Risk of suicide within 1 year of cancer diagnosis.

The association of the risk of suicide with cancer at different time points after a new cancer diagnosis is unclear. This study explored the suicide hazard at different time points after a first cancer diagnosis during the 1-year period before suicide. This case-crossover study included 2,907 suicide cases from 2002 to 2012 in Taiwan and compared the odds of suicide risk at different time points during one year after any cancer diagnosis with self-matched periods. The 13th month preceding the suicide date was used as the control period, and the hazard period was the duration from the 1st to 12th month in the conditional logistic regression for case-crossover comparisons. Among major groups of cancers, group of lip, oral cavity and pharynx cancers tended to have higher risk of suicide than other groups of cancers. The first month of cancer diagnosis was associated with the highest risk of suicide compared with the 13th month before suicide. The odds ratio (OR) of suicide were significantly in the first six months after cancer diagnosis but declined afterwards. For example, the adjusted OR was 3.47 [95% confidence interval (CI) = 2.60-4.62] in the first month and 1.53 (95% CI = 1.11-2.12) in the sixth month following cancer diagnosis. These findings provide clinicians with a vital reference period during which sufficient support and necessary referral to mental health support should be provided to reduce the risk of suicide among patients with newly diagnosed cancer morbidity.