Causes of Death Following Nonmetastatic Colorectal Cancer Diagnosis in the U.S.: A Population-Based Analysis

Abstract

Introduction: Because of the improved colorectal cancer (CRC) survival in the U.S., patients may live long enough after CRC diagnosis to the point where non–cancer-related comorbidities may considerably impact their overall survival. In this study, we perform a long-term analysis of causes of death (CODs) following nonmetastatic CRC with respect to different demographic and tumor-related criteria. Materials and Methods: We gained access to the Surveillance, Epidemiology, and End Results data to review patients diagnosed with nonmetastatic CRC during 2000–2015. We calculated standardized mortality ratios (SMRs) for each COD following CRC. SMRs represented the change of risk of a specific COD following CRC diagnoses when compared with the risk in the general U.S. population. Results: We reviewed 302,345 patients, of whom 112,008 died during the study period. More deaths (68.3%) occurred within 5 years following nonmetastatic CRC diagnosis, with 76,486 deaths. CRC was the most common COD (51.4%) within 5 years of diagnosis followed by heart disease (15.2%) and other cancers (8.4%). As time passed after diagnosis, the number of CRC deaths decreased, and other noncancer causes increased to the point that after 10 years only 10.4% of deaths were attributed to CRC, 15.3% were attributed to other cancers, and 34.2% were secondary to heart disease. Conclusion: Following nonmetastatic CRC diagnosis, most deaths remain secondary to CRC. Other causes, including other cancers and cardiovascular disease, represent a significant number of deaths, especially in the 5 years following initial CRC diagnosis. Our findings help guide counseling patients with CRC regarding future health risks. Implications for Practice: Most common causes of death following nonmetastatic colorectal cancer (CRC) are heart diseases, other cancers, chronic obstructive pulmonary disease, and cerebrovascular diseases. Physicians should counsel patients regarding survivorship with cancer screening and focus on prevention of noncancer deaths. These findings should be considered by physicians who give care for survivors of nonmetastatic CRC.