Incidence of Death From Unintentional Injury Among Patients With Cancer in the United States

IMPORTANCE: Previous studies have suggested that patients with cancer may be at an increased risk of death from unintentional injury, but to our knowledge, no large studies have examined the rates of death from unintentional injury among patients with cancer. OBJECTIVE: To characterize the incidence of death from unintentional injury among patients with cancer in the United States. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included patients diagnosed with a first primary cancer between January 1, 1973, and December 31, 2015, identified from the Surveillance, Epidemiology, and End Results (SEER) program data. Comparisons with the general US population were based on mortality data collected by the National Center for Health Statistics. Analyses were performed from February 1, 2019, to August 15, 2019. MAIN OUTCOMES AND MEASURES: Rates and standardized mortality ratios (SMRs) of death from unintentional injury among patients with cancer. RESULTS: A total of 8 271 020 patients with cancer were included in this study (50.2% female; mean [SD] age, 63.0 [15.7] years). Among them, 40 599 deaths from unintentional injury were identified. The rates of death from unintentional injury were 81.90 per 100 000 person-years among patients with cancer and 51.21 per 100 000 person-years in the corresponding US general population. The SMR of death from unintentional injury was 1.60 (95% CI, 1.58-1.61). Higher rates of death from unintentional injury were associated with increasing age at diagnosis (≥80 years; rate ratio [RR], 2.91; 95% CI, 2.84-2.98; P < .001), male sex (RR, 1.69; 95% CI, 1.66-1.73; P < .001), American Indian or Alaskan Native population (RR, 1.48; 95% CI, 1.30-1.68; P < .001), and being unmarried (RR, 1.23; 95% CI, 1.18-1.28; P < .001). Rates of death from unintentional injury were the highest in patients with cancers of the liver (200.37 per 100 000 person-years), brain (175.04 per 100 000 person-years), larynx (148.78 per 100 000 person-years), and esophagus (144.98 per 100 000 person-years). The SMRs were the highest in the first month after cancer diagnosis. CONCLUSIONS AND RELEVANCE: This study found that the incidence of death from unintentional injury among patients with cancer was significantly higher than that in the general population in the United States. The rates of death from unintentional injury varied by age, sex, race/ethnicity, marital status, cancer site, disease stage, and time since diagnosis. The findings suggest that death from unintentional injury among patients with cancer requires further attention and that initiatives to identify patients at risk and to develop targeted prevention strategies should be prioritized.