Subsequent risk of suicide among 9,300,812 cancer survivors in US: A population-based cohort study covering 40 years of data

BACKGROUND: Large cohort studies that estimate the variation in suicide risk among cancer patients, depending on disease type and patient characteristics, are lacking. We aimed to investigate suicide risk among patients with different cancers types in the United States (US) and to identify subsets of patients at particularly high risk. METHODS: A total of 9,300,812 cases of cancer in the Surveillance, Epidemiology, and End Results (SEER) database that were diagnosed between 1975 and 2016 were included in the study. Standardized mortality ratio (SMR) and absolute excess risk (AER) of suicide were estimated. FINDINGS: From the included cases, 14,423 cancer patients were identified as having died by suicide, representing 0.26% of all deaths. We found that cancer patients had a higher risk of suicide compared with the general population, which equated to 0.8 excess deaths per 10,000 person-years. Greater suicide risk was correlated with the following: specific cancer sites, male sex, American Indian/Alaskan Native ancestry, being divorced, being uninsured, distance of metastasis, aged between 60 and 69 at diagnosis, and having a more recent diagnosis. The greatest SMR and AER were found in patients with cancers of the respiratory system, followed by those of the oral cavity and pharynx, myeloma, bones and joints, digestive system, and brain and other nervous system cancers. INTERPRETATION: Suicide risk among cancer patients varies greatly and depends on both disease type and patient characteristics. A tailored clinical management should be considered for patients at a higher risk of suicide. FUNDING: Natural Science Foundation of China.