[1] Chiba Univ, Grad Sch Med, Dept Thorac Surg, Chuo Ku, Chiba 2608670, Japan
[2] Chiba Univ, Grad Sch Med, Dept Diagnost Pathol, Chuo Ku, Chiba 2608670, Japan
[3] Chiba Univ, Grad Sch Med, Dept Respirol, Chuo Ku, Chiba 2608670, Japan
[4] Chiba Canc Ctr, Div Thorac Dis, Chiba, Japan