Trends in suicide mortality among cancer survivors in the US, 1975-2020

Background: Suicide in cancer survivors is a major public health concern, but its trends and risk factors are not well understood. This study aimed to investigate the standardized mortality rate (SMR) and trends in suicide among cancer survivors in the United States. Methods: Using data from the SEER -9 database and US Mortality data, we identified 3,684,040 cancer survivors diagnosed between 1975 and 2020. The SMR of suicide among cancer survivors was calculated, and Poisson regression analysis was used to evaluate trends in suicide risk. Subgroup analyses were performed based on age, gender, race, tumor site, and stage. A competing risk model was used to calculate the 10 -year cumulative incidence of suicide. Results: Among cancer survivors, the overall SMR of suicide was 1.49 (95%CI: 1.46-1.53) times higher than that of the general population in the US. The risk of suicide varied significantly by cancer site, with the highest risk found in patients with malignant respiratory system cancer. Overall, we observed a significant downward trend in the suicide mortality rate among cancer patients. The cumulative incidence of suicide mortality among cancer survivors across four study periods exhibited significant statistical differences (P<0.001). Conclusions: Our study highlights the need for targeted suicide prevention efforts for cancer survivors, particularly those diagnosed with respiratory system cancer. The trend of declining suicide mortality rates among cancer survivors is promising, but continued efforts are needed to understand and address the underlying risk factors.