Infectious diseases as a cause of death among cancer patients: a trend analysis and population-based study of outcome in the United States based on the Surveillance, Epidemiology, and End Results database

BACKGROUND: Infectious diseases are a major cause of morbidity and mortality among cancer patients. We aimed to determine the incidence of infectious diseases as a cause of death among cancer patients and analyze the trends and risk factors associated with mortality. METHODS: In total, 151,440 cancer patients who died from infectious diseases in the US diagnosed between 1973 and 2014 from the Surveillance, Epidemiology, and End Results program were enrolled. A trend analysis of annual cancer deaths caused by infectious diseases was conducted. Cox proportional hazards model and survival decision tree model were performed. RESULT: The most common infectious diseases were pneumonia and influenza (n = 72,133), parasitic and other infectious (n = 47,310) diseases, and septicemia (n = 31,119). The patients’ mean age was 66.33 years; majority of them were male (62%). The overall incidence from 1973 to 2014 showed an insignificant decrease (annual percentage change = − 0.3, 95% confidence interval [CI] = − 2.2–1.7, P = 0.8). Parasitic and other infectious diseases, including HIV (standardized incidence ratio [SIR] = 1.77, 95% CI = 1.69–1.84), had the highest incidence, followed by septicemia (SIR = 0.84, 95% CI = 0.81–0.88), tuberculosis (SIR = 0.72, 95% CI = 0.51–0.99), and pneumonia (SIR = 0.63, 95% CI = 0.61–0.64). Based on the Cox regression analysis, old black male patients with intrahepatic tumor or acute leukemia of different grades, except the well-differentiated grade, had the highest risk of dying from infectious diseases. CONCLUSION: Infectious diseases remain the major cause of morbidity and mortality among cancer patients. Early recognition of risk factors and timely intervention may help mitigate the negative consequences on patients’ quality of life and prognosis, improving the prognosis and preventing early death from infection, which is preventable in most cases. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13027-021-00413-z.