title: No Need of Immediate Treatment for Hypovascular Tumors Associated with Hepatocellular Carcinoma.
abstract: Hypovascular tumors associated with hepatocellular carcinoma (HCC) can be diagnosed, but it remains unknown whether such lesions should be treated immediately. This study aimed to clarify the clinical significance of treating hypovascular liver nodules.
  
  
  
  After diagnosis of hypovascular tumors smaller than 3 cm, 104 patients underwent liver resection immediately (Group 1), while 93 patients were placed under observation (Group 2). In Group 1, 98 patients were diagnosed as having HCC (Group 1'), while 80 patients in Group 2 underwent liver resection after vascularization or appearance of other hypervascular HCC (Group 2'), eight patients had been observed, and five patients could not undergo operation due to appearance of other multiple HCCs. To avoid lead time bias for tumor vascularization, survival rates of patients after diagnosis of hypovascular tumors as well as those after operation in the two groups were compared.
  
  
  
  After a median follow-up of 3.3 years (range 0.6-11.2), the 5-year overall survival rates after liver resection of Group 1' (74.8 %; 95 % CI 64.3-86.1) was significantly higher than that of Group 2' (59.2 %; 46.4-75.6; P = 0.027). However, the 5-year overall survival rates after diagnosis of hypovascular liver nodules of Group 1' (74.7 %; 66.1-85.0) was not significantly different from that of Group 2' (77.1 %; 67.0-88.6; P = 0.761). Consequently, the 5-year overall survival rate after diagnosis of Group 2 (75.6 %; 64.7-83.1) was not significantly different from that of Group 1 (73.2 %; 67.5-86.1; P = 0.591) by intention-to-treat analysis.
  
  
  
  It is not necessary to treat hypovascular liver tumors immediately after diagnosis.
authors.affiliation: Department of Digestive Surgery, Nihon University School of Medicine, 30-1 Oyaguchikami-machi, Itabashi-ku, Tokyo, 173-8610, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Midorikawa
authors.affiliation: Department of Digestive Surgery, Nihon University School of Medicine, 30-1 Oyaguchikami-machi, Itabashi-ku, Tokyo, 173-8610, Japan. takayama.tadatoshi@nihon-u.ac.jp.
authors.forename: Tadatoshi
authors.initials: T
authors.lastname: Takayama
authors.affiliation: Hepato-Biliary-Pancreatic Surgery Division, National Cancer Center Hospital, Tokyo, 104-0054, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nara
authors.affiliation: Division of Hepato-Biliary-Pancreatic Surgery and Transplantation Surgery, Japanese Red Cross Medical Center, Tokyo, 150-8935, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Hashimoto
authors.affiliation: Department of Surgery, Saitama Cancer Center, Saitama, 362-0806, Japan.
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Omichi
authors.affiliation: Department of Digestive Surgery, Nihon University School of Medicine, 30-1 Oyaguchikami-machi, Itabashi-ku, Tokyo, 173-8610, Japan.
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Ebisawa
authors.affiliation: Department of Digestive Surgery, Nihon University School of Medicine, 30-1 Oyaguchikami-machi, Itabashi-ku, Tokyo, 173-8610, Japan.
authors.forename: Tokio
authors.initials: T
authors.lastname: Higaki
authors.affiliation: Genome Science Division, Research Center for Advanced Science and Technologies, University of Tokyo, Tokyo, 153-8904, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Tsuji
authors.affiliation: Department of Surgery, Saitama Cancer Center, Saitama, 362-0806, Japan.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: Hepato-Biliary-Pancreatic Surgery Division, National Cancer Center Hospital, Tokyo, 104-0054, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Shimada
authors.affiliation: Division of Hepato-Biliary-Pancreatic Surgery and Transplantation Surgery, Japanese Red Cross Medical Center, Tokyo, 150-8935, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Makuuchi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000401:mortality* / Q000601:surgery; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply / Q000401:mortality* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic; D015996:Survival Rate