Death by suicide, other externally caused injuries and cardiovascular diseases within 6 months of cancer diagnosis (J-SUPPORT 1902).

OBJECTIVE

To conduct the first national population-based study in Japan to characterize risks of death by suicide, other externally caused injuries and cardiovascular diseases within 6 months of cancer diagnosis.

METHODS

Cancer patients diagnosed between 1 January and 30 June 2016 and registered in the National Cancer Registry in Japan were followed up until death or 6 months after diagnosis. We calculated standardized mortality ratios and excess absolute risks per 10 000 person-years for death by suicide, other externally caused injuries and cardiovascular diseases compared with the Japanese general population.

RESULTS

Of 546 148 patients with cancer (249 116 person-years at risk), we observed 145 suicides, 298 deaths due to other externally caused injuries and 2366 cardiovascular deaths during the follow-up period. Standardized mortality ratios within 6 months were 2.68 for suicide (95% confidence interval, 2.26-3.16; excess absolute risk, 3.65), 1.49 for other externally caused injuries (95% confidence interval, 1.32-1.67; excess absolute risk, 3.92) and 1.38 for cardiovascular diseases (95% confidence interval, 1.33-1.44; excess absolute risk, 26.85). Risks were highest during the first month after cancer diagnosis (standardized mortality ratios: suicide, 4.06 [95% confidence interval, 2.90-5.53]; other externally caused injuries, 2.66 [95% confidence interval, 2.17-3.12] and cardiovascular diseases, 2.34 [95% confidence interval, 2.18-2.51]).

CONCLUSIONS

The first 6 months, and especially the first month, after cancer diagnosis were found to be a critical period for risks of death by suicide, other externally caused injuries and cardiovascular diseases. Our findings suggest that oncologists need to evaluate suicidal and cardiovascular risks of patients immediately after cancer diagnosis and provide preventive interventions.