Causes of Death After Colorectal Cancer Diagnosis: A Population-Based Study

Background: Non-cancer causes of death in patients with colorectal cancer (CRC) have not received much attention until now. The purpose of the current study is to investigate the non-cancer causes of death in patients with CRC at different periods of latency. Methods: Eligible patients with CRC were included from the Surveillance, Epidemiology, and End Results (SEER) database, and standardized mortality ratios (SMRs) were calculated using the SEER*Stat software 8.3.8. Results: A total of 475,771 patients with CRC were included, of whom 230,841 patients died during the follow-up period. Within 5 years, CRC was the leading cause of death. Over time, non-cancer causes of death account for an increasing proportion. When followed up for more than 10 years, non-cancer deaths accounted for 71.9% of all deaths worldwide. Cardiovascular diseases were the most common causes of non-cancer deaths, accounting for 15.4% of the total mortality. Patients had a significantly higher risk of death from septicemia within the first year after diagnosis compared with the general population (SMR, 3.39; 95% CI, 3.11-3.69). Within 5-10 years after CRC diagnosis, patients had a significantly higher risk of death from diabetes mellitus (SMR, 1.27; 95% CI, 1.19-1.36). During the course of more than 10 years, patients with CRC had a significantly higher risk of death from atherosclerosis (SMR 1.47; 95% CI, 1.11-1.9). Conclusions: Although CRC has always been the leading cause of death in patients with CRC, non-cancer causes of death should not be ignored. For patients with cancer, we should not only focus on anti-tumor therapies but also pay attention to the occurrence of other risks to prevent and manage them in advance.