Suicide Rates and Risk Factors among Korean Cancer Patients, 1993-2005

BACKGROUND: As the number of cancer survivors increases, suicide risk approaches that of the general population. We therefore investigated suicide rates and risk factors among Korean cancer patients. METHODS: We observed 816,295 cancer patients for 3,007,294 person-years from 1993 to 2005 through a nationwide cancer registry. We calculated their sex- and age-standardized mortality ratios (SMR) and studied suicide risk factors using rate ratios (RR) based on a log-linear Poisson regression model. RESULTS: Compared with the Korean general population, the suicide rate among cancer patients was high [SMR, 2.00; 95% confidence interval (95% CI), 1.91-2.08]. The rates were highest in the year following the cancer diagnosis (SMR, 3.45; 95% CI, 3.19-3.73) and were still elevated 5 years later (SMR, 1.23; 95% CI, 1.12-1.36). The clinical groups at highest risk were male pancreas cancer patients (SMR, 6.01; 95% CI, 4.33-8.33) and female lung cancer patients (SMR, 3.55; 95% CI, 2.55-4.94). The sociodemographic groups at highest risk were those who had no spouse versus those who were married (RR, 1.50; 95% CI, 1.35-1.68), those who were not employed versus those who were (RR, 1.39; 95% CI, 1.26-1.54), and those who did not have high school education versus those who had (RR, 1.52; 95% CI, 1.30-1.79). CONCLUSIONS: Korean cancer patients are at increased risk of suicide. Both clinical and sociodemographic factors play a role. IMPACT: There is a need for social support and suicide prevention strategies for cancer survivors in Korea.