Incidence rate and risk factors for suicide in patients with breast cancer in the USA: A surveillance, epidemiology, and end results analysis (SEER)

Abstract

Purpose

To investigate suicide mortality and the related factors among female breast cancer patients in the United States.

Methods

The SEER database was used to identify 716,422 patients diagnosed with breast cancer between 2010 and 2018 to calculate a standardized mortality rate (SMR). An analysis of risk factors for suicide death was conducted using the univariate and multivariate Cox proportional risk model. An estimation of suicide probability was performed through a nomogram model.

Results

Compared with the expected suicide cases (n = 155) in the general population of the United States at the corresponding period (a suicide death rate of 5.71 per 100,000 person-years), the suicide rate among 716,422 breast cancer patients was followed during 2010–2018 and showed a relatively higher rate of 9.02 per 100,000 person-years. The SMR was 1.58 (95%CI: 1.39–1.79). White and other races were nine and seven times more likely to complete suicide than Black race, respectively (aHR = 9.013, 95%CI: 3.335–24.36, P < 0.001; aHR = 7.129, 95%CI: 2.317–21.931, P = 0.001); unmarried or single patients were at higher risk than married patients (aHR = 1.693, 95%CI: 1.206–2.377, P = 0.002). Patients receiving radiotherapy (aHR = 0.731, 95%CI: 0.545–0.980, P = 0.036) were less likely to complete suicide than those who did not.

Conclusion

Female breast cancer patients in the United States have a higher suicide rate than the general public, and the risk factors consist of non-black ethnicity, being single or unmarried, and not being treated with radiotherapy. As a result of this study, clinicians may be able to identify female breast cancer patients who are at high risk of suicide, thus providing appropriate psychological support at the early stage.