Objective: to evaluate the excess risk in the deaths due to suicide in a huge case-series of cancer patients and in particular in a group with recent diagnosis.
Design: observational cohort.
Setting and participants: population-based study based on 136,105 patients of the cancer registry of Tuscany Region, incident during 1985-2005, 42,321 of whom diagnosed during 2000-2005.
Main outcome measures: standardised mortality ratio (SMR) of suicide by sex, age, prognosis, time since diagnosis and period of incidence.
Results: deaths due to suicide were 0.2% of all the deaths observed in the cohort of patients. Overall cases, 1985-2005, showed a SMR of 1.47 (p<0.05), it was higher than expected for men (SMR =1.50), for subjects older that 54 years, especially for cancers with poor prognosis (SMR=2.27), particularly during the first year after diagnosis (SMR=2.87) but also in the following years. Cases diagnosed in 2000-2005 had a SMR=1.19 (n.s.), confirmed the high risk for the age 55-64 years (SMR=2.27), for cancers with worse prognosis (SMR=3.23) and during the first year after diagnosis (SMR=2.64). Trend analysis showed that the excess in the risk of suicide death among cancer patients decreased over time (p=0.042).
Conclusion: although suicide is not one of the major cause of death among cancer patients, we confirmed that those patients had a higher risk than the general population. SMR higher than expected were documented for the age 55-64 years, for cancers with poor prognosis and during the first year after diagnosis. Trend analysis shows that excess in the risk of suicide death among cancer patients is decreasing over time. This may be due, among other possible explanations, to the relevant development of the palliative care system in the area based both on hospices and on home care. Although suicide deaths are rather rare, their prevention among cancer patients is still a priority, due to its likely depressive etiology and to the effects on the family and on the health system.