Causes of Death in Patients with Cancer: A Scoping Review.

With improved survival, noncancer causes of death have become increasingly relevant in cancer care. Excess noncancer mortality may reflect treatment-related toxicity, comorbidities, shared risk factors, and psychologic distress. This scoping review aimed to map the population-based evidence on the causes of death in patients with cancer and identify research gaps. PubMed, Web of Science, Cochrane Library, EMBASE, and Scopus were searched until April 2025. A total of 203 population-based studies using standardized mortality ratios (SMR) to compare cause-specific mortality among patients with cancer with that of the general population were included. Noncancer mortality was consistently elevated among patients with cancer [median SMR 1.60; interquartile range (IQR) 1.24-2.51], especially during the first year after diagnosis (3.42; 1.45-6.92), and remained higher over 10 years after diagnosis (1.51; 1.08-5.49). Younger patients and those with advanced-stage cancers demonstrated higher noncancer mortality. Among specific causes, cardiovascular disease (1.37; 1.09-2.34), suicide (1.73; 1.32-2.77), stroke (1.36; 0.98-2.17), infectious diseases in general (2.20; 1.35-4.16), septicemia (2.84; 1.64-5.47), and pneumonia/influenza (1.57; 1.08-2.69) were consistently elevated. Patients with cancer have demonstrated substantial noncancer mortality. These findings identify priority areas for targeted prevention and further investigation into cause-specific mortality patterns beyond cancer-related deaths to improve outcomes.