Cumulative overall survival of patients with WHO-RA. (A) Among all patients with WHO-RA, Japanese patients had a more favorable prognosis than did German patients (P < .001). (B) In patients aged 60 years or younger, Japanese patients had a more favorable prognosis than did German patients (P = .004). (C) In patients aged older than 60 years, Japanese patients did not show a more favorable prognosis than did German patients (P = .56).