[1] Hokkaido Univ, Fac Med, Dept Resp Med, Sapporo, Hokkaido, Japan
[2] Hokkaido Univ, Grad Sch Med, Sapporo, Hokkaido, Japan
[3] Natl Hosp Org Hokkaido Canc Ctr, Dept Resp Med, Sapporo, Hokkaido, Japan
[4] Obihiro Kosei Gen Hosp, Dept Resp Med, Obihiro, Hokkaido, Japan
[5] JCHO Hokkaido Hosp, Ctr Resp Dis, Sapporo, Hokkaido, Japan
[6] Fukushima Med Univ, Sch Med, Dept Pulm Med, Fukushima, Japan
[7] Natl Hosp Org Asahikawa Med Ctr, Dept Resp Med, Asahikawa, Hokkaido, Japan
[8] KKR Sapporo Med Ctr, Dept Med Oncol, Sapporo, Hokkaido, Japan
[9] Teine Keijinkai Hosp, Dept Resp Med, Sapporo, Hokkaido, Japan
[10] Hirosaki Univ, Dept Resp Med, Grad Sch Med, Hirosaki, Aomori, Japan
[11] Asahi Chuo Hosp, Dept Resp Med, Asahi, Japan
[12] Hokkaido Univ, Fac Med, Dept Med Oncol, Sapporo, Hokkaido, Japan