Suicide among 915,303 Austrian cancer patients: who is at risk?

The aim of this study was to determine whether time since first diagnosis, site, and stage of cancer impacted suicide risk within a nationwide cohort of Austrian cancer patients.

Data for this population-based study were derived from the Austrian National Cancer Registry and Austrian Statistics on Causes of Death. The study of population comprised 915,303 patients diagnosed with cancer between 1983 and 2000 and 14,532,682 person-years of follow-up. Standardized suicide mortality ratios (SMRs) were calculated by sex, time since first diagnosis, site, and stage of cancer.

A total of 2877 suicides were registered among all cancer patients over the observation period. Indicating excess suicide risk relative to the general Austrian population, the SMR for the patient cohort was 1.23 (95% CI: 1.19-1.28), and was higher for men (1.41; 95% CI: 1.35-1.47) than women (1.24; 95% CI: 1.15-1.34). This excess risk varied with time since first cancer diagnosis. SMRs peaked in year one after diagnosis (3.17; 95% CI: 2.96-3.40). An excess suicide risk was observed for patients with late locally advanced (SMR=1.59; 95% CI: 1.47-1.71) or metastasized cancer (SMR=4.07; 95% CI: 3.58-4.61), and cancers of the lung (SMR 3.86; 95% CI: 3.36-4.42) and central nervous system (SMR 2.81; 95% CI: 1.92-3.97).

No data were available on psychiatric comorbidities, genetic variables, family characteristics, social factors, and community characteristics.

Our study shows that cancer patients have an excess risk for suicide, relative to the general population, which varies with time since first diagnosis, disease severity, and anatomical site. The diagnostic process needs to be sensitive and responsive to their mental health needs. Psychological care should be an integral component of cancer treatment programs.