korea between 2011 and 2014 were analyzed. Based on age, patients were divided into three groups: not-old patients (< 65), young-old patients (65 to 74 years old) and old-old patients (≥ 75 years old). Results: We included 71,513 CRC patients. The median follow-up duration was 3.2 years (range, 0.003 to 5.5). Male patients constituted 60%. The median age of patients was 65 years (range, 18 to 102). Colon was the cancer site in 59.8% of not-old patients, 62.9% of young-old patients, and 66.1% of old-old patients. Compared to not-old patients, young-old and old-old patients were more likely to be diagnosed with colon adenocarcinoma and well/moderate differentiation or adequate differentiation (all p < 0.001). Old patients underwent more emergency operation (p < 0.001) and received less adjuvant therapy in stage I–III (p < 0.001). The probability of 3-year survival of young-old or old-old patients was worse than that for not-old patients (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.46 to 1.64) (HR, 3.19; 95% CI, 3.03 to 3.37). Conclusions: Old patients with CRC show different histology from younger patients. They are more frequently to have colon as primary lesion. They undergo less adjuvant therapy. Further studies and evidence-based guidelines for older patients with CRC are warranted to improve their outcome.