Real-world data on initial treatment strategies for older adult patients with endometrial cancer in Japan.

Current strategies for the treatment of endometrial cancer in older adult patients require re-evaluation given the global trend in population aging, especially in Japan. We sought to evaluate initial treatment offered to older adult patients with endometrial cancer in Japan. We retrospectively analyzed data on the standard treatment by age group in patients with endometrial cancer who underwent surgery between January 2005 and December 2013 at the National Cancer Center Hospital (Tokyo, Japan). Patients were stratified into four groups according to age: a younger group, aged 64 years or younger; older adult group 1, aged 65-69 years; older adult group 2, aged 70-74 years; and older adult group 3, aged ≥75 years. Among 551 patients with endometrial cancer diagnosed and treated at our hospital, data from 531 eligible patients were analyzed. The proportion of patients in the older adult groups 1 or 2 who received standard treatment was the same as in the younger group. However, significantly fewer patients in older adult group 3 received standard treatment compared with the younger group (26% vs. 71%, p = 0.0001). Furthermore, the proportion of patients in older adult group 3 who underwent standard surgery was significantly lower than that in the younger group (26% vs. 72%, p = 0.0001). The results indicate that age 75 years and older might represent a cutoff for the development of age-based treatment strategies for endometrial cancer. This information could be used to determine the upper age limit for participation in clinical trials in Japan.