Suicide risk among patients with cancer by sex in Japan: A population-based study

Background: In Japan, few studies have examined suicide risk for five-year relative survival 3 rates for cancer sites. Since five-year relative survival rates differ by sex, we aim to examine 4 suicide risk for patients with cancer separately for men and women. Methods: We estimated the risk of suicide among patients with cancer by sex in Japan 6 compared to the general population, using standardized mortality ratios (SMRs). Patients 7 with cancer diagnosed between January 1, 1985-December 31, 2013 and registered in the 8 Osaka Cancer Registry were followed -up with for up to 10 years. The outcome was suicide 9 death. In addition, cancer sites were classified into three prognosis groups based on five-year 10 relative survival rates: good (> 70%), moderate (40-70%), poor (< 40%). Results: Among 623 995 patients with cancer observed for 2 349 432 person -years, 1210 12 patients died by suicide (867 men and 343 women). The SMRs were almost equal for men 13 (1.66, 95% CI, 1.55-1.77) and women (1.65, 95% CI, 1.48-1.83). SMRs for cancer prognosis 14 groups were 1.01 (95% CI, 0.84-1.22) for men and 1.47 (95% CI, 1.24-1.73) for women in 15 the good group, 1.53 (95% CI, 1.39-1.68) for men and 1.74 (95% CI, 1.47-2.05) for women 16 in the moderate group, and 2.54 (95% CI, 2.27-2.85) for men and 1.87 (95% CI, 1.43-2.46) 17 for women in the poor group. Conclusions: In this population, both sexes had higher suicide risk with poor prognosis, but 19 the difference in SMRs between the good and poor groups was smaller for women than men.