Risk of Suicide After Cancer Diagnosis in England

Abstract

Importance: A diagnosis of cancer carries a substantial risk of psychological distress. There has not yet been a national population-based study in England of the risk of suicide after cancer diagnosis.

Objectives: To quantify suicide risk in patients with cancers in England and identify risk factors that may assist in needs-based psychological assessment.

Design, setting, and participants: Population-based study using data from the National Cancer Registration and Analysis Service in England linked to death certification data of 4 722 099 individuals (22 million person-years at risk). Patients (aged 18-99 years) with cancer diagnosed from January 1, 1995, to December 31, 2015, with follow-up until August 31, 2017, were included.

Exposures: Diagnosis of malignant tumors, excluding nonmelanoma skin cancer.

Main outcomes and measures: All deaths in patients that received a verdict of suicide or an open verdict at the inquest. Standardized mortality ratios (SMRs) and absolute excess risks (AERs) were calculated.

Results: Of the 4 722 099 patients with cancer, 50.3% were men and 49.7% were women. A total of 3 509 392 patients in the cohort (74.3%) were aged 60 years or older when the diagnosis was made. A total of 2491 patients (1719 men and 772 women) with cancer died by suicide, representing 0.08% of all deaths during the follow-up period. The overall SMR for suicide was 1.20 (95% CI, 1.16-1.25) and the AER per 10 000 person-years was 0.19 (95% CI, 0.15-0.23). The risk was highest among patients with mesothelioma, with a 4.51-fold risk corresponding to 4.20 extra deaths per 10 000 person-years. This risk was followed by pancreatic (3.89-fold), esophageal (2.65-fold), lung (2.57-fold), and stomach (2.20-fold) cancer. Suicide risk was highest in the first 6 months following cancer diagnosis (SMR, 2.74; 95% CI, 2.52-2.98).

Conclusions and relevance: Despite low absolute numbers, the elevated risk of suicide in patients with certain cancers is a concern, representing potentially preventable deaths. The increased risk in the first 6 months after diagnosis may indicate an unmet need for psychological support. The findings of this study suggest a need for improved psychological support for all patients with cancer, and attention to modifiable risk factors, such as pain, particularly in specific cancer groups.

Figure.. Suicide Standardized Mortality Ratios (SMRs) and Absolute Excess Risks (AERs) per 10 000 Person-Years at Risk by Follow-up Period

Estimates of SMRs (A) and AERs (B) are presented in eTable 5 in the Supplement. Error bars indicate 95% CIs.