Prognostic value of K-ras mutation status and subtypes in endoscopic ultrasound-guided fine-needle aspiration specimens from patients with unresectable pancreatic cancer

Takeshi Ogura, Kenji Yamao, Kazuo Hara, Nobumasa Mizuno, Susumu Hijioka, Hiroshi Imaoka, Akira Sawaki, Yasumasa Niwa, Masahiro Tajika, Shinya Kondo, Tsutomu Tanaka, Yasuhiro Shimizu, Vikram Bhatia, Kazuhide Higuchi, Waki Hosoda, Yasushi Yatabe