To describe the incidence and risk of suicide in cancer patients in Western Australia from 1981 to 2002.

Retrospective cohort study of patients diagnosed with cancer in WA from 1981 to 2002, using data from the WA Linked Database.

Age-standardised mortality ratios (SMRs).

A total of 121 533 patients were diagnosed with cancer, corresponding to a total of 543 696 person-years at risk. There were 129 suicides in this group (108 in men). The SMR for suicide in cancer patients was 1.61 (95% CI, 1.36–1.92). An initial period of peak risk was seen in the first 3 months after cancer diagnosis (SMR, 5.75; 95% CI, 3.89–8.51), mainly in patients with a poor prognosis. A second peak period of risk was found to occur 12–14 months after diagnosis (SMR, 2.33; 95% CI, 1.11–4.89) in those with a good or moderate prognosis.

The rate of suicide in cancer patients in WA is low and represents an excess of two to three suicides per year, or 0.3% of all cancer deaths, comparable to studies in other Western countries. The risk is highest in the first 3 months after diagnosis, and a second period of increased risk 12–14 months after diagnosis may occur in response to cancer recurrence or treatment failure.