Abstract
PURPOSE: Colorectal cancer (CRC) is a common and aggressive gastrointestinal cancer, and the prognostic impact associated with chemotherapy in super elderly (over 80 years old) patients remains poorly defined. We aimed to define the effect of chemotherapy on the prognosis of patients with CRC over 80 years old. PATIENTS AND METHODS: A retrospective study including CRC patients over 80 years old was conducted. The patients were screened from the Surveillance Epidemiology and End Results (SEER) database from 2010 to 2015. Overall survival (OS) and cancer-specific survival (CSS) were applied as the primary and secondary outcome. Cox proportional hazards regression models were used to evaluate factors associated with OS and CSS. Survival curves of OS and CSS were estimated by Kaplan-Meier method and compared by log-rank test. RESULTS: In total, 14,748 CRC patients over 80 years old were included in this study. The median patient age was 85 (IQR: 82-87). All patients were divided into surgical group and non-surgical group. The OS and CSS of the surgical group were significantly better than those of the non-surgical group (P < 0.001). Chemotherapy can improve OS and CSS for patients with stage III and IV (P < 0.001) in surgical group. For the super elderly patients with CRC, chemotherapy significantly improved OS and CSS in all TNM stages in non-surgical group. CONCLUSION: For super elderly patients with colorectal cancer, tumor treatment should not be abandoned because of their age. It is necessary to carry out clinical trials in super elderly patients.